The role of spatial complexity in the perception of speech and pure tones in dichotic listening

Ear advantages for CV syllables were determined for 28 right-handed individuals in a target monitoring dichotic task. In addition, ear dominance for dichotically presented tones was determined when the frequency difference of the two tones was small compared to the center frequency and when the frequency difference of the tones was larger. On all three tasks, subjects provided subjective separability ratings as measures of the spatial complexity of the dichotic stimuli. The results indicated a robust right ear advantage (REA) for the CV syllables and a left ear dominance on the two tone tasks, with a significant shift toward right ear dominance when the frequency difference of the tones was large. Although separability ratings for the group data indicated an increase in the perceived spatial separation of the components of the tone complex across the two tone tasks, the separability judgment ratings and the ear dominance scores were not correlated for either tone task. A significant correlation, however, was evidenced between the laterality measure for speech and the judgment of separability, indicating that a REA of increased magnitude is associated with more clearly localized and spatially separate speech sounds. Finally, the dominance scores on the two tone tasks were uncorrelated with the laterality measures of the speech task, whereas the scores on the tone tasks were highly correlated. The results suggest that spatial complexity does play a role in the emergence of the REA for speech. However, the failure to find a relationship between speech and nonspeech tasks suggest that all perceptual asymmetries observed with dichotic stimuli cannot be accounted for by a single theoretical explanation.     

Marijuana's effects on human cognitive functions, psychomotor functions, and personality

Marijuana is complex chemically and not yet fully understood, but it is not a narcotic. Like alcohol, marijuana acts as both stimulant and depressant, but it lingers in body organs longer than alcohol. Smoking marijuana can injure mucosal tissue and may have more carcinogenic potential than tobacco. Research has indicated that marijuana intoxication definitely hinders attention, long-term memory storage, and psychomotor skills involved in driving a car or flying a plane. Expectations and past experience with marijuana have often influenced results more than pharmacological aspects have. Marijuana has triggered psychotic episodes in those more vulnerable. Psychological and some instances of physiological dependence on marijuana have been demonstrated. As a psychoactive drug, marijuana surely alters mental functioning. Although it is possible that chronic use of marijuana produces irreversible damage to mind or brain areas, this has not been determined by research.     

The effect of stress on the linguistic generalization of bilingual individuals

Spanish-English coordinate bilinguals were subjects in a GSR linguistic conditioning experiment using strong and mild buzzer conditions and spoken stimuli. Each subject was randomly assigned to one of two lists of words and one of two levels of buzzer sounds. A Spanish word from the Spanish list and an English word from the English list functioned as a conditioned word (CS). The lists were Spanish and English words related semantically and phonemically and unrelated to the CS. Generalization was studied under conscious and unconscious conditions. We found that both buzzer conditions resulted in significantly greater GSR responses to semantic and phonemic words than to words unrelated to the CS. Generalization to semantic words was not significantly greater than to phonemic words. There was a tendency toward greater phonemic than semantic generalization in the strong buzzer condition. The opposite was observed regarding the mild buzzer. The results were the same in both lists and languages. Under a conscious and unstressful condition, generalization to semantic words was found to be more prominent than to phonemic words. This suggests that under normal condition semantic generalization is mediated by conscious cognition. We concluded that strong emotion produces an increase in phonemic, as compared to semantic, generalization in both languages. Hence, primitivization of the subjects' cognitive and linguistic functioning is assumed to have occurred. These results are important in understanding the deleterious effect that stressful situations may have on linguistic functioning and cognition in bilinguals.     

Attentional deficits in head-injured children: An information processing analysis

Attentional problems of closed head-injured (CHI) children were examined using an information processing (IP) approach. Based on Sternberg's (1969) additive factor method (AFM), the study examined attentional processes in terms of four stages and their corresponding task variables. A visual-spatial choice reaction-time task was undertaken with two groups of CHI children (severe and mild to moderate) and corresponding matched control groups. Results indicated that for this task both the CHI and the normal children exhibited a similar mode of linear, sequential information processing. It was found that the severe group was impaired not only in terms of slowed motor execution but also in terms of response selection. This group showed no impairment on the feature extraction, stimulus identification, and motor adjustment stages of processing. No evidence of impairment on any of the stages was found for the mild group. The utility of the AFM and implications of these findings are discussed with reference to CHI children and to neuropsychological assessment and rehabilitation.     

Measuring the stop point of rapid smoking

A method and an apparatus are described for measuring the point at which subjects elect to stop smoking when cigarette smoke is delivered more rapidly than in typical smoking. The device allows either the subject or the experimenter to control the volume of smoke and the interval between puffs. The device delivers reliable quantities of particulate matter from cigarette smoke. Subjects retested a week apart exhibited consistent stopping points.     

The role of working memory capacity and knowledge access in text inference processing

Individual differences in drawing bridging inferences during text comprehension were examined. We measured reader differences in working memory capacity, using the reading span task, and in access to relevant knowledge, using Potts and Peterson’s (1985) integration task. The dependent measure of greatest concern was answer time about facts posited to validate the bridging inference. Reading span and access were negligibly correlated, an outcome that supports their independence. Answer times were lower both for high reading span and high-access readers. In addition, readers who were either high on both reader traits or low on both traits exhibited qualitatively different inference effects from the typical pattern. It is proposed that knowledge access during comprehension is facilitated by the extraction of integrated situation models from text and that it is individuals with efficient reading processes who can construct these models.     

Prosodic form and parsing commitments

This paper examines the question of whether there are effects of prosody on the syntactic parsing of temporarily ambiguous sentences containing complement verbs. It reports the results of five experiments employing cross-modal response tasks where the visually presented target word was either an appropriate or an inappropriate continuation in terms of the prosodic form of the preceeding auditory sentence fragment. Two experiments employing cross-modal naming only showed indications of sensitivity to syntactic and appropriateness manipulations when coupled with a simultaneous appropriateness judgment task. In contrast, the experiments employing cross-modal lexical decision showed greater sensitivity to syntactic and appropriateness effects. However, while the results from these studies replicated our earlier auditory parsing results and provided support for the suggestion that there are differences in visual and auditory parsing processes and for a constituent-based, minimal commitment type auditory parser, none of the studies demonstrated an effect of prosodic form on the parsing process.     

Measuring clients' experience of careers guidance interviews: Exploratory studies

Initial findings of the development of a measure of client experience of the careers guidance interview are reported. Initially based on the Medical Interview Satisfaction Scale (Wolf et al., 1978), items were derived which sampled across affective, cognitive and behavioural components of careers interviewing. The scale is pilot tested on 60 15 and 16 year-old school pupils, of low academic potential and all of whom had experienced a careers interview with a careers officer. Initial results are only partially supportive of the findings of Wolf et al. (1978). Results of a further field study of the 20-item scale based on 54 careers interviews are also reported where factor analytic data are promising. The contribution of the scale in testing related hypotheses (e.g. met expectation hypothesis) is indicated.