bluuebunny/crossref_metadata_2025 huggingface dataset:
I: Effect of Delayed Auditory Feedback on Speech and Keytapping
Authors: Chase Richard Allen , Harvey Seth , Standfast Susan , Rapin Isabelle , Sutton Samuel
Published: March 2008

The effects of delayed auditory feedback (DAF) on the performance of simple speech and keytapping tasks were compared. In the first experiment, each of the fourteen young adult subjects was asked to repeat the speech sound “b” in groups of three sounds. The subject heard his undelayed speech sounds through earphones. Under the delay condition, the speech sounds were delayed 244 millisec. before being returned to the subject's earphones. In the second experiment, each of the same subjects was asked to tap on a key in groups of three taps. The subjects heard an undelayed click through earphones each time they tapped on the key. Under the delay condition, the clicks were delayed 244 millisec. before being returned to the earphones. Graphic recordings were made of the time and intensity characteristics of tapping under both conditions.

The changes which occurred in speech and keytapping under DAF were qualitatively the same and consisted of increases in intensity and unit-to-unit time of both taps and speech sounds. When performing under DAF, the subjects also exhibited a tendency to repeat more sounds or to tap more times than had been requested. The percentage of change in intensity and time characteristics for speech and keytapping performances which occurred under DAF were not significantly different for the two motor systems. The amount of change in speech performance under DAF did not correlate significantly with the amount of change in keytapping performance.
II Sensory Feedback Influences on Keytapping Motor Tasks
Authors: Chase Richard Allen , Rapin Isabelle , Gilden Lloyd , Sutton Samuel , Guilfoyle George
Published: March 2008

Subjects were trained to tap a key continuously at a specific rate, and with a specific amount of pressure (regularity task). Performance of this task was studied under conditions of: (a) decreased auditory feedback (masking noise through earphones), (b) decreased visual feedback (tapping hand screened from view), (c) vibration (vibrators applied to forearm in order to “mask” proprioceptive feedback), (d) digital block of tapping finger, and (e) combination of all four conditions. Significant changes in rate and intensity of tapping resulted under conditions of decreased auditory feedback, vibration, and the combined condition.

In the second part of the study, the effects of different delayed sensory events on keytapping were examined. The five conditions of delayed sensory feedback were: (a) delayed auditory feedback, (b) delayed visual feedback, (c) delayed tactile feedback, (d) the first three delayed sensory events presented simultaneously, and (e) condition (d) repeated with digital block of the tapping finger.

The conditions of delayed sensory feedback did not markedly alter performance of the regularity task. The same conditions of delayed sensory feedback did, however, produce highly significant changes in the performance of a more complex pattern task. All of these delay conditions produced parallel changes in the pattern task, namely increased intensity and decreased rate of tapping. The fact that the pattern task is more disturbed by delayed sensory feedback than the regularity task suggests that temporal complexity of the task is one determinant of the degree to which it will be disturbed by a delay in sensory feedback.
Shorter Articles and Notes
Authors: Pickersgill Mary J.
Published: March 2008

Experiments were performed to determine whether it is possible to discriminate which eye or eyes are being stimulated by a point source of light in a dark room when the subject is unaware which eye, if any, is occluded.

There were two stimulus conditions, (a) a continuous source of light, and (b) a flash. The results show that in these conditions discrimination is faulty and, in some instances, at chance level, although there is considerable individual variation. The implications of these results for the argument from transfer, as applied to after-effects, and the theory of depth perception are considered.
Handedness, Eye-Dominance, and Immediate Memory
Authors: Sampson H. , Spong P.
Published: March 2008

Twenty male university students varying in handedness and eye-dominance recalled conventional and unconventional digits under two conditions: (1) when the same type of digit was projected simultaneously to each eye, and (2) when a different type of digit was projected simultaneously to each eye.

Forty trials were given, each consisting of four pairs of digits with a different numeral projected to each eye. Performance was analysed in terms of percentage recalled correctly and time of onset of each response.

Right eye-dominant groups, particularly a right handed and right eye-dominant group, were superior in both accuracy of recall and speed of response to left eye-dominant groups. Least able in recall were left handed, left eye-dominant subjects. Superiority of right eye-dominant groups was especially marked when a different type of digit was projected to each eye.

In accord with results reported by Broadbent for the ears (1956, 1957), other results suggest it is possible for the eyes to operate simultaneously as independent information sources. However, unlike the case for audition, present subjects did not report all information from one eye before that from the other, but gave it in pairs. It seems that the capacity of the eyes to function independently depended upon eye-dominance and handedness, while serial ordering of responses reflected imposition of an habitual response organization.
Apparatus: A Collimator Stabilizing System for the Retinal Image
Authors: Pritchard R. M.
Published: March 2008

When an observer is fixating a stationary target as closely as possible, continuous involuntary rotations of the eyeball cause proportional displacements of the retinal image. In order to study the functional importance of these movements in the visual process, many methods of maintaining the image in a fixed retinal position have been reported. The limitations of each experimental technique impose restrictions on the type of problem that can be investigated. A method of producing a stabilized image is here described. It is simple, cheap to construct and yet overcomes most of the limitations of the methods referred to below.
Has Apparent Size Been Tested as a Factor in Figural After-Effects?
Authors: Story Anne W.
Published: March 2008

This experiment was designed to demonstrate that the effect of apparent size on the FAE has not been adequately tested. The subjects were run under binocular and under monocular viewing conditions. Binocular vision gave essentially the same results that had been obtained in previous binocular investigations. Monocular vision gave different results. It was concluded that the effect of apparent size on the FAE has not been demonstrated.
Retinal Size as a Determiner of the Direction of Size Distortion in Figural After-Effects
Authors: Terwilliger Robert F.
Published: March 2008

When dealing with size distortions, the direction of the distortion is determined by the retinal size of the T-figure with respect to the retinal size of the I-figure. When the T-figure is retinally smaller than the I-figure it is distorted toward appearing even smaller; when it is retinally larger than the I-figure it is distorted toward appearing even larger; and when the two are retinally equal, there is no distortion. If the T-figures are too much larger or smaller than the I-figure, the distortion ceases. The traditional distance paradox is observed where the distance is defined retinally. The apparent size of the figures is irrelevant to a prediction of what sort of distortion takes place. Sutherland's hypothesis that apparent size determines the direction of distortion when retinal sizes are equated is not supported.
Changes in the Visual Threshold as a Function of Subception
Authors: Dixon N. F. , Haider M.
Published: March 2008

In a previous paper (Dixon, 1958b) one of the authors reported an experiment which suggested that apparent changes in the threshold for one eye occur as a function of the emotionality of stimulus material presented below threshold to the other eye. The following experiment describes an attempt to investigate further the validity of this conclusion. The results are consistent with those from the previous research.
The Relative Intelligibility Threshold for One's Own Name Compared with other Names
Authors: Howarth C. I. , Ellis K.
Published: March 2008

Two recent experiments (Moray, 1959; Oswald, Taylor and Treisman, 1960) have shown that in dichotic listening, and in sleep one's own name seems to be responded to selectively. We have shown for 10 subjects, each listening binaurally to the same recording of a list of their names repeated at random 10 times, and masked by noise, that the subject's own name had a significantly lower threshold than other names. The effect we found was not significantly different from the one found by Oswald et al. during sleep and by Moray for the dichotic situation.

These three experiments taken together suggest that the same pattern-analysing mechanism is involved in normal listening, dichotic listening to the rejected message, and in discrimination during sleep.
Physiological Drives Investigated by Means of Injections into the Cerebral Ventricles of the Rat
Authors: Herberg L. J.
Published: March 2008

A technique is described for permanently implanting a cannula in the lateral ventricle of the rat, and the effects on certain physiological drives of various substances injected by this route were investigated.

Food intake was significantly reduced by intraventricular glucose, while intra-ventricular fructose, insulin, glucagon and a lipid-mobilizing agent were without effect. Drinking was elicited by hypertonic saline and suppressed by hypotonic solutions. The intake of salt was not effected by intraventricular low-sodium solutions. Intraventricular procaine, but not alcohol, induced an akinetic state. Intraventricular glucose failed to relieve hypoglycaemic coma.

The significance of some of these findings is discussed in relation to the hypothalamic regulation of hunger.
Binocular Rivalry and Stereoscopic Depth Perception
Authors: Treisman Anne
Published: March 2008

An investigation was made of stimulus factors causing retinal rivalry or allowing stereoscopic depth perception, given a requisite positional disparity. It is shown that similar colour information can be “filtered” out from both eyes; that stereopsis is not incompatible with rivalry and suppression of one aspect of the stimulus, and that the strongest cue for perception of stereoscopic depth is intensity difference at the boundaries of the figures in the same direction at each eye. Identity of colour can also act as a cue for stereopsis. The brightness of different monocular figures seen in the stereoscope in different combinations was estimated by a matching technique, and it is suggested that the perceived brightness is a compromise between the monocular brightness difference between figure and ground seen in relation to the binocular fused background, and the mean brightness of the figures. The results are discussed in terms of neurophysiological “on,” “off” and continuous response fibres.
A Statistical Test of a Prediction from Information Theory in a Card-Sorting Situation
Authors: Laming D. R. J.
Published: March 2008

Previous work with cards left the joint effects of varying entropy and discriminability on choice-reaction times somewhat in doubt. A card-sorting situation is here constructed in which entropy and discriminability can be varied independently. Two experiments are described with naive subjects and two different treatments of the practice effect. The effect of varying entropy with discriminability held constant is. shown to be significantly non-linear, contrary to the prediction from information theory. Finally a statistical model is proposed which shows at least, qualitative agreement with the results of these experiments.
On Choosing between Bets
Authors: Dale H. C. A.
Published: March 2008

Most attempts to account for the way persons choose between bets emphasize the use which is made of information about their basic attributes, i.e. the gains and losses which might be incurred and their respective probabilities. In experimental investigations of betting behaviour this is usually the only information which the subjects are given (e.g. Edwards, 1955; Hurst and Siegel, 1956). Everyday observation suggests, however, that if given the opportunity subjects will also use information about the outcome of bets. In the experiments to be reported, experimental subjects were told what gains had accrued from three bets in the past, the purpose being to see how this information affected their betting.
The Influence of the Number of Alternatives on the Perceptual Recognition Threshold
Authors: Fraisse P. , Blancheteau M.
Published: March 2008

A study of the recognition thresholds for nonsense syllables previously presented in lists containing from 2 to 15 syllables is reported. The threshold is found to increase in proportion to the logarithm of the number of alternatives (i.e. the length of the list from which a given test syllable is drawn). It is therefore concluded that recognition threshold is a function of the amount of information transmitted.
Practice, Familiarity and Reading Rate for Words and Nonsense Syllables
Authors: Conrad R.
Published: March 2008

Two experiments were carried out to test a number of hypotheses regarding the effects of practice and S-R familiarity on choice reaction times. In Experiment 1 subjects read lists of nonsense syllables of varying levels of association value and differing degrees of choice. It was found that the slope of reading time per syllable was linear with respect to the log of the number of choices, but that the slope was steeper for syllables of lower association value. In Experiment 2, 4-and 32-choice lists of the same average association value nonsense syllables were read on three successive days, as were lists of common three-letter words. The words showed zero slope against number of choices, and the slope for the nonsense syllables decreased with practice. These results are considered to support recent modifications to views on the role of information theory in psychology.
Size-Weight Interaction in Judgements of Compound Stimuli
Authors: Anthony W. S. , Holding D. H. , Lion Judith S. , Sluckin W.
Published: March 2008

Recent work in the fields of multidimensional information transmission and perceptual accentuation due to value has led to theories concerning unidimensional judgements of compound stimuli. The present study attempts to explore these theories, adding the dimension of size to judged weight, following negative results with judgements of size when brightness is varied.

Three sets of stimulus objects were prepared. Variation of weight was the same in each set. However, the size of the objects was the same in one set, while in another set size increased with weight, and in a third set size and weight were negatively correlated. Three groups of 16 subjects were asked to make replicated absolute judgements of the weights in each set.

It appeared that judgements of weight are more affected by density when density varies than when changes of size produce constant density. As predicted, contrast between successive stimuli is greatest when size and weight are negatively correlated, and least with positive correlation. The extent of the judged scales, and the means of these scales, follow the same pattern. Differences in discriminability between the three series, whilst in the expected direction, are not significant. The hypothesis that these effects would be more apparent in the psychologically linked dimensions of size and weight, than in the relatively neutral case of size and brightness, was largely confirmed. These findings both amplify and modify the previous suggestions concerning compound stimuli.
Size of Test Patch and Simultaneous Contrast
Authors: Burgh Peter , Grindley G. C.
Published: March 2008

Two experiments were done to find the effect on simultaneous brightness contrast of placing test patches in, as against outside, the fovea. When the display was magnified so that the test patches were outside the fovea no statistically significant effect was found. Very short exposures, to eliminate eye movements, did not appear to reduce contrast.
Immediate Memory in Dialling Performance with and without Simple Rehearsal
Authors: Heron Alastair
Published: March 2008

This experiment was designed to explore the effects of simple rehearsal on immediate memory in telephone dialling performance in a sample of 36 men aged 45 to 60 for whom data on intelligence, vocabulary, emotional stability and occupation were available.

The eight-digit messages were the same as those previously used by Conrad in a study of telephone operators which compared performance on dialling and keysender equipment. Using a Latin square design, subjects were required to dial 10 eight-digit messages in each of six conditions (three with auditory and three with visual presentation). Dialling was carried out (1) immediately the message had been presented; (2) after it had been once vocally rehearsed by the subject; (3) after it had been written down while being vocally rehearsed. A complete record was obtained of all performances, at rehearsal and at dialling.

It was found that with auditory serial presentation, immediate vocal rehearsal and immediate dialling are equally good and both superior to dialling which followed vocal rehearsal. With visual simultaneous presentation, immediate vocal rehearsal is clearly superior to dialling with or without rehearsal, which do not differ. Performance after written-down rehearsal was the worst in both modes of presentation.

A non-linear relationship between intelligence and performance was found, and acute individual differences in performance were observed among the subjects of the highest intelligence.
An Investigation of Changes in Auditory Sensitivity during the Performance of a Mental Task
Authors: Symons J. R. , Mackay C. K.
Published: March 2008

Auditory thresholds were measured while the subject was relaxed and while he was doing mental arithmetic. Thresholds were lowered under the second condition. Some possible explanations are briefly considered.
An Apparatus for Recording Figural After-Effects
Authors: Wilson J.
Published: March 2008

A simple apparatus is described by which Figural After-effects may be recorded directly from the subject's adjustments of a test figure. Curves which have been recorded confirm the results of other workers obtained by more laborious methods.
An Electronic Stimulus Randomizer
Authors: Gregory A. H. , Devine J. H.
Published: March 2008

A circuit is described which enables two stimuli to be presented in random sequence with either equal or different probabilities. The choice of stimuli is determined by sampling the condition of a two-state circuit. Experimental tests of randomness have been satisfactory.
Choice Reaction Times and the Theory of Intermittency in Human Performance
Authors: Davis R.
Published: March 2008

One visual signal, drawn from two equi-probable alternatives, was followed at a variable interval by a similar signal, also drawn from two equi-probable alternatives. The relationship between reaction time to the second signal and the interval between signals was studied under the following conditions: (1) Subjects were trained from the beginning to regard the first signal as irrelevant. (2) Subjects were asked to report on the nature of the first signal after they had responded to the second. The interval between signals was one of the five values, 50, 100, 150, 200, 250 millisec. In the regular interval situation the same interval was used over a block of 20 trials. In the random interval situation the values of the interval were randomly arranged, with equal frequency within each block of 20 trials.

The results showed: (1) In the random interval situation there was a definite disturbing effect of the first signal on the reaction time to the second, despite the fact that subjects were trained to disregard the first signal. However, the delays in reaction time were significant only at the shortest interval, 50 millisec. (2) In the regular interval situation this disturbing effect was not evident. (3) The additional requirement of having to report on the nature of the first signal produced no consistent increase in reaction time to the second signal. Some implications of these results for the conception of the human operator as a channel of limited capacity are discussed.
The Effect of Intermittent Illumination on the Visual Acuity Threshold
Authors: Gibbins K. , Howarth C. I.
Published: March 2008

Senders (1949) reported that with intermittent illumination short flashes needed less energy than larger ones to make a visual acuity target visible. This apparent breakdown of the reciprocal relationship between time and intensity, which has been found almost universally by earlier workers under a very wide range of experimental conditions, raised a number of interesting theoretical issues such as the relationship between visual acuity and intensity discrimination thresholds, and the plausible importance of eye movements in each. Unfortunately we have been unable to repeat Senders' result in spite of the most determined efforts to reproduce her experimental conditions. We are unable to suggest why our results differ from hers, but feel that our experiments at least show that her data are very difficult to reproduce and hence no general theoretical argument can be based on them.

In view of this we felt at liberty to predict results on the basis of a model, we had tentatively constructed, which we regarded as integrating Bloch's and Talbot's laws. This enabled us to make predictions about the effect of frequency of repetitive stimulation on thresholds. Experiments were carried out to ascertain how far these predictions were substantiated. Agreement was remarkably good.
Noise and Loss of Sleep
Authors: Corcoran D. W. J.
Published: March 2008

Two experiments are reported in which human performance was compared under continuous 90 dB. white noise, after loss of sleep, under a combination of the two and under appropriate control conditions. The results suggest that noise is effective in reducing the deterioration in performance, characteristic of loss of sleep. The relevance of the result to the arousal theory of loss of sleep is discussed.
Repeated Reversal of Training in Octopus
Authors: Young J. Z.
Published: March 2008

Octopuses were trained by successive presentations to discriminate between two figures by means of a combination of food rewards and electric shocks. This was followed by a series of up to nine daily sets of trials in which reward and punishment were systematically reversed on alternate days. It was found that performance became progressively less accurate with successive reversals until it reached a random level; this appeared largely due to a continual fall in the total number of attacks at the figures. At the same time, such attacks as were made were mainly at the positive figures and there was evidence that performance as judged by this criterion became more accurate during each day and perhaps progressively more accurate on successive days. Octopuses lacking the vertical lobe showed a fall in the total number of attacks but did not show this improvement within each day or over successive days. A theoretical interpretation of the results is put forward.
The Effect of an After-coming Random Pattern on the Perception of Brief Visual Stimuli
Authors: Kinsbourne M. , Warrington Elizabeth K.
Published: March 2008

The perception of briefly exposed visual forms is shown to be masked by an after- coming random pattern stimulus of approximately equal intensity. This effect occurs only under certain well defined conditions; it is limited by the minimum stimulus exposure time in excess of threshold which overcomes masking (critical stimulus duration) as well as by the minimum interval between presentation of the two stimuli which permits evasion of the masking action (critical interval). Over the range of stimulus duration in which masking occurs, critical interval varied with stimulus duration in such a way that the interval multiplied by the stimulus duration equals a constant. Critical stimulus duration and critical interval at threshold are shown to vary little under a variety of conditions. The effect of the random pattern stimulus is limited to the part of the visual field to which it is presented.
Eliminative and Enumerative Behaviour in a Conceptual Task
Authors: Wetherick N. E.
Published: March 2008

P. C. Wason's paper “On the Failure to Eliminate Hypotheses in a Conceptual Task” is criticized on the grounds that the task set is in important respects untypical of problem solving situations in general. It is suggested that few or no subjects are “Eliminators” in Wason's sense and that although many are “Enumerators” in his sense, enumerative behaviour is a function of the situation. An experiment is reported in which it appears that modification to the situation can sharply reduce the incidence of enumerative behaviour and increase the subject's chance of success at an early stage. The frequency with which hypotheses are directly eliminated is shown to be very low in all groups.
An After-effect in Haptic Space Perception
Authors: Gibson James J. , Backlund Fredrik A.
Published: March 2008

After-effects in haptic perception have been little studied. But they seem to be prominent, and easy to elicit. An after-effect of the perception of the vergence of two surfaces is described, and is shown to be independent of the slant of the surfaces. It is not “figural.” Spatial perception with the hands, as well as with the eyes, is apparently based on a fluid and adaptable receptive system.
Repetition and Confirmation of Messages Received by Ear and by Eye
Authors: Carterette Edward C. , Cole Michael
Published: March 2008

A rating method was used to obtain operating characteristics for 60 heterogeneous words. A single message was heard in noise, or seen briefly in a tachistoscope. It was repeated until it had been assigned to the highest accuracy category (“confirmed”) or sent a maximum of six trials. The comparisons showed that it matters little whether reception is by eye or by ear. Whether within a trial or over successive repetitions, accuracy of reception is a direct function of the confidence rating and is relatively independent of the intelligibility level. Neither do the accuracy of reception or the distributions of rating categories change markedly over trials. Although no direct test was made, it appears that accuracy of reception is not lessened by the task of rating. Both visual and auditory data are fitted reasonably well by predictions made from a simple stochastic model based on the assumptions that (1) intelligibility, (2) probability of a correct acceptance, and (3) probability of an incorrect acceptance remain constant over successive repetitions. The model fits the visual better than the auditory data, as might be expected, since conditions of reception are more homogeneous over trials for vision than for audition.
Detection of Visual Patterns Disturbed by Noise: An Exploratory Study
Authors: Van De Geer J. P. , Levelt W. J. M.
Published: March 2008

An introductory study of the perception of stochastically specified events is reported. The initial problem was to determine whether the perceiver can split visual input data of this kind into random and determined components. The inability of subjects to do so with the stimulus material used (a filmlike sequence of dot patterns), led to the more general question of how subjects code this kind of visual material. To meet the difficulty of defining the subjects' responses, two experiments were designed. In both, patterns were presented as a rapid sequence of dots on a screen. The patterns were more or less disturbed by “noise,” i.e. the dots did not appear exactly at their proper places. In the first experiment the response was a rating on a semantic scale, in the second an identification from among a set of alternative patterns. The results of these experiments give some insight in the coding systems adopted by the subjects. First, noise appears to be detrimental to pattern recognition, especially to patterns with little spread. Second, this shows connections with the factors obtained from analysis of the semantic ratings, e.g. easily disturbed patterns show a large drop in the semantic regularity factor, when only a little noise is added.
Differences and Interactions between Stresses
Authors: Broadbent D. E.
Published: March 2008

This paper reviews a number of experiments in which different stresses have been applied to comparable subjects performing similar tasks. It is argued that, since the effects of the stresses are different, it is not legitimate to think of a single mechanism mediating reaction to stress. Experiments on the simultaneous application of two stresses show that the effects of heat appear to be independent of those of noise and sleeplessness, while the latter two conditions partially cancel each other. It is therefore argued that noise and sleeplessness affect the same mechanism in opposite directions, while heat affects some other mechanism. Tentatively, noise is regarded as over-arousing and lack of sleep as under-arousing.
Reversal Learning in Octopus Vulgaris Lamarck with and without Irrelevant Cues
Authors: Mackintosh N. J. , Mackintosh J.
Published: March 2008

Three groups of eight octopuses each were trained on a brightness discrimination and its reversal. Within each group half the animals were overtrained on the original problem and half were not. For Group I the discrimination was a simple one, for the other two groups irrelevant cues were introduced (for Group II position and for Group III orientation).

It was found that the overtrained animals learnt the reversal significantly faster than the non-overtrained only where irrelevant cues were present (i.e. only in Groups II and III). The results are discussed in relation to various theories of discrimination reversal.
The Effect of Various Heteromodal Stimuli on Visual Sensitivity
Authors: Symons J. R.
Published: March 2008

Ten experiments are reported. In each the effect of a heteromodal stimulus on visual sensitivity is investigated. With one exception all the stimuli produced a small increase in visual sensitivity. A number of possible explanations of intersensory facilitation are considered.
Shape Discrimination in Tropical Fish
Authors: Hemmings G. , Matthews W. A.
Published: March 2008

Two experiments are reported using Egyptian mouthbreeders as subjects in which circle/square discriminations were attempted. In Experiment 1, using large stimuli in a maze type situation, no learning was shown by any of the six subjects. In Experiment II, using a conditioned operant technique of nose banging with smaller stimuli, some learning was shown by only one of the five fish. Rapid learning of other discriminations using the square or circle as negative stimuli was subsequently shown.
The Refractory Period and Serial Choice-reactions
Authors: Borger Robert
Published: March 2008

An experiment is described in which subjects had to make consecutive 2-choice reactions to light and sound stimuli, the interval between signals being fixed for anyone series of presentations. When under these conditions, reaction times to the second signal are compared to those obtained when the first signal is used only as a warning, delays are found for short intervals. These results and the wide individual differences obtained are discussed in relation to theories that have been put forward to account for the delays obtained in serial reaction tasks.
Retention of Shape Discrimination after Regeneration of the Optic Nerves in the Toad
Authors: Parriss J. R.
Published: March 2008

Using a method of successive discrimination previously described by the author eight toads (Bufo bufo), were trained to discriminate first between horizontal and vertical rectangles, each 3.5 × 7.5 cm., and second between horizontal and vertical rectangles each 5.0 × 7.5 cm. Immediately after training, both optic nerves were severed in four animals and allowed to regenerate. After a period of 10 weeks without training both the operated and non-operated animals retained the capacity to discriminate both the large and the small rectangles at a level either not significantly different from training or significantly better than training.
Drive Level Effects on Tasks of Narrow and Broad Attention
Authors: Agnew Neil , Agnew Mary
Published: March 2008

Easterbrook (1959) has predicted that (a) performance on tasks involving the use of a wide range of cues will be impaired under high-drive conditions and that (b) performance on tasks requiring the use of only a narrow range of cues will be facilitated under such conditions.

Using the Porteus Maze Test, relatively clear evidence was obtained to support the first prediction. Using the Stroop Colour Word Interference Test some evidence was obtained in support of the second prediction.
A Reply to John W. Senders and Virginia L. Senders (Quart. J. exp. Psychol., 14, 176–7)
Authors: Gibbins K. , Howarth C. I.
Published: March 2008

Senders has put forward a very relevant criticism of our experiments in so far as they are attempts to reproduce her findings. It is fair to say, however, that our primary interest was to discover whether the “Senders' effect” is a common one likely to turn up and confuse the results of any unwary research worker. This it would seem is now obviously not the case.

The apparently convincing argument, however, about the effect of fixation does not appear to hold. In February 1960 a simple experiment was carried out to test just this point. The equipment used was that described in Experiment 3 with repetition rate of 5.26 cps., except that:—

The fixation system was a sheet of glass reflecting an illuminated “cross” with the centre removed in which lay the rectangular grill, the subject being told to fixate the point where the centre of the cross should be. The open cross was used rather than crossed hairs or a point source as it was thought that these might interfere with the stimulus light at the point of fixation. A chin rest was used and the subject was fitted into a “skin diving mask” from which the face plate had been removed and replaced with a piece of wood with a hole opposite the left eye and the whole of the contraption was attached very firmly to a retort stand, which in turn was clamped to the bench. A cylindrical tube fitted into the hole in the mask and this again was attached to the bench via supports. Into the tube was let in the “fixation” glass reflector.
The Recording of Continuous Variation along Four Dimensions
Authors: Dixon N. F.
Published: March 2008

A system is described for signalling, recording and analysing continuous changes in up to four dimensions applicable to the visual after-image and other phenomena. Some advantages of the method are discussed.
The Basis of a Method of Perimetry with Monkeys
Authors: Cowey Alan
Published: March 2008

The value of perimetry as a means of studying the visual system is stressed. Perimetry has never been done with animals because it is difficult to record and control their fixation. Existing methods of determining eye position cannot readily be used with monkeys, chiefly because the subject's head must be prevented from moving more than fractions of a millimetre. Other limitations are mentioned. A new method of determining fixation is described. Although not nearly as precise as other methods it is unaffected by head movements as great as 1/2 in.; it is straightforward to restrict a monkey's head movements to this amount. The eye position is found from the relative positions of four corneal reflections and the borders of the iris. These relative positions change very much more after an eye rotation than they do after a head movement in which fixation has been maintained.
A Perimetric Study of Visual Field Defects in Monkeys
Authors: Cowey Alan , Weiskrantz Lawrence
Published: March 2008

The visual fields of rhesus monkeys have been studied perimetrically before and after removal of parts of the striate cortex. The operations produced visual field defects of the expected size, shape, and position but an animal's ability to respond to a flash of light which appeared in the defective part of the field was diminished rather than abolished. It is suggested that this residual ability enables an animal to detect changes in illumination, which might be cues to other visual events. A study of fixation indicates that the animals probably do not recognize or respond to objects when they lie within the impaired region of the visual field. The results are compared with those found in earlier studies of simian and human subjects.
Intraretinal Transfer and the Function of the Optic Lobes in Octopus
Authors: Muntz W. R. A.
Published: March 2008

A method of training octopuses was developed which allowed the part of the retina stimulated to be controlled during training and subsequent transfer tests. Using this method the following results were obtained, (1) There was more stimulus generalization when the edge of the retina was stimulated than there was when the centre of the retina was stimulated, suggesting that discrimination is better with the centre of the retina. (2) Intraretinal transfer is more nearly complete than interocular transfer. (3) Continuity of the optic lobes between the projection areas of different parts of the retina is necessary if receptor transfer is to occur between them. The optic lobes are therefore involved in visual learning in the situation used.
Decrement of Visual and Haptic Müller-lyer Illusion on Repeated Trials: A Study of Crossmodal Transfer
Authors: Rudel Rita G. , Teuber Hans-Lukas
Published: March 2008

Twenty adults, 10 male and 10 female, ranging in age from 22 to 54 years, were asked to set the centre arrowhead of a Müller-Lyer pattern for 80 consecutive trials. Ten of the subjects did so visually, while 10 blindfolded subjects made the settings haptically, i.e. by active palpation. Following the 80th trial, those subjects who had been making settings visually were blindfolded and were asked to make six haptic settings. Conversely, those who had made 80 haptic settings proceeded to make six settings visually.

The initial size of the illusion was essentially identical for the visual and haptic groups. Both groups showed significant decrement, since 19 of the 20 subjects had a smaller illusion on trials 71–80 than on trials 1–10. There was significant transfer of the decrement to the six settings made in the other modality. However, transfer effects were greater for the subjects who went from touch to vision than for those who went from vision to touch. Verbalization did not appear to be the vehicle of these crossmodal transfer effects.
Immediate Memory and Simultaneous Visual Stimulation
Authors: Sampson H.
Published: March 2008

Ten right-handed, right eye-dominant aircrew trainees recalled digits and colours projected simultaneously one to each eye, under five binocular viewing conditions that precluded overlap in visual fields.

Results of this experiment favour the view that Broadbent's theory of immediate memory is a special case which, though not typical, is applicable to vision. Relevance of present findings for the problem of cerebral dominance is also discussed.
Sensory Scaling and the Psychophysical Law
Authors: Treisman Michel
Published: March 2008

Sensory scaling is analysed as a sensori-motor task for which two relations must be determined, the first, S = f(I), being the relation between I, the stimulus intensity, and S, a measure of the neural effect of the stimulus, and the second being the relation between the subject's response, R, and S. It is shown that for any scaling procedure the relation between R and S can be arbitrarily specified, and according to the choice made S = f(I) will be found to be either a power function or a logarithmic function; these two “psycho- physical laws” do not reflect empirical differences between scaling procedures but conventional differences in the assumptions made when interpreting these procedures. A model is then elaborated in which S = f(I) is fixed and the relation between R and S depends on the demands of the psychophysical task and the effects of previous learning. With this more complex model the empirical implications of the power function and log function differ; it is shown that if the latter is accepted explanations can be given for two major problems in scaling theory, the disparity between the functions given by category scaling and the direct methods, and the difference between prothetic and metathetic continua.
The Effect of Self-Contradiction on Fallacious Reasoning
Authors: Wason P. C.
Published: March 2008

A serial task was used in which the possibility of making related valid and fallacious inferences was alternated over a series of trials. The hypothesis was investigated that if valid inferences are forced to contradict previously made fallacious inferences, then subsequent fallacious inferences will be withheld. The results showed that self-contradiction tended to extinguish fallacious inferences in an all-or-none manner without affecting valid inferences.
The Effect of Touch on a Visually Ambiguous Three-dimensional Figure
Authors: Shopland Charmian , Gregory Richard L.
Published: March 2008

The effect of haptic (i.e. tactile-kinaesthetic) information on the perception of an ambiguous visual figure was investigated. The figure used was a self-luminous, threedimensional wire cube viewed in darkness. It was found that visual reversals still took place when the cube was explored with the hands, but the reversal rate was reduced and the time increased during which the cube looked as it “really” was.
The Origin of the After-effect of Movement
Authors: Pickersgill Mary J. , Jeeves M. A.
Published: March 2008

Previous experimental work on the origin of the after-effect of seen movement is discussed and the relevance of the argument from transfer, which is generally used to demonstrate that the effect is central, is brought into question. The problem is reformulated in terms of whether a retinal contribution is necessary throughout the aftereffect and experiments are described which support the hypothesis that it is necessary. It is suggested that perception of the movement after-effect also involves normal movement perception, which itself is dependent on the integrity of cerebral functioning.
Is The Weber Fraction a Function of Physical or Perceived Input?
Authors: Ross Helen E. , Gregory R. L.
Published: March 2008

It is well known that a given physical input (e.g. intensity of light or sound, length or weight of an object) does not always give rise to the same sensation. For example, arrow heads affect the perceived length of lines (Muller-Lyer illusion) and size affects the apparent weight of an object (size-weight illusion). It is generally assumed that the differential threshold is a simple function of the physical intensity of the stimulus. We may however ask whether the differential threshold is affected by illusions.

To try to answer this question we estimate differential thresholds under a pair of conditions in which the relevant input is the same but appears different. Using the size-weight illusion, we have found that the differential threshold for weight is greater for a set of small weights than for a set of larger and apparently lighter weights.
Two Tests of All-or-none Learning and Retention
Authors: Brown John
Published: March 2008

A number of recent experiments have seemed to imply that the basic associations of learning are formed in an all-or-none manner. However, the evidence provided by these experiments has been essentially indirect since the presence of an association has been assessed by an all-or-none method, viz. simple recall. By allowing the subject more than one attempt at recall or recognition more direct evidence can be obtained. All-or- none learning implies that the probability of success during further attempts will be at the chance level. The experiments described show that this is not the case for the stimulus materials used. On the other hand the uncertainty in bits during further attempts was a fairly high proportion of the uncertainty expected on the all-or-none hypothesis. For this reason the results may indicate only a minor breakdown of the hypothesis. In a retention test administered after a week, fewer first-attempt successes were achieved than in the immediate test but, despite this, the uncertainty after a first- attempt failure was about the same as in the immediate test. The experiments also incorporated a second test of the all-or-none hypothesis. This involved comparing 2-choice and 4-choice recognition scores and recognition scores with recall scores. After corrections for guessing, these scores should be identical, if the hypothesis is correct. Results of this corrected-comparisons test tended to support those of the further-attempts test.
The Persistence of Some Effects of Handling in Infancy on the Behaviour of the Adult Rat
Authors: Du Preez P. D.
Published: March 2008

An attempt was made to discover how persistent the effects of handling before weaning are on activity, grooming, emotional elimination and learning in adult rats; whether there is an interaction of the effects of handling and the effects of cage size on the behaviour of rats; and whether the daily removal of the mother during nursing has any effects on the pups.

Since all differences between handled and undisturbed animals found at 50 or 100 days were found at 220 days, it was concluded that the effects of handling in infancy are persistent. The hypothesis that cage size and removal of the mother during nursing significantly affect adult behaviour was not supported by the results.
Tactile Discrimination of Shape by Octopus
Authors: Wells M. J.
Published: March 2008

Experiments are described showing that Octopus can be trained to distinguish by touch between a cube and a sphere, a surprising result since previous work has always indicated that octopuses cannot take proprioceptive information into account in learning. It can be shown, however, that the cube/sphere discrimination is made by detecting the distortion imposed on the rims of individual suckers in contact with the corners of the cube. Thus it is shown (1) that a cube with the corners even slightly rounded is less readily distinguishable from a sphere than a cube with sharp corners and, more important, (2) that a narrow rod is readily accepted in place of the cube by trained animals. Indeed, the rod seems to be a “better” cube than the original, and errors of discrimination decrease when it replaces the cube, presumably because it lacks flat surfaces liable to be confused with the surface of the sphere by a system depending on information from sense organs arranged in circles on the rims of the suckers.
Probability-learning in the Monkey
Authors: Wilson Wm. A. , Oscar Marlene , Bitterman M. E.
Published: March 2008

Tested in a choice-situation, two rhesus monkeys showed a correspondence between choice-ratios and reinforcement-ratios. The basis of this event-matching proved to be different in the monkey from that in lower forms.
Modification of the Diving-in Response of the Red-eared Terrapin, Pseudemys Ornata Callirostris
Authors: Mrosovsky N.
Published: March 2008

A terrapin will dive off a platform into water. This response was used in a simple apparatus with alternative water compartments to study discriminations. A white side was chosen in preference to a black side. By introducing shock it was possible to reverse this or, in some animals, inhibit diving-in. The variability of terrapins and the limitations and advantages of the present method for training them are considered.