Temporal control of behavior: schedule interactions

In Experiment I the response that terminated the postreinforcement pauses occurring under a fixed-interval 60-second schedule was reinforced, if the pause duration exceeded 30 seconds. The percentage of such pauses, rather than increasing, decreased. There were complex effects on the discriminative control of the pause by the reinforcer terminating the previous fixed interval, depending on whether the fixed interval and the added reinforcer were the same or different. In Experiments II(a) and II(b), each reinforcement initiated an alternative fixed-interval interresponse-time-greater-than-t-sec schedule, the schedule values being systematically varied. When the response following a pause exceeding a given duration was reinforced, fewer such pauses occurred than when they were not reinforced, i.e., on the comparable simple fixed-interval schedule. There was no systematic relationship between mean interrinforcement interval and duration of the postreinforcement pause. The pause duration initiated by reinforcement was directly related to the dependency controlling the shortest pause at that time, regardless of changes in mean interreinforcement interval.     

Peripheral visual changes and spatial attention.

Three experiments are reported investigating the attentional effects of peripheral visual changes. In agreement with previous work, experiment 1 demonstrated facilitatory and inhibitory effects of a peripheral visual change on the latency of peripheral target detection. However, after a few minutes practice the facilitatory effect disappeared entirely. The inhibitory effect, though slightly reduced in later blocks, remained significant. Hence, the two effects are dissociable and not inter-dependent as argued by Maylor (1985). In experiments 2 and 3 the perceptual salience of the peripheral cue was manipulated. With a low energy, barely noticeable cue there was no reduction in either facilitation or inhibition as a function of practice. In contrast, the attentional effects of cues higher in energy tended to diminish with practice. Theoretical implications of these data are discussed.     

Emotional Empathy in a Courtroom Simulation: A Person-Situation Interaction1

A pair of experiments were conducted using a simulated courtroom trial of a criminal case. In Experiment I subject-jurors were asked by defense counsel either to imagine themselves as the defendant (empathy-inducing appeal) or to pay close attention to evidence (nonempathy appeal). Later the judge delivered only general instructions or, in addition, charged jurors to give consideration only to the facts presented. When there was no Fact-focused judge's charge, juror-subjects who heard the empathy-inducing appeal rated the defendant's actions as more lawful and attributed less of the cause for the incident to his personality than did their counterparts in the nonempathy condition. Experiment II included individual differences in the tendency to empathize as an additional mediating variable. The original pattern of effects found for the manipulated variables in Experiment I appeared again, but were overshadowed by the stronger effects of the individual difference variable and of subject sex. Subject-jurors who scored high on the empathy individual difference measure rated the defendant less guilty, assigned less cause to him, and showed corresponding mood shifts when they heard the empathy-inducing appeal. In addition, male subjects empathized more strongly with the male defendant and viewed him more favorably.     

Temporal control of behavior and the power law

The performance of rats and pigeons under fixed-interval schedules was studied in two experiments. The duration of postreinforcement pause was a declining proportion of fixed-interval duration. For pigeons this was true both when the duration of the reinforcer was fixed and when it was increased in direct proportion to increases in fixed-interval duration; the longer reinforcer durations did, however, lengthen the postreinforcement pause at higher schedule values. A quantitative analysis of data from Experiments 1 and 2 and from other studies showed that fractional exponent power functions described the relationship between postreinforcement pause and fixed-interval value; similar functions have previously been observed in studies of temporal differentiation. It was concluded that power functions reflect a direct causal, rather than artifactual, relationship between performance and the temporal requirements of reinforcement schedules.     

Gender-deviant boys compared with normal and clinical control boys

The physical movement and social characteristics of effeminate behavior-problem, referred boys (N=13)were compared with those of normal boys (N=25)and boys (N=12)referred for nongender problems. Parent reports, observer ratings, and videotapes were collected in a series of structured tasks. As expected, mothers described gender-problem sons as much more feminine than the other two groups in interests, activities, and mannerisms. Gender-problem sons were also seen as relatively inactive and introverted. Further, they were non-significantly lower than the clinical control boys in perceived behavior problems, but both groups had marginally more problems than the normal boys. Gender-problem and clinical control boys both showed more body constriction than normal boys in ratings of a videotaped interview. They also both showed less ideal ball-throw form than normal boys on a set of variables scored with slow-motion video. However, in a set of behaviors directly rated in the various tasks, the gender-problem boys gave a uniquely general impression of uncoordination. The groups did not differ on seven additional variables.The research was supported in part by USPHS Grant MH17072. The authors are indebted to the more than two dozen research staff members who contributed many essential services at various stages of the project, to the families who generously participated, to the clinicians who referred their clients to our project, and to Marion Hee for computational assistance.     

Visual timing in hitting an accelerating ball

To investigate the timing of actions relative to events in the environment, we observed subjects leaping to punch a falling ball. We analysed their knee and elbow angles as functions of time for three ball-drop heights, finding that the differences in the functions for the different heights could be explained on the basis that the subjects were gearing their actions to a particular optic variable. This variable specifies the time remaining before contact with an object if the closing velocity is constant; for the falling ball it gives an increasingly accurate estimate of the time-to-contact. Our visuo-moto control model incorporates a delay parameter, the value of which was estimated from the data. In addition, correlations indicated that the knee and elbow were generally quite tightly coupled. The relationship of this task to laboratory tracking tasks and to the timing of actions in everyday life is described.     

Human Structure,Bildung and Freedom: Edith Stein’s Philosophy of Education

Journal of Indian Council of Philosophical Research - Philosophy since Nietzsche and Heidegger has been averse to essentialism and considered to be old-fashioned and outmoded in the mainstream flow...     

Pigeons are attracted to a perceived gain without an actual gain

Reference dependence refers to the reduced value of a reward that is less than expected, or the added value of a reward that is greater than expected. There is evidence that when pigeons are offered an alternative that has 1 pellet versus an alternative that has 2 pellets, but one of the two pellets offered will be removed, the pigeons prefer the originally presented 1 pellet (loss aversion). In the present research, we tested for the opposite effect (gain attraction). In Experiments 1 and 2, pigeons could choose between 2 pellets, each one on a distinctive background. If they chose the optimal alternative, they received a second pellet. In Experiment 2, the second pellet obtained was the one not initially chosen (a task sometimes referred to as the ephemeral reward task). Pigeons learned to choose optimally in both experiments. In Experiment 3, we tested the pigeons for reference dependence. Pigeons were given an alternative that offered them one pellet or two pellets, if they chose the one-pellet alternative, they received an additional pellet, and if they chose the two-pellet alternative, they received the two pellets. In keeping with the reference dependence hypothesis, the pigeons preferred the 1-pellet alternative that gave them an extra pellet. These effects are related to similar findings with humans, including the endowment effect.