Non-verbal and verbal judgements of length invariance by young children.

One hundred and fifty non-conservers in length were assessed for their ability to make a non-verbal judgement of length invariance on a task employing a train-transfer design in which the stimuli were pairs of pencils. Seventy per cent of the children from the group who had to respond to length equality as opposed to inequality made the correct invariance judgement and could, moreover, characterize their choices in invariance language (e.g. 'same size') whilst still failing the standard verbal task in which such phrases were used by the experimenter. This is regarded as supporting the hypothesis that the non-conserver's linguistic difficulty is not with framing the verbal judgement but in interpreting a question which he believes has to be interpreted unidimensionally in such a context of perceptual change.     

Hemispheric laterality and dissociative tendencies: differences in emotional processing in a dichotic listening task

The present work investigates whether the hemispheric processing of both verbal and emotional stimuli, studied by means of a dichotic listening task, differs between normal high and low dissociators as assessed by the Dissociative Experiences Scale (DES; Bernstein & Putnam (1986). Development, reliability and validity of a dissociation scale. Journal of Nervous and Mental Disease, 174(2), 727-735). Two groups of subjects (50 high and 50 low dissociators), participated in the experiment. The task consisted in identifying both verbal and emotional stimulus-targets, respectively, on successive sessions. Reaction time and response accuracy were registered and analysed using ANOVA (Analysis of Variance). The interaction between stimuli (verbal, emotional), channel (right ear, left ear), and dissociation level (high, low) reached statistical significance in terms of accuracy measures (d': F(1,98)=4.75; p<.05). Both high and low dissociators exhibited the expected right ear advantage (REA effect) on verbal targets. On the other hand, whereas low dissociators exhibited the expected left ear advantage (LEA effect) on emotional targets, high dissociators failed to follow this typical pattern of hemispheric asymmetry: both hemispheres exhibited similar performances. These results confirm the hypothesis that dissociation is related to changes in hemispheric processing, specifically of emotional information.     

Hemispheric specialization for processing of visually presented verbal and spatial stimuli

Two “same-different” reaction time experiments, analogous in task demands made on the S, were designed to test laterality differences in. perception. Ten normal right-handed Ss performed a verbal task in which they decided whether or not two three-letter words belonged to the same conceptual class. Ten different Ss performed a spatial task in which they decided whether two 16-cell matrices with 3 blackened cells were identical. Reaction times were found to be sensitive to laterality differences in perception. Verbal stimuli were processed faster when presented in the right visual field, and thus projected directly to the left cerebral hemisphere; spatial stimuli were processed faster when presented in the left visual field, and thus projected directly to the right cerebral hemisphere. These results were analyzed in terms of implications regarding hemispheric asymmetries for processing of verbal and spatial material and the nature of interhemispheric transfer of information.     

Dimensions of the perception of art: verbal scales and similarity judgements

Abstract.— An INDSCAL analysis was performed on subjects' similarity judgements of all pairs of 12 landscape paintings. Three principal INDSCAL dimensions were identified by analysing responses to 24 unidimensional rating scales derived from previous experiments. The present findings, together with those of previously published studies, suggest that three of the principal dimensions of perception of art appear to be (1) Hedonic-Representational, (2) Clarity, (3) A Dynamic factor involving activity, balance and symmetry. It is suggested that although Complexity may be an important factor influencing responses to simple stimuli, its rôle in the perception of paintings is small, and has frequently been over-emphasised.     

Effects of concurrent verbal rehearsal and temporal set upon judgements of temporal duration

Subjects (N = 252, college students) rehearsed a 30-item free-recall list, or rested for one of three intervals (32, 42 or 54 sec), on the first, third, or ninth study trial. At the conclusion of the interval, subjects made an absolute judgement of interval duration. Half the subjects were informed that this time judgement would be required prior to the interval (prospective), and the remainder were not informed of the required time judgement until after the interval (retrospective). As the number of previous trials increased, judged time (1) increased linearly in the prospective-rehearsal group, (2) decreased linearly in the retrospective-rehearsal group, and (3) had no effect on the nonrehearsal groups. Prospective judgements were greater than retrospective. It was concluded that retrospective time judgements are a function of the amount of information the subject remembers having processed during the interval.     

Deficits in temporal sequencing of verbal material: The effect of laterality of lesion

Temporal sequencing of verbal materials (digits, words, and geometric forms) presented in two sensory modalities (auditory and visual) to three groups of subjects (Broca's with left anterior lesions, patients with right hemisphere lesions, and normals) was examined. Each subject was asked to point to a set of stimuli in the same sequence as presented by the examiner. Results indicated that patients with left hemisphere lesions were more impaired on all tasks than the right hemisphere lesioned patients who, in turn, were impaired compared to normal controls. Response to auditory presentation was superior to response to visual presentation. Also, digits were the easiest for all groups, and words were easier than geometric forms. Of special interest was the finding which suggested that right hemisphere lesions are associated with impairment of verbal temporal sequencing under either auditory or visual presentation.     

Effects on pupil size of manual and verbal indicators of cognitive task fulfillment

A total of20 Ss attempted to generate images to concrete and abstract stimulus words while pupillary activity was continuously photographed. One group (N =5) was required to press a key when an image occurred, a second to describe the image, and a third to press a key as well as describe the image. No overt indicator was required of a fourth group. Results showed that greater dilation occurred during the imagery task than during a control period only in those conditions in which an overt response indicated task fulfillment. Consistent with earlier findings significantly greater dilation occurred to abstract than concrete stimulus words in the key press condition.     

Hemispheric differences for verbal and nonverbal stimuli in Japanese- and English-speaking subjects assessed by Tsunoda's method

This investigation compared the performance of Japanese- and English-speaking subjects on T. Tsunoda's DAF key-tapping task, which he purports assesses cerebral dominance for language (1975, Brain and Language, 2, 152–170). Twenty-three native speakers of Japanese and 23 English-speaking subjects were employed in this study. Each subject was administered the DAF key-tapping task utilizing the vowel /a/ and a 1000-Hz pure tone. The results revealed an effect of intensity, whereby an increase in DAF/SAF ratios resulted in an increase in performance disruption. No differences were observed between the two language groups, ears, or between the 1000-Hz pure tone and the vowel /a/. Only 15.5% of the subjects showed the hypothesized right ear advantage for the tone when subjected to an analysis similar to Tsunoda's. All other subjects revealed variable degrees of advantage to either ear, to the same ear, or to to neither ear. It was concluded that no significant functional auditory asymmetry was observed for either group, suggesting that the DAF key-tapping task may not be a sensitive procedure to determine cerebral dominance for language among normals.     

Concurrent verbal and emotion laterality effects exhibited by normally achieving and learning disabled children.

This study assessed both left- and right-hemisphere functions simultaneously when two-syllable words differing only in the initial stop consonant and spoken in different emotional tones were paired dichotically. Seventy-two right-handed normally achieving children, 12 boys and 12 girls at each of grades 1, 3, and 5, were instructed to detect either the presence of a specific word or of a specific emotion. In addition, 30 right-handed learning disabled (LD) children (age-matched to the normal controls) were assessed to determine whether LD children distribute verbal and nonverbal functions to different hemispheres. Results indicated that although both control and LD children demonstrated an overall REA for word stimuli and an LEA for emotional stimuli, and that emotional stimuli were easier to process than word stimuli, LD children were less accurate in processing both types of stimuli than their control counterparts. 'Complementary specialization,' as assessed through distribution of laterality effects, was found to be greater for control children than for LD children. However, the lack of consistency in complementary specialization found among the three developmental grade levels may be indicative that independent brain mechanisms underlying verbal and emotional processing have yet to be fully established in children. Further, in contrast to adult findings, a larger LEA was obtained for the emotion 'happy' than for the emotion 'sad.' It was concluded that whereas independent hemisphere processing for words and emotions is somewhat prevalent for control children, LD children might not be as strongly lateralized for opposite hemisphere processing of these functions.     

Temporal precision of coding as a basic factor of laterality effects in the retention of verbal auditory stimuli.

It is proposed that the encoding of temporal or sequential information is of crucial importance for the explanation of the laterality effect. Evidence favoring this hypothesis is provided by reanalysing the experiment recently published by Mainka and Hörmann (1971). These investigators instructed Ss in a dichotic listening experiment to attend exclusively to material presented either to the right or the left ear. In the present paper free recall performance for words presented to the right and to the left ear was analysed separately with respect to the correspondence between the sequence of presentation and that of recall. It was found that the sequence of presentation and the sequence of recall correspond to a greater extent in the case of right ear material.It is suggested that the well-known laterality effect can be accounted for by assuming differences in the temporal precision of encoding the items presented to the right and left side. This interpretation is substantiated by a review of the research literature. It was assumed that this different accuracy in encoding the sequential aspects of a series of verbal items should result in a different speed in the retrieval of this series. This expectation was confirmed by the data of the experiment of Mainka and Hörmann. Thus, the encoding of temporal or sequential information is supposed to be effected primarily by the left hemisphere.     

Intelligence in Hong Kong measured for Spearman's g and the visuospatial and verbal primaries

Values for Spearman's g for Hong Kong are calculated from data derived from the administration of Raven's Standard Progressive Matrices to several thousand children. The results indicate that the mean IQ in Hong Kong for the mid 1980s is approximately 108 in relation to a Caucasian mean of 100 for the United States and the United Kingdom. Values for the spatial and perceptual speed primaries are also substantially higher in Hong Kong. On the other hand Hong Kong children are relatively weak on the word fluency primary. The pattern of abilities of Chinese Hong Kong children is broadly similar to that obtained on other Mongoloid populations.     

Discounting in causality and covariation judgements

In two experiments, humans were asked to judge the strength of a moderate contingency between a cue and an outcome in the presence of a second strong contingency between another cue and the outcome. The first experiment replicated the discounting effect whereby a strong contingency causes subjects to reduce or discount judgements of a moderate contingency. This experiment used a video-game procedure in which subjects camouflaged a tank to make it safe from mines. The second causal cue was the presence or absence of a spotter plane. Experiment 1 also ruled out the possibility that judgements might be determined by the number of co-occurrences of the cue and outcome as opposed to the level of contingency. The second experiment used an abstract scenario in which discounting was demonstrated when subjects were asked to judge the relationship between the occurrence of geometric objects. The instructions were neutral to discourage causal hypotheses. These results support the notion that judgements result from associative or connectionist processes and not from a two-step cognitive retrospective process in which an estimate of covariation is calculated between cue and outcome and then in a second step this information is used in a normative manner when a decision is made.     

Dichotic perception and laterality in neonates

Groups of 4-day-old neonates were tested for dichotic discrimination and ear differences with the High-Amplitude-Sucking procedure. In the first experiment, dichotic speech discrimination was attested by comparison with a control group. Furthermore, among those subjects who showed a substantial recovery of sucking response at least after one of the two syllable changes, it was observed that significantly more subjects manifested a stronger reaction to a right-ear change than to a left-ear change. In the second experiment, 4-day-old neonates were tested on syllable and music timbre discrimination. The significant Stimulus Type x Ear interaction observed suggests perceptual asymmetries indicative of very precocious brain specialization.     

Discriminability and central intermittency in same-different judgements

Four sets of paired visual stimuli (OO, XX, XO, or OX) were judged by 48 subjects to be either “same” or “different.” Decision latencies of the same and different judgement were studied as a function of the inter-stimulus interval (ISI). In Experiments I and II, in which stimulus durations were 70 millisec., decision latencies showed marked increases when the ISI was reduced to 100 millisec., but in Experiments III and IV, in which the stimulus durations were only 40 millisec., comparable increases did not occur until the ISI was reduced to 50 millisec. These increases were more marked for “same” than for “different” judgements, although overall decision latencies were generally shorter for “same” judgements. The effects of varying ISIs and stimulus durations are interpreted in terms of masking; they fail to support an hypothesis of central intermittency.     

Differentiating between verbal and spatial encoding using eye-movement recordings

Visual information processing is guided by an active mechanism generating saccadic eye movements to salient stimuli. Here we investigate the specific contribution of saccades to memory encoding of verbal and spatial properties in a serial recall task. In the first experiment, participants moved their eyes freely without specific instruction. We demonstrate the existence of qualitative differences in eye-movement strategies during verbal and spatial memory encoding. While verbal memory encoding was characterized by shifting the gaze to the to-be-encoded stimuli, saccadic activity was suppressed during spatial encoding. In the second experiment, participants were required to suppress saccades by fixating centrally during encoding or to make precise saccades onto the memory items. Active suppression of saccades had no effect on memory performance, but tracking the upcoming stimuli decreased memory performance dramatically in both tasks, indicating a resource bottleneck between display-controlled saccadic control and memory encoding. We conclude that optimized encoding strategies for verbal and spatial features are underlying memory performance in serial recall, but such strategies work on an involuntary level only and do not support memory encoding when they are explicitly required by the task.     

Probabilistic judgements in deluded and non-deluded subjects

An experiment is described in which deluded subjects were compared with a non-deluded psychiatric control group and a normal control group on a probabilistic inference task. Deluded subjects were found to request less information before reaching a decision and to express higher certainty levels than either control group. They also exhibited over-confidence on estimates of the probability of a future event.

Delusion. A false personal belief based on incorrect inference about external reality and firmly sustained in spite of what almost everyone else believes and in spite of what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person's subculture. [American Psychiatric Association, 1980]