Cerebral lateralization of function and bilingual decision processes: Is thinking lateralized?

Four experiments utilizing tachistoscopic presentation of verbal and spatial stimuli to visual half-fields are presented. Three experiments failed to find any cerebral lateralization effect of the type predicted from existing models of cerebral lateralization processes. One experiment found marked lateralization effects. Since the experiments differ only in the ratio of trials to experimental stimuli, it is argued that cerebral lateralization experiments are detecting only a memory process occurring after subjects have learned all the stimuli to be presented. When new stimuli are presented on each trial, no cerebral lateralization effects are found, suggesting that active ongoing cognitive processing is independent of lateralization.     

Attention to eye contact opportunity and facial motion by three-month-old infants

Thirty-two 3-month-old infants participated in two experiments showing color videotapes of facial stimuli in a paired comparison format. In Experiment 1, the experimenter, serving as the stimulus, looked either directly at the infant or averted his gaze to the side; the face was presented either still or in motion. Eye contact opportunity had no effect while motion of the head was an effective attractor of visual fixation. In Experiment 2, the amount of available eye contact opportunity was parametrically varied by occluding the eyes with different patterns of blinking, each at the same rate. The no-motion 100% eye contact available condition received less attention than the three blinking stimuli, which were all equally attended to, though they varied with respect to the amount of eye contact opportunity they afforded. The contrast in effect of eye contact availability and rather subtle stimulus motion would imply that 3-month-old infants are comparatively insensitive to being the object of another's visual regard.     

Career satisfaction and role harmony in a sample of young women physicians

In a sample of young women physicians, self-ratings of Career Satisfaction and Role Harmony were correlated with a group of situational, achievement, and personality variables. Career Satisfaction was extremely high with about 88% reporting they are satisfied or very satisfied. However, over half experienced at least a moderate amount of strain in integrating professional and sex roles. In addition women who were high on both Career Satisfaction and Role Harmony were compared with the others in the sample and individual differences were apparent: These women were exceptionally confident, intellectually resourceful, and tolerant; they tended to have clear priorities with either family or work coming first. Overall their current level of personality adjustment was superior to the others who, as a group, were very well-functioning women.     

Writers and critics: Two types of vocational consciousness in the art system

Vocational interests, personality, work environment, and background of authors and critics, male and female, in children's literature are examined in terms of Holland's theory of vocational types, supplemented with concepts of an art system and styles of consciousness. On SVIB indicator scales, both authors and critics score as artistic types with “consistent” profiles, but authors are more “differentiated.” Critics have stronger social interests and less aversion to conventional activities, appropriate to their position as gate-keepers in the art system. In work style there are again common features, but authors describe themselves as having “alternative” states of consciousness, where critics emphasize their social roles and rationality. Both groups have peaks on Achievement via Independence (CPI), but the critics are more socially ascendant, efficient, and conventional. Most critics have full-time employment under institutional auspices; most writers do not. Difference in occupations of fathers of authors and critics are consistent with interest patterns of the subjects. Several personality and background findings, including interactions between sex and field, are interpreted as supporting the usefulness of supplementing Holland's theory.     

The development of basic mechanisms of pattern vision: spatial frequency channels

The mature visual system possesses mechanisms that analyze visual inputs into bands of spatial frequency. This analysis appears to be important to several visual capabilities. We have investigated the development of these spatial-frequency channels in young infants. Experiment 1 used a masking paradigm to test 6-week-olds, 12-week-olds, and adults. The detectability of sine wave gratings of different spatial frequencies was measured in the presence and the absence of a narrowband noise masker. The 12-week data showed that at least two spatial-frequency channels with adultlike specificity are present at 12 weeks. The 6-week data did not reveal the presence of narrowband spatial-frequency channels. Experiment 2 used a different paradigm to investigate the same issue. The detectability of gratings composed of two sine wave components was measured in 6-week-olds and adults. The results were entirely consistent with those of experiment 1. The 12-week and adult data indicated the presence of narrowband spatial-frequency channels. The 6-week data did not. The results of these experiments suggest that the manner in which pattern information is processed changes fundamentally between 6 and 12 weeks of age.     

Structures and strictures: Some functional limitations on the course of cognitive growth

A functional (as opposed to structural) theory of intellectual development is presented, and used to generate specific performance models for Piagetian tasks involving the control of variables. On the basis of these models, it is concluded that intelligent, field independent 7- and 8-year-olds should be able to acquire the control of variables scheme, even though they have not yet acquired either conservation of weight or the combinatorial system. Preliminary data (n = 52) are presented to support this conclusion. They are discussed with regard to Piaget's formal theory of intellectual development, and the functional limitations of development on learning.     

A house divided? Cognitive functioning with callosal agenesis

An anatomical and behavioral review of 29 reported cases of corpus callosum agenesis is presented. This review addresses itself to two questions: (1) Do acallosals manifest split-brain symptoms? (2) Is the corpus callosum necessary for the establishment of lateralization? Unlike the commissurotomy cases, acallosals show few symptoms of hemispheric disconnection. Behavioral strategies, use of noncallosal commissures, elaboration of ipsilateral pathways, and bilateral representation of function are discussed and evaluated as possible mechanisms of compensation. An impairment in spatiomotor functioning often accompanies callosal agenesis. Results of acallosal lateralization testing are examined and problems in interpretation are discussed. Current evidence does not conclusively establish that the corpus callosum is needed for lateralized development of some functions. However, the corpus callosum may play a role in the satisfactory performance of “lateralized” (i.e., spatial, linguistic) functions.     

Critical flicker frequency and intelligence

Tests of verbal intelligence (Concept Mastery Test) and nonverbal intelligence (Raven's Advanced Progressive Matrices) showed nonsignificant zero-order correlations and a nonsignificant multiple correlation with critical flicker frequency (CFF), in 100 university students. Age-partialled correlations were even lower, and corrections for attenuation and restriction of range yielded unimpressive results. It was concluded that CFF has a negligible relationship to psychometric intelligence and is probably a poor tool in the investigation of the nature of g.     

The roles of stimulus repetition and hemispheric activation in visual half-field asymmetries

Hardyck, Tzeng, and Wang (1978, Brain and Language, 5, 56–71) hypothesized that ample repetition of a small number of stimuli is required in order to obtain VHF differences in tachistoscopic tasks. Four experiments, with varied levels of repetition, were conducted to test this hypothesis. Three experiments utilized the general task of object-picture naming and one utilized a word-naming task. Naming latencies constituted the dependent measure. The results demonstrate that for the object-naming paradigm repetition is required for RVF superiority to emerge. Repetition was found to be unnecessary for RVF superiority in the word-naming paradigm, with repetition actually reducing RVF superiority. Experiment I suggested the possibility that RVF superiority developed for the second half of the trials as a function of practice or hemispheric activation, regardless of repetition level. Subsequent experiments, better designed to assess this possibility, clearly refuted it. It was concluded that the effect of repetition depends on the processing requirements of the task. We propose that, for tasks which can be processed efficiently by one hemisphere, the effect of repetition will be to reduce VHF asymmetries; but tasks requiring substantial processing by both hemispheres will show shifts to RVF superiority as a function of repetition.     

Family resemblances: Studies in the internal structure of categories

Six experiments explored the hypothesis that the members of categories which are considered most prototypical are those with most attributes in common with other members of the category and least attributes in common with other categories. In probabilistic terms, the hypothesis is that prototypicality is a function of the total cue validity of the attributes of items. In Experiments 1 and 3, subjects listed attributes for members of semantic categories which had been previously rated for degree of prototypicality. High positive correlations were obtained between those ratings and the extent of distribution of an item's attributes among the other items of the category. In Experiments 2 and 4, subjects listed superordinates of category members and listed attributes of members of contrasting categories. Negative correlations were obtained between prototypicality and superordinates other than the category in question and between prototypicality and an item's possession of attributes possessed by members of contrasting categories. Experiments 5 and 6 used artificial categories and showed that family resemblance within categories and lack of overlap of elements with contrasting categories were correlated with ease of learning, reaction time in identifying an item after learning, and rating of prototypicality of an item. It is argued that family resemblance offers an alternative to criterial features in defining categories.     

An examination of culture bias in the wonderlic personnel test

Internal evidence of cultural bias, in terms of various types of item analysis, was sought in the Wonderlic Personnel Test results in large, representative samples of Whites and Blacks totaling some 1,500 subjects. Essentially, the lack of any appreciable Race × Items interaction and the high interracial similarity in rank order of item difficulties lead to the conclusion that the Wonderlic shows very little evidence of cultural bias with respect to the present samples which, however, differ appreciably in mean scores. The items which account for the most variance within each racial group are, by and large, the same items that show the largest interracial discrimination.     

Basic objects in natural categories

Categorizations which humans make of the concrete world are not arbitrary but highly determined. In taxonomies of concrete objects, there is one level of abstraction at which the most basic category cuts are made. Basic categories are those which carry the most information, possess the highest category cue validity, and are, thus, the most differentiated from one another. The four experiments of Part I define basic objects by demonstrating that in taxonomies of common concrete nouns in English based on class inclusion, basic objects are the most inclusive categories whose members: (a) possess significant numbers of attributes in common, (b) have motor programs which are similar to one another, (c) have similar shapes, and (d) can be identified from averaged shapes of members of the class. The eight experiments of Part II explore implications of the structure of categories. Basic objects are shown to be the most inclusive categories for which a concrete image of the category as a whole can be formed, to be the first categorizations made during perception of the environment, to be the earliest categories sorted and earliest named by children, and to be the categories most codable, most coded, and most necessary in language.     

What makes triangles point: Local and global effects in configurations of ambiguous triangles

Perceived pointing of ambiguous triangles was investigated in three experiments. The results show that the probability of seeing an equilateral triangle point in a given direction is strongly influenced by (a) the direction of the ambiguous alternatives, (b) the orientational characteristics of the configuration of elements surrounding the triangle, and (c) the shape of the surrounding elements. These findings are interpreted as supporting the hypothesis that perceived pointing is determined by perceptual reference frames induced at multiple levels of globality: one for the general visual field, one for the entire configuration, and one for the local elements of the configuration.     

Evoked potential and visual half-field evidence for task-dependent cerebral asymmetries in congenitally deaf adults

Evoked potentials to laterally presented stimuli were collected from left and right tempero-parietal sites during performance of two visual half-field tasks, lexical decision, and line orientation discrimination. Reaction time and accuracy data were simultaneously collected. The behavioral data indicated the development of a right field advantage for the lexical decision task as a function of practice. A principal components analysis revealed three independent evoked potential components which displayed task-dependent hemispheric asymmetries. Multiple regression analyses revealed that visual half-field asymmetries in response accuracy were closely related to hemispheric asymmetries on several independent evoked response components. Subject's scores on independent tests of verbal reasoning and spatial relations were also found to be closely related to hemispheric asymmetry on several independent evoked response components. These data support a multidimensional concept of cerebral specialization. They also suggest that visual field asymmetries reflect the confluence of several underlying processes which have independent lateralization distributions across the population. In general, the results underscore the need for further research on the nature of the relationship between cerebral and perceptual asymmetries.     

Cognitive reference points

Two methods were used to test the hypothesis that natural categories (such as colors, line orientations, and numbers) have reference point stimuli (such as focal colors, vertical and horizontal lines, and numbers that are multiples of 10) in relation to which other stimuli of the category are judged. In Experiment I, subjects placed pairs of stimuli into sentence frames consisting of linguistic “hedges” such as “— is essentially—.” Results were that the supposed reference stimuli were most often placed in the second (reference) slot. In Experiment II, the subject placed a stimulus in physical space to represent his feeling of the psychological distance of that stimulus from another spatially fixed stimulus. Results showed that, when supposed reference stimuli were fixed, other stimuli were placed closer to them than vice versa. The results have substantive implications for the understanding of internal structure of categories and methodological implications for the mapping of reference points, quantification of linguistic intuitions, and the assumption of symmetry in psychological distance judgments.     

The development of elaborative propensity in adolescence

A series of three experiments was conducted to verify the hypothesis that age differences in paired-associate learning proficiency across adolescence stem from the development of increasing elaborative propensity. An auxiliary aim was to determine whether previous study-to-study discrepancies in the pertinent age functions should be attributed to corresponding variations in learning materials or in characteristics of the populations sampled. Taken together, the results of the experiments provided support for the hypothesis. They also indicated, however, that students in late adolescence vary markedly in elaborative propensity, to the point that a substantial proportion of them are hardly distinguishable from preadolescents.     

Event knowledge,elaborative propensity,and the development of learning proficiency

An experimental test was made of two hypotheses formulated to account for age differences across adolescence in the learning of arbitrary associations. One hypothesis ascribes such differences to two factors: the propensity to elaborate coherent relationships among initially disparate items, and accessibility to event knowledge that can form the bases of such relationships. The other hypothesis assumes that propensity remains constant across age, and that development stems entirely from increases in the accessibility of relevant event knowledge. These hypotheses are evaluated with reference to the performance of 11- and 17-year-olds in learning relationships among paired nouns. The results discredited both hypotheses, instigating the formulation of a revised conception of the relationship between knowledge and propensity as developmental determinants.     

Stammering: A stress index in Caribbean classrooms

Speech communities in the British West Indies typically include two major dialect or code distinctions: (1) a standard variety of British West Indian English, and (2) a local variety of English-based dialect. Each dialect or code is intimately linked with political, social, racial, and economic class distinctions. In bicultural settings, characterized by diglossia, there are special situations in which loyalty to one's mother tongue conflicts with social, economic, and political expediency. “No win” speech events or contests, the product of conflicting sociocultural values, become salient features of this particular kind of bicultural setting. A comparatively high incidence of teacher-reported stammering found in two British West Indian speech communities supports this notion and suggests that stress, originating at a sociocultural level, is symbolically expressed through attitudes toward and usages of language. These results further suggest that the classroom, now a “battleground”, will suffer as an effective teaching/learning environment. This paper presents arguments for the teaching of Standard English as a second language with an emphasis on giving regional dialects appropriate and long overdue recognition.     

"Square-wave stimuli" and neonatal auditory behavior: some comments on Ashton (1971), Hutt el al. (1968) and Lenard et al. (1969)

Recent work reporting neonatal auditory responses to complex tones generated by applying electrical square-wave stimuli to loudspeakers is reviewed with reference to the nature of the acoustic stimulus. Attention is particularly drawn to the harmonic structure of such tones in relation to the nonlinear frequency response of small loudspeakers. A $\text{1}\text{3}\text{-}\text{octave}$ band analysis of some “square-wave tones” is given to illustrate the difficulties of interpreting the results of work using such complex stimuli. The findings of the previous studies are ascribed essentially to differences in the stimulus bandwidth, rather than to differences in audiofrequency, and difficulties apparently generated by using differences in stimulus bandwidth as the sole explanation are at least partially resolved.