bluuebunny/crossref_metadata_2025 huggingface dataset:
Cognitive Categories and Memory Span. III. Effects of Similarity on Recall
Authors: Sanders A. F. , Schroots J. J. F.
Published: July 2007

The effects of similarity on short-term recall are investigated, by presenting lists of six consonants followed by short lists of consonants and more or less remote cognitive categories, i.e. digits, tones or spatial positions. Some evidence for release from interference, due to dissimilarity of interfering material, is found with consonants and tones, while almost complete release is shown when consonants are followed by spatial positions. Control experiments are included to account for alternative explanations, such as relative difficulty of the various categories, and different memorizing strategies for items, made up of many as opposed to two alternatives. The latter factor appeared to be of particular importance.
Recall of Digits Projected to Temporal and Nasal Hemi-Retinas
Authors: Sampson H.
Published: July 2007

Fourteen right-handed, right eye dominant subjects recalled digits when different ones were projected simultaneously to either temporal or nasal retinas. The principal findings were: (a) Recall of digits projected to nasal retinas was significantly better than when projected to temporal retinas; (b) information projected to the right eye was recalled significantly better than that projected to the left eye. It is shown that the relative ineffectiveness of the recall of input from the non-dominant eye can be attributed almost wholly to the relative inefficient recall of digits projected to the left temporal retina.
Stimulus Change Effects of Forcing on Maze Arm Selection in Hamsters
Authors: Hughes R. N. , Blackman D. E.
Published: July 2007

Hamsters were forced to enter one arm of a T-maze on four succesive runs by means of either a grey door of the same brightness as the rest of the apparatus or by a black or white door. During four successive free choices the subjects entered the previously blocked arm significantly more often following forcing with the black or white door.
Prior Stimulation and the Perception of Causality
Authors: Brown H. V. , Miles T. R.
Published: July 2007

An attempt was made to discover whether, in conditions similar to those of Michotte, the number of causal responses given by subjects was influenced by stimulation during the period just before the main experiment. Time-intervals between the arrival of object A and the departure of object B were systematically varied within the range 60 to 390 msec. Those who had earlier been exposed to shorter time-intervals (60 to 210 msec.) gave fewer causal responses than those who had been exposed to longer ones (150 to 300 msec. and 240 to 390 msec.). A possible explanation is offered in terms of the modification of existing “schemata.”
Tactile Short-Term Memory
Authors: Gilson Elizabeth Q. , Baddeley A. D.
Published: July 2007

Subjects tried to recall the location of a tactile stimulus on the underside of the forearm after delays of 0, 3, 5, 10, 15, 30, 45 and 60 sec. When “rehearsal” was prevented by requiring subjects to count backwards during the delay, accuracy of recall decreased systematically reaching an asymptote after 45 sec. When subjects were left free to “rehearse,” this did not affect the decline in accuracy over the first 10 sec. Between 10 and 15 sec. there was a significant increase in accuracy followed by a slow decline which had not reached asymptote by 60 sec. It is suggested that tactile STM (short-term memory) depends on two processes, a fading sensory trace which is unaffected by distraction and a less labile system which does not appear to be verbal but which depends on “rehearsal.”
Retrieval Time as a Function of Memory Ensemble Size
Authors: Briggs G. E. , Swanson J. M.
Published: July 2007

A direct test was performed of Oldfield's (1966) derivation of the relationship between naming response latency and memory ensemble size. The results confirmed Oldfield in every particular. Further, the results support Sperling's (1967) suggestion of a recognition buffer-memory mechanism between the initial stimulus-encoding stage and the long-term memory stage of human information processing.
The Effect of Object Familiarity on the Perception of Size and Distance
Authors: Gogel Walter C.
Published: July 2007

The perceived sizes and perceived distances of familiar objects were investigated in two experiments in which images of familiar objects were presented monocularly, one at a time, in an otherwise dark field of view. It was found that the angular size of the objects as well as their familiar size determined reported size. Reported distances were increasingly underestimated as a function of increasing simulated distances of the objects. The results are consistent with the conclusion that, as a function of the retinal size of the objects, the observer perceives the familiar objects as off-sized, and, that as a consequence of these off-sized perceptions, the observer's judgements of the object distances reflect inferential rather than perceptual processes.
Using Several Modalities to Perceive one Temporal Pattern
Authors: Handel Stephen , Buffardi Louis
Published: July 2007

In two experiments, subjects identified temporal patterns. The patterns consisted of eight dichotomous (left-right) elements, e.g. LLRRLRLR, continuously repeated until the subject was able to identify the pattern. In Experiment 1, one pattern was presented either separately in the auditory, tactual, or visual modalities or one pattern was presented simultaneously in two modalities (compatible presentation). In Experiment 2, one pattern was simultaneously presented in two modalities, but the pattern was presented in one modality and the complement of the pattern (the complement of LLRRLRLR is RRLLRLRL) was presented in the second modality. Therefore, opposite spatial elements appeared in each modality (incompatible presentation).

The results indicated that the rate of pattern identification was the same for compatible and incompatible presentation. These methods produce better performance than individual modality presentation at fast presentation rates (2 elements/sec. and faster) although individual modality presentation was better at slower rates. This suggests that when a pattern is presented in two modalities, the pattern in each modality is integrated, not the particular spatial elements in each modality. Furthermore, the rate of pattern identification using individual modalities did not predict the difficulty using pairs of modalities. These results demonstrate the Gestalt nature of pattern perception; the pattern is perceptually salient and the performance of pairs of modalities depends on the inherent properties of the individual modalities.
Improvement in Memory with Time
Authors: Huppert Felicia A. , Deutsch J. A.
Published: July 2007

Groups of rats which had incompletely learnt to escape from shock into the lit arm of a Y-maze, were tested for retention of the habit at various times after training. These times ranged from 30 min. to 17 days. Retention was found to be poor from 30 min. to 5 days, showed a marked improvement at 7 to 10 days and a subsequent decrement after 14 days. These results parallel those previously found for the differential susceptibility to cholinergic drugs of habits of different age. They provide further evidence that memory strength increases with time up to a point, and then gradually decreases.
Some Evidence for Parallel Comparisons in a Letter Recognition Task
Authors: Cohen Gillian
Published: July 2007

Subjects were asked to judge successively presented letter trigrams “same” or “different.” The different stimuli were divided into four groups; not confusable (NC), acoustically confusable (AC), visually confusable (VC), and both visually and acoustically confusable (VC & AC). Reaction times (RT) were lengthened only by the double confusability. It is argued that comparisons are normally made in both channels, so that confusability in a single channel has no effect since the alternative channel is unimpaired. RTs are only increased when both channels are slowed down. A further experiment confirms this interpretation. When the situation is manipulated so that only the visual channel is employed, the VC group shows the same increase as the VC & AC group.
Syntactic Structure Modifies Attention during Speech Perception and Recognition
Authors: Abrams Kenneth , Bever Thomas G.
Published: July 2007

The present paper demonstrates the interaction of syntactic structure and speech perception with a response task which minimizes the effects of memory: reaction time (RT) to clicks during sentences. (1) In 12-word unfamiliar sentences each with two clauses, RT is relatively slow overall to clicks located at the end of the first clause but decreases as a function of clause length. Clicks at the beginning of the second clause are not affected by length of the preceding clause. (2) In familiar sentences, RT is relatively fast to clicks located at the end of a clause while RT to clicks at the beginning of clauses is relatively unaffected by familiarity. (3) RT is not fastest overall to clicks located between clauses either in novel or familiar sentences. (4) As in previous studies, the subject's subsequent judegment of the location of the click tone are towards the clause break. (5) We could find no systematic interaction between RT and subjective click location. Findings (1) to (3) are consistent with the view that perceptual processing alternates between attending to all external stimuli and developing an internal representation of the stimuli. Finding (3) is in conflict with an “information channel” view of immediate attention to speech, which would predict high sensory attention to non-speech stimuli between clauses. However, findings (4) and (5) indicate that the channel view of perception may be correct for that perceptual processing which occurs after the immediate organization of the speech stimulus into major segments.
The Perception of Briefly Exposed Point-Sources of Light
Authors: Burns B. Delisle , Mandl G. , Pritchard R , Webb Cordelia
Published: July 2007

Point-sources of light (dots) were exposed for 10 to 50 msec, before five dark-adapted subjects in a dimly illuminated room. During voluntary fixation with one eye, the target was exposed some 10° on the nasal side of the optic axis. The intensity X duration of all targets was 2 X threshold and they consisted of either a single dot, or a pair of dots separated by a distance that was less than that required for two-point discrimination. In two-thirds of trials both the single-dot and the two-dot targets were perceived as short thin lines of various orientation. Although individual percepts were unpredictable, there was a preferred or most likely orientation for responses to the single-dot target; this was near to the horizontal for all five subjects. There was no significant difference between the preferred orientations for single-dot targets tested at sites more than 1° apart in the visual field. When two single-dot targets, separated by about 1°, were exposed simultaneously, the orientations of the perceived lines sometimes differed by as much as 80°; occasionally, one target was reported as a dot while the other was seen as a thin line. If the single-dot was briefly exposed between two continuously visible and parallel straight lines, the target usually appeared as a thin line, parallel to the framing lines. Some of these results appear to be consistent with the hypothesis that the human visual cortex, like that of the cat and monkey, contains neurones that are orientation specific.
Discrimination of Circles and Squares with and without Knobs by Goldfish
Authors: Sutherland N. S. , Bowman Rosemary
Published: July 2007

Different groups of goldfish were trained to discriminate between a circle and either a square, a diamond, a square with a knob added at the top or a diamond with a knob. All subjects readily mastered the discrimination, and there was no significant difference between the groups in the number of trials taken to criterion. In transfer tests it was found that: (i) while there was no transfer from square to diamond or vice versa, the presence of knobs on these shapes did mediate transfer from one to the other, provided the knob remained in the top part of the shapes; (ii) all groups learned much more about the tops of the shapes than about the bottom halves; (iii) animals discriminated the square from the circle largely by detecting the presence of a strong horizontal edge at the top of the figure; (iv) two features of the diamond were discriminated—the presence of oblique contours and the existence of a point in the upper half of the shape. The results are discussed in terms of a proposed model of shape recognition.
When is a Weight not Illusory?
Authors: Ross Helen E.
Published: July 2007

Weight illusions occur whenever some aspect of an object—such as its size, material or colour—arouses the expectation that its weight will be heavier or lighter than it actually is. The direction of the illusion normally contrasts with the expected weight. When objects are hidden from sight and lifted by strings they can provide no misleading cues, and a correct weight-expectation should be achieved after one or two trials. When a visible object has the same physical and apparent weight as a hidden object, it can be defined as non-illusory. Weighted tins and polystyrene blocks of various sizes were compared with hidden weights. Tins were found to be non-illusory when their density was about 1.7, and polystyrene blocks when their density was about 0.14.

Weight illusions may be due to a central scaling process which enables a wide range of weights to be estimated, different ranges being selected according to the expected value of the weight. If the selected range is inappropriate an illusion occurs. Changes in expected value could also allow for the operation of “weight-constancy” during changes in proprioceptive stimulation.
An Experimental Study of Angular Subtension
Authors: Fisher Gerald H.
Published: July 2007

The confusion arising over judgements of the sizes of angular forms is described. Three experiments are reported. In the first, the apparent-sizes of acute and obtuse angles are estimated. In the second, judgements of the sizes assumed by upward- and downward- and left- and right-facing angles are compared. The third experiment is concerned with tactile reproduction of angles of specified sizes. In discussion an attempt is made to clarify the logical and empirical problems involved.
Effects of Changes in the Intensity of White Noise on Simultaneity Judgements and Simple Reaction Time
Authors: Sanford A. J.
Published: July 2007

On the basis of earlier work and informal observation it was suspected that the effect of loudness on simple reaction time (RT) could not be accounted for by changes in the time it takes the subject to hear the stimulus. Two experiments are described in which an increment in the level of background random noise is presented to the subject. The effect of increment size on RT and on a simultaneity judgement are investigated using a range of increments from just above difference threshold to moderately loud and clear. The difference in the size of loudness effects in the two tasks lends some support to a model which explains the influence of loudness on RT largely in terms of latency of response initiation.
Effects of Information Load, Sensory Modality, and Age on Paced Inspection Performance
Authors: Fozard James L. , Carr Gordon D. , Talland George A. , Erwin Donald E.
Published: July 2007

The effects on paced inspection performance of amount of stimulus information, presentation of information visually, as opposed to visually and auditorily, and age were investigated. In comparison to performance with one sequence of visual information, correct identifications of signals declined and false alarms increased when two sequences of visual information were monitored. Increasing the number of classes of signals in the two sequences did not significantly affect performance. However, when one of the two sequences was presented visually and the other auditorily, performance improved. There was a tendency for performance to be lower among older subjects in most experimental conditions.
Generalized and Lateralized Effects of Concurrent Verbalization on a Unimanual Skill
Authors: Kinsbourne Marcel , Cook Jay
Published: July 2007

After practice, subjects balanced a dowel rod on the right and on the left index finger while speaking and while remaining silent. As compared to control, the verbal condition yielded shorter balancing times for the right hand, but longer ones for the left. A speculative model postulates enhancement of the practised skill by virtue of the distraction effect of the concurrent activity. This is counteracted on the right by interference with right-sided motor control by the left cerebral hemisphere due to verbal activity programmed by the same hemisphere.
Syntactic Form and Semantic Function
Authors: Greene Judith M.
Published: July 2007

The experiments reported here were designed to investigate the effects on linguistic performance of varying the interaction between the syntactic form of sentences and their semantic function. The experimental task required subjects to decide whether pairs of sentences had the same or a different meaning. The results of Experiment I confirmed the prediction that the times taken to decide about pairs of affirmative and negative sentences would be shorter when the negative was performing its natural function of signalling a change of meaning. To a lesser extent, performance on pairs of active and passive sentences was facilitated when the two sentences meant the same thing. These results were found both with “meaningful” sentence material and with abstract x–y sentences. A second experiment provided a control for the possibility that the results were due to syntactic derivational factors rather than to the semantic function interaction.
Insight into a logical relation
Authors: Johnson-Laird P. N. , Wason P. C.
Published: July 2007

Two experiments are reported which aimed to investigate factors affecting the gain of insight into the logical relation of implication. In the first experiment, subjects had to make a series of inferences about either a conditional sentence or a quantified sentence, both of which had the same underlying logical form. Under one condition the sentences had to be proved true, and under another condition, false. Proving a sentence false facilitated gain of insight, but the linguistic form of the sentence exerted no significant effect on the main dependent variable. In the second experiment, implication was not expressed as a sentence but was inherent in the structure of the task. The experimental material differed in complexity and allowed the cognitive load imposed on the subject to be varied. Results suggested that insight was not all-or-none. It was spontaneously gained when the material was simple, but temporarily lost when it was complex.
Visual Search without Eye Movement
Authors: Grindley G. C. , Townsend Valerie
Published: July 2007

Two experiments have been made on the problem of visual search using six patterns which were geometrically simple, and familiar to the subject.

In each case the subject's task was to say where, among the complex of patterns, a particular pattern (the “test object”) appeared when the exposure of the whole display was so brief as to prevent scanning by the eyes. He could be informed visually (in Experiment I) or verbally (in Experiment II) which pattern was to be regarded as the “test object.”

In both experiments it was found that foreknowledge of what was to be the test object gave a significantly higher standard of accuracy than knowledge given later. This suggests that something analogous to visual search can occur without eye movements.
Visual Orientation during Lateral Head Tilt When Upright and Supine
Authors: Wade N. J.
Published: July 2007

Egocentric visual orientation was investigated with lateral head tilts relative to the upright and supine trunk. A significant difference was found in the trend of visual head axis judgments between 40° left and 40° right head tilt for the two conditions, such that they varied systematically with the degree of tilt for the upright but not for the supine condition.
Reproduction and Recognition in Short-Term Visual Memory
Authors: Cohen Ronald L. , Granström Kjell
Published: July 2007

Reproduction and recognition in short-term visual memory was tested. In Experiment I, it was confirmed that the ability to reproduce visual figures in STM correlated with the ability to describe them. No such correlation was obtained when recall was by recognition. In Experiments II and III the mechanisms involved in the two types of recall were investigated by varying the character of the task interpolated in the retention interval. Results support the view that reproduction has a verbal component which is lacking in recognition.
Effect of Contralateral Shock Stimulation on Laterality Differences in the two Shock Threshold
Authors: Murphy E. H. , Venables P. H.
Published: July 2007

Contralaterally presented shock was found to bring about marked changes in two shock threshold determined for the right finger but not for the left finger. The results are discussed in terms of a suggestion that the level of excitability of the left hemisphere may be more easily disturbed than that of the right hemisphere.
Activity of Inbred and F1 Mice in a Residential Maze
Authors: Barnett S. A. , Smart J. L.
Published: July 2007

Male mice of strains A2G/Tb, C57BL/Tb and the F1 produced by crossing them were studied singly for 3 days in an artificial environment (a “plus-maze”), in which movement was recorded automatically. There was a central nest box with an opaque cover, from which three passageways led to food, water and soft (balsa) wood, respectively; a fourth arm was left empty. The number of visits to the arms was always highest on the first day. On a given day, the number of visits was much the same for each arm, that is, it was not influenced by the incentives. In contrast, while time spent out of the nest box was about the same from day to day, the time spent in individual arms differed greatly and was in the order food> balsa wood> water> empty arm. In terms of visits, the F1 and C57BL/Tb mice were more active than A2G/Tb; and the F1 mice varied less than either inbred strain. The lack of correspondence between visits and duration of stay is discussed in relation to the concept of neophilia.
The Effect of Shock Duration and Intensity on the Ingestion of Food of Varying Palatability
Authors: Strongman K. T. , Coles M. G. H. , Remington R. E. , Wookey P. E.
Published: July 2007

One hundred and fifty 23-hr. deprived rats were run in a 2 × 5 × 3 balanced analysis of variance design to determine the effect of prior shock on food intake. The main factors were time spent in shock box (3, 30 sec.), intensity of shock (0, 0.5, 1.5, 2.5, 3.5 mA) and percentage of sucrose adulteration of food (0, 10, 25 per cent).

Results showed a general enhancement of intake following 3-sec. shock and a suppression following 30-sec. shock. Variations in shock intensity were of no significance.
The Effect of Stimulus Relevance on the Cortical Evoked Potentials
Authors: Hartley L. R.
Published: July 2007

Past research has proved equivocal in providing a correlation between the amplitude of cortical evoked potentials and attended or unattended stimuli. The present experiment is a further investigation of the relationship between selective attention and the cortical evoked potentials and avoids some methodological artifacts. The results of the experiment provide no direct support for the postulated correlation between the two variables, but do suggest two possible explanations of this state of affairs.
Discriminative and Associative Aspects of Retroactive Inhibition
Authors: Bahrick Harry P.
Published: July 2007

Original learning of paired drawings of meaningful objects or of modified Chinese characters was followed by interpolated learning in which details of drawings were changed in one of two degrees with or without rearrangement of the original pairings. Subjects were tested for accuracy of identification of the original drawings and for associative matching of the original pairs. Identification errors were attributed jointly to confusion between original and interpolated drawings, and to unlearning of those features of original drawings which were in conflict with comparable features of interpolated drawings. Rearrangement of pairs during interpolated learning produced not only associative interference on the matching test, but also additional discriminatory interference on the identification test. Effects of associative and discriminative interference upon individual drawings were uncorrelated for meaningful material and only slightly correlated for meaningless material.
Lateral Dominance in Tachistoscopic word Recognitions of Children at Two Levels of Ability
Authors: McKeever Walter F. , Huling Maurice D.
Published: July 2007

Monocular tachistoscopic word recognition performance as a function of word placement to the right or left of fixation was studied in 20 seventh grade children. Half the subjects possessed normal reading skills, while the other half read at a third grade level. Words directed to the left cerebral hemisphere (right field words) were recognized significantly more often ( P < 0.005) in both groups than words channelled to the right hemisphere. The result supports the view that right field recognition superiority reflects the language specialization of the left hemisphere rather than “training” of the left hemiretinae through the acquisition of reading proficiency.
Memory Coding for Binary Sequences in Children
Authors: Frith Uta
Published: July 2007

Younger children with a short memory span and older children with a long memory span recalled binary word sequences of different structure. It was found that the difficulty of recall was mainly determined by the run-structure but not by the cyclicity of the sequences.

Incorrectly recalled sequences were systematically analysed in terms of two supposed coding mechanisms, i.e. “feature extraction” and “pattern imposition”. It could be demonstrated that certain features of the presented sequences were preserved while others usually were not. While the extracted feature served as a basis for reconstruction of the sequence in recall, the obtained sequences showed in addition certain characteristics which appeared to be unrelated to the input.

Some differences in the efficiency of coding were found between 4- and 6-year-olds. However, it appeared that the coding strategies were similar at lower and higher levels of memory capacity and development.
Fixed Interval Schedules and Delay of Reinforcement
Authors: Morgan M. J.
Published: July 2007

In a fixed interval schedule of reinforcement the only responses to be reinforced are those made when a certain time interval has elapsed since the previous reinforcement. The behaviour of three rats on such a schedule was compared with their behaviour on a schedule where a response made at any time during the interval was reinforced by setting up a reward which was delivered when the interval had elapsed. Response rates were higher in the ordinary fixed interval schedule than in its modified version, and it is argued that this rules out attempts to explain the maintenance of fixed interval performance by delayed reinforcement. Despite the clear difference in response rates, there was considerable similarity between the post-reinforcement pauses developed in the two schedules, and this suggests that pausing is influenced more by temporal than by response contingencies.
The Preference-for-Signalled-Shock Phenomenon: Signalling Shock is Reinforcing only if Shock is Modifiable
Authors: Biederman Gerald B. , Furedy John J.
Published: July 2007

Inescapable, unavoidable, 5-sec. shocks were preceded by 5-sec. white-noise signals contingent on previously food-trained (FR 40) bar pressing of 20 rats. Twenty yoked-control subjects receiving the same, but non-contingent, series of signals indicated that the signal was reliably reinforcing only if the shocks were delivered through an alternate, rather than scrambled, floor-grid system. Implications are discussed for previous reports of the preference for signalled shock phenomenon.
Temporal Summation and Phenomenal Simultaneity: Experiments with the Radius Display
Authors: Allport D. A.
Published: July 2007

This study explores the phenomenon of subjective simultaneity between multiple successive positions of a target, which consisted here of an illuminated radial line in both stepwise and continous rotation around a fixation point. In four experiments the span of phenomenal simultaneity ( M) was measured under varying intensities of target and surround, and with two different estimation procedures. M was found to change as a power function of target intensity, with an exponent of −0.13 or −0.16, for both stroboscopic and continuous illumination of the target. Variation of surround intensity affected M only for 9 out of 15 subjects (Experiment III.) For these subjects M varied inversely with log I of the surround; for the remaining 6 subjects M remained approximately constant over a range of 5 log units of I. Auditory noise tended slightly to decrease M in the former group and to increase it in the latter. Under simultaneous continuous and stroboscopic illumination of the target a paradoxical, single-valued M was obtained (Experiment IV). Higher values of M were found when subjects attempted to estimate the number of apparently simultaneous radii (Experiment I). The function relating M to target intensity closely parallels that for the critical duration of temporal brightness summation. The possibility that both measures reflect the same underlying process is discussed.
Classification without Identification in Visual Search
Authors: Brand Joan
Published: July 2007

Six subjects scanned displays of random consonants for a single target which was (a) another consonant; (b) a given number; or (c) any number. A second group of six subjects took part in three comparable conditions with number displays, and letters or numbers as targets. Scanning time for a number in a letter display or a letter in a number display was more rapid than scanning for a target drawn from the same set as the background. Several unpractised subjects, and all the subjects who practised the task, were able to scan as fast through letters for “any number” as for a specific number, or conversely through digits. The finding of different scanning rates for two precisely physically specified targets, depending on which class they were drawn from, runs counter to an explanation of high-speed scanning in terms of the operation of visual feature analysers. It is suggested that familiar categorization responses may be immediate and may provide the basis for the discrimination of relevant from irrelevant items in rapid visual scanning.
Evidence for Alternative Strategies of Sentence Retention
Authors: Wright Patricia , Kahneman Daniel
Published: July 2007

Measurements of pupil size were taken while subjects listened to sentences and either tried to repeat them (R) or answered a question about them (QuA), after either a 3 or 7 sec retention interval. Pupil dilations were larger for R than for QuA, both towards the end of presentation and during the retention interval. Similar results were obtained by Kahneman and Wright (1971) when comparing total and partial recall of word lists. They attributed the differences in pupil dilations to differences in rehearsal strategy. However, the interaction between recall condition and retention interval was less convincing with sentential material, and an alternative explanation is suggested in terms of the level of abstraction at which the sentences are processed. This interpretation is supported by other evidence relating to the existence of alternative sentence retention strategies.

Pupil dilations failed to reveal phrase juncture phenomena, although two levels of ambient illumination were used in the hope of detecting such effects. In a modified question condition (QuB), where the question was given before the sentence, pupil dilations varied as a function of the part of the sentence providing the answer. These data indicated that people did not begin to frame their answer until they encountered in the sentence those words used in the question.
The Influence of Visual Texture Density Gradients on Relative Distance Judgements
Authors: Newman Colin V.
Published: July 2007

A hypothesis derived from J. J. Gibson's psychophysical theory of space perception was tested. Subjects made monocular relative distance judgements by moving a marker to the apparent physical mid-point between two other fixed markers which were placed on a surface along the subjects' line of sight. Judgements were significantly influenced by the texture density gradients of stimulation derived from the surface over which they were made.
Blocking as a Function of Novelty of CS and Predictability of UCS
Authors: Mackintosh N. J. , Turner C.
Published: July 2007

Kamin (1969) reported that after rats had been trained with one CS predicting shock, they learned virtually nothing about a second CS added to the first to form a compound—provided that the shock remained unchanged. If, however, the shock was either increased or omitted at the same time that the new CS was added, it acquired significant excitatory or inhibitory strength. Both these results were confirmed in the present experiment. In addition, however, it was found that this excitatory or inhibitory conditioning to the added element could itself be blocked if the shock remained unchanged for the first four trials after the addition of the new element. This finding implies that blocking is not due to any limitation on attentional or associative capacity, but rather occurs when subjects learn that a particular stimulus is redundant, i.e. that it predicts no change in reinforcement.
Dichotic Backward Masking of Complex Sounds
Authors: Darwin C. J.
Published: July 2007

In the first experiment subjects identified a consonant-vowel syllable presented dichotically with a known contralateral masking sound at a stimulus onset asynchrony of ± 60 msec. When the mask followed the target syllable, perception of place of articulation of the consonant was impaired more when the mask was a different consonant-vowel syllable than when it was either a steady-state vowel or a non-speech timbre. Perception was disturbed less when the mask preceded the target, and the amount of disruption was independent of which mask was used. Greater backward than forward masking was also found in the second experiment for the identification of complex sounds which differed in an initial change in pitch. These experiments suggest that the extraction of complex auditory features from a target can be disrupted by the subsequent contralateral presentation of a sound sharing certain features with the target.
The Fate of Old Memories
Authors: Warrington Elizabeth K. , Sanders Helen I.
Published: July 2007

A questionnaire relating to past events, and a well-known faces recognition test, were devised to provide an objective and quantitative assessment of recent and remote memories. Normal subjects aged from 40 to 89 were tested on recall and recognition versions of each test. It was found that performance declined with increasing age for all time periods sampled. No evidence was obtained to support the widely held belief that memory is inversely related to the remoteness of event in older subjects.
Comparisons of Two Measures of Free-operant Avoidance under Two Conditions of Response Feedback
Authors: Hurwitz Harry M. B. , Harzem Peter , Kulig Beverley
Published: July 2007

Lever-pressing responses of 6 rats were studied under a free-operant avoidance procedure, in 6 two-hour sessions. Three of the subjects were given an added visual feedback for each response; they avoided shocks more effectively than the subjects without the feedback. Two different measures of overall performance in free-operant avoidance were applied to the results of the experiment. There was little difference between the measures: both reflected the subjects' performance equally well. Relative merits of the measures and the criteria for selecting one of them were discussed.
Encoding and Memory for Verbal and Pictorial Stimuli
Authors: Wells J. Elisabeth
Published: July 2007

Memory for visually presented verbal and pictorial material was compared using stimuli chosen to minimize non-essential differences between the two types of material. Experiment I required retention of a short list; verbal and pictorial stimuli were remembered equally well. Experiment II required recall of single items after 30 s of backwards counting; recall was much superior for pictorial stimuli. The type of task appeared to affect encoding, with verbal encoding reported to be predominant in Experiment I and visual encoding, or imagery, common in Experiment II.
Evidence for an Integration Theory of Visual Masking
Authors: Coltheart Max , Arthur Barbara
Published: July 2007

When letters are superimposed upon a pattern of black and white squares, they are easier to identify when the pattern is regular than when it is random. If backward masking consists of the superimposition of a masking pattern upon the decaying visual trace of a target display, a regular pattern should be less effective as a backward mask than a random pattern. This was found to be so for both multiple-letter and single-letter displays. This result is predicted by an integration theory of visual masking but not by an interruption theory.
The Overtraining Reversal Effect in Rats: A Function of Task Difficulty
Authors: Richman Charles L. , Knoblock Karol , Coussens Wayne
Published: July 2007

Two experiments were conducted with rats. The first study showed that in the T-maze a brightness discrimination learning problem was more difficult than a spatial learning problem, but in a Ross-maze a brightness problem was less difficult than a spatial task. T-maze brightness and Ross-maze spatial tasks were found to be of equal difficulty.

In the second experiment rats were trained either on a brightness or spatial discrimination reversal problem in the Ross-maze. It was found that overtraining facilitated reversal performance in the spatial task but not in the brightness problem. The theoretical implications of these results were discussed.
What is Both Necessary and Sufficient to Maintain Avoidance Responding in the Shuttle Box?
Authors: Katzev Richard
Published: July 2007

To learn what maintains the frequency of shuttle box avoidance responses, male rats from the Berkeley S1 strain, after 200 trials of standard discriminative avoidance training, were given 100 additional trials under one of four different conditions. Responding at the maximum rate was maintained when animals performed under the training conditions or when responses continued to terminate the warning signal immediately, even though shock was never given for failing to respond. In contrast, avoidance responding was reduced markedly if, and only if, trials were given in which the signal ceased to terminate immediately (i.e. it shut off either well before or well after a response). This decrement occurred even though avoidance responses continued to avert shock. Thus, under the conditions of this experiment prompt signal offset was both necessary and sufficient to maintain the occurrence of well-established shuttle box avoidance responses.
A Test between the Selective Attention and Stimulus Generalization Interpretations of the Easy-to-hard Effect
Authors: Sweller J.
Published: July 2007

The selective attention and stimulus generalization interpretations of the easy-to-hard effect were tested by training one group of rats on an easy brightness discrimination and “reversing” them on a more difficult brightness discrimination. A control group, initially trained on the difficult discrimination, was reversed at the same time as the experimental group. The experimental group learned the reversal more rapidly and this was interpreted as supporting the selective attention interpretation.
Short-Term Visual Memory and Pattern Masking
Authors: Mitchell D. C.
Published: July 2007

The results of two experiments involving the matching of unfamiliar, nameless shapes (Gibson forms) indicated that a visual representation of a brief (30–100 ms) stimulus survives in a Short-Term Visual Memory (STVM) for 6 s or more after the onset of a pattern mask. On the basis of these results a possible alternative to Sperling's (1967) model for short-term memory for visual stimuli was presented. In this model it is assumed that recognition processes occupy several hundred milliseconds and continue after the arrival of the mask using the information available in STVM.
The Capacity for Rapid Shifts in Level of Mental Concentration
Authors: Blum Gerald S. , Porter Marcia L.
Published: July 2007

This investigation continues the exploration of a largely neglected topic in the field of attention, levels of mental concentration, by ascertaining under optimal conditions the capacity for shifting quickly from one level to another. Previous research in our laboratory had applied a set of five post-hypnotically cued levels of concentration or “cognitive arousal”, covering a very wide range, to a variety of perceptual and cognitive tasks. In the present study two highly trained undergraduate hypnotic subjects, one male and one female, were given progressively shorter time durations in which to respond to the post-hypnotic cues before viewing tachisto-scopically flashed consonants under cue influence. The results indicate a striking capacity to shift degrees of cognitive arousal very rapidly to one extreme or the other, on the order of 100 ms or less.
Specificity and Savings of Behavioural Habituation over a Series of Intra- and Inter-Modal Stimuli
Authors: File Sandra E. , Russell I. Steele
Published: July 2007

A series of four tone stimuli, differing either in tonal frequency or in melody, was presented at the rate of one presentation per day to a group of rats. Habituation was specific to the frequency of simple auditory stimuli and to the melody of patterned stimuli, as shown both by the distraction to stimulus change, and by the trials to habituate to the new stimulus. Savings in habituation occurred when a series of tone stimuli was presented, but was not found for a series of inter-modal stimuli.
Spatial and Verbal Codes and the Capacity of STM
Authors: Henderson Leslie
Published: July 2007

Subjects were required to report an array of consonants presented tachistoscopically for various durations. Concurrently, they held in memory a load of auditory digits, a load of spatial locations or no load. These several forms of information did not seem to compete for a fixed capacity short term store. Consonant report was unaffected by carrying a spatial load and barely affected by carrying the auditory digit load. An auditory-verbal loop cannot play a mandatory role in the coding and storage of visual information. Some criticisms of structural interpretations of immediate memory are suggested.
Acoustic Similarity and Interference in Short-term Recognition Memory: Some Results of a Decision-theory Analysis
Authors: Ingleby J. D.
Published: July 2007

The following three studies of single-probe recognition memory set out to show the effect on the signal-detectability measures of d′ and β (Tanner and Swets, 1954) of variations in the acoustic similarity of interfering material, which may either precede or follow the item to be remembered (proactive or retroactive interference —PI or RI). The first experiment studies a situation employed by Wickelgren (1966a), who reported that acoustically similar RI substantially reduced d′. It is shown that this effect could have been due to biases in Wickelgren's original designs, and that when a bias-free design is used, the fall in d′ is only of borderline significance.

To investigate this problem further, a design was evolved in which two items were presented for memorizing, which varied in acoustic similarity to each other, and (after a distracting task) a probe was presented with one of three questions: Was this the first item of the pair? Was it the second? or, Did it occur in either position? In the first case, recognition-memory with RI of varying acoustic similarity was being studied, and as in the first experiment, it was found that similarity slightly reduced d′. With the second question, PI effects were being studied, and here negligible differences were found. With the third type of question, a “location-free” test, no effects of similarity were found. The last result rules out Posner's (1967) “acid-bath” explanation of similarity effects in interference: an explanation in terms of “differentiation” (or “filtering”) was also invalidated by the results of a third experiment, in which the same effects were found even though similarity varied only between stimulus items and interference, and not between these and the probe. Wickelgren's (1966b) associative model appears to have least difficulty in accommodating these results, though even this needs certain ad hoc assumptions to be able to do so.
Effects of Electric Shock on Exploratory Behaviour in the Rat
Authors: Williams D. I.
Published: July 2007

Rats were given five daily 3-min trials in a Y-maze with two grey and one black-and-white striped arms. An initial preference was shown for the striped arm. Between Trials 3 and 4 half the subjects were given electric shock, half in a striped box and half in a box lined with aluminium foil. Shock resulted in reduced ambulation in the maze, but increased the preference for the striped arm in terms of initial choice and time spent in it. There was no significant difference between the two shock conditions. Results are consistent with the notion that mild fear may facilitate exploration.
Aspects of the Theory of Comprehension, Memory and Attention
Authors: Mackay Donald G.
Published: July 2007

This paper proposed a two-stage model to capture some basic relations between attention, comprehension and memory for sentences. According to the model, the first stage of linguistic processing is carried out in short-term memory (M1) and involves a superficial analysis of semantic and syntactic features of words. The second stage is carried out in long-term memory (M2) and involves application of transformational rules to the analyses of M1 so as to determine the deep or underlying relations among words and phrases. According to the theory, attention is an M2 process: preliminary analyses by M1 are carried out even for unattended inputs, but final analyses by M2 are only carried out for attended inputs. The theory was shown to be consistent with established facts concerning memory, attention and comprehension, and additional support for the theory was obtained in a series of dichotic listening experiments.
Vocal and Manual Response Latencies to Bilateral and Unilateral Tachistoscopic Letter Displays
Authors: White Murray J.
Published: July 2007

Bilateral rows of eight letters and unilateral rows of four letters were presented in randomized sequences for 100 ms. Subjects were required to recall all letters in a trial (Experiment I); recall letters from one hemifield cued at exposure (Experiment II); recognize a single letter, making a vocal response (Experiment III); recognize a single letter, making a manual response (Experiment IV). In Experiments I, II and III, identification errors were fewer and vocal response latencies were faster for RVF stimuli, except in the bilateral condition on Experiment I; in Experiment IV manual response latencies were the same, for left and right, bilateral and unilateral conditions. Collectively, the results could not be satisfactorily accounted for by any one hypothesis: report-order, trace-scanning, or cerebral dominance. The relative contribution of each process to the laterality effect was discussed.