Behavioral contrast in fixed-interval components: effects of extinction-component duration.

Seven albino rats were exposed to a multiple schedule of reinforcement in which the two components (fixed interval and extinction) alternated such that a presentation of the extinction component followed each fixed-interval reinforcement. In baseline sessions, the duration of the extinction component was constant and always one-third of the fixed-interval value. Probe sessions contained a probe segment in which the duration of the extinction component was increased; the response rate in fixed-interval components during the probe segment was compared with the response rate in the segments preceding and following the probe. The effect of increasing the duration of the extinction component was studied under three values of fixed interval: 30 s, 120 s, and 18 s, in three successive conditions. Response rate within fixed intervals was a direct function of duration of the extinction component. Pausing at the beginning of the fixed interval decreased as extinction duration increased. These effects were larger and more consistent for the shorter fixed-interval values (18 s and 30 s). These results indicate a functional relation between relative component duration and responding. For the component providing more frequent reinforcement, this could be stated as an inverse relationship between relative component duration and response rate. This relation is similar to findings regarding the ratio of trial and intertrial duration in Pavlovian conditioning procedures, and suggests that behavioral contrast may be related to Pavlovian contingencies underlying the multiple schedule.     

Social and emotional loneliness: an examination of Weiss's typology of loneliness

This study examined Weiss' conceptualization of social and emotional loneliness. Using data from an extensive survey of undergraduate and graduate students at the University of Iowa, we measured social and emotional loneliness, students' affective and behavioral reactions to loneliness, students' social relationships, and their judgments of the degree to which their relationships supply the six social provisions described by Weiss. As expected, we found differences in the subjective experiences of social and emotional loneliness, although both forms of loneliness were also characterized by a common core of experiences. The results generally supported Weiss's ideas concerning the determinants of social and emotional loneliness. Predictions concerning the affective and behavioral consequences associated with each type of loneliness, however, were only partly supported, although the two forms of loneliness were associated with different affective reactions and coping behaviors. The implications of these findings for Weiss's typology of loneliness are discussed.     

Cross-task validation of functional measurement

Ss judged average heaviness of two unseen lifted weights on a 20-step rating scale. They also rated heaviness of a single visible object of variable size and weight. The data for each task obeyed the parallelism prediction of the linear integration model. This within-task consistency validates jointly the model and the response scale. Functional measurement procedure yielded independent scales of subjective heaviness from each task. These were linearly related, a criterion of external consistency. The plot of subjective heaviness against objective weight was slightly negatively accelerated. These results disagree with those that have been obtained with magnitude estimation. Since the rating data satisfy both internal and external consistency, they constitute the true measure of sensation. Magnitude estimation, in contrast, must be biased and invalid.     

COMMONALITY OF WORD LISTING,PREDICTABILITY, ORIGINALITY AND CHUNKING

Les AA. analysent les données de deux épreuves verbales (liste de mots, créativité) auxquelles ont été soumis des adolescents hindous (N = 144) et américains (N = 96). Ils constatent que : (1) les sujets hindous montrent plus de variabilité dans la tendance à donner des mots identiques (commonality) dans une liste et se caractérisent par un nombre plus élevé de “ groupes ” de mots, liés entre eux dans une même chaîne de pensée; (2) les filies donnent plus de mots identiques que les garçons, mais seulement dans le groupe américain; (3) il existe une relation faible, mais de sens contraire, entre la prédictibilité et le groupement des mots dans les deux groupes linguistiques. La discussion est centrée sur la pertinence des ressemblances plutôt que des différences en matière de comparaisons interculturelles; les similitudes verbales pourraient refléter chez les sujets américains L'orientation vers le groupe des pairs et il est possible de donner d'autres explications à L'absence de Jiaison entre les similitudes verbales, la prédictibilité, I'originalité et la tendance à répondre par groupes de mots.     

Awide range timing circuit with two independent controls

The timer described in this note is an example of how a small increase in engineering complexity can lead to a marked increase in user convenience and overall system accuracy.     

Two types of short-term visual storage

Seven-letter words were flashed repetitively at various durations above and below the recognition threshold for single flashes. One form of a short-term storage effect was studied by measuring the interstimulus interval between flashes at which S reported that the stimulus became phenomenally discontinuous in time. Storage times reached a maximum of about 300 msec in this task. A second form of storage effect was measured by decreasing the interstimulus interval until S could correctly recognize a repeated stimulus whose duration was below the single-flash recognition threshold; this effect extended to 900 msec in some cases. Each of these effects was reliably obtained for both rare and frequent words. Both forms of storage were increased by providing a dark rather than a lighted adapting field between presentations of the test stimulus. Implications for Information processing of brief displays are discussed.     

Two parameters of a temporally defined schedule of negative reinforcement

Temporal schedules of negative reinforcement were derived in a manner analogous to those for positive reinforcement, and two parametric studies were carried out with two of the three defining variables. With some limiting values of the defining variables, escape schedules result and data obtained at these values were similar to those obtained in escape studies. At other values of the defining variables avoidance behavior was generated.