An aftereffect to discrete stimuli producing apparent movement and succession

After observing the sequential flashing of two lights that produced either the perception of apparent movement or the perception of the succession of two stationary lights, the presentation of the lights in the opposite direction produced the perception of a more rapid apparent movement or of a more rapid succession of the light flashes. These aftereffects suggest the presence of neural structures for the discrimination of sequential changes in spatial position which are subject to adaptation and respond with decreased sensitivity to the repetitive presentation of the two lights in a given spatial direction. The results are interpreted to support the hypothesis that the perception of apparent movement involves the excitation of specific neural mechanisms selectively responsive to sequential changes in stimulus position. An alternative hypothesis is that the perception of apparent movement involves an inference based on the separate registrations of the position of a stimulus at one point in time and the position of that stimulus at an earlier point in time.     

Private self-consciousness, canned laughter, and responses to humorous stimuli

Sefl-focused attention is hypothesized to (a) intensify emotional responses; (b) diminish susceptibility to suggestion; and (c) increase the consistency of self-report and behavior. These hypotheses were tested by having 82 undergraduates varying in private self-consciousness (PrSC) listen to humorous stimuli presented either with (laugh track group) or without (no laugh track group) canned laughter. Subjects' funniness ratings and overt laughter served as dependent measures. Regression analyses revealed that PrSC and funniness ratings were negatively correlated in the laugh track group, but uncorrelated in the no laugh track group. In contrast, PrSC and overt laughter were positively correlated in both groups. The association between funniness and laughter appeared stronger in high than in low PrSC subjects. Interpreted in light of research indicating that funniness ratings represent affect-free evaluations of humor stimuli, whereas laughter represents amusement, these results suggest that self-focus (a) intensified subjects' amusement; (b) decreased the extent to which their evaluations of the stimuli were biased by canned laughter; and (c) increased the consistency between their (self-reported) cognitive and (overt behavioral) affective responses (although this finding was equivocal).     

Differential thermometer for studying cerebral asymmetry

A device for measuring differences in temperature between the two sides of the head is described. The unit can be used for studying individual differences in cerebral asymmetry.     

Detection of auditory signals occurring at random times: Intensity and duration

Observers attempted to detect a weak auditory signal presented in noise. The onset of the signal was determined by a Poisson process, and only responses occurring 1 sec after signal onset were considered detections. Three latency distributions were measured, the time to a signal onset, the reaction time distribution, and the false-alarm distribution (of responses occurring before a signal onset). A simple two-state model is proposed to account for a discrepancy between the distribution of signal waits and the distribution of false alarms. The hazard functions of the reaction time distributions are considered in detail and a simple accumulation model is proposed to account for the results.     

Two classes of models for magnitude estimation

One class of models assumes that presentation of a signal results in an internal representation as a random variable. Depending on whether the signal is close to or far from the preceding signal, the variance of the representation is smaller or larger. Responses are determined largely by this random variable; however, when the signal is close to the preceding one, the response is generated by modifying the representation multiplicatively by some function of the ratio of the previous response to its representation. Power and linear functions are explored. The form of the random variable is assumed to be that arising from either the timing or the counting model operating on a Poisson process. Detailed analyses are carried out successfully only for the timing model with neural sample sizes independent of intensity; however, the data require the sample to increase with intensity. The linear response function coupled with the constant sample size counting model appears somewhat viable, but detailed calculations are very difficult to carry out. The second class of models postulates a power function relation between magnitude estimates and signals intensity for which the exponent is a Gaussian distributed random variable and the unit is the product of two log normal random variables. Again we assume an attention band such that succesive stimuli that are widely separated in intensity lead to independent samples of the random variables while a variety of assumptions is explored for successive stimuli that are near each other in intensity. Although they each give rise to the qualitative features of the data, estimates of parameters are sufficiently inconsistent that we are led to reject all of the submodels studied.     

THE ROLE OF SELF-ESTEEM IN COMPETITIVE CHOICE BEHAVIOR1

Le rôle de L'estime de soi dans les choix compétitifs — Un programme transnational de recherche sur les déterminants des processus de décision s'est concentré dans une première phase sur la relation entre L'estime de soi et le comportement compétitif dans un jeu de type « Dilemme du prisonnier ». Des étudiants américains, chez lesquels une grande estime de soi avait été induite, firent davantage de choix compétitifs que les sujets chez lesquels on avait induit une faible estime de soi. Une des deux expériences avec des étudiants français a reproduit les mêmes résultats, alors que des expériences avec des sujets italiens ont produit des résultats inverses. Différentes interprétations théoriques des résultats sont proposées et critiquées.