The effect of overtraining and repeated extinctions on speed of extinction in electrical self-stimulation

Fourteen rats with hypothalamic electrodes needed at least 3,000 reinforcements in self-stimulation before extinction scores reached their peak. In a series of up to 36 further extinctions and reconditionings, involving a total of 10,500 reinforcements, extinction scores fell to the extreme low values typical of self-stimulation. The extent of this fall was shown to depend on the number of extinctions administered, but not on the number of reinforcements, indicating that a process of conditioned inhibition may be partially responsible for rapid extinction after self-stimulation.     

Classification and identification thresholds for three types of verbal materials

The first two experiments found thresholds for classification into one of three categories of English words, Turkish words, and letter alternations to be significantly lower than thresholds for the identification of the specific items; parallel results were found with the two methods of measurement employed. Both thresholds were lowest for English words, and classification thresholds were lower for Turkish words than for letter alternations, but the identification thresholds of these two kinds of materials showed a reversal. The third experiment found classification thresholds for the same three types of materials to be higher than either of two three-choice identification thresholds, one a choice among three sametype items and the other, a choice among one English word, one Turkish word, and one letter alternation.     

Oculomotor adaptation to wedge prisms with no part of the body seen

When S looks at a visual target through prisms, adaptive shifts in reaching behavior occur even though he sees no part of his body through the prisms. These shifts are caused by a change in the judgment of the direction of gaze (oculomotor change), which in turn is caused by two secondary prismatic effects: (a) asymmetry of the visual display and (b) apparent rotation about a vertical axis of a panel or wall facing S. The “asymmetry” factor contributes 22% of the total oculomotor change, and the “rotation” effect contributes the remaining 78%. Oculomotor change is not facilitated by eye-movzment activity. The adaptive oculomotor change induces a non-adaptive proprioception change about one-tenth as large as the oculomotor change. These findings are capable of accounting for the previously unexplained results reported by Wooster in 1923, and also for the current controversy about the role of reafferent stimulation in sensorymotor adaptation.     

CULTURAL AND PHYSIOLOGICAL INFLUENCES UPON SPATIAL-PERCEPTUAL PROCESSES IN WEST AFRICA1 – PART I

Influences culturelles et physiologiques sur les processus spatio-perceptifs dans L'Ouest africain. 1^re partie. — Plusieurs études ont été réalisées dans le Sierra Leone pour tester la validité de certaines hypothèses relatives aux effets d'une culture tribale et d'un trouble endocrinien (Kwashiorkor) sur le développement de la dépendance vis-à-vis du champ et L'acquisition d'aptitudes spatio-perceptives. La première partie traite de la construction d'un test de tridimensionnalité, des variables culturelles et d'une expérience d'enseignement de la tridimensionnalité. La seconde partie présentera L'étude des variables endocriniennes et L'analyse factorielle pour L'ensemble des résultats.     

Reciprocal inhibition by aversion relief in the treatment of phobias

The treatment reported is a combination of Wolpeian reciprocal inhibition and aversion-relief therapies. The relief following termination of electric shock was substituted for Jacobsonian relaxation in the reciprocal inhibition of anxiety. Photographs of phobic objects and tape recordings of narrated phobic experiences were utilized in treating seven phobic patients and one ticqueur. Six of the seven phobic patients were free of phobic fears, without symptom substitution, at time of follow-up. Theoretical implications and research possibilities of the treatment procedure are discussed.