bluuebunny/crossref_metadata_2025 huggingface dataset:
The Low‐Latitude Ionosphere Sensor Network: Initial results
Authors: Valladares C. E. , Chau J. L.
Published: April 2012

The Low‐Latitude Ionospheric Sensor Network (LISN) is a distributed observatory designed to nowcast the state and dynamics of the low‐latitude ionosphere and to develop forecasts of the electric fields, densities, and equatorial spread F over the South American continent. The LISN observatory consists of three different types of instruments: GPS receivers, fluxgate magnetometers, and vertical incidence pulsed ionospheric radar (VIPIR) ionosondes. This report provides a succinct summary of recent observations obtained using the LISN GPS receivers and complemented with measurements from other instruments and GPS receivers that operate in South America. More specifically, the following are shown here: (1) observations of total electron content (TEC) enhancements that occur near local midnight, (2) maps of TEC perturbations associated with the passage of traveling ionospheric disturbances over South America, and (3) statistics of TEC depletions for 2 years of low solar activity. Near‐midnight TEC enhancements consist of sudden increases in TEC that occur after sunset at low latitudes on 30% of the days. These TEC enhancements last for several hours and can have amplitudes between 1 and 50 TEC units. On 11–12 March 2011 the largest TEC enhancement was observed in South America at times when the Jicamarca incoherent scatter radar operated and observed peak densities above 106 el/cc at 300 km altitude. It is suggested that a combination of zonal electric fields and meridional neutral winds are able to redistribute the plasma along the field lines and create regions of enhanced TEC. Maps of TEC perturbations associated with the passage of gravity waves (GWs) over South America have been used to measure the phase velocity and direction of propagation of GWs. The large number of GPS receivers over South America has allowed us to record bubble events for every day during 2008 and 2009. It was found that the number of TEC depletion detections varies with a periodicity of 28 days. It is mentioned how these new observations and the installation of the last four VIPIR ionosondes will lead to new discoveries in the near future.
Improving tsunami warning using commercial ships
Authors: Foster James H. , Brooks Benjamin A. , Wang Dailin , Carter Glenn S. , Merrifield Mark A.
Published: April 2012

Accurate and rapid detection and assessment of tsunamis is critical for effective mitigation. We show here that a modest ∼10 cm tsunami from the M8.8 27 Feb 2010 Maule, Chile earthquake was detected by kinematic Global Positions System (GPS) solutions from a ship underway in the open ocean ‐ the first time shipboard tsunami detection has been achieved. Our results illustrate how the commercial shipping fleet represents a vast infrastructure of potential open ocean GPS platforms on shipping lanes that provide extremely good spatial coverage around most tsunamigenic source regions. Given the affordability of geodetic GPS systems, and ever‐improving satellite communications, it would be possible to equip a significant portion of the shipping fleet with real‐time‐streamed GPS systems and create a cost‐effective tsunami monitoring network with denser and more distributed coverage. We project that such a system would have detected the 2004 Indian Ocean tsunami in less than an hour.
Age or Experience? The Influence of Age at Implantation and Social and Linguistic Environment on Language Development in Children With Cochlear Implants
Authors: Szagun Gisela , Stumper Barbara
Published: April 2012

Purpose

The authors investigated the influence of social environmental variables and age at implantation on language development in children with cochlear implants.

Method

Participants were 25 children with cochlear implants and their parents. Age at implantation ranged from 6 months to 42 months (
M
age
= 20.4 months,
SD
= 22.0 months). Linguistic progress was assessed at 12, 18, 24, and 30 months after implantation. At each data point, language measures were based on parental questionnaire and 45-min spontaneous speech samples. Children’s language and parents' child-directed language were analyzed.

Results

On all language measures, children displayed considerable vocabulary and grammatical growth over time. Although there was no overall effect of age at implantation, younger and older children had different growth patterns. Children implanted by age 24 months made the most marked progress earlier on, whereas children implanted thereafter did so later on. Higher levels of maternal education were associated with faster linguistic progress; age at implantation was not. Properties of maternal language input, mean length of utterance, and expansions were associated with children’s linguistic progress independently of age at implantation.

Conclusions

In children implanted within the sensitive period for language learning, children’s home language environment contributes more crucially to their linguistic progress than does age at implantation.
Influences of Sentence Length and Syntactic Complexity on the Speech Motor Control of Children Who Stutter
Authors: MacPherson Megan K. , Smith Anne
Published: April 2012

Purpose

To investigate the potential effects of increased sentence length and syntactic complexity on the speech motor control of children who stutter (CWS).

Method

Participants repeated sentences of varied length and syntactic complexity. Kinematic measures of articulatory coordination variability and movement duration during perceptually fluent speech were analyzed for 16 CWS and 16 typically developing children (CTD) between 4 and 6 years of age. Behavioral data from a larger pool of children were also examined.

Results

For both groups, articulatory coordination variability increased with sentence length. For syntactically simple sentences, CWS had higher coordination variability than CTD. There was no group difference in coordination variability for complex sentences. Coordination variability increased significantly with complexity for CTD, whereas that of CWS remained at the high level demonstrated for simple sentences. There was a trend for higher overall coordination variability in CWS compared with CTD. For both groups, movement duration was greater for syntactically complex, as compared with simple, sentences.

Conclusions

Results indicate more variable speech motor coordination during fluent speech production in many CWS as compared with CTD. Disproportionate effects of length and complexity on coordination variability and duration were not found for CWS. Considerable individual differences in performance were observed.
An Alternative Programme
Authors: Briggs Asa
Published: April 2012

This chapter focuses on the British Broadcasting Corporation's (BBC) introduction of an alternative programme in September 1939 after it was restricted to only one programme at the start of World War 2. It explains that while the Air Ministry was adamant on the subject of a single programme, the BBC Control Board did not drop the subject which quickly began to be linked with the question of how best to entertain British Expeditionary Forces (BEF) stationed in France. It highlights the Air Ministry's approval of the use of 342-meter wavelength for BBC's programmes for BEF.
Britain and France
Authors: Briggs Asa
Published: April 2012

This chapter focuses on British broadcasting in France during the months of June and July 1940. It explains that during this period, there was a need for urgent action in relation to France, which passed quickly from friendship and alliance to non-belligerence and tacit hostility after the German blitzkrieg attack. It discusses the British Broadcasting Corporation's (BBC) first use of the term French Armistice in its broadcast to France during this period. It also highlights Charles De Gaulle's decision to broadcast his message to Occupied France from London.
‘Sounds of War’
Authors: Briggs Asa
Published: April 2012

This chapter examines the pattern of broadcasting after the autumn of 1940 and the second winter of the World War 2. It discusses how broadcasting responded to Germany's victory in East Africa and Iraq and to the deployment of German troops to North Africa in February 1941. It highlights Haw-Haws' decision to reveal his true identity to the British public as being William Joyce and describes the government's reaction to learning Haw-Haw's identity. It mentions the British government's disappointment with the British Broadcasting Corporation for failing to provide an up-to-date war broadcast which led British audience to listen to Haw-Haw.
The Pattern of Programmes
Authors: Briggs Asa
Published: April 2012

This chapter examines the changes in the patterns of radio programming of the British Broadcasting Corporation (BBC). It explains that during the war, familiar old issues continued to be raised such as whether Happidrome should be broadcast in the Forces programme opposite the religious service. BBC continued to be judged by most of its listeners in terms of the home programmes it provided. This provides a detailed description of the reorganization of BBC's programming.
Politics, Religion, and Society
Authors: Briggs Asa
Published: April 2012

This chapter focuses on the British Broadcasting Corporation's (BBC) wartime broadcasting about politics, religion, and society. It describes the criticisms of listeners to BBC broadcasters, including J.B. Priestly, for expressing their opinion about politics. It explains that that in 1942 the borderline between religion and politics seemed to be one of the most dangerous frontiers argued about. It discusses the dilemma of the BBC on whether to maintain free access to the microphone or exercise discipline in what the government believed were the interests of the nation.
A Year of Climax
Authors: Briggs Asa
Published: April 2012

This chapter discusses the British Broadcasting Corporation's (BBC) programming after the defeat of Germany. It explains that the BBC had begun to consider as early as October 1943 what form its programmes should take immediately following an armistice with Germany. It highlights BBC Director-General William Haley's plan to seek balance rejoicing, thanksgiving, tribute, and warning; and describes the talks prepared for the autumn of 1944 which included ‘full employment’ and ‘reconstruction’.
Therapy of acute spinal cord injury
Authors: Young Wise
Published: April 2012

Clinical and laboratory approaches to spinal cord injury maintain the traditional pessimism first expressed in the Edwin Smith Papyrus, which regarded the possibility of recovery from spinal cord injury as being so remote that it recommended letting spinal-injured warriors die. For example, most clinical categorizations of spinal injury segregate patients into two distinct groups: ‘complete’ and ‘incomplete’. The former are assumed not to recover. Medical care focuses on preservation and protection of peripheral organs, while surgical procedures continue to be oriented towards the stabilization of spinal fractures and the prevention of further spinal cord injury. Rehabilitative care of the spinal-injured emphasizes making the best use of residual function.
An introduction to functional magnetic resonance imaging of the brain
Authors: Matthews Paul M.
Published: April 2012

This chapter provides an overview of functional magnetic resonance imaging (fMRI) methods and applications, highlighting key concepts and strategies, and includes the full range of techniques by which physiological changes accompanying brain activity are defined. It focuses on the changes in blood oxygenation and flow that have been used for the functional magnetic resonance imaging methods. Direct imaging of the blood flow response using perfusion MRI is also discussed. The study furthermore deals with elegant methods that have been developed and allow an extension of this simple concept for one-dimensional imaging into methods for multi-slice two-dimensional or three-dimensional imaging. It outlines the major issues in statistical analysis for fMRI and addresses ways in which the data can be prepared for analysis to minimize artefacts and maximize sensitivity for the detection of activation changes. Finally, the chapter discusses the various applications of fMRI in neuroscience.
Brain energy metabolism and the physiological basis of the haemodynamic response
Authors: Gjedde Albert
Published: April 2012

. This chapter emphasizes the general principles of brain metabolism and the haemodynamic response to neuronal activity. The precise mechanisms responsible for the links between brain energy metabolism and brain work are not well defined. The chapter gives a detailed description of the nature of the metabolic work for information transfer in the brain, which provides an understanding of the link between changes in energy metabolism affecting physiological parameters such as blood flow and neuronal activity. It proceeds with a discussion of biochemical pathways that provide energy for brain work and also discusses the role of astrocytes in the regulation of the metabolic response to neuronal excitation. The chapter attempts to identify an alternative regulator that changes in response to work and influences the rate of energy metabolism.
Ultra-fast fMRI
Authors: Jones Richard A. , Brookes Jason A. , Moonen Chrit T.W.
Published: April 2012

Brain activation is known to lead to enhanced perfusion which, together with other physiological changes, results in a decreased deoxyhaemoglobin concentration in regions of neuronal activity. This effect is referred to as the blood oxygenation level dependent (BOLD) effect. The main purpose of this chapter is to outline the acquisition methods for ultra-fast BOLD functional magnetic resonance imaging (fMRI). It helps to explain the basics of echo planar imaging and alternative ultra-fast imaging techniques, discusses possible artefacts and pitfalls, and also studies the requirements for BOLD fMRI acquisition methods, focusing on echo planar imaging (EPI). The chapter discusses the two basic types of spin echo sequences that have been employed for fMRI studies, namely multiple echo sequences and spin echo EPI. The methods discussed traverse k-space in a rectilinear fashion. Moreover, the chapter also describes promising recent developments and mentions that ultra-fast 3D methods are under development which will potentially provide better signal-to-noise ratio and BOLD contrast per unit time than EPI, and which are also less sensitive to inflow effects.
Effective paradigm design
Authors: Donaldson David I. , Buckner Randy L.
Published: April 2012

Advances in functional magnetic resonance imaging (fMRI) are affording numerous new ways to design and analyse brain-imaging studies. A major driving force for these advances has been the widespread use of MRI scanners capable of ultra-fast imaging. This chapter aims to review key aspects of magnetic resonance imaging (MRI) technology and of the underlying physiology that constrains paradigm design for functional brain imaging. It reviews issues related to the design of event-related experimental paradigms and discusses how event related procedures have extended the range of questions that can be dealt. The chapter introduces the concept of mixed ‘blocked and event-related’ procedures. The development of such ‘mixed’ procedures widens the spectrum of task designs and analytical techniques that can be used. The chapter also extends the range of questions that can be addressed with fMRI, and presents a brief review of the underlying characteristics of the haemodynamic response, to provide a framework for discussion of event-related methods and their derivatives.
The scanner as a psychophysical laboratory
Authors: Savoy Robert
Published: April 2012

There has been steady progress, both in individual laboratories and in the development of integrated commercial systems, for the sophisticated control of stimulus presentation and response recording during magnetic resonance imaging (MRI). This chapter articulates some of this progress and the general considerations for anyone establishing a functional MRI research environment, focusing on the latest developments relevant to an investigator establishing their own psychophysical laboratory in the magnet. The technical problem of stimulus presentation and response recording provides a brief discussion of the general need to adapt the psychophysical tasks themselves to be more compatible with the MRI environment. The chapter also discusses stimulus presentation, subdivided by modality (visual, auditory, tactile, etc.) and voluntary response recording, and furthermore deals with physiological response recording, head movement and related safety issues. Finally, it discusses the tradeoffs between commercial systems, custom designed systems and the goal of a completely integrated psychophysiological laboratory in the MRI environment.
Head motion and its correction
Authors: Brammer Mick J.
Published: April 2012

The aim of functional magnetic resonance imaging (fMRI) data analysis is, in simple terms, to identify small, spatially localized changes in image intensity that accompany the performance of some experimental task. It gives rise to some of the problems that relate to head motion and signal to noise ratio. The purpose of this chapter is to illustrate some of these problems and to discuss some of the methods that have been developed to counter them. The realization that head motion is a potentially serious confound in fMRI has led to the development of a number of strategies for dealing with this problem. The chapter further reveals that motion correction is a computationally expensive process and discusses the practical implications of motion correction. Finally, it shows that subject motion remains a potentially serious problem in fMRI and describes some of the available methodology and the practical impact of correction on activation mapping.
fMRI: applications to cognitive neuroscience
Authors: Owen Adrian M. , Epstein Russell , Johnsrude Ingrid S.
Published: April 2012

This chapter provides an exhaustive review of functional magnetic resonance imaging (fMRI) studies of cognitive function or of the achievements of this field as a whole. It focuses paradigmatically on the areas where fMRI has augmented existing knowledge obtained using other techniques via the combination of its particular technical properties, and their innovative application to the solution of diverse and novel problems in the field of human cognition and on the areas where fMRI has superseded alternative methodological approaches by providing more accurate, faster, safer or more cost-effective information than was previously available. The chapter addresses each of these areas and evaluates their current relevance to, and future impact on, our understanding of normal cognitive function in humans.
Why Develop a Neck?
Authors: Gans Carl
Published: April 2012

The Random House Dictionary defines the word “neck” as “the part of the body of an animal or man that connects the head and the trunk.” Therefore, in classical terms, the neck would only be expected to happen in animals that have heads different from their trunks. Heads are expected to serve the organism in roles such as ingestion, mating, sensation, and defense. Trunks are expected to have roles in visceral function such as reproduction, digestion, circulation, and respiration. Other significant roles of trunks are transport, maintenance of posture, as well as attachment.
The Head-Neck System of the BlowflyCalliphora:2. Functional Organization and Comparisons with the Sphinx MothManduca sexta
Authors: Milde Jürgen J. , Gronenberg Wulfila , Strausfeld Nicholas J.
Published: April 2012

In this chapter, the motion-sensitive responses of particular neck muscles motoneurons in the fly Calliphora erythrocephala are characterized and compared to those in an analogous system in the sphinx moth Manduca sexta. Even though both species are considerably separated on the phylogenetic tree, the main characteristics of the neck motor organization appear to be analogous, manifesting a normal “blueprint” for holometabolous insects. The chapter also demonstrates similarities between the response characteristics of visual neurons and neck motoneurons that are activated by specific direction and velocities of moving gratings. Lastly, the chapter demonstrates that descending visual interneurons do indeed respond to panoramic visual motion, as well as to mechanosensory stimuli that would be perceived during flight.
Reflex Contributions to the Control of Head Movement in the Lizard
Authors: Wang Dave H. B. , Anderson John H.
Published: April 2012

There are some tough problems in comprehending the control of head movements. The head-neck system is multijointed and the posture and the movement of the head can be controlled by distinct pairs of muscles that may subserve the same functions or help to perform a particular task. There seems to be considerable redundancy. The behavioral degrees of freedom are few, yet simple movements such as rotating the head may result from the contraction of many muscles acting in a coordinated manner manifesting the necessity for some constraints. Another problem is that different tasks may need to be performed and the organization of the sensory inputs and the motor outputs must be appropriate for a particular task, such as controlling gaze or posture or both at the same time.
Biomechanical Models of the Head-Neck System
Authors: Dimnet Johannes
Published: April 2012

In this chapter, a classification of biomechanical models of the head-neck system is proposed. Generally, these models are developed to study the responses of head-neck structures to impact and dynamic loading. In global models, in which dynamic loading is considered as input and ensuing displacements as output, the whole body acts as a black box whose mechanical components are determined in real time. In physical models, a human replica is constructed and instrumented. The behavior of the system under static loading is adjusted so as to correspond to that of a cadaver specimen. In numerical models, three-dimensional lumped-parameter models of the human head-neck system have been developed to predict the motion of the system under specific initial conditions.
Muscle Behavior May Solve Motor Coordination Problems
Authors: Hogan Neville , Mussa-lvaldi Ferdinando A.
Published: April 2012

Like many biologic systems, one of the differentiating features of the head and neck is its mechanical intricacy. The head-neck system includes approximately thirty muscles; each spans multiple joints, and each joint has multiple degrees of freedom. The sensory system includes several radically different types of sensory organs. At first, this intricacy may seem tough, yet it must be confronted squarely if a deep comprehension of sensory-motor coordination is to be made. One aspect of sensory-motor coordination that is epitomized by the head-neck system is the general problem of coordinate transformations. The root of the problem is that several parts of the process of doing an action in response to sensory stimuli are each largely described in their own terms.
Somatosensory Pathways from the Neck
Authors: Tracey David J. , Bolton Philip S.
Published: April 2012

The neck is full of mechanoreceptors that play a significant role in the control of posture. However, it is only lately that we have gathered detailed information about the terminations of these receptors in the spinal cord and medulla, and comparatively little was known about their main connections and the ascending pathways that convey data from neck receptors to higher centers. The ascending pathways that convey data from somatosensory receptors to the cerebral cortex have been studied for many years. For technical reasons, most early research was executed on pathways from mechanoreceptors in the hindlimb of the cat, which involve medullary relays in the gracile nucleus and nucleus z.
Physiologic Properties and Central Actions of Neck Muscle Spindles
Authors: Wilson Victor J.
Published: April 2012

Activation of proprioceptors in the neck suggests reflexes that are abundant in the decerebrate cat and presumably contribute to the posture of the alert, behaving animal. Because they appear to contribute afferent input to these reflexes, the properties of neck muscles spindles are of considerable interest. Their distribution and structure have been studied in great detail and described in recent reviews. This chapter discusses their dynamic behaviors and their role in segmental stretch reflexes and their relation with the vestibular system. The first physiologic research on neck muscle spindles were those by Richmond and Abrahams who recorded from single dorsal root fibers in anesthetized cats paralyzed by Flaxedil.
Eye and Neck Proprioceptive Messages Contribute to the Specification of Gaze Direction in Visually Oriented Activities
Authors: Roll Régine , velay Jean Louis , Roll Jean-pierre
Published: April 2012

When talking about proprioceptive knowledge of eye position sense, Steinbach pointed out that: “a most vexing problem in trying to understand the role of proprioception is to come up with some clear, unequivocal evidence for its function.” In this chapter, the authors provide some experimental evidence in favor of the functional contribution of eye and neck proprioceptive afferents to visually oriented activities. The fact that the most behavioral activities are based first and foremost on the visual grasping of a target says that the gaze direction might play a crucial role in body and limb orientation. The exact nature and origin of the extraretinal signal have not yet been firmly established.
Influence of Neck Receptor Stimulation on Eye Rotation and on the Subjective Vertical: Experiments on the Tilt Table, under Water, and in Weightlessness
Authors: Wetzig Joachim , Baumgarten Rudolf J. Von
Published: April 2012

Since the head is pivoted in all directions on the trunk, verticality of the trunk and equilibrium must be computed from at least two sources, the otolith system and the proprioceptive system of the neck. To study the influence of neck receptors on subjective space orientation and on eye movement is quite a tough task because most procedures on the ground include neck receptor stimulation and the vestibular organ at the same time. Experiments were conducted on a land-based special tilt table that allows tilting the whole body together with the head or tilting the head relative to the body or maintaining a fixed position of the head while deflecting the body against the head.
Cervico-ocular Reflexes with and without Simultaneous Vestibular Stimulation in Rabbits
Authors: Barmack Neal H. , Errico Pierangelo , Ferraresi Aldo , Pettorossi Vito E.
Published: April 2012

The horizontal cervico-ocular reflex (HCOR) comprises compensatory eye movements that are evoked by rotation of the body about the fixed head. This head goes together with the horizontal vestibulo-ocular reflex (HVOR) in the sense that a counterclockwise rotation of the body about the fixed head evokes a counter clockwise compensatory eye movement. This counterclockwise eye movement is evoked if the head and body are rotated in a clockwise direction or if the head is rotated clockwise about the body. The gain of the HCOR is maximal for relatively low-frequency stimuli. In addition to the compensatory slow-phase eye movement, the HCOR is depicted by a fast-phase eye movement that is compensatory as well.
Gravitational, Inertial, and Coriolis Force Influences on Nystagmus, Motion Sickness, and Perceived Head Trajectory
Authors: Lackner James R. , DiZio Paul
Published: April 2012

An intricate pattern of stimulation is generated when a rotating individual tilts his head about an axis that is not parallel to the axis of rotation. His semicircular canals undergo cross-coupled angular accelerations, and his head and otolith organs are exposed to a Coriolis force. Such head movements elicit nystagmus, motion sickness symptoms, and disorientation. The disorientation has two major components: during the head movement, the individual will misperceive the actual trajectory of his head in relation to his torso, and for some time afterward, he will have a confusing illusion that his whole body is rotating. If an individual seated at the center of the platform rotating counterclockwise at constant angular velocity tilts his head backward, then his yaw canal receives a clockwise velocity impulse because it loses angular momentum on moving out of the plane of rotation.
Eye and Head Movements as Specialized Functions of Vestibular Circuits
Authors: Schaefer Kurt-peter , Lothar Meyer Dietrich
Published: April 2012

The aim of this chapter is to focus on the huge extent to which eye-head movements mirror specialized functions of the vestibular system, or circuits derived from this system. Accordingly, the authors argue that many of the physiologic phenomena described can only be understood if the evolutionary background is appreciated. Apparently, evolution shaped the vestibular systems long before a mobile neck evolved, and the “problems” under consideration at this conference were created by nature. Originally, the vestibular system's main function has been to stabilize the eyes in space during active and passive body movements. Without such a mechanism, visual functions would be significantly impaired.
Properties of Vestibulo-ocular and/or Vestibulocollic Neurons in the Cat
Authors: Uchino Yoshio , Isu Naoki
Published: April 2012

The vestibulo-ocular reflexes help to stabilize the visual image on the retina, and the vestibulocollic (vestibular neck) reflexes play a role in restoring the head position in space during head movements. The vestibular nucleus neurons play a crucial role in both reflex pathways. It was observed that individual vestibular relay neurons receive inputs from two to three semicircular canal pairs, or from canals and otolith organs, when natural stimuli were applied in alert cats. However, according to observations in anesthetized cats, it has been considered that the primary afferent fibers from each semicircular canal have their own target neurons in the vestibular nuclei.
Involvement of the Interstitial Nucleus of Cajal in the Midbrain Reticular Formation in the Position-Related, Tonic Component of Vertical Eye Movement and Head Posture
Authors: Fukushima Kikuro , Fukushima Junko
Published: April 2012

The interstitial nucleus of Cajal (INC) in the midbrain reticular formation, which has a reciprocal connection with the vestibular and prepositus nuclei, sends major outputs to the oculomotor and neck motor nuclei. This chapter discusses four major research findings that suggest that the midbrain region within, and in the close vicinity of, the INC is involved in vertical eye position generation in saccades and the vestibulo-ocular reflex (VOR). Involvement of the INC region in the control head posture is reviewed thereafter. Vertical eye position after saccade is not maintained in cats with bilateral lesions in the INC; the vertical VOR is impaired by bilateral lesions of the INC; average discharge rate during vertical saccades is significantly positively correlated with tonic discharge rate; and gain of response of vertical burst-tonic neurons to pitch rotation changes.
Electromyographic Activity of Neck Muscles in Relation to the Initiation of Head Turning Induced by Stimulation of the Caudate Nucleus in the Cat
Authors: Ohno Tadao , Tsubokawa Hiroshio
Published: April 2012

Electrical stimulation of the caudate nucleus on one side induces a contraversive lateral fixation of the neck which is often followed by postural asymmetry and circling in the cat and other species. Caudate-induced HT (Cd-HT) can be regarded as being closely related to a process of the postural control exerted by the basal ganglia. Conversely, lesions in the striatum of the rat produced by both kainic acid and 6-hydroxydopamine resulted in impairment in sensory-motor orientation of the head to contralateral stimuli. Hassler and Dieckmann recorded that eye and head movements in the same direction were induced by stimulation of the pallidum of the cat. The effects of stimulation of the caudate nucleus on eye movements, however, have not been analyzed systematically.
Multidimensional Analysis of Head Stabilization—Progress and Prospects
Authors: Peterson Barry W. , Baker James F. , Keshner Emily A.
Published: April 2012

The ultimate objective in studying the vestibulocollic (VCR) and cervicocollic (CCR) reflexes is to understand their dynamic and spatial properties at three levels: the kinetics of movement of the head, neck vertebrae, and neck muscles following perturbation of the body in any direction; the dynamics of activation of each class of receptor and each neck muscle; and spatial and dynamic properties of neuronal circuits that transform receptor input to muscle output. Current progress and future prospects for understanding each of these aspects are summarized. Three-dimensional power spectral characteristics of movements of the head-neck system have been measured during functional activities. Significant power was observed in the pitch and yaw planes, with the wider bandwidth for pitch occurring for walking in place.
Eye-Head Main Sequence in Midsagittal Vertical Plane in Humans
Authors: André-deshays Claudie , Ron Samuel
Published: April 2012

The vertical gaze displacement has seldom been studied systematically. Also, gaze-orienting movement in the vertical plane to a continuously visible target offset has not been investigated. The main sequence of eye saccade and head movement was studied in three subjects in order to determine the eye and head contributions to gaze in the midsagittal plane under visually guided conditions. The methods conducted were the one with a bite board in a head-fixed condition and the one with a head-free condition. The main finding in these experiments was that the saccade main sequence in the vertical midsagittal plane is asymmetrical for upward and downward saccades, particularly for those larger than 20°.
Mechanisms of Gaze Control and Eye-Head Coupling in the Cat Whose Head is Unrestrained
Authors: Guitton Daniel , Munoz Douglas P. , Galiana Henrietta L.
Published: April 2012

There is evidence supporting the existence of common driver signals to the eye and head motor systems. Moreover, there are observations related to the broad mosaic of movement strategies in head-free gaze shifts. In this chapter, the experimental observations that probe the degree of coupling between the eye and head motor systems during gaze shifts made by the head-free cat are reviewed. The authors consider different experimental paradigms which could affect the metrics of saccades in head-fixed animals. The covariation of eye and head movement metrics in different behavioral tasks is discussed here, as well as the evidence that eye motor signals drive head motion.
Modeling Head-Free Gaze Control in the Cat
Authors: Galiana Henrietta L. , Guitton Daniel , Munoz and Douglas P.
Published: April 2012

Two primary issues are being studied in relation to the control of coordinated eye and head movements. The first one is the possible interaction of the vestibulo-ocular reflex (VOR) during the saccadic component of a gaze shift and the second one is the possible coordination of eye and head trajectors through shared access to a common premotor drive. This chapter presents an alternate view of central eye-head coordination, using global gaze error as a precursor of motoneural drives. The model of eye-head coupling is also conceptually justified in this chapter. Some simulation examples are presented, including the gaze shifts within and beyond the oculomotor range and coupling of eye and head trajectories.
Visual, Vestibular, and Somatosensory Control of Compensatory Gaze Nystagmus during Circular Locomotion
Authors: Solomon David , Cohen Bernard
Published: April 2012

This chapter reviews the data from the studies which recorded head and eye movements of alert monkeys while they ran around in light and in darkness. The data have shown that the head contributes importantly to gaze compensation during circular locomotion. The study asks several questions, such as whether neck proprioceptors play a role in the control of head movements, and what is the relative contribution of the head and eyes to gaze stabilization. It is shown in this study that there is active movement of the head and eyes to produce compensatory gaze nystagmus. It is also inferred that a major function of velocity storage is to support gaze compensation during locomotion.
Preferential Activation of the Sternocleidomastoid Muscles by the Ipsilateral Motor Cortex during Voluntary Rapid Head Rotations in Humans
Authors: Mazzini Letizia , Schieppati Marco
Published: April 2012

This study aims to readdress the question of voluntary innervation of the sternocleidomastoid (SCM) in man using a simple reaction time (RT) paradigm. The rationale of the study was that the RTs of the agonist muscle should be shorter for rotation toward the stimulus if the pathway was ipsilateral, and shorter for rotations from it if the pathway was crossed. The experiments included the eight subjects with their reaction times being measured on store traces from the onset of the stimulus to the beginning of the SCM electromyogram. The main finding of this study is the demonstrated difference in the RT of the right SCM and the left SCM in response to a lateralized stimulus delivered to the left index finger.
Signal Transduction and Protein Phosphorylation
Authors: Schulman Howard
Published: April 2012

Higher functions of the central nervous system are based on communication between functional units consisting of many neurons. Communication within and between functional units of neurons is largely based on the chemical transmission of signals with time courses ranging from milliseconds to seconds and minutes. Most chemical transmission requires a cascade of enzymatic steps that are relatively slow, but provide for essential modulation of fast transmission and of effects that are independent of ion channels. This typically involves receptors that are coupled to membrane-bound, GTP-binding proteins (G proteins). This chapter discusses G-protein-coupled signal transduction, protein phosphorylation, multifunctional CaM kinase, and functional studies.
Synaptic Plasticity in Hippocampus and Neocortex: A Comparison
Authors: Malenka Robert C.
Published: April 2012

Over the last decade, long-term potentiation (LTP) in the hippocampus has been the most intensively studied model of activity-dependent synaptic plasticity in the mammalian brain primarily because it can be elicited reliably in isolated slices of hippocampus, a preparation that offers many experimental advantages. As a result of this research effort, we now know a great deal about the cellular mechanisms responsible for hippocampal LTP, particularly at the synapses between Schaffer collateral/commissural afferents and CAl pyramidal cells. This chapter begins by briefly reviewing some of the salient aspects of the LTP elicited in CAl cells in the hippocampus, which will serve as a model to which the various forms of LTP observed in cortical preparations can then be compared.
Neurotransmitter Signaling Before the Birth of Neurons
Authors: Loturco Jo J. , Kriegstein Arnold R.
Published: April 2012

Recent advances in cellular physiological techniques, particularly the development of in situ whole-cell patch-clamp recording, have permitted detailed physiological and pharmacological studies of proliferating cells in the ventricular and subventricular zones of embryonic neocortex. The results are beginning to shed light on the kinds of signals and cellular interactions that may underlie the regulation of cell-cycle events and gene expression in cortical progenitor cells. This chapter discusses the following topics: gap-junction channels provide an avenue for intracellular communication among cortical progenitors; uncoupling blocks DNA synthesis; the principal excitatory and inhibitory amino acid receptors are expressed before neuronal differentiation; cell-cycle events in the embryonic cortex are influenced by GABA and glutamate; GABA depolarizes ventricular zone cells because of high intracellular chloride concentration maintained by a chloride exchange pump; depolarization mediates the DNA synthesis inhibition induced by GABA and glutamate.
Development of Cortical Excitation and Inhibition
Authors: Deisz Rudolf A. , Luhmann Heiko J.
Published: April 2012

The sequence of developmental modifications in allo- and neocortical areas is similar in most mammals; however, the exact time course of these alterations is species and area dependent. This chapter describes age-dependent changes in the structure and function of the cortical excitatory and inhibitory systems. It covers experimental observations obtained predominantly from the neocortex of one species—the rat—in which most of the electrophysiological in vitro studies were performed. To allow a correlation between the different anatomical and physiological parameters and to minimize the influence of layer-specific differences due to the “inside first–outside last” pattern of neocortical development, data from layers II/III of the rat neocortex are presented when available. To highlight certain aspects of excitatory and inhibitory transmission, findings from other cortical areas, structures, and species are considered.
Glutamate Receptors and Neuronal Death: A Beginning
Authors: Choi Dennis W.
Published: April 2012

The 1980s was a time of rapid advances in excitatory amino acid pharmacology and physiology, which permitted specific exploration of John Olney's “excitotoxicity” notion: the idea that the neurotoxicity of endogenous transmitter glutamate could be responsible for some of the neuronal loss associated with disease states. Key experiments provided strong support for this idea in the specific setting of brain hypoxia-ischemia. Early work with kainate injections into the brain raised the interesting speculation that excitotoxicity might be involved in the pathogenesis of Huntington's disease. This chapter reviews studies on excitotoxicity.
Muscles: Electromyography
Authors: Stern Robert M. , Ray William J. , Quigley Karen S.
Published: April 2012

There are many reasons for recording muscle activity. Physical therapists record muscle action to document disabilities, to measure therapeutic progress, and to evaluate orthotic and prosthetic devices. The psychologist studying learning measures muscular activity in order to record the development of motor skills. The psychophysiologist also records muscle action, often when no movement occurs, as in the case of tension headaches or, more generally, to study the patterns of bodily reaction to stimulation, as in the startle response. One of the most significant uses of our muscles is to communicate emotional expressions. Another use of muscles is to help us move quickly, as when we are startled. Today, many psychophysiologists use the startle reflex as a way to measure emotionality. This chapter discusses the use of electromyography (EMG) to study muscles, the physiological basis of EMG, psychophysiological recording procedure, electrodes and electrode placement, typical recordings, common problems associated with EMG, analysis and quantification, and requirements for amplification of EMGs.
Skin: Electrodermal Activity
Authors: Stern Robert M. , Ray William J. , Quigley Karen S.
Published: April 2012

Electrodermal activity (EDA) has been recorded in thousands of psychophysiological studies. Many who record EDA today share the basic belief expressed by Carl Jung in 1907 and also by present-day lie detector operators that verbal responses do not tell all, but that EDA does reveal the secrets of “mental life”. Today, EDA is used as a measure of the state of the organism's interaction with its environment, a reflection of emotional responding that is also elicited by cognitive activity. If we think of the skin as a giant receptor separating humans from the rest of the world, is it any wonder that responses obtained from it would be of interest to psychologists? This chapter discusses the four common descriptions of EDA: skin conductance level, skin conductance response, skin potential level, and skin potential response (SPR). The physiological basis of EDA and its psychophysiological recording are explored.
Applications of Psychophysiological Recording
Authors: Stern Robert M. , Ray William J. , Quigley Karen S.
Published: April 2012

Once an individual is able to record psychophysiological measures successfully, the question arises as to how these measures might be used in understanding the interdependence between psychological and physiological processes. What fields of study might significantly benefit from psychophysiological approaches? Before beginning a discussion of applications of psychophysiological recording, some of the principles of psychophysiology are considered. Psychophysiological studies can be grouped into five categories: response variables, stimulus/situational variables, subject variables, correlational variables, and the applications of psychophysiological research. Studies involving the responsible variables are primarily concerned with properties of the psychophysiological response. Examples include examining the relation between electroencephalogram (EEG) alpha activity and metabolic activity in the thalamus. Three examples of application studies are biofeedback, lie detection, and brain plasticity and pain. Areas that have benefited from psychophysiological techniques are those of attention and cortical plasticity and reorganization after injury.
Ostracism
Authors: Williams Kipling D. , Zadro Lisa
Published: April 2012

Originated from the Athenian practice, ostracism or the temporary exclusion by consensus and the act of ignoring is analyzed by Kip William and Lisa Zadro. Laboratory manipulations and real-life observations are the main data-gathering procedures of the study. Apart from the emphasis that ostracism may occur across all ages, the experimental efforts particularly set the foundations of numerous frameworks for the field. Even if there has been small amount of psychological literature about the phenomenon, enough studies have illustrated its short- and long-term consequences. Conformity and increased motivation for better performance comprise the short-term effects, while for long-term results, internalization of low levels of self-esteem and control, as well as suicide attempts, are evident. New models are devised in the attempt to capture the complexities of ostracism, which were not noted by early researches. These frameworks come with various data-gathering methods such as structured interviews, narratives, and contingency plans.
Two Sides of Romantic Rejection
Authors: Baumeister Roy F. , Dhavale Dawn
Published: April 2012

This chapter revolves around the kind of rejection accompanied by special feelings toward the person who initiated the refusal of an aspiring lover's proposal. Discussed here are the perception differences of the rejected and the rejector, as well as their corresponding implications. Unreciprocated feelings result in self-degradation, despair, and lack of enthusiasm to engage in future relationships. Maintenance of a certain level of friendship or acquaintance can be hindered by the awkward aftermaths of mismatched affections. Recognition of the fact that not all emotions are mutually rewarded all the time will enable people with heartbreaking experiences to move on. Additional tips to soothe the getting-over phase are as follows: understanding the reasons of unrequited love, diverting attention to other aspects (mainly the future), as well as appreciating time alone and the presence of families, friends, and others who care.