Transection of direct anterior thalamic afferents from the hippocampus: effects on activity and active avoidance in rats

This investigation demonstrates the importance of the direct hippocampo-anterior thalamic component of the postcommissural fornix in the control of general locomotion and active avoidance. Transection of anterior thalamic afferents from the hippocampal formation (subicular cortex), at the point where they exit from the fornix posterior to the septum, is sufficient to enhance bidirectional active avoidance acquisition and increase general activity. This transection may also interrupt fibers to or from other thalamic nuclei and the anterior septum. However, destruction of connections of the anterior septum with the hippocampus, habenula, and thalamus by transection in the coronal plane anterior to the descending fornix columns, without damage to the subiculothalamic fibers, increases general activity levels without damage to the subiculothalamic fibers, increases general activity levels without affecting active avoidance behavior. The activity increase in this case resembles that seen after septal lesions rather than that seen after hippocampal lesions. Thus, destruction of a single fornix component contributing afferents to the anterior thalamic nuclei reproduces at least part of the hippocampal syndrome. This suggests that these fibers contribute significantly to the control of these behaviors and may mediate active avoidance changes resulting from hippocampal and fornix damage.     

The effects of delayed auditory feedback on the overt behaviors of stutterers

This study investigated the differential effect of delayed auditory feedback (DAF) upon general (e.g., repetitions) and specific (e.g., repetitions of initial, medial, and final syllables) overt types of dysfluent behaviors. Ten moderate to severe stutterers performed an oral reading task under both NDAF and DAF (200 msec). DAF resulted in a significant increase in the total number of dysfluencies but had a differential effect upon certain general and specific behaviors. Blocks decreased significantly, prolongations increased significantly, and repetitions and interjections did not change significantly in frequency of occurence. To a limited extent, DAF had a differential effect on specific behaviors. All specific prolongation behaviors increased significantly while only one specific block behavior (ddelays in starting words) decreased. The authors discuss these results in terms of the vocal changes that occurred under DAF and speculate as to their importance in establishing fluency. DAF is viewed as promoting prolongations and prolongations are viewed as inhibiting excessive stoppages of the breathstream, thus promoting fluency (e.g., delays in starting words).     

Cross-cultural model testing: toward a solution of the etic-emic dilemma

A model for the prediction of behavior from attitudinal components, developed by Triandis, was tested with samples of U.S. and Mexican women, and with fertility relevant behaviors. The elements of the model are etic, but the operationalizations of the various variables were done emically. Results support the model in both cultures. While the predictive utility of the model is equivalent in two cultures, there are social class differences on which component of the model is most emphasized. The U.S. upper-middle-class sample and the Mexican upper-middle-class sample emphasized the person's attitude toward the act, while the Mexican lower SES (socio-economic status) sample emphasized the person's normative beliefs (moral obligations).     

Effects of signals preceding and following shock on baseline responding during a conditioned-suppression procedure

Long-Evans rats were exposed to a succession of conditioned-suppression procedures involving pairings of (1) signal-shock, (2) shock-signal, and (3) a signal-shock-signal sequence in which first and second signals were at first physically identical. Traditional suppression of food-reinforced responding was obtained under the signal-shock arrangement, and exposure to the shock-signal sequence resulted in conditioned enhancement of responding during the signal. The signal-shock-signal condition reliably suppressed responding during the first signal, but produced no differential effect on response rate during the second signal. Baseline responding was least changed from preshock rates under the signal-shock-signal procedure, but baseline rate was considerably reduced under the signal-shock and shock-signal arrangements, the latter yielding most substantial reductions. A second experiment indicated that the magnitude and direction of changes in baseline responding reported in Experiment I were not confined to cases in which the first and second signals in the signal-shock-signal arrangement were physically identical. It is suggested that the major effects of the conditioned-suppression procedure on response rate might not be confined to presentations of the signal.     

Language acquisition following hemidecortication: Linguistic superiority of the left over the right hemisphere

The language development of three 9- and 10-year-old children possessing only a right or a left hemisphere was studied. Surgical removal of one brain half antedated the beginning of speech, so each child has acquired speech and language with only one hemisphere. Different configurations of language skill have developed in the two isolated hemispheres: phonemic and semantic abilities are similarly developed but syntactic competence has been asymmetrically acquired. In relation to the left, the right brain half is deficient in understanding auditory language, especially when meaning is conveyed by syntactic diversity; detecting and correcting errors of surface syntactic structure; repeating stylistically permuted sentences; producing tag questions which match the grammatical features of a heard statement; determining sentence implication; integrating semantic and syntactic information to replace missing pronouns; and performing judgments of word interrelationships in sentences. Language development in an isolated right hemisphere, even under seizure-free conditions, results in incomplete language acquisition.     

Patterns of self-disclosure in homosexual and heterosexual college students

Two hypotheses concerning self-disclosure were investigated and confirmed in the present study, comparing homosexual and heterosexual college students. The first hypothesis was that self-disclosure, as measured by the Jourard Self-Disclosure Questionnaire, would be positively correlated with psychological femininity. The second hypothesis was that homosexual males and heterosexual females would exhibit similar patterns of high disclosure and femininity. No significant differences were found in total disclosure between homosexuals and heterosexuals, although homosexuals disclosed less to father, and more to friends than to parents. The conclusion was that psychological femininity and masculinity are more important than biological sex in determining self-disclosure.