Testing the reinforcing properties of S-: a replication of Lieberman''s procedure

A critical issue in testing theories of observing is whether the stimulus associated with extinction (the S-) reinforces observing responses. In previous experiments, subjects have been trained to make observing responses that produce both the S- and the stimulus correlated with reinforcement (the S+). Then, either the S+ or the S- has been withheld. Conflicting results have been attributed to differences among species. In the present experiments, pecking one key by master pigeons was reinforced with grain on a variable-ratio extinction schedule. Yoked pigeons received the grain on a variable-interval, extinction schedule controlled by the variable-ratio performances of the master birds. For both groups, concurrent pecking on a second key was reinforced on a variable-interval schedule with displays of discriminative stimuli. Subsequently, either the S+ or the S- was eliminated from the procedure. Omission of S+ produced a large decrease, as predicted by traditional conditioned reinforcement accounts of observing. By itself, S- did not maintain observing. A smaller and less reliable decrease, comparable to that obtained by Lieberman (1972) with rhesus monkeys, occurred when S- was eliminated. This replication with pigeons of Lieberman's results indicates that they are not species-specific, and the fact that observing was not maintained by S- alone suggests that the decrease obtained when S- was omitted is not attributable to the reinforcing power of S-.     

Laboratory control of toe-sucking in a young rhesus monkey by two kinds of punishment

Both response-contingent withdrawal of a visual reinforcement and response-contingent presentation of an aversive stimulus (loud noise) were found to be effective in suppressing toe-sucking in a young rhesus monkey.     

Acute aerobic exercise improves memory across intensity and fitness levels

ABSTRACT

The present study was designed to examine the impact of exercise intensity and aerobic fitness on free recall, judgments of learning (JOLs), and metacognitive accuracy. In Experiment 1, 30 college students engaged in either (1) no exercise, (2) light exercise (55% of predicted maximal heart rate), or (3) moderate exercise (75% of predicted maximal heart rate) on three different days. In Experiment 2, 29 high-fit students (VO₂ max?≥?70th percentile) and 28 low-fit students (VO₂ max?≤?50th percentile) completed sedentary and light exercise conditions. In both experiments, free recall scores significantly increased in the exercise conditions compared with the sedentary condition, but JOL magnitude and metacognitive accuracy were largely unaffected. These results demonstrate that exercise can improve recall at both light and high intensities, and that the benefit can be obtained by individuals regardless of their fitness level.     

To Balance or not to Balance: Confirmatory Factor Analysis of the Affect-Balance Scale

This study examined the psychometric quality of the Affect-Balance Scale (ABS) (Bradburn, 1969) using data collected from 292 middle-aged and older adults, living independently. The dimensionality of the scale was examined, the quality of individual items was tested, and the validity of the ABS was studied. Using a tetrachoric correlation matrix with the robust weighted least squares (WLSMV) estimation method of the Mplus program, we found that two moderately correlated (r = -0.37) constructs are needed to adequately account for the pattern of item scores in the ABS. Two of the 10 ABS items were found to be problematic. When raw sum scores were used in analysis, the correlation between the positive-affect and the negative-affect subscales was lower (r = -0.17), indicating that random and nonrandom measurement error masked the relationship between the two. While affect-balance correlated substantially with five criterion well-being measures, the negative-affect subscale (which constitutes half of the ABS) had a similar pattern of correlations, with only slightly lower magnitude. The theoretical construct of nobreak 'balance' is also questioned. The 'balance' scoring method (subtracting the negative-affect subscale score from the positive-affect subscale score) nets exactly the same score as does summing scores from both subscales together. Accordingly, the summed scores have the very same correlations with other variables as do the balance scores.     

The prevalence of compulsive hoarding and its association with compulsive buying in a German population-based sample

The aims of the study were to estimate the prevalence rate of compulsive hoarding, and to determine the association between compulsive hoarding and compulsive buying in a nationally representative sample of the German population (N = 2307). Compulsive hoarding was assessed with the German version of the Saving Inventory-Revised (SI-R; Frost, R.O., Steketee, G., & Grisham, J. (2004). Measurement of compulsive hoarding: saving inventory-revised. Behaviour Research and Therapy, 42, 1163-1182.). The point prevalence of compulsive hoarding was estimated to be 4.6%. Individuals with compulsive hoarding did not differ significantly from those without compulsive hoarding regarding age, gender, and other sociodemographic characteristics. Significant correlations were found between the compulsive hoarding and the compulsive buying measures. Participants with compulsive hoarding reported a higher propensity to compulsive buying than respondents without hoarding. About two thirds of participants classified as having compulsive hoarding were also defined as suffering from compulsive buying. In summary, these results suggest that compulsive hoarding may be relatively prevalent in Germany and they confirm the close association between compulsive hoarding and compulsive buying through the investigation of a large scale representative sample.     

When autocratic leaders become an option--uncertainty and self-esteem predict implicit leadership preferences

We investigated the impact of uncertainty on leadership preferences and propose that the conjunction of self-esteem level and stability is an important moderator in this regard. Self-threatening uncertainty is aversive and activates the motivation to regain control. People with high and stable self-esteem should be confident of achieving this goal by self-determined amelioration of the situation and should therefore show a stronger preference for democratic leadership under conditions of uncertainty. By contrast, people with low and unstable self-esteem should place their trust and hope in the abilities of powerful others, resulting in a preference for autocratic leadership. Studies 1a and 1b validate explicit and implicit leadership measures and demonstrate a general prodemocratic default attitude under conditions of certainty. Studies 2 and 3 reveal a democratic reaction for individuals with stable high self-esteem and a submissive reaction for individuals with unstable low self-esteem under conditions of uncertainty. In Study 4, this pattern is cancelled out when individuals evaluate leadership styles from a leader instead of a follower perspective.     

Perceived social support, self-efficacy, and adjustment to abortion

Prior to their having a 1st trimester abortion, women's perceptions of social support from their partner, family, and friends and self-efficacy for coping were assessed. Depression, mood, physical complaints, and anticipation of negative consequences were measured after the 30-min recovery period. As predicted, perceived social support enhanced adjustment indirectly through its effects on self-efficacy. Women who perceived high support from their family, friends, and partners had higher self-efficacy for coping. Higher self-efficacy, in turn, predicted better adjustment on the psychological measures but not on the physical complaint measure. No direct path between social support and adjustment was observed. In addition, women who told close others of their abortion but perceived them as less than completely supportive had poorer postabortion psychological adjustment than either women who did not tell or women who told and perceived complete support.