Cerebral activation, as measured by subjects' lateral eye movements, is influenced by experimenter location

Cognitive consequences of asymmetrical visual distraction

The authors explored whether manipulating the location of distraction in the participants' visual field influences the degree of competition between visual and other cognitive processes. If a cognitive task is lateralized to a particular hemisphere, visual distraction directed toward that same hemisphere should impair performance on that task more than should visual distraction directed toward the other hemisphere. Consistent with this hypothesis, the authors found in Experiments 1 and 2 that participants better recalled words of high imageability in a verbal memory task when the examiner was in the participant's left visual field (right hemisphere) than when the examiner was in the participant's right visual field (left hemisphere). In Experiment 3, the authors found that this effect reversed for performance on a right-hemisphere spatial task.

Body asymmetry affects conjugate lateral eye movement

A. H. Baker (1989) and A. H. Baker and A. I. Ledner (1990) reported that asymmetrical visual stimulation affects conjugate lateral eye movement (CLEM). In the present article, the authors explored whether asymmetrical body position similarly affects CLEM. The authors assessed CLEMs twice in a counterbalanced design. In the control (symmetric) condition, each participant sat in a completely symmetrical position facing a wall devoid of any asymmetrical features. In the experimental (asymmetrical) condition, half the participants rotated their heads 68 degrees clockwise relative to their bodies to face the experimenter, and the other half rotated their heads 68 degrees counterclockwise, also to face the experimenter. CLEM was predominantly toward the body's position in the asymmetrical condition rather than toward the body's position in the symmetrical condition.

Corroborative evidence for difference in arousability between internal and external scorers on Rotter's I-E Locus of Control Scale

Here we report data about the answers on the Hopkins Symptom Check List for 68 students who participated in an experiment. About random half of the subjects were submitted to sham physiological measurements, the others not. Scores on Rotter's I-E Locus of Control Scale were also available. Analysis indicated that sham physiological measurement treatment is associated with more health complaints and more among external scorers on the Locus of Control Scale. These findings are interpreted as the result of increased arousal by the treatment and higher arousability among external scorers.

Hemisphericity style, sex, and performance on a letter-detection task

Subjects classified by scores on the Preference Questionnaire as preferring either a left- or a right-hemisphericity style were asked to read a one-page passage and to circle each letter t they encountered as they read the passage. There were no statistically significant differences in letter detection between the 58 right- and the 64 left-style scorers. However, contrary to previous findings, the 73 women detected significantly more ts, including unsounded ts, than the 55 men. Our results suggest that hemisphericity style is not an important factor in letter detection.

Bilateral electrodermal activity: reliability, laterality and individual differences

A first aim of the present study was to estimate the short- and long-term stability of individual response patterns in bilateral electrodermal activity (EDA). A second aim was to examine the relationship of individual brain laterality to both peak amplitude and peak time based electrodermal asymmetry. Additionally, subjects were presented with verbal and spatial tasks to estimate the balance of left/right asymmetry in cerebral activation at time of testing. Finally, the influence of smoking, coffee consumption and subjective circadian phase (morningness/eveningness, subjects' rise time) on bilateral asymmetry and EDA lability was examined. Results indicated moderate to high short-term reliabilities of EDA laterality coefficients, but insufficient long-term stability. Handedness and conjugate lateral eye movements (CLEMs) were not related to asymmetry of EDA, but a significant interaction between CLEM tendency and smoking/nonsmoking on laterality of both EDA parameters was observed. Amount of coffee consumption was also significantly related to electrodermal asymmetry. Analysis of performance data demonstrated that intraindividual shifts of EDA laterality from one recording session to a following one were associated with corresponding shifts in accuracy of verbal/spatial performance. Degree of subjects' electrodermal lability differentiated significantly between speed and accuracy of performance in both verbal and spatial tasks, and was substantially related to subjects' rise time.

The dual nature of lateral eye movements

This study investigated the validity of lateral eye movements (LEM) as a measure of the individual differences and task demands aspects of LEM by comparing eye movements to information questions that had no clear hemispheric locus with eye movements to rhyme questions that demanded specific left hemisphere involvement. Fifty subjects were asked to respond to the two types of questions and the initial direction of their eye movement was recorded. The results indicated that LEM are a reliable measure of individual differences because both test-retest and split half reliabilities were high (.78 to .85). LEM were also shown to be responsive to task demands. The number of leftward LEM did not differ from rhyme and information questions, but there were more rightward LEM and fewer stares to the rhyme question. These results suggest that LEM are a reliable individual difference measure and are sensitive to task differences. There is clear evidence that LEM have neuropsychological implications, but every task demands the integrated functioning of the whole brain and these implications should not be overgeneralized.

Sources of between-subjects variability in perceptual asymmetries: a meta-analytic review

A number of studies have reported correlations between subjects' asymmetry scores on left and right hemisphere specialized tasks. In this paper we report the results of meta-analyses performed on these correlations. Results showed positive correlations between subjects' asymmetry scores on left and right hemisphere specialized tasks in both modalities (asymmetry scores were computed as R-L for both left and right hemisphere specialized tasks). Thus, in both modalities, some of the between-subjects variability in asymmetry scores appears to reflect non-stimulus specific individual differences in perceptual asymmetry. For the visual asymmetry tasks, results also showed that the subjects' asymmetry scores on left and right hemisphere specialized tasks were more highly correlated under conditions of bilateral than unilateral input. This finding suggests that bilateral tasks may be more sensitive to "characteristic perceptual asymmetry" than unilateral tasks.

A computerized visual-search task as a measure of cerebral dysfunction and organization

This study examined differences in performance on a visual-search task between dysphonetic dyslexic children and three other groups of youngsters (other dyslexic, brain-damaged, and normals) on measures of cerebral dysfunction and cerebral organization. Subjects were required to match a centrally located design to an identical image, yielding a measure of cerebral dysfunction, i.e., latency. Cerebral organization of the diagnostic groups was studied by measuring the conjugate lateral eye movements of each child. Prior research suggests that initial direction of lateral eye movement on a cognitive task is indicative of lateralized cerebral activation. Analysis indicated that the dysphonetic dyslexics group, as predicted, differed significantly on latency from the normal and brain-damaged groups but not from the other dyslexic group. The dysphonetic dyslexic group differed significantly from all other groups on the measure of cerebral organization.

Are variations among subjects in lateral asymmetry real individual differences or random error in measurement? Putting variability in its place

The current research investigates sources of variability in subjects' asymmetry scores on commonly used laterality tasks. In particular, subjects' asymmetry scores on four bilateral tachistoscopic tasks and one free-vision task were entered into a principal component analysis (PCA) in order to investigate components that explain the maximum variance of the sample. The results indicate that about half of the variation (45.2%) in asymmetry scores on both tachistoscopic and free-vision tasks is attributable to individual differences in characteristic perceptual asymmetry. The amount of variance explained by this characteristic perceptual asymmetry component is similar in a sample of dextrals and a sample of sinistrals. No significant relation was revealed between individual differences in characteristic perceptual asymmetry and performance on various verbal and spatial cognitive tasks.

Hemispheric preference and obesity

This study investigated the relationship of hemispheric preference--the tendency to activate one hemisphere rather than the other--and obesity, on 37 right-handed, male university students. Hemispheric preference was assessed by the directionality of conjugate lateral eye movements, and the degree of obesity was determined by the body mass index (BMI). The results showed that right hemisphere preferent subjects ("left-movers") are less obese than left hemisphere preferents ("right-movers").

Conjugate lateral eye movements: a second look

It has been suggested that conjugate lateral eye movements (CLEM) are related to cerebral lateralization. Two types of research have developed: studies examining individual differences (hemisphericity) and studies examining the type of questions used to elicit eye movements (hemispheric specialization). In a 1978 review, Ehrlichman and Weinberger questioned the notion that CLEM is related to cerebral lateralization, particularly with regard to individual differences. However, since their review, a substantial number of studies have been published which are pertinent to the validity of CLEM. The following paper reviewed the validity of CLEM through three avenues, neurophysiological evidence, relationships with other measures of laterality and relation to spatial and verbal stimuli. Overall, it was concluded that there is sufficient evidence to support the CLEM model. Converging evidence from studies on EEG, electrical stimulation, ablation, brain damage, sodium amytal testing, blood flow, positron emission tomography, dichotic listening, and visual half fields was found to be, for the most part, supportive. The results for verbal and spatial task performance were mixed. Studies examining verbal abilities or a verbal to spatial comparison were generally supportive. The findings for spatial abilities alone were more equivocal. Evidence on question-type was found to be weak but positive, with about half the studies showing the predicted asymmetry and the other half reporting nonsignificant results. The implications of an interaction between hemisphericity or characteristic arousal and hemispheric specialization were also discussed.

Individual differences in cognitive strategy and personality traits as measured by the Sixteen Personality Factor Questionnaire

The relationship between personality and preference for use of the right or left hemisphere of the brain in cognitive processing was investigated. Lateral eye movements were recorded as 50 female and 20 male right-handed subjects considered questions requiring reflection. The questions were not obviously "verbal" or "spatial" in nature but did require differing levels of reflection. Questions requiring higher levels of reflection produced a higher rate of lateral eye movement responses. Percent right eye movement for individual subjects was then correlated with scores on the Sixteen Personality Factor Questionnaire, using both first-order factors and the second-order factor Cortertia, which has some face validity as describing the personality generally ascribed to those who produce mostly right lateral eye movements. No correlation was found between the preferred directions of eye movements and 16 PF factors, which suggests that the lateral eye movements reflect thinking and problem-solving strategies but are not associated with personality styles.

The interaction of hemispheric related strategies and individual differences in learning

The present study examined both the theoretical and practical applications of the Lateral Eye Movements (LEM) in an educational setting. Normal fifth and sixth grade students were tested on their ability to recall and recognize word pairs before and after exposure either to a verbal rehearsal or to an imagery strategy. There was an interaction between the type of strategy taught and the predominant direction of LEM. Right movers showed a significant improvement using a verbal rehearsal strategy but no change using an imagery strategy. Left movers showed a significant improvement with an imagery strategy, but a significant decrease with a verbal rehearsal strategy. These results both verify the validity of LEM as an individual difference variable and provide an initial decision mechanism for choices involving educational strategies.

Lateral eye movements as an indication of hemispheric preference: an EEG validation study

The hemispheric asymmetry model of lateral eye movements (LEM), hypothesizing a relation between a predominance of lateral gazes to one side with a predominance of activity in the hemisphere contralateral to the preferred direction of gaze, was tested in male, right-handed subjects. During presentation of cognitive tasks (verbal synonym tasks and spatial orienting tasks) the decrease in alpha-power from a reference period to each of four activation periods (anticipation, task-presentation, first LEM, answer) for 6 derivations from each hemisphere was calculated using the method of 'Event-related desynchronisation'. Evidence for the hypothesis was found only during the EEG-epoch one second before the answer. Discrimination between subjects with a predominance of left vs right eye movements (left- vs right-movers) was best at temporal (T3, T4) and central (C3, C4) sites. These results were significant for the entire alpha-band (8-12 Hz) and--even more pronounced--for the alpha-2-band (10-12 Hz). The alpha-1-band (8-10 Hz) did not produce significant differences. Comparing the two types of tasks, synonym tasks yielded results which were more congruent with the hypothesis. The results suggest that lateral eye movements indicate individual differences in hemispheric EEG-asymmetries under certain experimental conditions (task, segment of EEG-analysis, site, frequency band).

Perceiver bias in the processing of human faces: neuropsychological mechanisms

Previous research has suggested that in face-to-face contexts perceivers are biased to judge the side of the poser's face to their left as more similar to the full face than the side to their right. Traditional explanations of the perceiver bias have presumed that it is a visual field effect, with the side of the poser's face falling within the perceiver's left visual field dominating impressions of the full face. In this study, five experiments are reported. In the first experiment, the validity of the perceiver bias phenomenon was supported. The remaining experiments examined three alternative accounts of the neuropsychological processes that underlie the perceiver bias. No support was obtained for the visual field explanation, nor for an account of the bias as due to asymmetry in gaze patterns. Support was obtained for an account emphasizing a hemispatial bias in central processing. Despite equivalent intake of information from both sides of space, the brain may differentially weight information as a function of hemispatial origin. Practical and theoretical implications are discussed.

Relationship of lateral eye movements recorded in the dark to verbal and spatial question types

Lateral eye movements (LEMs) were recorded in normal subjects to verbal and spatial questions in the dark using infra-red recording techniques to assess whether clearer LEM-question type relationships are observed when the potentially confounding effects of visual stimulation are absent. Verbal questions elicited more rightward LEMs than spatial questions. However, spatial questions were not associated with leftward LEMs. It is argued that while infra-red recording techniques may be optimal for recording LEMs to verbal questions, the above results question the generalizability of strong LEM-spatial relationships obtained for a single blind subject by GRIFFITHS and WOODMAN [Neuropsychologia 23, 257-262, 1985].

The effects of emotion and ocular dominance on lateral eye movement

Lateral eye movements (LEMs) in response to emotional and nonemotional instructions were examined. For the emotional task, a new procedure is utilized which requires subjects to generate emotional images of positive and negative valence in auditory, visual and tactile modalities. Forty-four normal adult males and females (22 right-handers, 22 left-handers) participated in the experiment. Overall, subjects looked significantly more to the left than to the right in response to emotional instructions, suggesting greater right hemisphere involvement in the generation of emotional images. The same subjects showed no directional bias in response to nonemotional instructions. Although gender, handedness and familial sinistrality did not mediate the direction of eye movements, ocular dominance had an effect. For left-handed subjects, the direction of eye movements to nonemotional instructions was consistent with eyedness, e.g., right-eyed subjects produced right-sided LEMs, and left-eyed subjects produced left-sided LEMs.

Hemisphere asymmetries, spelling ability, and classroom seating in fourth graders

Fourth grade children (N = 159) from eight classes who were free to select their seating location in the classroom were tested for spelling ability. On 100 word spelling lists, the children (males and females) seated on the right side of the classroom (facing the teacher) were superior to children on the left. Analysis of spelling errors for reliance on phonological processing in a subsample (N = 28) revealed that right sitters made more phonetically inaccurate misspellings, whereas, on the left, females, but not males, committed more phonetically accurate misspellings. The results support the view that hemispheric information processing is correlated with classroom seating location or preference, but casual inferences regarding the neuropsychological mechanisms underlying these findings are unwarranted pending clarification of several major theoretical issues.

Visual hemispace differences reflect hemisphere asymmetries

The relationship between the representation of the extracorporeal visual hemispace and the contralateral hemisphere has been investigated by presenting visual stimuli foveally either in the right or in the left hemispace. In a lexical decision task (Exp. 1) and a face-familiarity decision task (Exp. 2) lateral asymmetries very similar to those obtained using the divided visual field technique have been found. These results suggest that under particular circumstances the hemispace representation in the contralateral hemisphere overrides the retinal representation. Finally, it was found that in a lexical decision task performance with stimuli in the right hemispace was very similar to that with stimuli in a central position. The physiological and adaptive meaning of this phenomenon is discussed.

The effects of distance between interactants and subject anxiety on conjugate lateral eye movements

Ehrlichman and Weinberger (1978, Psychological Bulletin 85, 1080-1101) have suggested that the distance between participants during face-to-face interviewing may be a significant determinant of directional patterns of conjugate lateral eye movements (CLEMS). As predicted, at the longer, social distance CLEMS were dependent on the verbal or spatial nature of questions; when interactants were at a closer, personal distance CLEMS became more consistent in direction, regardless of problem type. Distance manipulation also differentially altered CLEM patterns for the two sexes.

Motoric indicators of laterality and determination of lateral dominance in schizophrenia

The literature suggests that schizophrenics exhibit reduced or reversed cerebral lateral dominance relative to normal control subjects. An hypothesis which predicted reduced or reversed cerebral laterality for schizophrenics was tested on 60 young, familially right-handed males, with 20 men in each of the following three groups: schizophrenic inpatients, nonschizophrenic psychiatric inpatient controls, and normal controls. The subjects were administered a battery of seven measures of cerebral laterality. The application of multivariate statistical techniques showed groups did not differ significantly in the degree or the direction of their cerebral lateral dominance. Also there were no significant correlations between the measures of laterality. The findings suggest that cerebral lateral dominance is not necessarily altered concomitantly with psychopathology but rather that it is a complex phenomenon which may not be reliably determined on the basis of simple behavioral characteristics.

Effects of eye movements on the recognition and localization of dichotic stimuli

Three experiments examined the effect of gaze shifts on overall performance and ear differences in dichotic listening. In the first two experiments, lights were switched on and off so as to induce rightward, leftward, or upward gaze during dichotic stimulation. The dichotic material consisted of musical passages in Experiment 1 and two kinds of verbal material in Experiment 2. Vertical eye movements enhanced the accuracy of identification of music but not verbal material. The lateral direction of eye movements affected subjects' ability to localize targets in Experiment 1: localization was more accurate in the direction toward which subjects were looking. In the third experiment it was found that optokinetic nystagmus (OKN) influenced the asymmetry of performance on a dichotic consonant-vowel (CV) test. The right-ear advantage was greatest when the OKN drum rotated from left to right and least when it rotated from right to left. The effect was due to corresponding variation in left-ear scores. Possible mechanisms through which shifts of gaze affect auditory identification and localization are proposed.

Hemisphericity, locus of control, and grade point average among middle and high school boys and girls

The Learning Style Questionnaire and the Children's Nowicki-Strickland I-E Control Scale were given to 128 boys and girls in Grades 8 and 11 in the La Grande (Oregon) School District. Each subject's previous year's grade point average was obtained to determine the relationships among hemisphericity, locus of control, and achievement. Also assessed, including interactions, were differences in hemisphericity, locus of control, and achievement by sex and grade. There was a significant relationship (of low practical value) between locus of control and GPA only. The difference in hemisphericity scores with respect to grade was significant.

Effects of subject-to-experimenter distance and instructions on lateral eye movement

Lateral eye movements and heart rate were recorded as 32 right-handed men answered verbal and spatial questions. Experimenter-to-subject distance (.8 and 1.5 m) and attention demand of instructions were manipulated in a 2 X 2 design. A significant main effect for distance and an interaction of distance by instructions appeared on the direction of eye movements independent of type of question. The greatest number of leftward eye movements occurred at the short distance with instructions demanding higher attention. These findings are consistent with evidence that emotional arousal produces greater right- than left-hemisphere activation.

Conjugate lateral eye movements and cognitive mode: blindness as a control for visually-induced oculomotor effects

The relationship between lateral eye movement directionality and type of cognitive task was investigated in a single blind subject with septo-optic dysplasia. Results from an 80-item test showed that rightward eye movements were significantly associated with verbal tasks and leftward eye movements with spatial tasks. As visual influences on oculomotor behaviour were eliminated, the findings suggested that lateralized eye movements might have arisen as a consequence of asymmetrical activation of cognitive origin triggering the frontal eye field orienting mechanism.

Variations in patterns of lateral asymmetry among dextrals

Evidence supporting individual variations in patterns of hemispheric involvement in the recognition of visuo-spatial and verbal stimuli among dextrals is reported. In Experiment 1, subjects' asymmetry scores on a task that was nonlateralized for the group as a whole were significantly correlated with their asymmetry scores on right-hemisphere-specialized tasks, including face recognition. In Experiment 2, subjects' asymmetry scores on a task that was nonlateralized for the group as a whole were significantly correlated with their asymmetry scores on a left-hemisphere-specialized word recognition task. These results suggest that individual dextrals' asymmetry scores on lateralized tasks are a joint function of a subject's underlying hemispheric specialization for that task and stable individual variations in asymmetric hemispheric reliance.

Some evidence for the hemispheric asymmetry model of lateral eye movements

The relationship between lateral eye-movement patterns and visual spatial abilities was investigated for a sample of 94 right-handed junior high school boys and girls. Direction of gaze was recorded during reflection on a complex gross motor skill. Subjects were administered the Group Embedded Figures Test, the Kohs ' Block Design Test, the Hidden Figures Test, the Hidden Patterns Test, the Closure and Perceptual Speed Tests. Apart from the Group Embedded Figures Test and the Hidden Figures Test, low but significant positive relationships between proportion of left lateral eye-movements and visual spatial test scores were found. If lateral eye-movements are indicators of differential hemispheric activation, people with right-hemisphere predominance are more successful in solving certain visual-perceptual problems than people with left-hemisphere predominance. Finally, it is proposed that in studying relationships between lateral direction of eye-movements and field-dependence/independence, a more fruitful approach would be to investigate how people differ in their problem-solving styles to cope with embedded-figures test material in addition to determination of the performance level.

Effects of predictors of hemispheric specialization on individual differences in hemispheric activation

In two studies predictors of variation in hemispheric specialization--handedness, sex, familial history of sinistrality, writing posture and sighting dominance--were found not to be independent of individual differences in characteristic activation asymmetry. Predominant direction of conjugate lateral eye movements was used to assess activation asymmetry. The lack of independence between these two dimensions of individual difference, predictors of variation in hemispheric specialization and in activation asymmetry, suggests caution in interpreting the results of studies in which one dimension is examined and the other is uncontrolled.

Hemispheric routing of tactilely delivered words for dyslexic males

This investigation sought to determine the effect of delivering unknown spelling words via a tactile modality to the left and right cerebral hemispheres of 10 dyslexic boys of about 14 yr. of age whose vision was occluded during word palpation. More words were learned through either condition of right- and left-hand delivery than control words. Spelling meaningful words when vision is occluded can be accomplished by either hand delivery for older dyslexic boys.

Lateral eye movement as a measure of cognitive ability and style

Research on lateral eye movements has examined personality and cognitive correlates with the hope of establishing such eye movements as a measure of preference for the different modes of information-processing associated with each of the cerebral hemispheres. Unfortunately, a review of this research provides only conflicting, tenuous substantiation for such hypotheses. The present study attempts to resolve the conflict within previous research by investigating the validity of the measure across a variety of tests of cognitive ability and preference, utilizing several procedures for scoring and classifying subjects on the measure. However, evidence for this measure's ability to predict cognitive performance linked to hemispheric specialization--in any of our conditions--was extremely meager. The usefulness of lateral eye movements as a diagnostic tool must be considered highly suspect; despite this fact, the measure may yet prove to be of some theoretical significance.

A cognitive-motor network demonstrated by positron emission tomography

The rate of local cerebral glucose metabolism was measured in subjects receiving a verbal (n = 4) and a spatial (n = 4) task. The verbal task produced greater metabolism in Wernicke's area relative to the right hemispheric homotopic region, whereas the spatial task produced greater metabolic activity in the right hemispheric homotopic region. Broca's area and its right hemisphere counterpart showed symmetrical activity during the verbal task, but there was a significant asymmetry to the right during the spatial task. Lateralized task effects were also obtained in the frontal eye fields, supporting a hypothesized neural network linking cognitive activity with motor orientation.

Emotional stimulation, defensive orientation, and hemispheric activation

Lateral eye movements (LEM) were measured for 32 right-handed subjects while responding to questions rated for verbal and visual-spatial cognitive content and for varying levels of emotionally stimulating content. The results indicated that eye movements were distributed to the right and left in response to verbal and spatial items, respectively, and that emotional content enhanced leftward responding. In addition, the defensive style of subjects, as measured by a defense mechanism inventory, interacted with the cognitive and affective dimensions of questions and was a determinant of LEM.

Lateral eye movements to verbal and spatial questions as a function of questioner location

Fifty right-handed females thought about answer to verbal and spatial reasoning questions asked by a questioner seated either in front of or behind them. Ss in the questioner-in-front condition predominantly exhibited left lateral eye movements regardless of the question type, while the lateral eye movements of the questioner-in back Ss showed no directional trend in response to either question type. S's self-reported anxiety was not associated with lateral eye movements in either questioner-location condition.

Functional asymmetry in the chimpanzee

Consistency of conjugate lateral eye movements is demonstrated by one 5-yr.-old chimpanzee, Jane, but not by Fanny a chimpanzee of approximately 4 ½ yr. Jane displayed right-sided eye movements on both language problems, including those considered to be spatial, and also during play periods. Some implications of this research are discussed.

Affective behavior in patients with localized cortical excisions: role of lesion site and side

The perception of emotion in verbal and facial expression, and the spontaneous production of conversational speech were studied in patients with unilateral focal excisions of frontal, temporal, or parieto-occipital cortex. Lesions of the left hemisphere impaired the matching of verbal descriptions to appropriate verbal categories of emotional states, whereas with lesions of the right hemisphere, the matching of different faces displaying similar emotional states was impaired. The effects of lesions of both left and right hemisphere occurred regardless of the locus of the lesion. On the other hand, frontal-lobe lesions had differential effects upon unsolicited talking; lesions of the left frontal lobe virtually abolished this behavior, whereas lesions of the right frontal lobe produced excessive talking. These data suggest that the nature of the behavioral stimulus as well as the locus and side of damage must be considered in the study of the neural basis of affective behavior.

Lateral eye movements as indicators of processing strategies in paired-associate learning: their effect on recall, recognition, and error type

Subjects, classified as left- or right-movers on the basis of their lateral eye movements, were presented with paired-associates designed to elicit processing by either the left hemisphere (low-imagery synonyms) or the right hemisphere (high-imagery rhymes), followed by both recall and recognition tests. While recall of high-imagery pairs exceeded that of low-imagery pairs, there were no differences in recognition between the two types of paired-associates. There were no differences in retention between left- and right-movers, suggesting that if these groups differ in cognitive style, such differences may not be reflected in measures of information retention. The types of errors the groups made appeared to be influenced more by differences in information processing strategies.

The interaction of hemispheric preference, laterality, and sex in the perception of emotional tone and verbal content

Twenty male and 20 female subjects, divided into those who showed a right or left hemispheric preference, listened to auditory messages with conflicting verbal content and emotional tone. The messages were presented to each ear to determine whether the effect of hemisphere of input on the evaluation of the messages was modified by hemispheric preference. Except for left preference males, subjects responded on the basis of preference rather than laterality.

Differential hemispheric activation in good and poor readers

good and poor readers were found to differ on a cognitive style variable based on the differential use of one hemisphere over the other. While 20 good readers were equally divided (9 to 11) between right and left hemisphere activators, 17 of the 20 poor readers were right activators. The finding of no difference between the groups on a lateralized discriminative reaction time task when integrated with previous research led to the conclusion that some types of dyslexia result from a deficit in visual to auditory recoding.