Reliability of verbal-manual interference

Considerable recent research has used unimanual finger tapping with concurrent vocalization to assess hemispheric lateralization for language. This study examined whether an index finger tapping task is a reliable measure in adults and whether the task demonstrates sex differences in hemispheric specialization for language. Thirty right-handed subjects, fifteen male and fifteen female, between the ages of 18 and 25 were tested. The task measured the differences in tapping rate for each hand between tapping with and without a concurrent verbal task. The task was completed once each day for 3 consecutive days to determine reliability. The tapping task was found to be a reliable measure. No significant differences were found between tapping scores of males and females.     

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.     

The effects of prior task experience in the modeling situation

An investigation was made into the effects of observers' previous experience with the experimental task on acquisition and subsequent performance of modeled task behavior. The task was socially neutral and the subjects were second grade boys and girls. Recall of modeled actions increased with prior experience, indicating greater acquisition. This finding supports Bandura's (1973) assertion that task familiarity may enhance attentiveness to the model. Contrary to previous research, performance of imitation did not decrease with experience. The present performance results are possibly due to the ambiguity of the preexperience and novelty of the experimental task.     

The effects of situational performance constraints on intrinsic motivation and satisfaction: The role of perceived competence and self-determination

Situational performance constraints, task interest, and pay contingencies were manipulated in a laboratory study in order to investigate the cognitive mechanisms associated with the previously observed detrimental effects of constraints on affective task reactions. It was hypothesized that feelings of task competence and self-determination would account for both the direct and the interactive effects of constraints on motivation and satisfaction. The results of the study indicated that despite the fact that participants' performance was being constrained and they were aware of these constraints, the mere presence of the constraints alone failed to result in lower levels of satisfaction or motivation on a proofreading task. Post hoc analyses suggested that the constraints, in fact, led to negative affective task reactions when they also reduced participants' feelings of competence and self-determination. Interestingly, participants' generalized locus of control was associated with such effects. Internals tended to maintain stronger feelings of competence and self-determination than externals in the presence of constraints, thereby also maintaining greater motivation and satisfaction.     

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.     

Personality research and psychophysiology: General considerations

A general discussion of psychophysiological methods in relationship to personality research is presented for the investigator without an extensive knowledge of psychophysiology. The paper is organized in four sections: (a) advantages inherent in the use of psychophysiological measures (e.g., continuous measurement, sensitivity to sublimal responses); (b) psychophysiological constructs that are particularly well suited to personality research (e.g., different kinds of physiological arousal, normal/pathological distinctions, perceptual states); (c) how to choose a set of psychophysiological measures and special considerations involved with their use (e.g., obstrusiveness, context and timing of measurement, costs, and capabilities); and (d) whether or not to “psychophysiologize” personality research. Within each section, illustrative applications of psychophysiology to personality research are described.     

Rhythm length and hemispheric asymmetry

Conflicting evidence has appeared in the literature concerning hemispheric asymmetry in the perception of rhythm. The present study investigated the effects of rhythm length on relative cerebral dominance. Twenty-four subjects were presented with sequences of one to four time intervals bounded by light flashes. The subjects' task was to determine if two such sequences were the same or different. The first rhythm was presented in both visual fields and the second only to one visual field. Reaction times and number of errors were recorded. It was found that increasing rhythm length resulted in a shift in cerebral dominance from left to right hemisphere. An interpretation of these findings was suggested in terms of the preferred mode of processing of each hemisphere, analytic vs. holistic.     

Perceptual speed and short term retention of visual stimuli in preschool children

Ninety children aged 26 to 69 months were tested individually on two tasks. The first required the identification of tachistoscopically presented visual stimuli. Presentation times were shortened after every fourth stimulus until a child no longer made three correct identifications out of a series of four. The second task required that similar identifications be delayed by intervals of 10, 20, and 40 seconds following presentation. The presentation time required for correct identification of the stimuli declined significantly across the age range examined while the maximum delay interval after which a correct response could be obtained increased. In addition, the two measures were statistically independent of each other although both were related to the age of the child. The results indicate that some of the perceptual processes which have been shown to be instrumental in the acquisition of reading skills exhibit a marked developmental change during the preschool years.     

Situation-specific variables as determinants of perceived environmental aesthetic quality and perceived crowdedness

It was hypothesized that relevant situation-specific variables may act along with objective physical conditions to determine environmental perception, and that the exclusive use of the physical level of an environmental stimulus to predict behavior may, therefore, be inadequate. A 2 × 4 between-subjects design was employed in which an attitudinally similar or dissimilar confederate interacted with a subject at one of four distances. As hypothesized, subjects who interacted with a similar confederate judged the environment to be of higher aesthetic quality, perceived themselves to be less crowded, and felt affectively more positive than subjects who interacted with a dissimilar other. The results were also interpreted as supporting the utility of the Byrne-Clore (1970) reinforcementaffect model of evaluative responses as a means of predicting environmental perception and the behavioral response to environmental stimuli.     

Perceptual asymmetries in face recognition

Four experiments were carried out to investigate perceptual asymmetries in face recognition. Perceptual asymmetries favoring the half-face on the observer's left were found under free viewing conditions for both unfamiliar faces (Experiment 1) and famous faces (Experiment 3). For unfamiliar faces, this asymmetry was not obtained when fixation was controlled by presenting faces tachistoscopically (Experiment 2). For famous faces, the perceptual asymmetry favoring the half-face normally seen on the left did not appear to be retained in memory (Experiments 3 and 4). Asymmetries in face perception have been explained in terms of a direct access model of laterally effects. However, these results raise the possibility that asymmetric scanning or attentional factors may be important.     

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 specialization and social-verbal development in preschool children

Forty-two 2 1/2- to 5 1/2-year-old children's social and verbal behaviors were observed during free play in a preschool. A test measuring lateral specialization of verbal function and a standardized psychometric test of verbal ability were also administered. Analysis of variance indicated that the right ear (left hemisphere) is predominant in processing verbal stimuli in children as young as 2 1/2. Multiple regression analyses revealed significant relations between the right ear accuracy score for dichotically presented verbal stimuli and both psychometrically measured verbal ability and a social-verbal factor score derived from play behavior. After the increase related to age was statistically partialled out from both verbal ability and social-verbal scores, verbal expression, length of verbal utterances, time spent in conversation, and peer social interactions increased and parallel play decreased as a function of right ear (left hemisphere) accuracy for verbal stimuli. The relationship between left ear (right hemisphere) accuracy scores for verbal stimuli and social-verbal behavior, however, was not linear. Very high and very low levels of left ear recall predicted an increase in the frequency of parallel play and low social-verbal behavior while moderate levels of left ear accuracy scores predicted the reverse.     

There's method in our madness: Interpersonal attraction as a multidimensional construct

The convergent validity and number of dimensions common to six measures of interpersonal attraction (three verbal and three nonverbal) were explored in this investigation. Convergent validity was found within verbal and nonverbal modes of measurement, but not between modes. No general factor was found to be common to the six measures of attraction. It was, therefore, concluded that method bias influences experimental results, threatening the comparability of results from research programs using different modes of measuring attraction. The results also question the assumption that social attitudes, such as attraction, are closely related to behavior, and imply that predictions derived from theories based on different modes of measuring attraction will have unequal utility.     

Memory for pure and verb-derived nouns: implications for hemispheric specialization

Memory for pure and verb-derived nouns was assessed in two long-term memory experiments. The two types of nouns were matched for word frequency and number of syllables. The results of both experiments indicated that pure and verb-derived nouns do not differ in their demands on the information processing capacities of normal subjects when confounding factors are controlled. The implications of these findings for studies of hemispheric specialization for language are discussed.     

Face memory and hemispheric preference: Emotionality and extraversion

Subjects made arousing or nonarousing judgments about photographs of strangers, then had an unannounced recognition test over the photographs. Emotional orienting tasks led to better retention than nonemotional tasks. Assuming emotionality is predominantly a right-hemisphere activity, then this result is consistent with other research showing a right-hemisphere advantage in processing faces. This difference was most clear for subjects with a right-hemisphere cognitive style. Extraversion had no effect on face recognition, nor did a subject's cognitive style seem to be associated with extraversion or neuroticism scores.     

Prediction as a means of inducing tolerance

Female subjects were exposed individually to the attitude item responses of a similar or dissimilar stranger. They were asked either to copy down the stranger's attitudes or to predict (with accurate feedback) how the stranger answered each item. Predict subjects were found to be more tolerant of the dissimilar stranger than were Copy subjects, while both groups were equally attracted to the similar stranger. It was suggested that training people to anticipate disagreements may be a useful way of fostering tolerance.     

Performance differences following exposure to predictable and unpredictable noncontingent outcomes in high and low achievers

Two experiments are described in which subjects rated as high or low in achievement motivation were exposed to uncontrollable outcomes on a cognitive task. Effects on subsequent performance on a different cognitive task were shown to depend on level of achievement motivation, on whether the uncontrollable outcomes were predictable or unpredictable, and on whether the uncontrollable outcomes were positive or negative. These findings have important theoretical implications which are discussed.     

Sex task and processing strategy effects in hemispheric alpha asymmetries for the recall and recognition of arousal words: results from perceptual and motor tasks in males and females

Hemispheric alpha asymmetries of males and females were observed during perceptual and motor tasks requiring recall and recognition of words controlled for level of arousal (positive, negative, and neutral). Verbal reports of individual processing strategy were collected and analyzed relative to hemispheric alpha ratios. Results showed greater alpha suppression in the left relative to right hemisphere for recall as compared to recognition tasks and for word presentation when contrasted with motor conditions. High positive correlations were found between narrative report of processing strategy and hemispheric alpha data. A separate analysis revealed that seven subjects identified as highly analytic processors showed greater alpha suppression in the left relative to right hemisphere across tasks, conditions, and stimuli than did seven highly visual processors who, in contrast, demonstrated greater right hemispheric alpha suppression. Task difficulty and individual differences in processing style that modify cerebral laterality effects are discussed.     

Left-handers show greater test-retest variability in auditory and visual asymmetry

Left-right difference scores were analyzed for groups left- and right-handed subjects administered the same dichotic listening and visual half-tests on four separate days. The left-handed subjects showed greater test to test variability than the right handers for both modalities.     

Androgyny and traditional versus nontraditional major choice among college freshmen

The present study investigated the relationship of psychological androgyny to career choice among college freshmen. Women in home economics and engineering and men in engineering (N = 231) completed the Bem Sex-Role Inventory and rating scales of satisfaction with and certainty of college major and intended occupation. As a group, women in engineering scored in a more androgynous direction than did either men in engineering or women in home economics. Among sex-typed subjects, more women in engineering scored in a masculine sex-typed category than did women in home economics. Men and women in engineering did not differ on satisfaction and certainty ratings of major or career; however, feminine-typed women were significantly less satisfied with and tended to be less certain of their choice of major than other women in engineering.