bluuebunny/crossref_metadata_2025 huggingface dataset:
Is There a Constant Minimum Perceptual Duration?
Authors: Allan Lorraine G.
Published: July 2007

It has been suggested in the recent literature that all stimuli briefer than a critical duration have identical perceptual durations. Relevant simultaneity, reaction time, temporal order and duration discrimination data are discussed, and new data are presented. It is concluded that the relationship between the physical duration of a stimulus and its perceptual duration is not yet understood.
The Role of Two Types of Outcome on Storage and Retrieval Processes in Memory
Authors: Nilsson Lars-Göran
Published: July 2007

Two experiments are reported which demonstrate the typical finding of better performance on responses given positive outcomes as compared to performance on responses given negative and neutral outcomes. These effects of reinforcement are studied in more detail in the context of storage and retrieval processes. “Right” or “wrong” and monetary gain or loss were used as outcomes in the experiments. Both these types of outcome were found to have similar effects on storage, while the former tended to affect retrieval more than the latter outcomes did. The results clearly reject the notion that an outcome is stored along with the response to facilitate retrieval. A prerequisite for such a facilitation is a presentation of cues for retrieval at the time of test.
Laterality Effects in Judgment of the Identity and Position of Letters: A Signal Detection Analysis
Authors: Robertshaw Sally , Sheldon Michael
Published: July 2007

In two experiments subjects received 100 ms tachistoscopic presentations, either to left or right of fixation, of a rectangular matrix of 12 cells. On each trial three cells were filled, each with a different symbol drawn from a set of 12 letters and digits. In one (the “letter” experiment) subjects had to decide whether a particular letter (nominated at the end of the trial) had been one of the three presented. In a second (the “position” experiment) they had to decide whether a cell in the matrix (again nominated at the end of the trial) had been one of those that contained a symbol. Judgments were made on a four-point rating scale, and measures of sensitivity and response bias were calculated. In the letter experiment sensitivity was greater for presentations to right of fixation, and in the position experiment for those to left.
Effect of Task Difficulty on the Division of Attention between Nonverbal Signals: Independence or Interaction?
Authors: Long John
Published: July 2007

Models of divided attention are grouped into two classes according to whether they assume that efficiency on one task is independent of or interacts with the level of difficulty on a second simultaneously performed task. On the basis of contradictory evidence from previous studies, four necessary requirements are proposed for an empirical test between the two classes of model. Two experiments successfully embodying these requirements were run, in which subjects performed a two-choice recognition task, involving frequency and intensity signals presented together and alone. The independent variable was the level of difficulty on one dimension; the dependent variable was the accuracy of performance on a second dimension presented at the same time. The results from both experiments showed an interactive trend, performance becoming worse as the difficulty of the accompanying task was increased. In neither case was the effect significant. When pooled over experiments the effect appeared to be reliable, although small. The outcome is interpreted as supporting interactive models of divided attention rather than independent models. Possible reasons for the smallness of the effect are considered. The most likely reason appears to be the competing demands between two of the test requirements adopted initially. An alternative to one of the requirements is proposed.
Two Visual Stores and Two Processing Operations in Tachistoscopic Partial Report
Authors: Bongartz Walter , Scheerer Eckart
Published: July 2007

A two-stage interpretation of the processes underlying tachistoscopic partial report performance is suggested. It is assumed that partial report is mediated by two kinds of visual store (a sensory store and a short-term store) and by two processing operations (selection and naming). In Experiment I, the accuracy and latency of two types of partial report (report by location and report by colour) were compared for cue stimulus-test stimulus intervals ranging from —500 ms to + 500 ms. It was concluded that selection by colour takes longer than selection by location; an explanation in terms of differential decay of attributes in the sensory store was rejected. In Experiment II, cue stimulus delays of 0, 150 and 300 ms were employed, and a backward masking stimulus followed the cue stimulus with a delay of 200, 300, 400 or 600 ms. The amount of masking depended on the cue stimulus-masking stimulus interval, rather than on the test stimulus-masking stimulus interval. It was concluded that selection operates on the sensory store and that backward masking can affect the naming of a stimulus representation which is residing in the visual short-term store.
The Perception and Identification of Mirror-Reversed Patterns
Authors: Bradshaw John , Bradley Dianne , Patterson Kay
Published: July 2007

Many species have difficulty in discriminating between mirror-image stimuli, especially those about a vertical axis, and when identificatory rather than purely perceptual processes are involved. Various theories are reviewed. In two experiments involving same-different judgments for pairs of stimuli, triangles or semicircles, these were simultaneously presented either unilaterally or bilaterally, and in mirror or aligned orientations with respect to each other. Mirror oriented stimuli presented to opposite cerebral hemispheres were no more readily matched than those possessing the same orientations (aligned), thus suggesting that at the perceptual level there is no interaction between mirror-corresponding points in the two visual cortices. Foreknowledge of stimulus orientations failed differentially to affect the findings. Two other studies were performed involving manual identification of single letters, correct or mirror oriented, in either visual field. Here, for most subjects, mirror reversal proved either less disruptive or even advantageous when in the visual field which is normally inferior with correctly oriented material. It was concluded that mirror-image confusion at the level of memory is almost certainly a consequence of reversed coding, in some form, in the opposite sides of the brain. A number of incidental findings were made with respect to visual field effects.
Learning to Ignore Irrelevant Stimuli: Variations within and between Displays
Authors: Hall Geoffrey
Published: July 2007

Pigeons were exposed to stimuli differing in orientation. Some birds received both horizontal and vertical on every trial; others received two horizontals on some trials and two verticals on other trials. These stimuli were irrelevant, i.e., did not predict reliably the availability of reinforcement. When required to learn a discrimination between horizontal and vertical, the birds that had experienced the stimulus variation within each display learned more slowly. This was true whether the test problem was a simultaneous or a successive discrimination. It is argued that this result implies that animals will actively learn to ignore stimuli that are irrelevant.
Recognition of Transposed Melodic Sequences
Authors: Cuddy Lola L. , Cohen Annabel J.
Published: July 2007

Accuracy of recognition for short (three-note) transposed melodic sequences was measured and compared with accuracy predicted by three models of recognition each of which described a different degree of abstraction and synthesis of the musical intervals contained in the sequence. For subjects with musical training, recognition was best described by a model that assumed abstraction and synthesis of the musical intervals between both adjacent and non-adjacent tones of the sequence. For subjects without musical training, recognition was much less accurate but there was some evidence that intervals between adjacent tones were abstracted. Of major theoretical interest, however, was the finding that none of the models provided a comprehensive account of the data. Not merely the size of the intervals contained in a sequence determines accuracy of recognition of the sequence, but also the order or configuration of the intervals. It is suggested that particular interval configurations facilitate the abstraction of tonal structure.
Pitch Control in the Human Voice
Authors: Rostron A. B.
Published: July 2007

Deutsch and Clarkson have suggested that pitch control corrections made by subjects attempting to sing a fixed frequency occur about 10 times/s, i.e. much faster than those found in other perceptual-motor tasks. This evidence was evaluted using the technique of delayed auditory feedback, with delay intervals of up to 120 ms. A distinction was made between an explanation in which control corrections are applied on every half cycle of the vibrato, as Deutsch and Clarkson suggested, and one in which the output is sampled over a longer period before any control correction is imposed. There was no indication that exceptionally fast control corrections can be made in vocal pitch regulation.
Buffer Storage Modality and Identification Time in Tachistoscopic Recognition
Authors: Mitchell D. C.
Published: July 2007

According to Sperling's (1967) model of short-term memory briefly presented masked stimuli are rapidly read into a non-visual Recognition Buffer (the RB model). An alternative interpretation of the data is that the stimulus information is coded into a non-iconic Visual Buffer where it is held while a much slower recognition process takes place (the VB model). The high frequency of errors in experiments with sequentially presented stimuli appears to refute the possibility that recognition is as rapid as suggested by the RB model. However these data may be attributed to variations in effective stimulus duration and stimulus quality rather than to slow recognition time. In an experiment to control for these effects, normal, laterally inverted and spaced digits were presented in a rapid sequence (1–10 items/s) with intervening pattern masks to keep the stimulus/mask interval constant. The recall data showed that order errors increased with rate of presentation but that item errors remained invariant. At the fastest rates of presentation there were fewer order errors for spaced than for coincident digits. It was argued that the results, as a whole, were more consistent with the VB than the RB model and that there is no evidence for identification times as fast as 10–40 ms/item.
Divided Attention, Order of Report and Responses to Immediately Successive Signals
Authors: Long John
Published: July 2007

Two effects, “divided-attention” and “order of report”, are operationally denned. Their relative contributions to the reduction in efficiency which accompanies the recognition of difficult nonverbal signals, presented simultaneously, is considered. Experiment I evaluated the two effects in the absence of a fixed order of report and emphasis instructions, confounding features of previous studies. The results showed: an overall impairment of performance with simultaneous signals; a contribution of both effects to the decrement, with a suggestion of the primacy of the “order of report” effect; and a significant interaction between the latter effect and modality, such that visual signals showed the greater effect. Experiment II using similar signals tested the assumption that simultaneity of presentation is a necessary condition for obtaining reduced efficiency with multiple signals. The assumption was only partially confirmed, a significant decrement in performance occurring only for the second of two successively presented signals. Similarities between the two sets of results are noted, as well as between these and modality differences obtained with verbal materials. Two possible accounts of the data are proposed, one based on “input”, the other on “storage” models of divided-attention. The hypothesis that subjects report the most clearly perceived signal first is rejected as an independent explanation.
Perceptual Categories for Musiclike Sounds: Implications for Theories of Speech Perception
Authors: Cutting James E. , Rosner Burton S. , Foard Christopher F.
Published: July 2007

Sawtooth acoustic stimuli of different rise times are identified as coming from a plucked string instrument (pluck) or a bowed one (bow). Like stop consonants, these sounds are perceived categorically—discrimination is poor for stimuli identified as belonging to a single class but good for those identified as members of different classes. Varying the interval between two successive musiclike stimuli hardly alters discrimination. Sawtooth stimuli lasting 750 ms are clearly perceived categorically; those lasting 250 ms are not. Prolonged exposure to a pluck or bow stimulus can shift the rise-time boundary between categories. Shifts due to such selective adaptation decrease as adapting and test stimuli share fewer characteristics. Adaptation of postulated “feature detectors” therefore may occur in input systems prior to the detectors themselves. Our findings contradict previous claims that categorical perception and selective adaptation are manifestations of psychological processes unique to speech perception.
Sequential Effects of Non-Reward in a Skinner Box
Authors: Still A. W. , Macmillan A. St. C.
Published: July 2007

The partial reinforcement extinction effect was examined within subjects in a simultaneous discrimination in a two bar Skinner box. Discrete trials were used, rats being required to press the bar under the illuminated cue light; one bar was correlated with 100% the other with 50% reinforcement. The three groups differed in the probability of a change in the cue light between trials during acquisition. When this probability was low, the 50% bar was preferred in extinction, while when it was higher (0.433 or 0.875) the 100% bar was preferred. These results confirm Capaldi's (1966) hypothesis of the partial reinforcement extinction effect, and support a suggested explanation of some conflicting results on partial reinforcement effects in a Skinner box.
Hemispheric Sensitivity Differences in the Perception of Colour
Authors: Davidoff Jules
Published: July 2007

Signal detection analysis was performed on data obtained from discrimination tasks using lateralized coloured stimuli. It was found that there was a right hemisphere superiority in discriminability to both hue and saturation.
The Role of Stimulus Material in Determining Release from Proactive Inhibition
Authors: Gardiner John M. , Klee Hilary , Redman Graham , Ball Michael
Published: July 2007

The release from proactive inhibition (PI) paradigm has been widely used as a technique for exploring the encoding dimensions of short-term memory for verbal items. PI release data have been used not only to infer particular memory codes but also to index their relative salience. In the present study, the effects of manipulating the colour (red or black) in which the stimulus material is printed were investigated in two separate experiments. No release effect was obtained in the first, where common two-syllable words were presented. In the second, where consonant trigrams were presented, a large effect was found. Since the same colour feature was manipulated in each experiment, it is argued that this pattern of results has serious implications for the use of PI release data as a technique for mapping the encoding dimensions of short-term memory.
Exposure to Non-Contingent Light Change in Separate Sessions Prior to Light-Contingent Bar Pressing
Authors: Russell Alan , Glow Peter H.
Published: July 2007

The reported experiment investigated the effects of prior exposure to non-contigent light change over five sessions on subsequent light-contingent bar pressing (LCBP) behaviour. Prior exposure reduced the frequency of LCBP over the initial sessions, but responding then increased so that the effect was no longer evident in the middle and terminal LCBP sessions. That is, prior exposure to non-contingent light change affected LCBP by retarding its acquisition. It was argued that this overall result is consistent with previous research on the effects of prior experience of reinforcement being non-contingent on subsequent response-contingent behaviour, where the effect has sometimes been characterized as “learned helplessness”. This previous research, however, has concentrated on the strong conventional reinforcers such as shock avoidance and food. The present findings show that intrinsically motivated behaviour with a weak reinforcer is also affected by prior experience of the reinforcer as an uncontrollable event.
Preference for Predicted over Unpredicted Shock
Authors: Frankel Paul W. , vom Saal Walter
Published: July 2007

Rats received unavoidable, inescapable shock at each end of a shuttle box. A predictive signal preceded the shock when the rat was at one end of the shuttle box, while a random signal was presented when the rat was at the other end. Subjects spent significantly more than 50% of their time at the end with the predictive signal. Examination of crossover data suggested that the occurrence of crossover responses from one end to the other was influenced by the consequences of those responses, and raised the possibility that preference for predicted shock in this and previous studies was due to differential consequences that normally exist for crossover responses in each direction.
The Acquisition of Conditioned Emotional Response as a Function of Intertrial Interval
Authors: Yeo Anthony
Published: July 2007

The effects of intertrial interval (ITI) and foreperiod duration on the acquisition of a conditioned emotional response were investigated using a four-trial conditioning procedure. The optimum ITI was found to be 60 s with a bidirectional gradient for conditioned suppression above and below 60 s. Conditioned supression was found to be directly related to foreperiod duration.
Physical and Name Codes in Auditory Memory: The Pursuit of an Analogy
Authors: Allard Frances , Henderson Leslie
Published: July 2007

Subjects decided whether successive auditory stimuli were the same word or not in an RT task. Same decisions tended to be faster when the second stimuli was physically identical. Intonation change and, even more, speaker change slowed some decisions. These voice effects were contributed by the slower responders and they disappeared over the six sessions of testing. Increasing the delay between the stimulus pair slowed RT but delay did not interact with voicing. These results suggest that the auditory analogy with visual physical and name codes is misleading. Non-linguistic information from the speech signal survives in various forms but this fact does not entail the existence of a literal physical code in audition.
Syllabic Complexity and Syntagmatic Rules for Syllable Production–a Comment on Aspects of the Syntax of Behaviour by D. G. Mackay
Authors: Kent R. D.
Published: July 2007

Using a metric of syllabic complexity derived from a syntagmatic theory of syllabic production, in which syllabic recoding expands a syllable into an optional initial consonant group and an obligatory vowel group, MacKay (1974) examined the relationship between the complexity of syllables and their durations in a task of rapid repetition. He concluded from spectrographic measurements of the test syllables that the complexity metric was a good predictor of the syllable durations, and hence syllable repetition rates. The present report demonstrates that comparable, if not better, predictions are made by a simpler theory based on the recoding of syllable structures as series of CV combinations, with appropriate reductions of C or V segments.
Selective Interference during the Retrieval of Visual Images
Authors: Janssen Wiel H.
Published: July 2007

Twenty-six subjects memorized lists of (low I and high I) noun pairs under imagery or verbal mediation instructions. At recall the subjects were presented a digit (“1” or “2”) either auditorily or visually as an interfering stimulus.

Visual interference was found to selectively affect the retrieval of high I response terms. Also, the retrieval of nouns studied by imagery mediation was found to be selectively disrupted by visual interference.

These results suggest that the qualities of a visual image are retained all the way from image acquisition to retrieval, and that the visual components of images generated at the acquisition stage are probably not lost by subsequent coding processes.
Transfer and Non-Transfer Successive Incentive Contrast Effects in the Rat
Authors: Wookey P. E.
Published: July 2007

Recent evidence concerning successive incentive contrast suggests the occurrence of both positive and negative contrast effects under both non-transfer and transfer conditions. There are three types of explanation for these contrast effects, based on frustration theory, sequential theory and adaptation level theory (perceptual accounts). One of the critical experiments favouring perceptual accounts, Collier and Marx (1959), is subject to a number of methodological criticisms. This experiment was repeated, with modifications to take account of these criticisms, and extended to include transfer, as well as non-transfer, conditions. There was no evidence of contrast. In a further experiment using Collier and Marx's procedure with lever pressing and panel pushing, positive and negative, transfer and non-transfer effects were found using Noyes pellets rather than sucrose as reward. It is suggested that these results contribute some support to perceptual accounts of incentive contrast, although no present theory is entirely satisfactory.
The Effect of Sequential Dependencies on Some Signal Detection Parameters
Authors: Macdonald Ranald R.
Published: July 2007

The values of various sensitivity and response criterion parameters were calculated under different experimental conditions for both detection and recognition tasks. The effects of feedback and stimulus probability were found to be consistent with previous studies. When the values of the parameters were computed depending on the nature of the immediately preceding trial, the criterion parameters were found to be dependent on the identity of the preceding response, while those measuring sensitivity were dependent on its correctness. The dependence of the sensitivity parameters could be explained as an artifact of statistical bias, while the effect on the criterion parameters appears genuine. The nature of the phenomenon of statistical bias is discussed.
Hemispheric Differences in Processing Visual Patterns
Authors: Bradshaw John L. , Gates Anne , Patterson Kay
Published: July 2007

The dichotomies verbal/visuospatial, serial/parallel and analytic/holistic are reviewed with respect to differences in hemispheric processing. A number of experimental parameters may be varied in such tasks, and together with certain frequently-occurring weaknesses of experimental design may account for the often discrepant results hitherto reported. The above factors are systematically reviewed, and three further experiments are reported which attempt to fill in the missing designs. Further evidence is given in support of the hypothesis that right-hemisphere superiority is most apparent in processes leading to identity matching. It is quantitative rather than qualitative, and may depend upon operations on the entire gestalt, such as holistic matching, mental rotation, reflection, distortion, etc., rather than, e.g., simultaneous (parallel) processing of discretely analysed or isolated features or elements. On the other hand left-hemisphere involvement in visuospatial processing is thought to reflect analysis of the configuration into its separable components; such processing may be either serial or parallel, and may frequently lead to a judgement different.
Multiple Orientation-Contingent Chromatic After-Effects
Authors: Mackay Valerie , Mackay Donald M.
Published: July 2007

McCollough's (1965) original demonstration of an orientation-contingent chromatic after-effect (OCCA) used two orthogonal inducing gratings in complementary colours. Fidell (1970) has shown that inducing gratings whose orientations are separated by less than 90° give progressively smaller OCCAs, becoming ineffective below 20° or so. Stromeyer (1969) found that with only a single inducing grating, orthogonal test fields still appeared tinted in complementary hues, and claimed that these hues could be “neutralized” by rotating the inducing grating by 90°.

These results raise the question whether (A) the neural representations of orthogonal orientations are coupled with respect to colour in “opponent” fashion, so that red-horizontal has similar effects to green-vertical; or (B) the representations of orientations separated by some minimum angle are chromatically independent, and can develop substantially independent OCCAs. We report the following results which favour hypothesis (B):

(1) With a single coloured inducing grating à la Stromeyer (1969), the measured OCCA at right angles shows no signs of “opponent processing”, if the hue of the test grating is compared against that of a plain field rather than an orthogonal grating.

(2) With inducing gratings at several orientations, the resultant OCCA has an angular distribution which is the algebraic sum of those for each grating separately.

(3) It is possible to associate the same colour with two orientations at right angles without mutual cancellation.

(4) Multiple OCCAs show independent time-courses of decay, and can be induced and retained for at least eight orientations at once.
The Poggendorff Illusion with Subjective Contours
Authors: Day R. H. , Dickinson R. G. , Jory M. K.
Published: July 2007

Gregory (1972) has claimed that the Poggendorff misalignment effect occurs when the collinear obliques are separated by subjective rather than real contours. He used two figures to demonstrate this variant of the illusion. Two experiments to test the claim are reported. The first showed that apparent misalignment in one of the two original figures is no greater than that with two obliques alone (the oblique line effect), but misalignment in the other is greater than with two oblique lines and than with a control without subjective contours. The second experiment showed that apparent misalignment in the second figure was less than in two control figures without subjective contours. Since this reduced effect was probably due to the nature of the intersection between the oblique and a semi-circular element, the role of subjective contours remains unsettled.
Linguistic Factors in Reasoning
Authors: Evans J. St. B. T.
Published: July 2007

An experiment is reported which attempts to demonstrate the effects of manipulating two linguistic variables on a propositional reasoning task, one relating to the linguistic form of the logical rule, and the other to the presence and absence of negative components. The results are discussed in relation to Evans' (1972a) distinction between interpretational and operational factors in reasoning. Problems arising from the application of this distinction are discussed in detail.
Aphasia, Dyslexia and the Phonological Coding of Written Words
Authors: Patterson K. E. , Marcel A. J.
Published: July 2007

A possible account of the reading difficulty of certain aphasic-dyslexic patients includes the notion that they are impaired in translating the written word into a phonological code via grapheme-phoneme conversion rules. This notion was tested in two experiments, both utilizing orthographically regular non-words (like dake) as stimuli. The first experiment provides an analysis of two patients' (largely successful) attempts to repeat non-words, and their (almost totally unsuccessful) attempts to read them. Second, in a lexical decision task (is this written letter-string a word or not?), the finding that normals are slowed by non-words homophonic with real words (like flore) was replicated using a modified technique. This effect, attributable to phonological coding, was not shown by the patients. At the same time, their ability to discriminate between words and non-words was essentially intact. Consideration was given to mechanisms which might underlie such patients' correct and erroneous readings of words and non-words.
A Contact-Pencil for Research on Writing
Authors: Crawshaw Martin , Ottaway Mary
Published: July 2007

A pencil is described which closes a circuit when the lead is in contact with the writing surface. Its advantages over previous devices lie in simplicity, cost and reliability; it leaves a normal pencil trace on ordinary paper; and due to its novel mode of action, the movement of the writing element is extremely small, comparable with normal writing instruments.
Response Selection Errors in Spatial Choice Reaction Tasks
Authors: Duncan John
Published: July 2007

In a “Consistent” spatial choice reaction task, the same spatial relationship obtains between each stimulus and its appropriate response. In an “Inconsistent” task this is not so. The present experiment concerns errors in Inconsistent tasks. Duncan (in press) has suggested that, when two spatial S-R relationships are involved in a task, the dominant type of error is a response bearing to the stimulus the wrong one of the two relationships. Duncan's results, however, may be described by a different generalization. Rabbitt and Vyas (1973) have suggested that confusions occur between responses which, when made correctly, bear similar spatial relationships to their stimuli. In the present experiment, a new Inconsistent task is studied. The results support the account of Duncan (in press) but provide no support for that of Rabbitt and Vyas (1973). Partly on the basis of error results, Duncan (in press) proposed a model of response selection in the spatial choice reaction task. Unlike previous accounts, this model is not based on a set of individual “S—R” associations; operations generating sets of S—R pairs are involved.
After-Effects of Responding and of Withholding Responses in C.RT Tasks
Authors: Rabbitt Patrick , Clancy Margaret , Vyas Subhash
Published: July 2007

The effects of response repetition on choice RT were compared in b-reaction and in c-reaction tasks [Experiments I(a) and I(b)]. The difference in RTs for repeated and for non-repeated responses was found to be less for c-reaction than for b-reaction tasks. This seemed to be because in c-reaction tasks subjects can prepare themselves to make the same response on every trial, so that there is little further RT reduction consequent on immediate response repetition. In b-reaction tasks subjects cannot always prepare to make the same response, so that the difference between response repetition RT and responce alteration RT is greater. Experiment II examined transitions between events in a serial, self-paced C.RT task in which subjects made a different response to each of two signals but withheld any response to the onset of a third. In this task responses were faster when they followed other, different responses than when they followed “no go” trials. The results of these experiments allow us to reject, even for very elementary tasks, a simple “S—R connection network” model for the processes involved in the identification of signals and the production of responses to them.
Memorability, Word Frequency and Negative Recognition
Authors: Brown J. , Lewis V. J. , Monk A. F.
Published: July 2007

Brown (1976) has provided an analysis of the effect of the memorability of an item on the confidence with which it is accepted or rejected in a test of recognition or recall. When the subject has no clear recollection of the inclusion of an item in an input list, he is assumed to evaluate its memorability in the context of the experiment before he decides whether to accept or reject it. If the judged memorability is high, the absence of a clear recollection is stronger evidence against the item than if it is low. A specific prediction is that memorable distractors in a recognition test will be more confidently rejected than non-memorable ones. This prediction was tested and confirmed in three experiments in which recognition was tested by 4-category rating. Except in Experiment I, items memorable to individual subjects were identified by administering a questionnaire. For example, in Experiment III forenames of immediate family were assumed to have high memorability. This experiment also included word frequency as a variable. Low-frequency distractors were rejected significantly more firmly than high-frequency distractors: extraction of memorable names enhanced this effect. The relationship of memorability to word frequency is discussed.
Speed of Aiming Movements
Authors: Kerr Barry A. , Langolf Gary D.
Published: July 2007

Fitts' Law describes human movement time in the horizontal and frontal planes, but its application to movement in the sagittal plane has been questioned by Beggs and Howarth. To evaluate the Law in this plane, eight subjects performed a forearm action, similar to dart-throwing without release, moving a stylus through the sagittal plane from a back contact plate forward to a target. Four movement distances, 8, 12, 16 and 20 in, were combined with four target widths, 1/4, 1/2, 1 and 2 in, in 16 experimental conditions. Following practice all subjects were tested in each condition, with visual knowledge of results. The plot of movement time against log 2A/W was essentially linear, accounting for 92.6% of the variance.
Vowel Recognition: Inferences from Studies of Forward and Backward Masking
Authors: Dorman Michael F. , Kewley-Port Diane , Brady Susan , Turvey M. T.
Published: July 2007

The recognition of brief vowels was studied in forward and backward masking tasks. In a series of experiments in which both target and mask parameters were systematically varied, two populations of subjects were identified. The majority (Nonmaskers) evidenced little masking at any interstimulus interval, while relatively fewer subjects (Maskers) evidenced backward masking (but not forward masking) over a 100-200 ms interval. Increasing target set size systematically increased masking for the Maskers but not for the Nonmaskers. Adding white noise to the targets increased the extent of masking for both groups. These results suggest (1) that masking does not impose a substantive constraint on vowel perception in running speech, and (2) that multiple strategies may exist for vowel recognition.
Higher Order Autoshaping
Authors: Leyland C Mark
Published: July 2007

A series of experiments is reported on appetitive higher order conditioning in the pigeon. Experiment I showed that second order autoshaping can be produced by pairing a neutral keylight with a keylight of another colour, previously paired with food. Experiment II employed an omission procedure to show that second order autoshaping is a consequence of the contingency between first and second order stimuli. In Experiment III, extinction of responding to the first order stimulus was shown to reduce responding to the second order stimulus. Experiments IV and V showed firstly that this reduction is not due to generalization of extinction, and secondly that second order key pecks may be produced in the absence of any pecking to the first order stimulus. The results suggest that second order autoshaping is based largely on a direct association between the first and second order stimuli.
Interference with Visualization
Authors: Phillips W. A. , Christie D. F. M.
Published: July 2007

It is often claimed that visualizing and perceiving interfere with each other because they compete for special purpose visual processing resources. The arguments for this view (e.g. Brooks, 1967, 1968) are criticised. Five experiments are then reported which attempt to determine whether specific processing activities interfere with the visualization of novel abstract patterns. Visualization was greatly interfered with by adding five digits but not by reading them. Presentation modality of the digits did not affect the interference they caused. When the intervening activity involved processing patterns similar to those being visualized, the amount of interference depended upon whether the subject had to form and use representations that outlived the icon. Perception caused interference when it involved formation of a maintainable representation, but not when it required only sensory storage.

It is concluded that visualization requires general purpose resources, and that interference between visualization and perception could be due to competition for these resources.
Symmetry and Transitivity Assumptions about a Nonspecified Logical Relation
Authors: Tsal Yehoshua
Published: July 2007

Twenty-five subjects were presented with eight problems involving a non-specified relation, devoid of its concrete content. This relation was signified by the symbol (—), thus logically precluding any knowledge about the properties of the relation. The problems were so designed that the truth evaluation of their solution statements reflected assumptions about the symmetry and transitivity properties of the relation. Six subjects assumed that the relation was both symmetrical and transitive, and 12 subjects assumed that it was symmetrical only. When these same 18 subjects were presented with problems which lent themselves to only one of these assumptions, all assumed that the relation was symmetrical rather than transitive. The remaining seven subjects made neither of these two assumptions in any of the problems. Examples of logical relations, given as part of the problems, and varying in their properties of symmetry and transitivity, had no effect on the subjects' assumptions. It is proposed that symmetrical and transitive relations are conceptual good figures which predisposed subjects to perceive the nonspecified relation as symmetrical or as transitive. The stronger tendency towards symmetry assumptions than towards transitivity assumptions suggests that symmetrical relations are better figures than transitive relations.
Knowledge of Spatial Relations: The Determination of the Relationship “Nearest to”
Authors: Wilton R. N.
Published: July 2007

After memorising the names and positions of a set of familiar towns, subjects were given the name of one of the towns followed by the name of a target town. The subjects' task was to state whether the given town was the nearest town in the memory set to the target. In three experiments analyses of reaction times suggested that subjects generate their responses by determining the distance from the given town to the target and comparing it with the distances of other towns to the target. The use of other methods, for example locating the nearest town on a mental map by scanning outward from the target and comparing it with the given town seem inconsistent with the data.
Spatial Organization in the Free Recall of Pictorial Stimuli
Authors: Moar Ian
Published: July 2007

Thirty-one young adults were presented with a series of visual arrays each containing drawings of objects. Free recall of the objects on each visual array could be organized by the spatial location of the objects or by another type of organization. The other type of organization was different on each array and comprised semantic, shape, colour, size, orientation or phonetic categories. The results showed that free recall could be organized by spatial location or by semantic, shape, colour or size categories. However, only semantic and colour category organization were found to correlate significantly with recall. To account for the correlation results, two distinct general forms of organization are hypothesized.
Time to Recognise Tones: Memory Scanning or Memory Strength?
Authors: Clifton Charles , Cruse Donna
Published: July 2007

Three experiments measured the time to decide whether a probe tone was a member of a set of one to four remembered tones. Reaction time increased with the size of the remembered set, and in one experiment the functions were similar to functions that have been reported for recognition of verbal items. Positive reaction time was largely determined by recency of presentation of the probed item. Variables thought to influence memory strength of tones (interpolated noise, delay, and tone duration) proved to affect recognition reaction time. However, the positive relation found between error rate and error reaction time disconfirmed a prediction of memory strength models based upon the theory of signal detection. Possible memory strength and memory scanning theories were considered.
What does a Man do after he Makes an Error? An Analysis of Response Programming
Authors: Rabbitt Patrick , Rodgers Bryan
Published: July 2007

When people make errors during continuous tasks they temporarily pause and then slow down. One line of explanation has been that they monitor feedback to detect errors, that they may make incidental responses when errors occur (e.g. they may swear) and that they may pause to analyse their errors. In all these cases they may be assumed to act as single channel information processing systems of limited capacity, and to be unable to recognise any new signal until these processes have been completed.

Analysis of response after errors shows that this cannot be the case. Responses after errors are inaccurate, but are not slow when they require the subject to make the response which he should have made on the previous trial (i.e. to make an error correction response). Subjects thus must recognise new signals as soon as they occur. The present results require a new model of error detection and correction, and a model for response programming and priming.
Evidence for Abstract Response Codes: Ear-Hand Correspondence Effects in a Three-Choice Reaction-Time Task
Authors: Hammond Nick , Barber Paul
Published: July 2007

A three-choice reaction-time task was used to investigate the source-of-stimulation effect, that is, the tendency for subjects to react faster and more accurately to a stimulus if the spatial locations of the stimulus and the response correspond than if they do not. Auditory stimuli varied on dimensions of tonal frequency and spatial location, although only the former was relevant for response selection. Responses were found to be faster for the conditions in which stimulus location and response location corresponded than for those in which they did not, but stimulus location had no effect on differences between the two hands with bimanual responses. These results support the hypothesis that the source-of-stimulation effect is due to response plans which interact at a level prior to the programming of the motor response.
Does Probe RT Measure Central Processing Demand?
Authors: McLeod Peter
Published: July 2007

Various authors have tried to assess the processing demands of a range of tasks by presenting a probe at different times during their performance. The assumption behind the technique is that the more processing capacity the main task requires the less will be left for processing the probe. Hence, it is claimed, the reaction time to the probe can be used to infer the capacity demands of the main task. An experiment is reported in which two groups of women combine manual responses to a visual Same/Different letter-match task with responding to an auditory probe. The only difference between the groups is that one responds manually to the probe and the other responds vocally. The two groups produce an entirely different pattern of interaction between the two tasks.

Were there an absolute central demand of the letter-match task which could be measured by the probe technique this should appear irrespective of the form of the probe task. Since the pattern of probe RTs does depend on the form of the response to the probe it is concluded that it is not possible to use a single form of probe task as a neutral measure of the central capacity demand of the main task.
The Effect of Prior Random Reinforcement on Brightness Discrimination Learning in Rats
Authors: Winefield A. H.
Published: July 2007

An experiment is described in which rats were transferred from an insoluble, random reinforcement problem to a brightness discrimination. A second group was given position training under 50% contingent reinforcement before the transfer task. Both treatments produced strong position stereotypes which continued during the transfer task, but learning was significantly slower for subjects which had experienced the insoluble problem. The effect occurred whether or not the brightness cues were present during the initial training, although their presence significantly impaired subsequent learning under both conditions. The results are interpreted in accordance with the hypothesis of learned irrelevance.
Behaviour of Rats in Multiple Schedules of Response-Contingent and Response-Independent Food Presentation
Authors: Bradshaw C. M. , Szabadi E. , Bevan P.
Published: July 2007

During Phase I, three rats were exposed to two-component multiple schedules of response-independent food presentation. Low rates of lever-pressing were observed, and response rates in one component did not increase when food presentation was withheld in the other component. During Phase II, the same rats were exposed to two-component multiple schedules of response-contingent reinforcement. Much higher rates of lever-pressing were observed. Moreover, when reinforcement was withheld in one component, response rates in the other component increased (positive contrast), and when reinforcement was reinstated in the changed component, response rates in the other component declined (negative contrast). During Phase III, when food was again delivered independently of responding, the response rates declined again to low levels. These results indicate that the occurrence of non-instrumental lever-pressing is not a prerequisite for the occurrence of behavioural contrast in the rat, and thus cast doubt on the general applicability of the autoshaping theory of behavioural contrast
Effects of Neonatal Testosterone and Progesterone on Open-Field Behaviour in the RAT
Authors: Stevens Robin , Goldstein Ralph
Published: July 2007

Rats treated on the day of birth with progesterone (50 üg) or testosterone pro-pionate (200 üg) or the oil injection vehicle alone were tested in the open-field on four consectuve days at 45 days and 85 days of age. Averages across treatments showed that females ambulated more and reared more than males at both ages, that they groomed more than males at 45 days of age, and defaecated less at 85 days of age. Progesterone treatment significantly reduced defaecation in males at 45 days of age, and reduced grooming in both sexes. At 85 days of age progesterone significantly increased activity in females. Testosterone-treated animals of both sexes groomed significantly less than same-sex controls at 45 days of age, whereas at 85 days of age activity scores were significantly reduced only in females although testosterone treated males were less active on 2 test days and more active on 1. Early postnatal treatment with progesterone appeared to feminise male rats, and testosterone to masculinise female rats. Both hormones also altered the behaviour of opposite sexed rats, indicating that male rats may be further masculinised by exogenous testosterone and female rats further feminised by progesterone. Progesterone may have acted as an anti-androgenic agent by blocking gonadal and adrenal androgens in males and adrenal androgens in females.