title: Æthelwulf, King of Wessex

text: Almost nothing is recorded of the first twenty years of Ecgberht's reign, apart from campaigns against the Cornish in the 810s. The historian Richard Abels argues that the silence of the "Anglo-Saxon Chronicle" was probably intentional, concealing Ecgberht's purge of Beorhtric's magnates and suppression of rival royal lines. Relations between Mercian kings and their Kentish subjects were distant. Kentish ealdormen did not attend the court of King Coenwulf, who quarrelled with Archbishop Wulfred of Canterbury (805–832) over the control of Kentish monasteries; Coenwulf's primary concern seems to have been to gain access to the wealth of Kent. His successors Ceolwulf I (821–23) and Beornwulf (823–26) restored relations with Archbishop Wulfred, and Beornwulf appointed a sub-king of Kent, Baldred.


title: Æthelwulf, King of Wessex

text: England had suffered Viking raids in the late 8th century, but no attacks are recorded between 794 and 835, when the Isle of Sheppey in Kent was ravaged. In 836 Ecgberht was defeated by the Vikings at Carhampton in Somerset, but in 838 he was victorious over an alliance of Cornishmen and Vikings at the Battle of Hingston Down, reducing Cornwall to the status of a client kingdom.


title: Æthelwulf, King of Wessex

text: Æthelwulf's father Ecgberht was king of Wessex from 802 to 839. His mother's name is unknown, and he had no recorded siblings. He is known to have had two wives in succession, and so far as is known, Osburh, the senior of the two, was the mother of all his children. She was the daughter of Oslac, described by Asser, biographer of their son Alfred the Great, as "King Æthelwulf's famous butler", a man who was descended from Jutes who had ruled the Isle of Wight. Æthelwulf had six known children. His eldest son, Æthelstan, was old enough to be appointed King of Kent in 839, so he must have been born by the early 820s, and he died in the early 850s. The second son, Æthelbald, is first recorded as a charter witness in 841, and if, like Alfred, he began to attest when he was around six, he would have been born around 835; he was King of Wessex from 858 to 860. Æthelwulf's third son, Æthelberht, was probably born around 839 and was king from 860 to 865. The only daughter, Æthelswith, married Burgred, King of Mercia, in 853. The other two sons were much younger: Æthelred was born around 848 and was king from 865 to 871, and Alfred was born around 849 and was king from 871 to 899. In 856 Æthelwulf married Judith, daughter of Charles the Bald, King of West Francia and future Carolingian Emperor, and his wife Ermentrude. Osburh had probably died, although it is possible that she had been repudiated. There were no children from Æthelwulf's marriage to Judith, and after his death she married his eldest surviving son and successor, Æthelbald.


title: Æthelwulf, King of Wessex

text: Æthelwulf was first recorded in 825, when Ecgberht won the crucial Battle of Ellandun in Wiltshire against King Beornwulf of Mercia, ending the long Mercian ascendancy over southern England. Ecgberht followed it up by sending Æthelwulf with Eahlstan, Bishop of Sherborne, and Wulfheard, Ealdorman of Hampshire, with a large army into Kent to expel sub-king Baldred. Æthelwulf was descended from kings of Kent, and he was sub-king of Kent, and of Surrey, Sussex and Essex, which were then included in the sub-kingdom, until he inherited the throne of Wessex in 839. His sub-kingship is recorded in charters, in some of which King Ecgberht acted with his son's permission, such as a grant in 838 to Bishop Beornmod of Rochester, and Æthelwulf himself issued a charter as King of Kent in the same year. Unlike their Mercian predecessors, who alienated the Kentish people by ruling from a distance, Æthelwulf and his father successfully cultivated local support by governing through Kentish ealdormen and promoting their interests. In Abels' view, Ecgberht and Æthelwulf rewarded their friends and purged Mercian supporters. Historians take differing views on the attitude of the new regime to the Kentish church. At Canterbury in 828 Ecgberht granted privileges to the bishopric of Rochester, and according to the historian Simon Keynes, Ecgberht and Æthelwulf took steps to secure the support of Archbishop Wulfred. However, Nicholas Brooks argues that Wulfred's Mercian origin and connections proved a liability. Æthelwulf seized an estate in East Malling from the Canterbury church on the ground that it had only been granted by Baldred when he was in flight from the West Saxon forces; the issue of archiepiscopal coinage was suspended for several years; and the only estate Wulfred was granted after 825 he received from King Wiglaf of Mercia.


title: Æthelwulf, King of Wessex

text: In 829 Ecgberht conquered Mercia, only for Wiglaf to recover his kingdom a year later. The scholar David Kirby sees Wiglaf's restoration in 830 as a dramatic reversal for Ecgberht, which was probably followed by his loss of control of the London mint and the Mercian recovery of Essex and Berkshire, and the historian Heather Edwards states that his "immense conquest could not be maintained". However, in the view of Keynes:


title: Æthelwulf, King of Wessex

text: In 838 King Ecgberht held an assembly at Kingston in Surrey, where Æthelwulf may have been consecrated as king by the archbishop. Ecgberht restored the East Malling estate to Wulfred's successor as Archbishop of Canterbury, Ceolnoth, in return for a promise of "firm and unbroken friendship" for himself and Æthelwulf and their heirs, and the same condition is specified in a grant to the see of Winchester. Ecgberht thus ensured support for Æthelwulf, who became the first son to succeed his father as West Saxon king since 641. At the same meeting Kentish monasteries chose Æthelwulf as their lord, and he undertook that, after his death, they would have freedom to elect their heads. Wulfred had devoted his archiepiscopate to fighting against secular power over Kentish monasteries, but Ceolnoth now surrendered effective control to Æthelwulf, whose offer of freedom from control after his death was unlikely to be honoured by his successors. Kentish ecclesiastics and laymen now looked for protection against Viking attacks to West Saxon rather than Mercian royal power.


title: Æthelwulf, King of Wessex

text: Ecgberht's conquests brought him wealth far greater than his predecessors had enjoyed, and enabled him to purchase the support which secured the West Saxon throne for his descendants. The stability brought by the dynastic succession of Ecgberht and Æthelwulf led to an expansion of commercial and agrarian resources, and to an expansion of royal income. The wealth of the West Saxon kings was also increased by the agreement in 838–39 with Archbishop Ceolnoth for the previously independent West Saxon minsters to accept the king as their secular lord in return for his protection. However, there was no certainty that the hegemony of Wessex would prove more permanent than that of Mercia.


title: Æthelwulf, King of Wessex

text: When Æthelwulf succeeded to the throne of Wessex in 839, his experience as sub-king of Kent had given him valuable training in kingship, and he in turn made his own sons sub-kings. According to the "Anglo-Saxon Chronicle", on his accession "he gave to his son Æthelstan the kingdom of the people of Kent, and the kingdom of the East Saxons [Essex] and of the people of Surrey and of the South Saxons [Sussex]". However, Æthelwulf did not give Æthelstan the same power as his father had given him, and although Æthelstan attested his father's charters as king, he does not appear to have been given the power to issue his own charters. Æthelwulf exercised authority in the south-east and made regular visits there. He governed Wessex and Kent as separate spheres, and assemblies in each kingdom were only attended by the nobility of that country. The historian Janet Nelson says that "Æthelwulf ran a Carolingian-style family firm of plural realms, held together by his own authority as father-king, and by the consent of distinct élites." He maintained his father's policy of governing Kent through ealdormen appointed from the local nobility and advancing their interests, but gave less support to the church. In 843 Æthelwulf granted ten hides at Little Chart to Æthelmod, the brother of the leading Kentish ealdorman Ealhere, and Æthelmod succeeded to the post on his brother's death in 853. In 844 Æthelwulf granted land at Horton in Kent to Ealdorman Eadred, with permission to transfer parts of it to local landowners; in a culture of reciprocity, this created a network of mutual friendships and obligations between the beneficiaries and the king. Archbishops of Canterbury were firmly in the West Saxon king's sphere. His ealdormen enjoyed a high status, and were sometimes placed higher than the king's sons in lists of witnesses to charters. His reign is the first for which there is evidence of royal priests, and Malmesbury Abbey regarded him as an important benefactor, who is said to have been the donor of a shrine for the relics of Saint Aldhelm.


title: Æthelwulf, King of Wessex

text: After 830, Ecgberht had followed a policy of maintaining good relations with Mercia, and this was continued by Æthelwulf when he became king. London was traditionally a Mercian town, but in the 830s it was under West Saxon control; soon after Æthelwulf's accession it reverted to Mercian control. King Wiglaf of Mercia died in 839 and his successor, Berhtwulf, revived the Mercian mint in London; the two kingdoms appear to have struck a joint issue in the mid-840s, possibly indicating West Saxon help in reviving Mercian coinage, and showing the friendly relations between the two powers. Berkshire was still Mercian in 844, but by 849 it was part of Wessex, as Alfred was born in that year at the West Saxon royal estate in Wantage, then in Berkshire. However, the local Mercian ealdorman, also called Æthelwulf, retained his position under the West Saxon kings. Berhtwulf died in 852 and cooperation with Wessex continued under Burgred, his successor as King of Mercia, who married Æthelwulf's daughter Æthelswith in 853. In the same year Æthelwulf assisted Burgred in a successful attack on Wales to restore the traditional Mercian hegemony over the Welsh.


title: Æthelwulf, King of Wessex

text: In 9th-century Mercia and Kent, royal charters were produced by religious houses, each with its own style, but in Wessex there was a single royal diplomatic tradition, probably by a single agency acting for the king. This may have originated in Ecgberht's reign, and it becomes clear in the 840s, when Æthelwulf had a Frankish secretary called Felix. There were strong contacts between the West Saxon and Carolingian courts. The Annals of St Bertin took particular interest in Viking attacks on Britain, and in 852 Lupus, the Abbot of Ferrières and a protégé of Charles the Bald, wrote to Æthelwulf congratulating him on his victory over the Vikings and requesting a gift of lead to cover his church roof. Lupus also wrote to his "most beloved friend" Felix, asking him to manage the transport of the lead. Unlike Canterbury and the south-east, Wessex did not see a sharp decline in the standard of Latin in charters in the mid-9th century, and this may have been partly due to Felix and his continental contacts. Lupus thought that Felix had great influence over the King. Charters were mainly issued from royal estates in counties which were the heartland of ancient Wessex, namely Hampshire, Somerset, Wiltshire and Dorset, with a few in Kent.


title: Æthelwulf, King of Wessex

text: An ancient division between east and west Wessex continued to be important in the 9th century; the boundary was Selwood Forest on the borders of Somerset, Dorset and Wiltshire. The two bishoprics of Wessex were Sherborne in the west and Winchester in the east. Æthelwulf's family connections seem to have been west of Selwood, but his patronage was concentrated further east, particularly on Winchester, where his father was buried, and where he appointed Swithun to succeed Helmstan as bishop in 852–853. However, he made a grant of land in Somerset to his leading ealdorman, Eanwulf, and on 26 December 846 he granted a large estate to himself in South Hams in west Devon. He thus changed it from royal demesne, which he was obliged to pass on to his successor as king, to bookland, which could be transferred as the owner pleased, so he could make land grants to followers to improve security in a frontier zone.


title: Æthelwulf, King of Wessex

text: Viking raids increased in the early 840s on both sides of the English Channel, and in 843 Æthelwulf was defeated by the companies of 35 Danish ships at Carhampton in Somerset. In 850 sub-king Æthelstan and Ealdorman Ealhhere of Kent won a naval victory over a large Viking fleet off Sandwich in Kent, capturing nine ships and driving off the rest. Æthelwulf granted Ealhhere a large estate in Kent, but Æthelstan is not heard of again, and probably died soon afterwards. The following year the "Anglo-Saxon Chronicle" records five different attacks on southern England. A Danish fleet of 350 Viking ships took London and Canterbury, and when King Berhtwulf of Mercia went to their relief he was defeated. The Vikings then moved on to Surrey, where they were defeated by Æthelwulf and his son Æthelbald at the Battle of Aclea. According to the "Anglo-Saxon Chronicle" the West Saxon levies "there made the greatest slaughter of a heathen that we have heard tell of up to the present day". The "Chronicle" frequently reported victories during Æthelwulf's reign won by levies led by ealdormen, unlike the 870s when royal command was emphasised, reflecting a more consensual style of leadership in the earlier period.


title: Æthelwulf, King of Wessex

text: In 850 a Danish army wintered on Thanet, and in 853 ealdormen Ealhhere of Kent and Huda of Surrey were killed in a battle against the Vikings, also on Thanet. In 855 Danish Vikings stayed over the winter on Sheppey, before carrying on their pillaging of eastern England. However, during Æthelwulf's reign Viking attacks were contained and did not present a major threat.


title: Æthelwulf, King of Wessex

text: The silver penny was almost the only coin used in middle and later Anglo-Saxon England. Æthelwulf's coinage came from a main mint in Canterbury and a secondary one at Rochester; both had been used by Ecgberht for his own coinage after he gained control of Kent. During Æthelwulf's reign, there were four main phases of the coinage distinguishable at both mints, though they are not exactly parallel and it is uncertain when the transitions took place. The first issue at Canterbury carried a design known as "Saxoniorum", which had been used by Ecgberht for one of his own issues. This was replaced by a portrait design in about 843, which can be subdivided further; the earliest coins have cruder designs than the later ones. At the Rochester mint the sequence was reversed, with an initial portrait design replaced, also in about 843, by a non-portrait design carrying a cross-and-wedges pattern on the obverse.


title: Æthelwulf, King of Wessex

text: In about 848 both mints switched to a common design known as Dor¯b¯/Cant – the characters "Dor¯b¯" on the obverse of these coins indicate either "Dorobernia" (Canterbury) or "Dorobrevia" (Rochester), and "Cant", referring to Kent, appeared on the reverse. It is possible that the Canterbury mint continued to produce portrait coins at the same time. The Canterbury issue seems to have been ended in 850–851 by Viking raids, though it is possible that Rochester was spared, and the issue may have continued there. The final issue, again at both mints, was introduced in about 852; it has an inscribed cross on the reverse and a portrait on the obverse. Æthelwulf's coinage became debased by the end of his reign, and though the problem became worse after his death it is possible that the debasement prompted the changes in coin type from as early as 850.


title: Æthelwulf, King of Wessex

text: Æthelwulf's first Rochester coinage may have begun when he was still sub-king of Kent, under Ecgberht. A hoard of coins deposited at the beginning of Æthelwulf's reign in about 840, found in the Middle Temple in London, contained 22 coins from Rochester and two from Canterbury of the first issue of each mint. Some numismatists argue that the high proportion of Rochester coins means that the issue must have commenced before Ecgberht's death, but an alternative explanation is that whoever hoarded the coins simply happened to have access to more Rochester coins. No coins were issued by Æthelwulf's sons during his reign.


title: Æthelwulf, King of Wessex

text: Ceolnoth, Archbishop of Canterbury throughout Æthelwulf's reign, also minted coins of his own at Canterbury: there were three different portrait designs, thought to be contemporary with each of the first three of Æthelwulf's Canterbury issues. These were followed by an inscribed cross design that was uniform with Æthelwulf's final coinage. At Rochester, Bishop Beornmod produced only one issue, a cross-and-wedges design which was contemporary with Æthelwulf's "Saxoniorum" issue.


title: Æthelwulf, King of Wessex

text: In the view of the numismatists Philip Grierson and Mark Blackburn, the mints of Wessex, Mercia and East Anglia were not greatly affected by changes in political control: "the remarkable continuity of moneyers which can be seen at each of these mints suggests that the actual mint organisation was largely independent of the royal administration and was founded in the stable trading communities of each city".


title: Æthelwulf, King of Wessex

text: The early 20th-century historian W. H. Stevenson observed that: "Few things in our early history have led to so much discussion" as Æthelwulf's Decimation Charters; a hundred years later the charter expert Susan Kelly described them as "one of the most controversial groups of Anglo-Saxon diplomas". Both Asser and the "Anglo-Saxon Chronicle" say that Æthelwulf gave a decimation, in 855, shortly before leaving on pilgrimage to Rome. According to the "Chronicle" "King Æthelwulf conveyed by charter the tenth part of his land throughout all his kingdom to the praise of God and to his own eternal salvation". However, Asser states that "Æthelwulf, the esteemed king, freed the tenth part of his whole kingdom from royal service and tribute, and as an everlasting inheritance he made it over on the cross of Christ to the triune God, for the redemption of his soul and those of his predecessors." According to Keynes, Asser's version may just be a "loose translation" of the "Chronicle", and his implication that Æthelwulf released a tenth of all land from secular burdens was probably not intended. All land could be regarded as the king's land, so the "Chronicle" reference to "his land" does not necessarily refer to royal property, and since the booking of land – conveying it by charter – was always regarded as a pious act, Asser's statement that he made it over to God does not necessarily mean that the charters were in favour of the church.


title: Æthelwulf, King of Wessex

text: None of the charters are original, and Stevenson dismissed all of them as fraudulent apart from the Kentish one of 855. Stevenson saw the decimation as a donation of royal demesne to churches and laymen, with those grants which were made to laymen being on the understanding that there would be reversion to a religious institution. Up to the 1990s, his view on the authenticity of the charters was generally accepted by scholars, with the exception of the historian H. P. R. Finberg, who argued in 1964 that most are based on authentic diplomas. Finberg coined the terms the 'First Decimation' of 844, which he saw as the removal of public dues on a tenth of all bookland, and the 'Second Decimation' of 854, the donation of a tenth of "the private domain of the royal house" to the churches. He considered it unlikely that the First Decimation had been carried into effect, probably due to the threat from the Vikings. Finberg's terminology has been adopted, but his defence of the First Decimation generally rejected. In 1994, Keynes defended the Wilton charters in group 2, and his arguments have been widely accepted.


title: Æthelwulf, King of Wessex

text: Historians have been divided on how to interpret the Second Decimation, and in 1994 Keynes described it as "one of the most perplexing problems" in the study of 9th-century charters. He set out three alternatives:


title: Æthelwulf, King of Wessex

text: Some scholars, for example Frank Stenton, author of the standard history of Anglo-Saxon England, along with Keynes and Abels, see the Second Decimation as a donation of royal demesne. In Abels' view Æthelwulf sought loyalty from the aristocracy and church during the king's forthcoming absence from Wessex, and displayed a sense of dynastic insecurity also evident in his father's generosity towards the Kentish church in 838, and in an "avid attention" in this period to compiling and revising royal genealogies. Keynes suggests that "Æthelwulf's purpose was presumably to earn divine assistance in his struggles against the Vikings", and the mid-20th-century historian Eric John observes that "a lifetime of medieval studies teaches one that an early medieval king was never so political as when he was on his knees". The view that the decimation was a donation of the king's own personal estate is supported by the Anglo-Saxonist Alfred P. Smyth, who argues that these were the only lands the king was entitled to alienate by book. The historian Martin Ryan prefers the view that Æthelwulf freed a tenth part of land owned by laymen from secular obligations, who could now endow churches under their own patronage. Ryan sees it as part of a campaign of religious devotion. According to the historian David Pratt, it "is best interpreted as a strategic 'tax cut', designed to encourage cooperation in defensive measures through a partial remission of royal dues". Nelson states that the decimation took place in two phases, in Wessex in 854 and Kent in 855, reflecting that they remained separate kingdoms.


title: Æthelwulf, King of Wessex

text: Kelly argues that most charters were based on genuine originals, including the First Decimation of 844. She says: "Commentators have been unkind [and] the 844 version has not been given the benefit of the doubt". In her view Æthelwulf then gave a 10% tax reduction on bookland, and ten years later he took the more generous step of "a widespread distribution of royal lands". Unlike Finberg, she believes that both decimations were carried out, although the second one may not have been completed due to opposition from Æthelwulf's son Æthelbald. She thinks that the grants of bookland to laymen in the Second Decimation were unconditional, not with reversion to religious houses as Stevenson had argued. However, Keynes is not convinced by Kelly's arguments, and thinks that the First Decimation charters were 11th or early 12th century fabrications.


title: Æthelwulf, King of Wessex

text: In 855 Æthelwulf went on pilgrimage to Rome. According to Abels: "Æthelwulf was at the height of his power and prestige. It was a propitious time for the West Saxon king to claim a place of honour among the kings and emperors of christendom." His eldest surviving sons Æthelbald and Æthelberht were then adults, while Æthelred and Alfred were still young children. In 853 Æthelwulf sent his younger sons to Rome, perhaps accompanying envoys in connection with his own forthcoming visit. Alfred, and probably Æthelred as well, were invested with the "belt of consulship". Æthelred's part in the journey is only known from a contemporary record in the "liber vitae" of San Salvatore, Brescia, as later records such as the "Anglo-Saxon Chronicle" were only interested in recording the honour paid to Alfred. Abels sees the embassy as paving the way for Æthelwulf's pilgrimage, and the presence of Alfred, his youngest and therefore most expendable son, as a gesture of goodwill to the papacy; confirmation by Pope Leo IV made Alfred his spiritual son, and thus created a spiritual link between the two "fathers". Kirby argues that the journey may indicate that Alfred was intended for the church, while Nelson on the contrary sees Æthelwulf's purpose as affirming his younger sons' throneworthiness, thus protecting them against being tonsured by their elder brothers, which would have rendered them ineligible for kingship.


title: Æthelwulf, King of Wessex

text: Æthelwulf set out for Rome in the spring of 855, accompanied by Alfred and a large retinue. The King left Wessex in the care of his oldest surviving son, Æthelbald, and the sub-kingdom of Kent to the rule of Æthelberht, and thereby confirmed that they were to succeed to the two kingdoms. On the way the party stayed with Charles the Bald in Francia, where there were the usual banquets and exchange of gifts. Æthelwulf stayed a year in Rome, and his gifts to the Diocese of Rome included a gold crown weighing , two gold goblets, a sword bound with gold, four silver-gilt bowls, two silk tunics and two gold-interwoven veils. He also gave gold to the clergy and leading men and silver to the people of Rome. According to the historian Joanna Story, his gifts rivalled those of Carolingian donors and the Byzantine emperor and "were clearly chosen to reflect the personal generosity and spiritual wealth of the West Saxon king; here was no Germanic 'hillbilly' from the backwoods of the Christian world but, rather, a sophisticated, wealthy and utterly contemporary monarch". The post-Conquest chronicler William of Malmesbury stated that he helped to pay for the restoration of the Saxon quarter, which had recently been destroyed by fire, for English pilgrims.


title: Æthelwulf, King of Wessex

text: The pilgrimage puzzles historians and Kelly comments that "it is extraordinary that an early medieval king could consider his position safe enough to abandon his kingdom in a time of extreme crisis". She suggests that Æthelwulf may have been motivated by a personal religious impulse. Ryan sees it as an attempt to placate the divine wrath displayed by Viking attacks, whereas Nelson thinks he aimed to enhance his prestige in dealing with the demands of his adult sons. In Kirby's view:


title: Æthelwulf, King of Wessex

text: On his way back from Rome Æthelwulf again stayed with King Charles the Bald, and may have joined him on a campaign against a Viking warband. On 1 October 856 Æthelwulf married Charles's daughter, Judith, aged 12 or 13, at Verberie. The marriage was considered extraordinary by contemporaries and by modern historians. Carolingian princesses rarely married and were usually sent to nunneries, and it was almost unknown for them to marry foreigners. Judith was crowned queen and anointed by Hincmar, Archbishop of Rheims. Although empresses had been anointed before, this is the first definitely known anointing of a Carolingian queen. In addition West Saxon custom, described by Asser as "perverse and detestable", was that the wife of a king of Wessex could not be called queen or sit on the throne with her husband – she was just the king's wife.


title: Æthelwulf, King of Wessex

text: Æthelwulf returned to Wessex to face a revolt by Æthelbald, who attempted to prevent his father from recovering his throne. Historians give varying explanations for both the rebellion and the marriage. In Nelson's view, Æthelwulf's marriage to Judith added the West Saxon king to the family of kings and princely allies which Charles was creating. Charles was under attack both from Vikings and from a rising among his own nobility, and Æthelwulf had great prestige due to his victories over the Vikings; some historians such as Kirby and Pauline Stafford see the marriage as sealing an anti-Viking alliance. The marriage gave Æthelwulf a share in Carolingian prestige, and Kirby describes the anointing of Judith as "a charismatic sanctification which enhanced her status, blessed her womb and conferred additional throne-worthiness on her male offspring." These marks of a special status implied that a son of hers would succeed to at least part of Æthelwulf's kingdom, and explain Æthelbald's decision to rebel. The historian Michael Enright denies that an anti-Viking alliance between two such distant kingdoms could serve any useful purpose, and argues that the marriage was Æthelwulf's response to news that his son was planning to rebel; his son by an anointed Carolingian queen would be in a strong position to succeed as king of Wessex instead of the rebellious Æthelbald. Abels suggests that Æthelwulf sought Judith's hand because he needed her father's money and support to overcome his son's rebellion, but Kirby and Smyth argue that it is extremely unlikely that Charles the Bald would have agreed to marry his daughter to a ruler who was known to be in serious political difficulty. Æthelbald may also have acted out of resentment at the loss of patrimony he suffered as a result of the decimation.


title: Æthelwulf, King of Wessex

text: Æthelbald's rebellion was supported by Ealhstan, Bishop of Sherborne, and Eanwulf, ealdorman of Somerset, even though they appear to have been two of the king's most trusted advisers. According to Asser, the plot was concerted "in the western part of Selwood", and western nobles may have backed Æthelbald because they resented the patronage Æthelwulf gave to eastern Wessex. Asser also stated that Æthelwulf agreed to give up the western part of his kingdom in order to avoid a civil war. Some historians such as Keynes and Abels think that his rule was then confined to the south-east, while others such as Kirby think it is more likely that it was Wessex itself which was divided, with Æthelbald keeping Wessex west of Selwood, Æthelwulf holding the centre and east, and Æthelberht keeping the south-east. Æthelwulf insisted that Judith should sit beside him on the throne until the end of his life, and according to Asser this was "without any disagreement or dissatisfaction on the part of his nobles".


title: Æthelwulf, King of Wessex

text: King Æthelwulf's ring was found in a cart rut in Laverstock in Wiltshire in about August 1780 by one William Petty, who sold it to a silversmith in Salisbury. The silversmith sold it to the Earl of Radnor, and the earl's son, William, donated it to the British Museum in 1829. The ring, together with a similar ring of Æthelwulf's daughter Æthelswith, is one of two key examples of nielloed 9th-century metalwork. They appear to represent the emergence of a "court style" of West Saxon metalwork, characterised by an unusual Christian iconography, such as a pair of peacocks at the Fountain of Life on the Æthelwulf ring, associated with Christian immortality. The ring is inscribed "Æthelwulf Rex", firmly associating it with the King, and the inscription forms part of the design, so it cannot have been added later. Many of its features are typical of 9th-century metalwork, such as the design of two birds, beaded and speckled borders, and a saltire with arrow-like terminals on the back. It was probably manufactured in Wessex, but was typical of the uniformity of animal ornament in England in the 9th century. In the view of Leslie Webster, an expert on medieval art: "Its fine Trewhiddle style ornament would certainly fit a mid ninth-century date." In Nelson's view, "it was surely made to be a gift from this royal lord to a brawny follower: the sign of a successful ninth-century kingship". The art historian David Wilson sees it as a survival of the pagan tradition of the generous king as the "ring-giver".


title: Æthelwulf, King of Wessex

text: Æthelwulf's will has not survived, but Alfred's has and it provides some information about his father's intentions. He left a bequest to be inherited by whichever of Æthelbald, Æthelred, and Alfred lived longest. Abels and Yorke argue that this meant the whole of his personal property in Wessex, and probably that the survivor was to inherit the throne of Wessex as well, while Æthelberht and his heirs ruled Kent. Other historians disagree. Nelson states that the provision regarding the personal property had nothing to do with the kingship, and Kirby comments: "Such an arrangement would have led to fratricidal strife. With three older brothers, Alfred's chances of reaching adulthood would, one feels, have been minimal." Smyth describes the bequest as provision for his youngest sons when they reached manhood. Æthelwulf's moveable wealth, such as gold and silver, was to be divided among "children, nobles and the needs of the king's soul". For the latter, he left one tenth of his hereditary land to be set aside to feed the poor, and he ordered that three hundred mancuses be sent to Rome each year, one hundred to be spent on lighting the lamps in St Peter's at Easter, one hundred for the lights of St Paul's, and one hundred for the pope.


title: Æthelwulf, King of Wessex

text: Æthelwulf died on 13 January 858. According to the Annals of St Neots, he was buried at Steyning in Sussex, but his body was later transferred to Winchester, probably by Alfred. As Æthelwulf had intended, he was succeeded by Æthelbald in Wessex and Æthelberht in Kent and the south-east. The prestige conferred by a Frankish marriage was so great that Æthelbald then wedded his step-mother Judith, to Asser's retrospective horror; he described the marriage as a "great disgrace", and "against God's prohibition and Christian dignity". When Æthelbald died only two years later, Æthelberht became King of Wessex as well as Kent, and Æthelwulf's intention of dividing his kingdoms between his sons was thus set aside. In the view of Yorke and Abels this was because Æthelred and Alfred were too young to rule, and Æthelberht agreed in return that his younger brothers would inherit the whole kingdom on his death, whereas Kirby and Nelson think that Æthelberht just became the trustee for his younger brothers' share of their father's bequest.


title: Æthelwulf, King of Wessex

text: After Æthelbald's death Judith sold her possessions and returned to her father, but two years later she eloped with Baldwin, Count of Flanders. In the 890s their son, also called Baldwin, married Alfred's daughter, Ælfthryth.


title: Æthelwulf, King of Wessex

text: Æthelwulf's reputation among historians was poor in the twentieth century. In 1935, the historian R. H. Hodgkin attributed his pilgrimage to Rome to "the unpractical piety which had led him to desert his kingdom at a time of great danger", and described his marriage to Judith as "the folly of a man senile before his time". To Stenton in the 1960s he was "a religious and unambitious man, for whom engagement in war and politics was an unwelcome consequence of rank". One dissenter was Finberg, who in 1964 described him as "a king whose valour in war and princely munificence recalled the figures of the heroic age", but in 1979 Enright said: "More than anything else he appears to have been an impractical religious enthusiast." Early medieval writers, especially Asser, emphasise his religiosity and his preference for consensus, seen in the concessions made to avert a civil war on his return from Rome. In Story's view "his legacy has been clouded by accusations of excessive piety which (to modern sensibilities at least) has seemed at odds with the demands of early medieval kingship". In 839 an unnamed Anglo-Saxon king wrote to the Holy Roman Emperor Louis the Pious asking for permission to travel through his territory on the way to Rome, and relating an English priest's dream which foretold disaster unless Christians abandoned their sins. This is now believed to have been an unrealised project of Ecgberht at the end of his life, but it was formerly attributed to Æthelwulf, and seen as exhibiting what Story calls his reputation for "dramatic piety", and irresponsibility for planning to abandon his kingdom at the beginning of his reign.


title: Æthelwulf, King of Wessex

text: In the twenty-first century he is seen very differently by historians. Æthelwulf is not listed in the index of Peter Hunter Blair's "An Introduction to Anglo-Saxon England", first published in 1956, but in a new introduction to the 2003 edition Keynes listed him among people "who have not always been accorded the attention they might be thought to deserve ... for it was he, more than any other, who secured the political fortune of his people in the ninth century, and who opened up channels of communication which led through Frankish realms and across the Alps to Rome". According to Story: "Æthelwulf acquired and cultivated a reputation both in Francia and Rome which is unparalleled in the sources since the height of Offa's and Coenwulf's power at the turn of the ninth century".


title: Æthelwulf, King of Wessex

text: Nelson describes him as "one of the great underrated among Anglo-Saxons", and complains that she was only allowed 2,500 words for him in the "Oxford Dictionary of National Biography", compared with 15,000 for Edward II and 35,000 for Elizabeth I. She says:


title: Justin Lin

text: Justin Lin (, born October 11, 1971) is a Taiwanese-American film director. His films have grossed US$2.3 billion worldwide as of March 2017. He is best known for his directorial work on "Better Luck Tomorrow" (2002), the "Fast & Furious" franchise from "" (2006) to "Fast & Furious 6" (2013) and "F9" (2021), and "Star Trek Beyond" (2016). He is also known for his work on television programs like "Community", and the second season of "True Detective".


title: Justin Lin

text: Lin was born on October 11, 1971, in Taipei, Taiwan. He immigrated to the United States at the age of eight and grew up in Buena Park, California. He graduated from nearby Cypress High School. Lin earned the rank of Eagle Scout in March 1989 while a member of Boy Scout Troop 670.


title: Justin Lin

text: Lin attended the University of California, San Diego (UCSD), for two years before transferring to the University of California, Los Angeles (UCLA), where he earned a BA in Film and Television and a MFA in Film Directing and Production from the UCLA School of Theater, Film and Television. He was given a Distinguished Alumni Award in 2017.


title: Justin Lin

text: Lin's first feature film was "Shopping for Fangs" (1997), which he co-directed with fellow UCLA Film School alumnus Quentin Lee when they were still at UCLA. The film stars John Cho and is considered to be a "cult classic" among independent Asian American films.


title: Justin Lin

text: Lin wrote and directed a documentary, "Crossover" (2000), which focused on the 70-year-old phenomenon of the Japanese American Basketball Leagues, which were established in the 1930s.


title: Justin Lin

text: Lin's solo directorial debut was "Better Luck Tomorrow" (2002), a film focusing on a circle of high-school-age Asian-Americans who become caught up in a cascading series of petty and then serious crimes. The film premiered at the Sundance Film Festival of that year, and in a question and answer session following a festival screening, Roger Ebert stood up and angrily responded to an audience member asking Lin if he thought it irresponsible to portray Asian-Americans in a negative light, saying, "[N]obody would say to a bunch of white filmmakers, 'How could you do this to your people?' ... Asian-American characters have the right to be whoever the hell they want to be. They do not have to 'represent' their people." Ebert's approval of the film drew the attention of major studios, eventually leading to MTV Films buying the film for distribution, MTV Films' first such acquisition. "Better Luck Tomorrow" was also an official selection of the 2002 Toronto International Film Festival, was nominated for a Grand Jury Prize at 2002 Sundance, and was a nominee for the John Cassavetes Award at the 2004 Independent Spirit Awards. "Variety" magazine named him one of the "Top 10 Directors to Watch" in 2002, citing the film.


title: Justin Lin

text: Lin's second feature film—and first film to be produced and distributed by a large studio, Touchstone Pictures—was "Annapolis" (2006), which starred James Franco, Tyrese Gibson, Donnie Wahlberg and Jordana Brewster. The film cost US$26 million to make, but grossed only $17 million worldwide.


title: Justin Lin

text: His third feature film, "", was released in North American cinemas on June 16, 2006. Despite mixed reviews, "Tokyo Drift" brought in over US$24 million on its opening weekend; the domestic box office would eventually total $62 million with a further $95 million accruing from the foreign box office, making total gross receipts $158 million. With "Tokyo Drift", Lin would begin his run as director of the next three "Fast & Furious" films, leading the franchise until "Furious 7". Lin was initially approached to direct the film after the success of "Better Luck Tomorrow" at Sundance, and after wrapping his first studio film "Annapolis", but wanted some "conditions" met, as the script presented him was about "cars drifting around Buddhist statues and geisha girls." Instead, Lin wanted to make a film about Japan, which was "much more postmodern" as he mentioned, and intended to have a film on a more global scale that went against preconceived stereotypes.


title: Justin Lin

text: After "Tokyo Drift", Lin directed a short film that also premiered at the Sundance Global Short Film Project, "La Revolución de Iguodala!" (2007), about one individual's message as that individual travels through time and becomes embodied in different races. He also went on to do an independent film, "Finishing the Game" (2007), a mockumentary on the events surrounding the production of Bruce Lee's final film, "Game of Death". It premiered at the 2007 Sundance Film Festival, and was also selected as the opening night film at a variety of North American film festivals, for instance at the 25th San Francisco International Asian American Film Festival.


title: Justin Lin

text: Lin returned to direct "Fast & Furious", the fourth in the film series, which opened on April 3, 2009. On its first day of release the movie grossed US$30.6 million, and peaked at the top spot of the weekend box office with $71.0 million. The film ultimately grossed $359 million worldwide.


title: Justin Lin

text: Lin directed the follow-up 2011 film "Fast Five", which holds the titles for the highest-grossing opening weekend ever in April (US$84 million), and for any car-oriented film. "Fast Five" also broke box office records for being the second highest spring opening weekend, and surpassed "Fast & Furious" (2009) to become the highest-grossing film in the franchise. It grossed over $625 million worldwide, making it number 63 on the all-time worldwide list of highest-grossing films (in unadjusted dollars), and the seventh highest-grossing film of 2011.


title: Justin Lin

text: Following the success of "Fast Five", Lin and his production company Barnstorm Pictures signed a two-year first-look deal with Universal Pictures, the company that owns the "Fast and Furious" franchise.


title: Justin Lin

text: Lin continued with its sixth installment, "Fast & Furious 6". It became the largest Memorial Day Weekend gross for a Universal Pictures film, setting a record of US$120 million and a worldwide total of $317 million. It also became the highest grossing Universal Pictures film in the UK, with an opening weekend UK gross larger than any other movie in the series. Specifically, the film took more than US$4.4 million on its opening day, the biggest opening day for both the franchise and the studio in that market, the second-highest opening of 2013 (behind "Iron Man 3" at $4.7 million), and the highest-grossing film of the day with 54% of the market. In the UK, the film also finished as the number one film of the weekend, taking around $14 million, making it the biggest opening for the franchise and Universal, and for a Vin Diesel or Dwayne Johnson film, and the second-biggest opening weekend of 2013 (again behind "Iron Man 3", at around $18 million). The film performed relatively well critically. Metacritic describes it as having "generally favorable reviews", and Rotten Tomatoes reports 75% approval from top critics, and 83% approval from viewers, as of March 2017.


title: Justin Lin

text: Lin co-wrote and co-produced the China-U.S. action-comedy co-production "Hollywood Adventures" (2015), starring Huang Xiaoming, Tong Dawei and Zhao Wei.


title: Justin Lin

text: Lin directed "Star Trek Beyond", released in July 2016. The film is the third in the series' feature film reboot.


title: Justin Lin

text: In October 2017, Lin was confirmed to be returning to the "Fast & Furious" franchise, directing "F9". Originally set for an April 2020 release, the film was ultimately released in June 2021 after several delays due to the COVID-19 pandemic. Lin was then slated to return for the franchise's tenth and eleventh installments but dropped out of directing the two films about a week into production.


title: Justin Lin

text: As of April 2012, "Variety" was reporting that Lin was in talks to direct a feature film adaptation of David Henry Hwang's, play "Chinglish".


title: Justin Lin

text: In August 2012, "Deadline" was reporting that Lin may possibly direct a film based on the 1992 Los Angeles riots entitled "L.A. Riots" for Universal Studios, with Brian Grazer producing.


title: Justin Lin

text: In November 2012, "The Hollywood Reporter" announced that Lin planned to direct a sci-fi film entitled "Hibernation".


title: Justin Lin

text: At the 2014 Sundance Film Festival, Lin acquired the narrative remake rights to the documentary, "The Battered Bastards of Baseball", the adaptation of which he reportedly plans to self-finance and produce through his Perfect Storm banner.


title: Justin Lin

text: In March 2014, "Deadline" and others reported Lin as having been slated to helm "Times Square", based on The Black List script by Taylor Materne and Jacob Rubin, a crime thriller about "set in the last days of the old Times Square, when it was transitioning from a seedy lawless Midtown Manhattan dump to a family-friendly corporate mecca; in that backdrop, when a secret from his past is unearthed, a young man's loyalties are divided between his neighborhood boss who raised him and the grizzled ex-cop who swore to protect him."


title: Justin Lin

text: In March 2015, "Deadline" reported Lin's plans to helm a 3D remake of "Shaolin Temple" under his banner Perfect Storm Entertainment, which focuses more on projects in China.


title: Justin Lin

text: In June 2016, "Variety" announced that producer Steven Paul's SP International Pictures had acquired the rights to produce a live-action English-language feature film remake of the "iconic" manga, "Lone Wolf and Cub", in an article where Lin went unmentioned, after a March 2012 announcement that Lin might direct such a film. In July 2016, Lin mentioned that he was re-attached as the director for an adaptation of the manga, and that he plans to have a predominantly Asian cast, saying


title: Justin Lin

text: In September 2017, it was announced that Lin would be directing and developing a narrative version of the documentary "Abacus: Small Enough to Jail" by Steve James ("Hoop Dreams"), who serves as an executive producer on the narrative film, with award-winning playwright and "House of Cards" writer Kenneth Lin will be responsible for writing the screenplay.


title: Justin Lin

text: Lin directed three episodes on the first season of the NBC comedy series "Community" between 2009 and 2010, which include "Modern Warfare", "Interpretive Dance", and "Introduction to Statistics". For his work on the show, Lin was nominated for two NAACP Image Awards for Outstanding Directing in a Comedy Series. In September 2011, Lin and his production company Barnstorm Pictures signed a first-look deal with Sony Pictures Television, who produced "Community".


title: Justin Lin

text: In October 2013, "Deadline" announced that Lin would be directing the pilot of "Scorpion", a CBS drama produced by Roberto Orci and Alex Kurtzman. The series is about an eccentric genius who leads an international team of super-intelligent experts tasked with guarding against complex threats of the modern age. The pilot would be based on the real life of information technologist Walter O'Brien. In addition to directing the first episode, Lin serves as one of the series executive producers, along with Nick Santora.


title: Justin Lin

text: Lin directed the first two episodes in 2015 of the second season of "True Detective", "The Western Book of the Dead" (S02E01) and "Night Finds You" (S02E02).


title: Justin Lin

text: In December 2018, Lin signed an overall TV deal with Apple, Inc., departing from his deal with Sony Pictures Television. In the fall of 2020, Lin's Perfect Storm Entertainment signed an overall film and television first look deal with Universal Studios.


title: Justin Lin

text: In 2009, Lin started the Asian American blog YOMYOMF which stands for "You Offend Me You Offend My Family." It was adapted into a YouTube channel in 2011.


title: Justin Lin

text: In 2022, Lin set a joint venture with (art)ificial, the art & tech studio behind the NFT sci-fi collection Galaxy Eggs, with the intention to be the first company to build a Hollywood franchise from original NFT art.


title: Sense

text: A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of stimuli. (For example, in the human body, the brain which is part of the central nervous system receives signals from the senses which continuously receive information from the environment, interprets these signals, and causes the body to respond, either chemically or physically.) Although traditionally five human senses were identified as such (namely sight, smell, touch, taste, and hearing), it is now recognized that there are many more. Senses used by non-human organisms are even greater in variety and number. During sensation, sense organs collect various stimuli (such as a sound or smell) for transduction, meaning transformation into a form that can be understood by the brain. Sensation and perception are fundamental to nearly every aspect of an organism's cognition, behavior and thought.


title: Sense

text: In organisms, a sensory organ consists of a group of interrelated sensory cells that respond to a specific type of physical stimulus. Via cranial and spinal nerves (nerves of the Central and Peripheral nervous systems that relay sensory information to and from the brain and body), the different types of sensory receptor cells (such as mechanoreceptors, photoreceptors, chemoreceptors, thermoreceptors) in sensory organs transduct sensory information from these organs towards the central nervous system, finally arriving at the sensory cortices in the brain, where sensory signals are processed and interpreted (perceived).


title: Sense

text: Sensory systems, or senses, are often divided into external (exteroception) and internal (interoception) sensory systems. Human external senses are based on the sensory organs of the eyes, ears, skin, nose, and mouth. Internal sensation detects stimuli from internal organs and tissues. Internal senses possessed by humans include the vestibular system (sense of balance) sensed by the inner ear, as well as others such as spatial orientation, proprioception (body position) and nociception (pain). Further internal senses lead to signals such as hunger, thirst, suffocation, and nausea, or different involuntary behaviors, such as vomiting. Some animals are able to detect electrical and magnetic fields, air moisture, or polarized light, while others sense and perceive through alternative systems, such as echolocation. Sensory modalities or sub modalities are different ways sensory information is encoded or transduced. Multimodality integrates different senses into one unified perceptual experience. For example, information from one sense has the potential to influence how information from another is perceived. Sensation and perception are studied by a variety of related fields, most notably psychophysics, neurobiology, cognitive psychology, and cognitive science.


title: Sense

text: Sensory organs are organs that sense and transduce stimuli. Humans have various sensory organs (i.e. eyes, ears, skin, nose, and mouth) that correspond to a respective visual system (sense of vision), auditory system (sense of hearing), somatosensory system (sense of touch), olfactory system (sense of smell), and gustatory system (sense of taste). Those systems, in turn, contribute to vision, hearing, touch, smell, and the ability to taste. Internal sensation, or interoception, detects stimuli from internal organs and tissues. Many internal sensory and perceptual systems exist in humans, including the vestibular system (sense of balance) sensed by the inner ear and providing the perception of spatial orientation; proprioception (body position); and nociception (pain). Further internal chemoreception- and osmoreception-based sensory systems lead to various perceptions, such as hunger, thirst, suffocation, and nausea, or different involuntary behaviors, such as vomiting.


title: Sense

text: Nonhuman animals experience sensation and perception, with varying levels of similarity to and difference from humans and other animal species. For example, mammals in general have a stronger sense of smell than humans. Some animal species lack one or more human sensory system analogues and some have sensory systems that are not found in humans, while others process and interpret the same sensory information in very different ways. For example, some animals are able to detect electrical fields and magnetic fields, air moisture, or polarized light. Others sense and perceive through alternative systems such as echolocation. Recent theory suggests that plants and artificial agents such as robots may be able to detect and interpret environmental information in an analogous manner to animals.


title: Sense

text: Sensory modality refers to the way that information is encoded, which is similar to the idea of transduction. The main sensory modalities can be described on the basis of how each is transduced. Listing all the different sensory modalities, which can number as many as 17, involves separating the major senses into more specific categories, or submodalities, of the larger sense. An individual sensory modality represents the sensation of a specific type of stimulus. For example, the general sensation and perception of touch, which is known as somatosensation, can be separated into light pressure, deep pressure, vibration, itch, pain, temperature, or hair movement, while the general sensation and perception of taste can be separated into submodalities of sweet, salty, sour, bitter, spicy, and umami, all of which are based on different chemicals binding to sensory neurons.


title: Sense

text: Sensory receptors are the cells or structures that detect sensations. Stimuli in the environment activate specialized receptor cells in the peripheral nervous system. During transduction, physical stimulus is converted into action potential by receptors and transmitted towards the central nervous system for processing. Different types of stimuli are sensed by different types of receptor cells. Receptor cells can be classified into types on the basis of three different criteria: cell type, position, and function. Receptors can be classified structurally on the basis of cell type and their position in relation to stimuli they sense. Receptors can further be classified functionally on the basis of the transduction of stimuli, or how the mechanical stimulus, light, or chemical changed the cell membrane potential.


title: Sense

text: One way to classify receptors is based on their location relative to the stimuli. An exteroceptor is a receptor that is located near a stimulus of the external environment, such as the somatosensory receptors that are located in the skin. An interoceptor is one that interprets stimuli from internal organs and tissues, such as the receptors that sense the increase in blood pressure in the aorta or carotid sinus.


title: Sense

text: The cells that interpret information about the environment can be either (1) a neuron that has a free nerve ending, with dendrites embedded in tissue that would receive a sensation; (2) a neuron that has an encapsulated ending in which the sensory nerve endings are encapsulated in connective tissue that enhances their sensitivity; or (3) a specialized receptor cell, which has distinct structural components that interpret a specific type of stimulus. The pain and temperature receptors in the dermis of the skin are examples of neurons that have free nerve endings (1). Also located in the dermis of the skin are lamellated corpuscles, neurons with encapsulated nerve endings that respond to pressure and touch (2). The cells in the retina that respond to light stimuli are an example of a specialized receptor (3), a photoreceptor.


title: Sense

text: A transmembrane protein receptor is a protein in the cell membrane that mediates a physiological change in a neuron, most often through the opening of ion channels or changes in the cell signaling processes. Transmembrane receptors are activated by chemicals called ligands. For example, a molecule in food can serve as a ligand for taste receptors. Other transmembrane proteins, which are not accurately called receptors, are sensitive to mechanical or thermal changes. Physical changes in these proteins increase ion flow across the membrane, and can generate an action potential or a graded potential in the sensory neurons.


title: Sense

text: A third classification of receptors is by how the receptor transduces stimuli into membrane potential changes. Stimuli are of three general types. Some stimuli are ions and macromolecules that affect transmembrane receptor proteins when these chemicals diffuse across the cell membrane. Some stimuli are physical variations in the environment that affect receptor cell membrane potentials. Other stimuli include the electromagnetic radiation from visible light. For humans, the only electromagnetic energy that is perceived by our eyes is visible light. Some other organisms have receptors that humans lack, such as the heat sensors of snakes, the ultraviolet light sensors of bees, or magnetic receptors in migratory birds.


title: Sense

text: Receptor cells can be further categorized on the basis of the type of stimuli they transduce. The different types of functional receptor cell types are mechanoreceptors, photoreceptors, chemoreceptors (osmoreceptor), thermoreceptors, electroreceptors (in certain mammals and fish), and nociceptors. Physical stimuli, such as pressure and vibration, as well as the sensation of sound and body position (balance), are interpreted through a mechanoreceptor. Photoreceptors convert light (visible electromagnetic radiation) into signals. Chemical stimuli can be interpreted by a chemoreceptor that interprets chemical stimuli, such as an object's taste or smell, while osmoreceptors respond to a chemical solute concentrations of body fluids. Nociception (pain) interprets the presence of tissue damage, from sensory information from mechano-, chemo-, and thermoreceptors. Another physical stimulus that has its own type of receptor is temperature, which is sensed through a thermoreceptor that is either sensitive to temperatures above (heat) or below (cold) normal body temperature.


title: Sense

text: Each sense organ (eyes or nose, for instance) requires a minimal amount of stimulation in order to detect a stimulus. This minimum amount of stimulus is called the absolute threshold. The absolute threshold is defined as the minimum amount of stimulation necessary for the detection of a stimulus 50% of the time. Absolute threshold is measured by using a method called signal detection. This process involves presenting stimuli of varying intensities to a subject in order to determine the level at which the subject can reliably detect stimulation in a given sense.


title: Sense

text: Differential threshold or just noticeable difference (JDS) is the smallest detectable difference between two stimuli, or the smallest difference in stimuli that can be judged to be different from each other. Weber's Law is an empirical law that states that the difference threshold is a constant fraction of the comparison stimulus. According to Weber's Law, bigger stimuli require larger differences to be noticed.


title: Sense

text: Magnitude estimation is a psychophysical method in which subjects assign perceived values of given stimuli. The relationship between stimulus intensity and perceptive intensity is described by Steven's power law.


title: Sense

text: Signal detection theory quantifies the experience of the subject to the presentation of a stimulus in the presence of noise. There is internal noise and there is external noise when it comes to signal detection. The internal noise originates from static in the nervous system. For example, an individual with closed eyes in a dark room still sees something—a blotchy pattern of grey with intermittent brighter flashes—this is internal noise. External noise is the result of noise in the environment that can interfere with the detection of the stimulus of interest. Noise is only a problem if the magnitude of the noise is large enough to interfere with signal collection. The nervous system calculates a criterion, or an internal threshold, for the detection of a signal in the presence of noise. If a signal is judged to be above the criterion, thus the signal is differentiated from the noise, the signal is sensed and perceived. Errors in signal detection can potentially lead to false positives and false negatives. The sensory criterion might be shifted based on the importance of the detecting the signal. Shifting of the criterion may influence the likelihood of false positives and false negatives.


title: Sense

text: Subjective visual and auditory experiences appear to be similar across humans subjects. The same cannot be said about taste. For example, there is a molecule called propylthiouracil (PROP) that some humans experience as bitter, some as almost tasteless, while others experience it as somewhere between tasteless and bitter. There is a genetic basis for this difference between perception given the same sensory stimulus. This subjective difference in taste perception has implications for individuals' food preferences, and consequently, health.


title: Sense

text: When a stimulus is constant and unchanging, perceptual sensory adaptation occurs. During this process, the subject becomes less sensitive to the stimulus.


title: Sense

text: Biological auditory (hearing), vestibular and spatial, and visual systems (vision) appear to break down real-world complex stimuli into sine wave components, through the mathematical process called Fourier analysis. Many neurons have a strong preference for certain sine frequency components in contrast to others. The way that simpler sounds and images are encoded during sensation can provide insight into how perception of real-world objects happens.


title: Sense

text: Perception occurs when nerves that lead from the sensory organs (e.g. eye) to the brain are stimulated, even if that stimulation is unrelated to the target signal of the sensory organ. For example, in the case of the eye, it does not matter whether light or something else stimulates the optic nerve, that stimulation will results in visual perception, even if there was no visual stimulus to begin with. (To prove this point to yourself (and if you are a human), close your eyes (preferably in a dark room) and press gently on the outside corner of one eye through the eyelid. You will see a visual spot toward the inside of your visual field, near your nose.)


title: Sense

text: All stimuli received by the receptors are transduced to an action potential, which is carried along one or more afferent neurons towards a specific area (cortex) of the brain. Just as different nerves are dedicated to sensory and motors tasks, different areas of the brain (cortices) are similarly dedicated to different sensory and perceptual tasks. More complex processing is accomplished across primary cortical regions that spread beyond the primary cortices. Every nerve, sensory or motor, has its own signal transmission speed. For example, nerves in the frog's legs have a 90 ft/s (99 km/h) signal transmission speed, while sensory nerves in humans, transmit sensory information at speeds between 165 ft/s (181 km/h) and 330 ft/s (362 km/h).


title: Sense

text: Perceptual experience is often multimodal. Multimodality integrates different senses into one unified perceptual experience. Information from one sense has the potential to influence how information from another is perceived. Multimodal perception is qualitatively different from unimodal perception. There has been a growing body of evidence since the mid-1990s on the neural correlates of multimodal perception.


title: Sense

text: The philosophy of perception is concerned with the nature of perceptual experience and the status of perceptual data, in particular how they relate to beliefs about, or knowledge of, the world. Historical inquiries into the underlying mechanisms of sensation and perception have led early researchers to subscribe to various philosophical interpretations of perception and the mind, including panpsychism, dualism, and materialism. The majority of modern scientists who study sensation and perception take on a materialistic view of the mind.


title: Sense

text: Humans respond more strongly to multimodal stimuli compared to the sum of each single modality together, an effect called the "superadditive effect of multisensory integration". Neurons that respond to both visual and auditory stimuli have been identified in the superior temporal sulcus. Additionally, multimodal "what" and "where" pathways have been proposed for auditory and tactile stimuli.


title: Sense

text: External receptors that respond to stimuli from outside the body are called exteroceptors. Human external sensation is based on the sensory organs of the eyes, ears, skin, vestibular system, nose, and mouth, which contribute, respectively, to the sensory perceptions of vision, hearing, touch, spatial orientation, smell, and taste. Smell and taste are both responsible for identifying molecules and thus both are types of chemoreceptors. Both olfaction (smell) and gustation (taste) require the transduction of chemical stimuli into electrical potentials.


title: Sense

text: The visual system, or sense of sight, is based on the transduction of light stimuli received through the eyes and contributes to visual perception. The visual system detects light on photoreceptors in the retina of each eye that generates electrical nerve impulses for the perception of varying colors and brightness. There are two types of photoreceptors: rods and cones. Rods are very sensitive to light but do not distinguish colors. Cones distinguish colors but are less sensitive to dim light.


title: Sense

text: At the molecular level, visual stimuli cause changes in the photopigment molecule that lead to changes in membrane potential of the photoreceptor cell. A single unit of light is called a photon, which is described in physics as a packet of energy with properties of both a particle and a wave. The energy of a photon is represented by its wavelength, with each wavelength of visible light corresponding to a particular color. Visible light is electromagnetic radiation with a wavelength between 380 and 720 nm. Wavelengths of electromagnetic radiation longer than 720 nm fall into the infrared range, whereas wavelengths shorter than 380 nm fall into the ultraviolet range. Light with a wavelength of 380 nm is blue whereas light with a wavelength of 720 nm is dark red. All other colors fall between red and blue at various points along the wavelength scale.


title: Sense

text: The three types of cone opsins, being sensitive to different wavelengths of light, provide us with color vision. By comparing the activity of the three different cones, the brain can extract color information from visual stimuli. For example, a bright blue light that has a wavelength of approximately 450 nm would activate the "red" cones minimally, the "green" cones marginally, and the "blue" cones predominantly. The relative activation of the three different cones is calculated by the brain, which perceives the color as blue. However, cones cannot react to low-intensity light, and rods do not sense the color of light. Therefore, our low-light vision is—in essence—in grayscale. In other words, in a dark room, everything appears as a shade of gray. If you think that you can see colors in the dark, it is most likely because your brain knows what color something is and is relying on that memory.


title: Sense

text: There is some disagreement as to whether the visual system consists of one, two, or three submodalities. Neuroanatomists generally regard it as two submodalities, given that different receptors are responsible for the perception of color and brightness. Some argue that stereopsis, the perception of depth using both eyes, also constitutes a sense, but it is generally regarded as a cognitive (that is, post-sensory) function of the visual cortex of the brain where patterns and objects in images are recognized and interpreted based on previously learned information. This is called visual memory.


title: Sense

text: The inability to see is called blindness. Blindness may result from damage to the eyeball, especially to the retina, damage to the optic nerve that connects each eye to the brain, and/or from stroke (infarcts in the brain). Temporary or permanent blindness can be caused by poisons or medications. People who are blind from degradation or damage to the visual cortex, but still have functional eyes, are actually capable of some level of vision and reaction to visual stimuli but not a conscious perception; this is known as blindsight. People with blindsight are usually not aware that they are reacting to visual sources, and instead just unconsciously adapt their behavior to the stimulus.


title: Sense

text: On February 14, 2013, researchers developed a neural implant that gives rats the ability to sense infrared light which for the first time provides living creatures with new abilities, instead of simply replacing or augmenting existing abilities.


title: Sense

text: According to Gestalt Psychology, people perceive the whole of something even if it is not there. The Gestalt's Law of Organization states that people have seven factors that help to group what is seen into patterns or groups: Common Fate, Similarity, Proximity, Closure, Symmetry, Continuity, and Past Experience.


title: Sense

text: The Law of Common fate says that objects are led along the smoothest path. People follow the trend of motion as the lines/dots flow.


title: Sense

text: The Law of Similarity refers to the grouping of images or objects that are similar to each other in some aspect. This could be due to shade, colour, size, shape, or other qualities you could distinguish.


title: Sense

text: The Law of Proximity states that our minds like to group based on how close objects are to each other. We may see 42 objects in a group, but we can also perceive three groups of two lines with seven objects in each line.


title: Sense

text: The Law of Closure is the idea that we as humans still see a full picture even if there are gaps within that picture. There could be gaps or parts missing from a section of a shape, but we would still perceive the shape as whole.


title: Sense

text: The Law of Symmetry refers to a person's preference to see symmetry around a central point. An example would be when we use parentheses in writing. We tend to perceive all of the words in the parentheses as one section instead of individual words within the parentheses.


title: Sense

text: The Law of Continuity tells us that objects are grouped together by their elements and then perceived as a whole. This usually happens when we see overlapping objects. We will see the overlapping objects with no interruptions.


title: Sense

text: The Law of Past Experience refers to the tendency humans have to categorize objects according to past experiences under certain circumstances. If two objects are usually perceived together or within close proximity of each other the Law of Past Experience is usually seen.


title: Sense

text: Hearing, or audition, is the transduction of sound waves into a neural signal that is made possible by the structures of the ear. The large, fleshy structure on the lateral aspect of the head is known as the auricle. At the end of the auditory canal is the tympanic membrane, or ear drum, which vibrates after it is struck by sound waves. The auricle, ear canal, and tympanic membrane are often referred to as the external ear. The middle ear consists of a space spanned by three small bones called the ossicles. The three ossicles are the malleus, incus, and stapes, which are Latin names that roughly translate to hammer, anvil, and stirrup. The malleus is attached to the tympanic membrane and articulates with the incus. The incus, in turn, articulates with the stapes. The stapes is then attached to the inner ear, where the sound waves will be transduced into a neural signal. The middle ear is connected to the pharynx through the Eustachian tube, which helps equilibrate air pressure across the tympanic membrane. The tube is normally closed but will pop open when the muscles of the pharynx contract during swallowing or yawning.


title: Sense

text: Mechanoreceptors turn motion into electrical nerve pulses, which are located in the inner ear. Since sound is vibration, propagating through a medium such as air, the detection of these vibrations, that is the sense of the hearing, is a mechanical sense because these vibrations are mechanically conducted from the eardrum through a series of tiny bones to hair-like fibers in the inner ear, which detect mechanical motion of the fibers within a range of about 20 to 20,000 hertz, with substantial variation between individuals. Hearing at high frequencies declines with an increase in age. Inability to hear is called deafness or hearing impairment. Sound can also be detected as vibrations conducted through the body by tactition. Lower frequencies that can be heard are detected this way. Some deaf people are able to determine the direction and location of vibrations picked up through the feet.


title: Sense

text: Studies pertaining to Audition started to increase in number towards the latter end of the nineteenth century. During this time, many laboratories in the United States began to create new models, diagrams, and instruments that all pertained to the ear.


title: Sense

text: There is a branch of Cognitive Psychology dedicated strictly to Audition. They call it Auditory Cognitive Psychology. The main point is to understand why humans are able to use sound in thinking outside of actually saying it.


title: Sense

text: Relating to Auditory Cognitive Psychology is Psychoacoustics. Psychoacoustics is more pointed to people interested in music. Haptics, a word used to refer to both taction and kinesthesia, has many parallels with psychoacoustics. Most research around these two are focused on the instrument, the listener, and the player of the instrument.


title: Sense

text: Somatosensation is considered a general sense, as opposed to the special senses discussed in this section. Somatosensation is the group of sensory modalities that are associated with touch and interoception. The modalities of somatosensation include pressure, vibration, light touch, tickle, itch, temperature, pain, kinesthesia. Somatosensation, also called tactition (adjectival form: tactile) is a perception resulting from activation of neural receptors, generally in the skin including hair follicles, but also in the tongue, throat, and mucosa. A variety of pressure receptors respond to variations in pressure (firm, brushing, sustained, etc.). The touch sense of itching caused by insect bites or allergies involves special itch-specific neurons in the skin and spinal cord. The loss or impairment of the ability to feel anything touched is called tactile anesthesia. Paresthesia is a sensation of tingling, pricking, or numbness of the skin that may result from nerve damage and may be permanent or temporary.


title: Sense

text: Two types of somatosensory signals that are transduced by free nerve endings are pain and temperature. These two modalities use thermoreceptors and nociceptors to transduce temperature and pain stimuli, respectively. Temperature receptors are stimulated when local temperatures differ from body temperature. Some thermoreceptors are sensitive to just cold and others to just heat. Nociception is the sensation of potentially damaging stimuli. Mechanical, chemical, or thermal stimuli beyond a set threshold will elicit painful sensations. Stressed or damaged tissues release chemicals that activate receptor proteins in the nociceptors. For example, the sensation of heat associated with spicy foods involves capsaicin, the active molecule in hot peppers.


title: Sense

text: Low frequency vibrations are sensed by mechanoreceptors called Merkel cells, also known as type I cutaneous mechanoreceptors. Merkel cells are located in the stratum basale of the epidermis. Deep pressure and vibration is transduced by lamellated (Pacinian) corpuscles, which are receptors with encapsulated endings found deep in the dermis, or subcutaneous tissue. Light touch is transduced by the encapsulated endings known as tactile (Meissner) corpuscles. Follicles are also wrapped in a plexus of nerve endings known as the hair follicle plexus. These nerve endings detect the movement of hair at the surface of the skin, such as when an insect may be walking along the skin. Stretching of the skin is transduced by stretch receptors known as bulbous corpuscles. Bulbous corpuscles are also known as Ruffini corpuscles, or type II cutaneous mechanoreceptors.


title: Sense

text: The heat receptors are sensitive to infrared radiation and can occur in specialized organs, for instance in pit vipers. The thermoceptors in the skin are quite different from the homeostatic thermoceptors in the brain (hypothalamus), which provide feedback on internal body temperature.


title: Sense

text: The gustatory system or the sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). A few recognized submodalities exist within taste: sweet, salty, sour, bitter, and umami. Very recent research has suggested that there may also be a sixth taste submodality for fats, or lipids. The sense of taste is often confused with the perception of flavor, which is the results of the multimodal integration of gustatory (taste) and olfactory (smell) sensations.


title: Sense

text: Within the structure of the lingual papillae are taste buds that contain specialized gustatory receptor cells for the transduction of taste stimuli. These receptor cells are sensitive to the chemicals contained within foods that are ingested, and they release neurotransmitters based on the amount of the chemical in the food. Neurotransmitters from the gustatory cells can activate sensory neurons in the facial, glossopharyngeal, and vagus cranial nerves.


title: Sense

text: Salty and sour taste submodalities are triggered by the cations and , respectively. The other taste modalities result from food molecules binding to a G protein–coupled receptor. A G protein signal transduction system ultimately leads to depolarization of the gustatory cell. The sweet taste is the sensitivity of gustatory cells to the presence of glucose (or sugar substitutes) dissolved in the saliva. Bitter taste is similar to sweet in that food molecules bind to G protein–coupled receptors. The taste known as umami is often referred to as the savory taste. Like sweet and bitter, it is based on the activation of G protein–coupled receptors by a specific molecule.


title: Sense

text: Once the gustatory cells are activated by the taste molecules, they release neurotransmitters onto the dendrites of sensory neurons. These neurons are part of the facial and glossopharyngeal cranial nerves, as well as a component within the vagus nerve dedicated to the gag reflex. The facial nerve connects to taste buds in the anterior third of the tongue. The glossopharyngeal nerve connects to taste buds in the posterior two thirds of the tongue. The vagus nerve connects to taste buds in the extreme posterior of the tongue, verging on the pharynx, which are more sensitive to noxious stimuli such as bitterness.


title: Sense

text: Flavor depends on odor, texture, and temperature as well as on taste. Humans receive tastes through sensory organs called taste buds, or gustatory calyculi, concentrated on the upper surface of the tongue. Other tastes such as calcium and free fatty acids may also be basic tastes but have yet to receive widespread acceptance. The inability to taste is called ageusia.


title: Sense

text: There is a rare phenomenon when it comes to the Gustatory sense. It is called Lexical-Gustatory Synesthesia. Lexical-Gustatory Synesthesia is when people can "taste" words. They have reported having flavor sensations they aren't actually eating. When they read words, hear words, or even imagine words. They have reported not only simple flavors, but textures, complex flavors, and temperatures as well.


title: Sense

text: Like the sense of taste, the sense of smell, or the olfactiory system, is also responsive to chemical stimuli. Unlike taste, there are hundreds of olfactory receptors (388 functional ones according to one 2003 study), each binding to a particular molecular feature. Odor molecules possess a variety of features and, thus, excite specific receptors more or less strongly. This combination of excitatory signals from different receptors makes up what humans perceive as the molecule's smell.


title: Sense

text: The olfactory receptor neurons are located in a small region within the superior nasal cavity. This region is referred to as the olfactory epithelium and contains bipolar sensory neurons. Each olfactory sensory neuron has dendrites that extend from the apical surface of the epithelium into the mucus lining the cavity. As airborne molecules are inhaled through the nose, they pass over the olfactory epithelial region and dissolve into the mucus. These odorant molecules bind to proteins that keep them dissolved in the mucus and help transport them to the olfactory dendrites. The odorant–protein complex binds to a receptor protein within the cell membrane of an olfactory dendrite. These receptors are G protein–coupled, and will produce a graded membrane potential in the olfactory neurons.


title: Sense

text: In the brain, olfaction is processed by the olfactory cortex. Olfactory receptor neurons in the nose differ from most other neurons in that they die and regenerate on a regular basis. The inability to smell is called anosmia. Some neurons in the nose are specialized to detect pheromones. Loss of the sense of smell can result in food tasting bland. A person with an impaired sense of smell may require additional spice and seasoning levels for food to be tasted. Anosmia may also be related to some presentations of mild depression, because the loss of enjoyment of food may lead to a general sense of despair. The ability of olfactory neurons to replace themselves decreases with age, leading to age-related anosmia. This explains why some elderly people salt their food more than younger people do.


title: Sense

text: Causes of Olfactory dysfunction can be caused by age, exposure to toxic chemicals, viral infections, epilepsy, some sort of neurodegenerative disease, head trauma, or as a result of another disorder. [5]


title: Sense

text: As studies in olfaction have continued, there has been a positive correlation to its dysfunction or degeneration and early signs of Alzheimers and sporadic Parkinson's disease. Many patients don't notice the decline in smell before being tested. In Parkinson's Disease and Alzheimers, an olfactory deficit is present in 85 to 90% of the early onset cases. [5]There is evidence that the decline of this sense can precede the Alzheimers or Parkinson's Disease by a couple years. Although the deficit is present in these two diseases, as well as others, it is important to make note that the severity or magnitude vary with every disease. This has brought to light some suggestions that olfactory testing could be used in some cases to aid in differentiating many of the neurodegenerative diseases. [5]


title: Sense

text: Those who were born without a sense of smell or have a damaged sense of smell usually complain about 1, or more, of 3 things. Our olfactory sense is also used as a warning against bad food. If the sense of smell is damaged or not there, it can lead to a person contracting food poisoning more often. Not having a sense of smell can also lead to damaged relationships or insecurities within the relationships because of the inability for the person to not smell body odor. Lastly, smell influences how food and drink taste. When the olfactory sense is damaged, the satisfaction from eating and drinking is not as prominent.


title: Sense

text: The vestibular sense, or sense of balance (equilibrium), is the sense that contributes to the perception of balance (equilibrium), spatial orientation, direction, or acceleration (equilibrioception). Along with audition, the inner ear is responsible for encoding information about equilibrium. A similar mechanoreceptor—a hair cell with stereocilia—senses head position, head movement, and whether our bodies are in motion. These cells are located within the vestibule of the inner ear. Head position is sensed by the utricle and saccule, whereas head movement is sensed by the semicircular canals. The neural signals generated in the vestibular ganglion are transmitted through the vestibulocochlear nerve to the brain stem and cerebellum.


title: Sense

text: The semicircular canals are three ring-like extensions of the vestibule. One is oriented in the horizontal plane, whereas the other two are oriented in the vertical plane. The anterior and posterior vertical canals are oriented at approximately 45 degrees relative to the sagittal plane. The base of each semicircular canal, where it meets with the vestibule, connects to an enlarged region known as the ampulla. The ampulla contains the hair cells that respond to rotational movement, such as turning the head while saying "no". The stereocilia of these hair cells extend into the cupula, a membrane that attaches to the top of the ampulla. As the head rotates in a plane parallel to the semicircular canal, the fluid lags, deflecting the cupula in the direction opposite to the head movement. The semicircular canals contain several ampullae, with some oriented horizontally and others oriented vertically. By comparing the relative movements of both the horizontal and vertical ampullae, the vestibular system can detect the direction of most head movements within three-dimensional (3D) space.


title: Sense

text: The vestibular nerve conducts information from sensory receptors in three ampulla that sense motion of fluid in three semicircular canals caused by three-dimensional rotation of the head. The vestibular nerve also conducts information from the utricle and the saccule, which contain hair-like sensory receptors that bend under the weight of otoliths (which are small crystals of calcium carbonate) that provide the inertia needed to detect head rotation, linear acceleration, and the direction of gravitational force.


title: Sense

text: Proprioception, the kinesthetic sense, provides the parietal cortex of the brain with information on the movement and relative positions of the parts of the body. Neurologists test this sense by telling patients to close their eyes and touch their own nose with the tip of a finger. Assuming proper proprioceptive function, at no time will the person lose awareness of where the hand actually is, even though it is not being detected by any of the other senses. Proprioception and touch are related in subtle ways, and their impairment results in surprising and deep deficits in perception and action.


title: Sense

text: Nociception (physiological pain) signals nerve-damage or damage to tissue. The three types of pain receptors are cutaneous (skin), somatic (joints and bones), and visceral (body organs). It was previously believed that pain was simply the overloading of pressure receptors, but research in the first half of the 20th century indicated that pain is a distinct phenomenon that intertwines with all of the other senses, including touch. Pain was once considered an entirely subjective experience, but recent studies show that pain is registered in the anterior cingulate gyrus of the brain. The main function of pain is to attract our attention to dangers and motivate us to avoid them. For example, humans avoid touching a sharp needle, or hot object, or extending an arm beyond a safe limit because it is dangerous, and thus hurts. Without pain, people could do many dangerous things without being aware of the dangers.


title: Sense

text: An internal sensation and perception also known as interoception is "any sense that is normally stimulated from within the body". These involve numerous sensory receptors in internal organs. Interoception is thought to be atypical in clinical conditions such as alexithymia.


title: Sense

text: Other living organisms have receptors to sense the world around them, including many of the senses listed above for humans. However, the mechanisms and capabilities vary widely.


title: Sense

text: An example of smell in non-mammals is that of sharks, which combine their keen sense of smell with timing to determine the direction of a smell. They follow the nostril that first detected the smell. Insects have olfactory receptors on their antennae. Although it is unknown to the degree and magnitude which non-human mammals can smell better than humans, humans are known to have far fewer olfactory receptors than mice, and humans have also accumulated more genetic mutations in their olfactory receptors than other primates.


title: Sense

text: Many animals (salamanders, reptiles, mammals) have a vomeronasal organ that is connected with the mouth cavity. In mammals it is mainly used to detect pheromones of marked territory, trails, and sexual state. Reptiles like snakes and monitor lizards make extensive use of it as a smelling organ by transferring scent molecules to the vomeronasal organ with the tips of the forked tongue. In reptiles the vomeronasal organ is commonly referred to as Jacobson's organ. In mammals, it is often associated with a special behavior called flehmen characterized by uplifting of the lips. The organ is vestigial in humans, because associated neurons have not been found that give any sensory input in humans.


title: Sense

text: Flies and butterflies have taste organs on their feet, allowing them to taste anything they land on. Catfish have taste organs across their entire bodies, and can taste anything they touch, including chemicals in the water.


title: Sense

text: Cats have the ability to see in low light, which is due to muscles surrounding their irides–which contract and expand their pupils–as well as to the tapetum lucidum, a reflective membrane that optimizes the image.


title: Sense

text: Pit vipers, pythons and some boas have organs that allow them to detect infrared light, such that these snakes are able to sense the body heat of their prey. The common vampire bat may also have an infrared sensor on its nose. It has been found that birds and some other animals are tetrachromats and have the ability to see in the ultraviolet down to 300 nanometers. Bees and dragonflies are also able to see in the ultraviolet. Mantis shrimps can perceive both polarized light and multispectral images and have twelve distinct kinds of color receptors, unlike humans which have three kinds and most mammals which have two kinds.


title: Sense

text: Cephalopods have the ability to change color using chromatophores in their skin. Researchers believe that opsins in the skin can sense different wavelengths of light and help the creatures choose a coloration that camouflages them, in addition to light input from the eyes. Other researchers hypothesize that cephalopod eyes in species which only have a single photoreceptor protein may use chromatic aberration to turn monochromatic vision into color vision, explaining pupils shaped like the letter U, the letter W, or a dumbbell, as well as explaining the need for colorful mating displays. Some cephalopods can distinguish the polarization of light.


title: Sense

text: Many invertebrates have a statocyst, which is a sensor for acceleration and orientation that works very differently from the mammalian's semi-circular canals.


title: Sense

text: Magnetoception (or magnetoreception) is the ability to detect the direction one is facing based on the Earth's magnetic field. Directional awareness is most commonly observed in birds, which rely on their magnetic sense to navigate during migration. It has also been observed in insects such as bees. Cattle make use of magnetoception to align themselves in a north–south direction.<ref name="BBC News - Science/Nature"></ref> Magnetotactic bacteria build miniature magnets inside themselves and use them to determine their orientation relative to the Earth's magnetic field. There has been some recent (tentative) research suggesting that the Rhodopsin in the human eye, which responds particularly well to blue light, can facilitate magnetoception in humans.


title: Sense

text: Certain animals, including bats and cetaceans, have the ability to determine orientation to other objects through interpretation of reflected sound (like sonar). They most often use this to navigate through poor lighting conditions or to identify and track prey. There is currently an uncertainty whether this is simply an extremely developed post-sensory interpretation of auditory perceptions or it actually constitutes a separate sense. Resolution of the issue will require brain scans of animals while they actually perform echolocation, a task that has proven difficult in practice.


title: Sense

text: Blind people report they are able to navigate and in some cases identify an object by interpreting reflected sounds (especially their own footsteps), a phenomenon known as human echolocation.


title: Sense

text: Electroreception (or electroception) is the ability to detect electric fields. Several species of fish, sharks, and rays have the capacity to sense changes in electric fields in their immediate vicinity. For cartilaginous fish this occurs through a specialized organ called the Ampullae of Lorenzini. Some fish passively sense changing nearby electric fields; some generate their own weak electric fields, and sense the pattern of field potentials over their body surface; and some use these electric field generating and sensing capacities for social communication. The mechanisms by which electroceptive fish construct a spatial representation from very small differences in field potentials involve comparisons of spike latencies from different parts of the fish's body.


title: Sense

text: The only orders of mammals that are known to demonstrate electroception are the dolphin and monotreme orders. Among these mammals, the platypus has the most acute sense of electroception.


title: Sense

text: A dolphin can detect electric fields in water using electroreceptors in vibrissal crypts arrayed in pairs on its snout and which evolved from whisker motion sensors. These electroreceptors can detect electric fields as weak as 4.6 microvolts per centimeter, such as those generated by contracting muscles and pumping gills of potential prey. This permits the dolphin to locate prey from the seafloor where sediment limits visibility and echolocation.


title: Sense

text: Spiders have been shown to detect electric fields to determine a suitable time to extend web for 'ballooning'.


title: Sense

text: Body modification enthusiasts have experimented with magnetic implants to attempt to replicate this sense. However, in general humans (and it is presumed other mammals) can detect electric fields only indirectly by detecting the effect they have on hairs. An electrically charged balloon, for instance, will exert a force on human arm hairs, which can be felt through tactition and identified as coming from a static charge (and not from wind or the like). This is not electroreception, as it is a post-sensory cognitive action.


title: Sense

text: The ability to sense infrared thermal radiation evolved independently in various families of snakes. Essentially, it allows these reptiles to "see" radiant heat at wavelengths between 5 and 30 μm to a degree of accuracy such that a blind rattlesnake can target vulnerable body parts of the prey at which it strikes. It was previously thought that the organs evolved primarily as prey detectors, but it is now believed that it may also be used in thermoregulatory decision making. The facial pit underwent parallel evolution in pitvipers and some boas and pythons, having evolved once in pitvipers and multiple times in boas and pythons. The electrophysiology of the structure is similar between the two lineages, but they differ in gross structural anatomy. Most superficially, pitvipers possess one large pit organ on either side of the head, between the eye and the nostril (Loreal pit), while boas and pythons have three or more comparatively smaller pits lining the upper and sometimes the lower lip, in or between the scales. Those of the pitvipers are the more advanced, having a suspended sensory membrane as opposed to a simple pit structure. Within the family Viperidae, the pit organ is seen only in the subfamily Crotalinae: the pitvipers. The organ is used extensively to detect and target endothermic prey such as rodents and birds, and it was previously assumed that the organ evolved specifically for that purpose. However, recent evidence shows that the pit organ may also be used for thermoregulation. According to Krochmal et al., pitvipers can use their pits for thermoregulatory decision-making while true vipers (vipers who do not contain heat-sensing pits) cannot.