Sex and handedness differences in EEG measures of hemispheric specialization

EEG alpha asymmetry was studied in 90 normal adults: right-handed, left-handed, and ambidextrous, male and female. Recordings were made from homologous central, parietal, and occipital leads, referenced to vertex, while subjects engaged in writing, speaking, reading, listening to speech, singing, and block design construction. These data confirm our previous findings that alpha asymmetry is task-dependent and extend them to a broader range of tasks, subjects, and leads. Among right-handers significant differences were found between the language tasks and the musical and spatial tasks: the $\text{R}\text{L}$ alpha ratio is higher in the language tasks. In addition, significant ordering of $\text{R}\text{L}$ alpha ratios was found among the language tasks themselves: WRITE å SPEAK > READ > LISTEN. No one “verbal” task can be considered representative of all language behaviors. Task differences in asymmetry were greater at the central than at the parietal leads, and no differences were found at the occiput. Differences among the handedness groups were found in $\text{R}\text{L}$ alpha ratio in specific tasks, in the relationship among tasks, and in alpha power level. Non-right-handers showed less task-dependent asymmetry. On some measures ambidexters appear to be a distinct group, not simply representing the middle range of a left-handed/right-handed continuum. Reversal of the “expected” right-handed pattern (SPEAK $\text{R}\text{L}$ ratio > BLOCKS $\text{R}\text{L}$ ratio) was seen in 10% of right-handers, and in 36% of left-handers, particularly among left-handed females (46%), suggesting a possible sex difference among non-right-handers. No sex difference was found among right-handers on any task with any measure at any lead.     

Exogenous, endogenous, and dialectical constructivism

Three constructivist paradigms are distinguished. Exogenous constructivism (rooted in a mechanistic metaphor) emphasizes the reconstruction of structures preformed in the environment. Endogenous constructivism (rooted in an organismic metaphor) emphasizes the coordination of previous organismic structures. Dialectical constructivism (rooted in a contextualistic metaphor) emphasizes the construction of new structures out of organism/environment interaction. It is suggested that more general metatheories integrating exogenous, endogenous, and dialectical aspects of the construction of knowledge can and should be formulated. Such formulations would not attempt an impossible synthesis of the root metaphors, but rather integrate them in a coherent metatheory by specifying the boundary conditions in which each root metaphor best applies. An example of such a metatheory, based primarily on Piagetian ideas, is presented.     

A sociolinguistic approach to the belief-similarity model of racial attitudes

This study examined the belief-similarity model of prejudice from a sociolinguistic perspective. It was hypothesized that normatively regulated speech styles strongly affect observers' assumptions about the cultural background of the speaker. These linguistically based cultural assumptions were expected to override racial characteristics in controlling intergroup attitudes. Stimulus speech styles were Black English Vernacular (BEV) and Standard English (SE). Speech style was expected to strongly affect prejudicial attitudes, with such effects mediated by assumed cultural similarity. Racial label and speech style were expected to be most salient to ratings of “intimate” behavior and among more ethnocentric subjects. Subjects heard taped statements in either BEV or SE, ostensibly delivered by a White or a Black speaker. Subjects rated the speaker on perceived cultural similarity, general evaluation, perceived aggressiveness, and social distance. Speech style had a substantial main effect on each of these variables. Racial label had a marginally significant effect on evaluation, and interacted with ethnocentrism for perceived similarity and social distance. All effects of speech, race, and ethnocentrism were substantially attenuated or eliminated when similarity was used as a covariate. Thus, speech style had substantial effects on prejudice, as did race within more ethnocentric subjects. Both effects were largely mediated by assumed cultural similarity.     

Dimensions of adolescent career development: A multi-instrument analysis

Dimensions of adolescent career development were assessed by several well-established, objectively scored instruments. Attention was given to the correlations between measures of academic achievement and career development. Correlations among 19 scales administered to 237 eleventh graders revealed three clusters of converging scale pairs, labeled “Certainty,” “Decision-Making,” and “Activity.” Four orthogonal factors were identified and given the following heuristic labels: “Cognitive Resources for Decision-Making,” “Decision-Making Style,” “Systematic Involvement in Career Decision-Making,” and “Decision-Making Stage/Certainty.” Results are discussed in relation to practical problems of instrument selection and score interpretation and in the context of theories of adolescent career development.     

Impact of adults' appeals for sharing on the development of altruistic dispositions in children

Third- and fourth-grade boys and girls (mean age 7 years, 10 months) were directly instructed to share half their winnings from a bowling game under one of three types of verbal appeal: a power assertive appeal emphasizing punitive consequences for noncompliance, an inductive appeal emphasizing the child's potential contribution to the well being of another person, or a neutral appeal. While they complied with this request, half the children were monitored by television camera; the other half were not. A measure of generalized sharing (noninstructed sharing under anonymous conditions) was then collected. It was predicted that generalized sharing would be greater for children who had heard the inductive appeal than for children who had heard the power assertive appeal and would be greater for children who had shared without television surveillance than for children who had shared under survellance. As predicted, generalized sharing was highest among children who had received the inductive appeal. However, prior surveillance depressed noninstructed sharing only for girls who had received the power assertive appeal. There was one additional and unexpected finding: when children were asked to reinforce themselves for having shared in the instructed sharing phase, boys who had shared in compliance with a power assertive appeal indulged themselves more than children in any other condition.     

Auditory evoked potentials and sex-related differences in brain development

Auditory evoked potentials (AEPs) were obtained to probe tones which were delivered during the presentation of complex verbal and nonverbal auditory stimulation to 3-month-old infants. Significant sex-dependent AEP amplitude asymmetries were found. Females produced higher-amplitude responses from the left hemisphere and males produced higher-amplitude responses from the right hemisphere during both the verbal and nonverbal presentations. No significant AEP asymmetries were obtained in an independent group of infants that received only the probe tones. These findings are consistent with theories and behavioral data suggesting differences between males and females in the development of language and spatial functions.     

Auditory processing and perceptual abilities of “organic” and “functional” stutterers

The present investigation was undertaken to determine whether significant differences in auditory processing and perceptual abilities exist between (1) stutterers as a supposedly homogeneous group when compared with controls, (2) two differentiated subgroups of stutterers, and (3) either of the stuttering subgroups when separately compared with controls. Dichotic listening and masking level difference (MLD) tasks were administered to the two groups of school-age stutterers and an age-matched nonstuttering control group. Stuttering subjects were differentiated into “organic” and “functional” subgroups on the basis of neuropsychological test performances. Organic stutterers performed significantly poorer than did controls on one MLD experimental condition. Functional stutterers performed more like control subjects than like organic stutterers.     

Occupational decision development over the high school years

This study described the development of occupational decision processes over the high school years. Five developmental trends derived from theory were examined separately for males and females in three rural schools. Growth was defined as increased frequency in classes of behavior from early 9th grade to late 12th grade. The key processes in occupational decision development for both sexes appeared to be an information search strategy and an elaborate rationale. Both processes increased in complexity and contributed to confident feelings about occupational choices in 12th grade. Implications for measurement of occupational decision processes and for developmental research are discussed.