Neuroendocrine hemisphere asymmetries: Salivary cortisol secretion during lateralized viewing of emotion-related and neutral films

The study set out to examine whether the cerebral hemispheres differ in their ability to regulate cortisol secretion during emotion-related situations. One hundred twenty-three adult subjects were shown either an emotionally aversive or a neutral film in the left or right hemisphere by means of a technique for lateralizing visual input that allows prolonged viewing while permitting free ocular scanning. The film-related changes of cortisol secretion were determined by salivary cortisol radioimmunoassay. Right hemispheric viewing of the emotionally aversive film resulted in a significantly higher increase of cortisol secretion than left hemispheric viewing of the same film. No such differences were observed with respect to the neutral film. Comparing the effects of the two films separately for each hemisphere revealed that only the right hemisphere was able to respond neuroendocrinologically in a different manner to the emotional and the neutral film. Therefore, it is concluded that cortical regulation of cortisol secretion in emotion-related situations is under primary control of the right hemisphere. The potential implications of asymmetric control of cortisol secretion with respect to the pathogenesis of psychosomatic and immunological disorders are discussed.     

Linear systems analysis of infant visual pattern preferences

Karmel's check-pattern preference data for 13-week-old infants were reanalyzed using linear systems analysis. The two-dimensional Fourier amplitude spectrum was calculated for each of his eight checkerboard and random check patterns. The mean contrast sensitivity data for 3-month-old infants of Banks and Salapatek and the spatial frequency amplitudes of the patterns were used to derive three metrics to predict the looking times observed by Karmel. One was based on the sensitivity of the visual system to the single pattern component highest above threshold (maximum amplitude), the second was based on the total amount of pattern energy above threshold (total summation), and the third was based on the maximum amplitude with summation over nearby spatial frequency components (limited summation). The predictive power of the maximum amplitude and the total summation metrics depended on whether the pattern type was checkerboard or random check. The limited summation metric predicted looking times well for both pattern types. A linear function of the logarithm of the limited summation metric accounted for 91% of the total variance in looking time.     

Transfer of a response controlling stimulus duration across discrimination problems

In the acquisition phase, pigeons learned to peck at a changeover key to shorten the duration of S? but not of S+ presented on the food key in a discrimination problem. In the transfer phase, the significance of S+ and S? was changed through extinction of both, equal reinforcement, or discrimination reversal, while the changeover key was not available. Transfer tests then showed appropriate modification of the changeover response. Similar transfer was demonstrated across orthogonal stimulus dimensions. Further analytic studies showed that this transfer of the changeover response did not depend upon mediation due to differential response rates to the food key. This research strategy enriches the study of the “second learning process” by providing an indicator of stimulus control in all phases of the procedure. Direct transfer between different problems also indicates that discriminative stimuli, although physically dissimilar, have the same “psychological value” for the subject.     

Loss of smell and taste within the scope of vitamin B 12 deficiency

The article deals with the case of a patient who had a partial gastrectomy and developed a vitamin B12 deficiency syndrome with anemia, myelopathy and complete loss of the senses of taste and smell. Regression of the symptoms followed liberal dosing with vitamin B12.     

The intervals at which homogeneous flashes recover masked targets

The recovery effect may be induced by the introduction of a homogeneous blank flash after a patterned mask. It is not clear which parameters optimize the effect. In this study, the effect of systematical variation of the different interstimulus intervals on performance was investigated. Conditions in which the blank flash preceded the patterned mask were included. The important parameter is shown to be the interval between Mask 1 and Mask 2. For optimal recovery, this value has to be 0–20 msec. It is argued that these results, as well as a number of other recovery findings, can be explained by the suppressing influence of homogeneous flashes on contour processing channels in the visual system.     

A COMPARISON OF COGNITIVE CONFLICT BETWEEN PERSONS IN WESTERN EUROPE AND THE UNITED STATES1

Etude comparative du conflit cognitif interpersonnel en Europe occidentale et aux Etats-Unis. — La recherche a été menée conjointement dans divers pays européens (Grande-Bretagne, France, Italie, RFA) et aux Etats-Unis, selon la même procédure. On induit des différences cognitives détetminées entre les 2 membres d'un groupe, en les entraînant différemment (ce dont ils ne sont pas conscients) dans une tâche d'apprentissage portant sur des problèmes politiques; il s'ensuit un conflit quand on réunit les deux sujets et qu'on leur demande d'aboutir à des solutions communes. Les résultats montrent que — a) les différences cognitives ne sont pas réduites en Europe alors qu'elles le sont, lentement, aux Etats-Unis; — b) les sujets européens aboutissent moins souvent que les sujets américains à des solutions de compromis; — c) les européens réagissent différemment à l'idée de « Contrôle de l'Etat ». Ce type de recherche peut être utilisé pour étudier le conflit cognitif sur une base interculturelle; les résultats font apparaître des problèmes importants qui n'ont pas encore été étudiés.     

Cognitive conditioning: Imagined stimulus contiguity and the third interval conditional GSR

The effect of repeatedly imagining paired or unpaired CSs and USs on the frequency of post-CS responses during real extinction was studied. Four groups of 10 Ss first received a model tone and shock. For two of the groups the stimuli were paired (delayed conditioning paradigm). For the others the stimuli were arranged in a long trace paradigm. The Ss then received a series of commands requiring them to imagine receiving paired CSs and USs, or to imagine the events singly. Then 10 real tone extinction trials were given. The groups which received delayed conditioning model stimuli were more responsive than trace groups, and groups which had imagined paired stimuli were more responsive than their unpaired controls. Cognitively oriented explanations of these findings were discussed.     

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