Sex differences in mental abilities, hemispheric lateralization, and rate of physical growth at adolescence.

Tested the hypothesis that sex differences in verbal and spatial abilities are related to sex differences in rates of physical maturation and that this relationship is mediated by variation in the organization of higher cortical functions. 40 males and 40 females, ranging in age from 10-16 yrs, were tested on 3 verbal measures (including the Digit Symbol subtest of the WISC and the Word Fluency subtest of the Primary Mental Abilities Test), 3 spatial measures (including the Block Design subtest of the WISC and a modified version of the Embedded Figures Test), and a dichotic test of phoneme identification. Late-maturing Ss of both sexes performed better than early maturers on tests of spatial ability, but the groups did not differ on tests of verbal ability. Among older Ss, the late maturers of both sexes showed greater hemispheric lateralization than early maturers. Sex differences on the ability measures, although in the predicted direction, did not reach significance. Results are discussed with respect to the relationship between hemispheric organization of function and mental abilities and the relationship between maturational rate and lateralization. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dichotic listening performance, cognitive ability, and cerebral organization.

Explored linkages between dichotic listening performance, cognitive ability, and cerebral organization, addressing 3 main questions: (1) the relationship of sex, handedness, and familial sinistrality to auditory laterality and to selected aspects of cognitive performance; (2) the relationship between laterality and cognitive ability; and (3) the relationship between verbal and musical laterality. Two dichotic listening tests (one involving recognition of stop consonant-vowel syllables and the other, recognition of melodic patterns) were administered to 120 college students balanced for handedness, sex, and familial sinistrality. Ss also underwent psychometric tests. Results indicate an independence of verbal and nonverbal laterality effects and support a componential (modular) theory of brain organization rather than one of complementarity. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cerebral laterality in deaf and hearing children.

Studied the development of lateralization of cerebral function in 20 hearing and 20 prelingually deaf children using the concurrent task paradigm. Ss were aged 5–6 and 11–12 yrs; all were right-handed. Concurrent processing of a nonverbal task did not cause a selective hand impairment monitored by a manual tapping task. However, deaf Ss were more impaired than hearing Ss in both age groups. Using a concurrent verbal task, both groups manifested a selective impairment of right-hand performance. The deaf also showed a greater left-hand decrement than did the hearing Ss. This result suggests that hemispheric specialization may be less apparent in the deaf than in hearing children. The factor of cognitive task difficulty is suggested as an explanation of these results. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amount of verbal information and ear-differences in 5- and 6-year old boys and girls

Tow experiments were performed. The first was to determine the effects of varying the amount of information in verbal instructions presented monaurally on differences between ears and sex in 5-yr.-old boys and girls. Verbal instructions were given for the performance of a visual-motor task. The results indicated that the amount of verbal information affects ear-asymmetry in girls and not boys. The second experiment was performed to determine the effects of varying the amount of verbal information in verbal instructions presented monaurally on differences between ears, sexes, and reading ability of 6-yr.-old boys and girls. The findings indicated that above average readers performed better than below average readers. Ear-asymmetry was observed across sex and reading abilities for sentences containing 7 and 8 stimulus attributes. No ear-asymmetry was observed in sentences containg 9 stimulus attributes. The results appear to support the progressive lateralization hypothesis which states that ear-asymmetry is dependent on task conditions. The results also support sex differences in the development of brain lateralization.     

Cognitive abilities and hemispheric lateralization in females following idiopathic precocious puberty.

Compared 12 right-handed adolescent females with a history of idiopathic precocious puberty (IPP) to 12 closely pair-matched normal controls of similar maturational status. All Ss were aged 13–20 yrs. Cognitive abilities were assessed by subtests of the WISC and Primary Mental Abilities Test, and by combination scales derived from these subtests. Brain hemispheric lateralization was measured by 2 dichotic listening tests. Results show that IPP Ss and controls did not differ in verbal abilities or in dichotic consonant–vowel discrimination. IPP was associated with lower spatial ability. It is concluded that pubertal maturation is associated with spatial but not verbal ability. Left-hemisphere functioning does not seem to constitute a mediating mechanism for this association but a slight weakness of right-hemisphere functioning is suggested by poor left-ear performance on the staggered spondaic word test. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ontogeny of cerebral dominance: Evidence from time-sharing asymmetry in children.

Used a dual-task procedure as a measure of speech lateralization in 151 normal, right-handed, 3–12 yr old children. Ss engaged in unimanual finger tapping with and without concurrent speech. It was hypothesized that if speech is left lateralized, talking should disrupt right-hand tapping (an instance of intrahemispheric interference) more than left-hand tapping (an instance of interhemispheric interference). Results for 2 different verbal tasks show the predicted overall asymmetry but no developmental trend in degree of asymmetry. The data suggest that lateralization is as marked in young children as in older children. About 70% of the Ss showed the predicted effect; there was no significant change in incidence as a function of grade level. Analyses of verbal production indicated that the performance asymmetry could not be attributed to an asymmetrical trade-off between talking and tapping. No sex differences in performance asymmetry were found. The results contradict the traditional model of progressive lateralization but corroborate the developmental invariance frequently observed using perceptual measures of language lateralization. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of directed attention on cerebral asymmetries in normal and learning-disabled children.

Using a dichotic listening task employing both undirected and directed attention conditions, cerebral asymmetries were examined in matched populations of 32 normal and 32 learning-disabled (LD) children (ages 7 yrs 6 mo–13 yrs 2 mo). The analysis of recall performance indicated that development was not a significant factor in either group; both the normal and LD Ss showed a right-ear effect, although the LD Ss performed at a degraded level and were unable to demonstrate a right-ear advantage (REA) when attention was directed to the left ear, unlike normal Ss, who produced the REA despite the directed attention conditions. Results suggest that LD children probably do not suffer from developmental delays but rather from a defect in callosal functioning that interferes with their ability to process verbal information simultaneously. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduced lateralization in verbal dichotic listening in adolescent psychopaths.

One possible explanation for previous findings of abnormal linguistic processing in psychopaths is that they are less lateralized for verbal processes. This study tests the hypothesis that adolescent psychopaths show evidence of reduced lateralization on a verbal dichotic listening task. Four self-report and behavioral measures of psychopathy were used to define psychopathy using cluster analytic techniques in 40 juvenile offenders aged 13 to 18 years. Psychopaths were found to have reduced ear asymmetries relative to nonpsychopaths, a result indicating reduced lateralization for verbal material. The effect does not appear to be mediated by group differences in age, ethnic background, IQ, overall performance, left-handedness, selective attention to one ear, or interhemispheric transfer deficits. This result suggests that the previous finding by R. D. Hare and L. M. McPherson (see record 1984-23362-001) is robust, provides some preliminary validity for the assessment of psychopathy before age 18, and indicates initial support for the utility of cluster analytic techniques in the assessment of psychopathy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognition and the corpus callosum: Verbal fluency, visuospatial ability, and language lateralization related to midsagittal surface areas of callosal subregions.

28 female, normal volunteers (aged 20–45 yrs) completed tests of visuospatial ability, verbal fluency, and language lateralization, and the midsagittal surface areas of the splenium, isthmus, midregion, and genu of the corpus callosum were measured from inversion recovery magnetic resonance images. Multivariate statistics were used to analyze patterns of correlations. Verbal fluency correlated positively with the area of the splenium and with the area of a posterior callosal factor defined largely by the splenium. The posterior callosum, particularly the splenium, also correlated negatively with language lateralization. There were no other consistent brain–behavior relationships. These results are relevant to understanding factors involved in the development of cognitive characteristics that show sex differences and to understanding the neural basis of language lateralization and verbal abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in perceptual asymmetries with clinical improvement of depression and schizophrenia.

16 depressed patients, 16 schizophrenic patients, and 16 normal controls (20–50 yrs old) were given 2 dichotic listening tests and 2 cognitive tests at intervals ranging from patients' initial hospitalization to recovery. Repeated-measures ANOVA revealed that severely depressed Ss failed to obtain normal ear-superiority in either dichotic test; however, normal superiorities emerged with recovery from depression. Schizophrenic Ss initially failed to show normal right-ear superiority on a dichotic-words test but did obtain the expected left-ear advantage on a dichotic-chords test. Following treatment, schizophrenics shifted from a left-ear to a right-ear advantage in dichotic chords and also increased (although not significantly) their right-ear advantage in dichotic words. Both patient groups showed normal word-fluency but impaired spatial ability, which did not improve with recovery. Results suggest that both depression and schizophrenia are associated with a breakdown in the process of interhemispheric inhibition that mediates perceptual asymmetry. In depression, treatment returned Ss' normal patterns of asymmetry, whereas in schizophrenia, treatment created an abnormal pattern of asymmetry that may have reflected the allocation of both verbal and nonverbal material to the left hemisphere. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the cognitive benefits of teaching.

In Exp I with 42 undergraduates, one group of Ss studied verbal material to learn it themselves while another group studied the material to teach it to another person. Ss preparing to teach scored reliably higher than controls on a subsequent retention test. Exp II assessed the effects of actual teacher–student interaction. For both a verbal and a problem-solving task, 121 undergraduates either worked alone, verbalized their thoughts aloud, or taught another person the task while performing. There were no reliable performance differences between conditions on either task. It is concluded that cognitive benefits of teaching do exist and result from the teacher's utilization of a different method of study. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification of emotion in a dichotic listening task: event-related brain potential and behavioral findings

The lateralization of emotion perception has been examined using stimuli in both auditory and visual modalities. Studies using dichotic stimuli have generally supported the hypothesis of right-hemisphere dominance for emotion perception, whereas studies of facial and verbal emotion perception have provided evidence for the right-hemisphere and valence hypotheses. A dichotic target detection task was developed to enable acquisition of event-related potentials (ERP) from subjects engaged in emotion detection. Nonsense syllables (e.g., ba, pa) stated in seven different emotional intonations were dichotically presented to 24 young adults, in a target detection task during four separate blocks (target emotions: happiness, interest, anger, or sadness). Accuracy and reaction time and ERP measures were also collected. ERPs were recorded from 14 scalp electrodes with a nose reference and quantified for N100, sustained negativity, late positivity, and slow wave. Significantly greater left- than right-ear accuracy was obtained for the identification of target prosodic emotion. Hemispheric asymmetries of N100 and sustained negativity were found, with left-hemisphere amplitudes greater than right-hemisphere amplitudes. These ERP asymmetries were not significantly correlated with the left-ear dichotic advantage and may be related more to early phonetic processing than to emotion perception. Since the behavioral evidence supports the right-hemisphere hypothesis for emotion perception, behavioral and ERP asymmetries evident in this task reflect separable patterns of brain lateralization.     

Sex differences in achievement: A test of alternate theories.

200 students in Grades 8–10 were given the following attitudinal measures regarding both math and English: self-concept of ability, subjective task value, perceived task difficulty, and continuing motivation. In a follow-up, Ss" math course enrollment decisions were assessed each year through high school. 142 of the Ss also were exposed to 2 sets of trials: a number sequence set and an anagram set. Outcome was manipulated across trials (success, failure, success). For each series, Ss provided estimates of their ability, their expectations for continued success, and causal attributions. Their response time, persistence, and accuracy were recorded. Finally, teacher estimates of learned helplessness were obtained in Year 1 of the study for all Ss. Subjective task value emerged as the strongest mediator of sex differences in achievement-related behaviors and plans. There was little support for learned-helplessness models of sex differences in achievement. There was some evidence of sex differences in ability attributions, but these differences occurred only among low-expectancy Ss. Verbal and behavioral indexes of achievement beliefs were often inconsistent. Implications for general attribution theory and for sex-difference theory are discussed. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental instability and cerebral lateralization

On the basis of prior studies of handedness, it was predicted that variations from modal asymmetry scores on cognitive tasks, in either direction from the mean, would be associated with an elevated incidence of classic markers of developmental instability (minor physical anomalies and fluctuating anatomic asymmetries). University students (N = 146) were administered 4 tasks that typically reveal functional asymmetries: the fused rhymed words dichotic listening task, the line bisection task, the chimeric faces task, and the cartoon faces task. A composite measure of developmental instability was computed from minor physical anomalies and fluctuating asymmetries. Participants with greater evidence of developmental instability had more atypical lateralization scores, deviating more from the sample mean, in either direction. Directional asymmetries were unrelated to developmental instability. These results suggest that developmental instability influences variation in the lateralization of cognitive skills as well as handedness.     

Cognitive style effects on sex status in student work groups.

Studied the mediating effect of field independence on sex difference in activity and influence in 27 task groups, each composed of 2 male and 2 female 9th-11th graders. All Ss were administered the Group Embedded Figures Test, portable rod-and-frame test, and Extended Range Vocabulary Test, Form B-3. Ss, matched for verbal ability and field independence within groups, were videotaped discussing a decision-making task. Videotapes were coded for individual verbal activity and influence. A hierarchical analysis of variance design was used, with the effects of cognitive style group, sex, and replication assessed in order. Results indicate Sex * Cognitive Style interaction effects, with males more active and influential than females in field-dependent groups, males more active but not more influential than females in middle-range groups, and males and females equally active and influential in field-independent groups. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of controlled background interference on test performance by right and left hemiplegics.

Studied the general and lateralized effects of background interference on verbal and perceptual/motor functioning as a function of presence and lateralization of brain damage. 30 non-brain-damaged control patients and 30 right and 30 left hemiplegics (all Ss 53–72 yrs old) were given a word-naming task and the Bender Gestalt Test under noninterference and background interference conditions. As hypothesized, (a) brain-damaged Ss had significantly greater overall interference effects than controls; and (b) laterality effects were significant; verbal interference was greatest in the left-hemisphere-damaged group, and perceptual interference was greatest in the right-hemisphere-damaged group. Implications for treatment programs with such patients are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulating transitions in moral reasoning as a function of stage of cognitive development.

Examined L. Kohlberg's proposition that cognitive development is necessary though not sufficient for moral development. The specific hypothesis tested, in a pre–posttest control group design involving 44 female adolescents (mean age 16.2 yrs), was that Moral Stage 3 Ss who have attained "early basic formal operations" are more susceptible to attempts to stimulate moral development than Stage 3 Ss who have attained only "beginning formal operations" and lack the cognitive prerequisites for moral transitions. A series of pretests (verbal reasoning and logico-physical problems, and Moral Judgment Interview) was used to obtain Ss who met the appropriate cognitive and moral criteria. The treatment exposed Ss to Stage 4 reasoning in individual role-playing situations. A moral judgment posttest followed 1 wk later. Results confirm the hypothesis, thus providing evidence for the proposition that cognitive development is necessary for moral reasoning development. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of fear arousal upon task performance and verbal behavior.

80 undergraduate females were classified as being either high or low in fear of speaking in front of a group. ? were told that they were to speak following a task; the remaining Ss did the task without expecting to speak. All Ss spoke about the task for 1 min. immediately following the task. Experimental Ss took significantly longer to perform the task, and naive judges were able to detect differences in the verbal productions of the groups. Formal aspects of S's verbal productions also discriminated among high- and low-fear Ss. Implications for theory and importance of assessing different types of behavior are briefly discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive interference and learned helplessness: The effects of off-task cognitions on performance following unsolvable problems.

Assessed the effects of individuals' proneness to cognitive interference on performance following failure. Ss responded to a questionnaire tapping proneness to cognitive interference and were exposed to either no feedback or failure. On completing these problems, Ss performed a cognitive task in which the memory load was varied systematically. The cognitive interference theory successfully predicted most of the group differences: (a) Only the performance of Ss with a habitual tendency to engage in off-task cognitions was debilitated by failure; (b) this performance impairment was only observed in performance accuracy in the high memory load version of the task; and (c) performance accuracy was associated with the frequency of off-task cognitions in the experiment. Results were discussed in terms of the cognitive interference interpretation of learned helplessness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)