Differential runway performance using goal box placement and running trials as discriminative stimuli

Two experiments compared the effects of reinforced, partially reinforced and nonreinforced intertrial goal box placements (ITR, ITP, and ITN respectively) on runway performance. In Experiment I differential responding (animals running slower on nonreinforced (N) trials than on reinforced (R) trials) was observed during acquisition for subjects receiving ITP preceding N trials or subjects receiving ITP before R trials, and also for subjects receiving ITR preceding N trials. No differential responding was observed in subjects receiving ITP prior to both N and R trials or ITN prior to N trials. In extinction, the subjects which had responded differentially during acquisition demonstrated reduced resistance to extinction in comparison to the subjects which had not. In Experiment II, a 2 × 2 factorial design was utilized with placement schedule (ITN and ITP) and type of trial predicted by placement (N and R) serving as the factors. Differential responding was observed in all four groups. The apparent contradiction between the results and the discrimination hypothesis proposed by Capaldi and Olivier (1967) to explain the attenuation of ITR and ITN effects on resistance to extinction is discussed.     

Factors affecting withdrawal from an escalating conflict: Quitting before it's too late

In an experimental study of “entrapping” conflicts —situations in which a decisionmaker may continue to expend resources in part to justify previous expenditures—subjects were given an initial stake of $4.00 and had the opportunity to win an additional $2.00 jackpot. Two independent variables (Process of Resource Allocation and Prior Limit-Setting) were combined in a 2 × 3 design. Once the subjects had started to invest, half of them had to make an “active” decision to continue. Unless they actively decided to continue, their investments automatically ceased and they were no longer eligible for the jackpot (Selfterminating condition). The other half only had to make a “passive” decision to continue. Unless they actively decided to dis continue, their investments for the jackpot automatically increased (Self-sustaining condition). In addition, before investments began, some subjects were asked to inform the experimenter of the nonbinding limit they had set on the amount they planned to invest (Public condition), some were asked to set a limit which they kept to themselves (Private condition), while a third group was not asked to set a limit (Control condition). Subjects invested significantly more money in the Self-sustaining condition. Also, investments were somewhat greater in the Control than the Public condition. Although the mean investments in the Public and Private conditions did not differ, those in the Public condition deviated significantly less from their earlier set limits, suggesting greater commitment to these limits. Theoretical and practical implications are discussed.     

Suicide ideation: its relation to depression, suicide and suicide attempt

A random sample of 3,935 adults from a general population were interviewed and asked to report how often they had thoughts of suicide as well as their opinion on the frequency of suicide ideation in others. Depression was found to be related to the respondent's reports of his/her own suicidal thoughts and to reports of frequent suicide ideation in others. A total of 5.4 percent of the respondents reported some degree of suicide ideation in the previous month and 9.1 percent reported that others think about suicide once a month or more. When the demographic characteristics of those who report suicide ideation in themselves or others were compared to those of suicide attempters and committers, some consistencies were found, suggesting that such questions may be useful in identifying those "at risk." Nevertheless, sufficient discrepancies were found which suggest that there may be a number of factors which increase or decrease the likelihood that someone with thoughts of suicide will attempt or commit suicide. Follow-up studies are necessary to uncover such factors and the degrees to which they influence the occurrence of suicide.     

Family and psychosocial predictors of obsessive compulsive disorder in a community sample of young adolescents

A two-stage epidemiologic study conducted between 1986 and 1988 in the southeastern United States investigated family and psychosocial predictors of obsessive compulsive disorder (OCD) and subclinical OCD in young adolescents. In the first stage, a life-event schedule and a family adaptability and cohesion scale were administered to a community sample of 3,283 adolescents. In stage two, the Schedule for Affective Disorders and Schizophrenia in School Age Children and the Children's Global Assessment Scale were administered to 488 mother-child pairs. In multivariable models family cohesion was the only significant correlate of OCD (odds ratio=0.95, 95% confidence interval 0.91–0.98). Gender, race, age, socioeconomic status, guardian status, adaptability, undesirable life events and desirable life events were not found to be significant predictors of OCD in models adjusting for cohesion. Note of the above variables were significantly associated with subclinical OCD. However, separate analyses of the 41 individual life events indicated seven specific events were significantly associated with OCD or subclinical OCD. These findings are at odds with the theory that overinvolvement of family members is a risk factor for OCD, though an association with overly rigid family structure cannot be eliminated based on these data. Further exploration of family characteristics is warranted.     

The effect of timing and spatial separation on the velocity of auditory apparent motion

Previously, it was shown that the minimum conditions for the illusion of auditory apparent motion (AAM) depend on stimulus timing but not spatial separation. In the present experiment, the effects of stimulus timing and source separation on the perceived velocity of AAM were examined. Eight listeners estimated the velocity, duration, and distance traveled of AAM, using a no-modulus, magnitude estimation procedure. Four burst durations (25, 50, 100, and 300 msec), 10 stimulus onset asynchronies (SOAs; 30, 40, 50, 60, 70, 80, 90, 100, 110, and 120 msec) and two separations (10° and 40°) were tested. Perceived velocity estimates were related to the total duration (burst duration + SOA) of the stimulus sequence. The effect of separation on velocity was extremely small but statistically significant. These results are similar to those obtained previously on the minimum conditions for AAM. Duration estimates were related only to total duration, but separation estimates were related to both separation and total duration. These results suggest that velocity is possibly a primary dimension of AAM that is independent of source separation.     

Rumination in Response to Stress as a Common Vulnerability Factor to Depression and Substance Misuse in Adolescence

The current study examined rumination in response to stress as a common vulnerability factor to both depression and substance use problems in adolescence. Specifically, we used a multi-wave longitudinal design to examine whether adolescents who tend to ruminate in response to stress exhibit increases in depressive symptoms and substance misuse following the occurrence of negative events. At time 1, adolescents (n = 161) completed measures assessing depressive symptoms, substance misuse, and the tendency to ruminate in response to stress. Every 6 weeks for the next 18 weeks participants completed measures assessing the occurrence of negative events, depressive symptoms, and substance misuse. Hierarchical linear modeling analyses indicated that adolescents who tend to ruminate in response to stress report greater elevations in depressive symptoms and substance misuse following elevations in negative events than other adolescents. The relationship between rumination, negative events, and substance misuse was moderated by age. Support was not obtained for fluctuations in depressive symptoms as a mediator of the relationship between negative events and substance misuse. Fluctuations in negative affect, however, were found to mediate this relationship.

Judgment under emotional certainty and uncertainty: the effects of specific emotions on information processing.

The authors argued that emotions characterized by certainty appraisals promote heuristic processing, whereas emotions characterized by uncertainty appraisals result in systematic processing. The 1st experiment demonstrated that the certainty associated with an emotion affects the certainty experienced in subsequent situations. The next 3 experiments investigated effects on processing of emotions associated with certainty and uncertainty. Compared with emotions associated with uncertainty, emotions associated with certainty resulted in greater reliance on the expertise of a source of a persuasive message in Experiment 2, more stereotyping in Experiment 3, and less attention to argument quality in Experiment 4. In contrast to previous theories linking valence and processing, these findings suggest that the certainty appraisal content of emotions is also important in determining whether people engage in systematic or heuristic processing.