Proactive behavioral effects of theta-blocking septal stimulation in the rat

The induction of hippocampal theta rhythm using low-frequency septal stimulation has been shown to proactively (1) facilitate the acquisition and (2) increase resistance to extinction of a food-rewarded fixed-ratio (FR) bar-press response (Holt & Gray, Quarterly Journal of Experimental Psychology, 35B, 97-118, 1983). Both (1) and (2) are also seen after septal lesions. This suggests that Holt and Gray's (1983) results may have been due either to stimulation-produced theta waves (the "theta" hypothesis), or a small septal lesion produced by the stimulating current (the "lesion" hypothesis). Both hypotheses were tested in the present experiment using high-frequency septal stimulation. In one of two treatment conditions male Sprague-Dawley rats, chronically implanted with a bilateral septal stimulating electrode and a unilateral bipolar hippocampal recording electrode, received (1) trains of continuous pulses at 77 Hz which blocked the hippocampal theta rhythm, or (2) trains of pulses at 100 Hz interrupted by a 30-msec interval at a frequency of 7.7 Hz. Control animals were implanted but not stimulated. Acquisition of a discrete-trial bar-press response on a fixed ratio 5 reinforcement schedule immediately followed the treatment phase. After 15 days' acquisition all animals were extinguished over the subsequent 12 days. Results indicated that both types of septal stimulation reduced resistance to extinction of barpressing; theta-blocking stimulation produced the greater effect. Theta-blocking stimulation retarded the acquisition of bar-pressing in the early stages of training. These overall results are exactly opposite to those produced by low-frequency (7.7 Hz) theta-driving septal stimulation (Holt & Gray, 1983) and contrary to the predictions of the lesion hypothesis. Furthermore, these findings support the idea that long-term changes in behavior may depend on stimulation-produced changes in the hippocampal theta rhythm.     

Adult but not juvenile Barbary macaques spontaneously recognize group members from pictures

For group-living animals, it is crucial to distinguish one’s own group members from those of other groups. Studies applying operant conditioning revealed that monkeys living in relatively small groups are able to recognize their own group members when tested with photographs of group members and other conspecifics. Employing a simple looking time paradigm, we here show that Barbary macaques living in two social groups comprising 46 and 57 individuals, respectively, at the enclosure ‘La Forêt des Singes’ at Rocamadour are able to spontaneously distinguish photographs of members of their own group from those depicting animals that belong to another group. This ability appears to develop with age, as juveniles did not discriminate between members of their own group and another group, although they showed generally more interest in the pictures than did adults. Juveniles frequently displayed picture directed behaviours such as lip-smacking, touching and sniffing in both conditions, indicating that the stimuli were highly salient to them. In conclusion, it appears that at least adult monkeys are able to memorize the faces of a large number of individuals. Whether the difference in behaviour is based on individual recognition of one’s own group members or simply the discrimination based on familiarity remains unresolved. However, both mechanisms would be sufficient for group membership identification.     

Body shape and size depictions of African American women in JET magazine, 1953-2006

Depictions of Caucasian women in the mainstream media have become increasingly thinner in size and straighter in shape. These changes may be inconsistent with the growing influence of African American beauty ideals, which research has established as more accepting of larger body sizes and more curvaceous body types than Caucasians. The present study looked at trends in the portrayal of African American women featured in JET magazine from 1953 to 2006. Beauty of the Week (BOW) images were collected and analyzed to examine body size (estimated by independent judges) and body shape (estimated by waist-to-hip ratio). We expected body sizes to increase and body shapes to become more curvaceous. Results revealed a rise in models' body size consistent with expectations, but an increase in waist-to-hip ratio, contrary to prediction. Our findings suggest that the African American feminine beauty ideal reflects both consistencies with and departures from mainstream cultural ideals.     

The Mental Changes Due to Frontal Lobe Damage

The literature suggests association between arousal, general activation, and anxiety on the one hand, and time judgments on the other hand, implying that reported differences in time judgment between nosological groups may be confounded by group differences in arousal-anxiety.

Self-report measures of anxiety, as well as magnitude estimates and magnitude productions of standards ranging from 500 to 2000 msec in 250 msec steps and presented in 10 randomized blocks, were obtained from 16 male normals and from 16 male hospitalized patients with a tentative diagnosis of chronic undifferentiated schizophrenia. Only 10 of the 16 patients were later found to have the same confirmed diagnosis. Data from nine normals and from seven chronic undifferentiated schizophrenics met a criterion of linearity of response functions for both time judgment methods and were further analyzed.

Magnitude estimates and magnitude productions showed underestimation of elapsed time, both types of judgment exhibited satisfactory reliability, estimates showed “shortening,” and productions showed “lengthening” over blocks of trials.

Intercepts of the response × standards functions were not generally equal to zero, were more negative in estimation than in production, had marginal reliability or were unreliable, did not correlate significantly between methods, and did not show significant trends over blocks of trials.

Following a model by Carlson and Feinberg, slopes of response × standard functions were used as estimates of the rate of the “internal clock.” (In estimation, the rate is equal to the slope; in production, it is equal to the reciprocal of the slope.) Average rates of the internal clock did not differ between methods for normals, but were higher in production than in estimation for the seven patients. Clock rates did not differ significantly between groups, were reliable, and exhibited positive correlation between methods. Clock rates exhibited trends over blocks of trials: arctan equivalents of clock rates were linearly related to ordinal numbers of blocks of trials and showed decreases, or “slowing” of the internal clock, in both methods.

Differences in mean anxiety between groups were not significant. In each group, anxiety scores showed positive average correlations with magnitude estimates and negative average correlations with magnitude productions, failed to correlate significantly with intercepts, but showed positive correlations with clock rates.

The data also suggest that anxiety and intrasubject variability may be interrelated.

To conclude: Reported differences in time judgments between nosological groups may not solely be due to nosological differences per se, but instead may be due to group differences in anxiety.     

A Cyclical Model of Motivational Constructs in Web-Based Courses

The current study investigates antecedents and outcomes of motivation to learn across nine Web-based courses. The results supported a cyclical model of motivational processes across courses in a training curriculum. Trainees' course expectations had a positive effect on motivation to learn, motivation to learn had a positive effect on trainee reactions, and trainee reactions predicted expectations for subsequent courses in the curriculum. In addition, motivation to learn decreased across the nine courses such that the average level of motivation was 0.30 points lower (on a 5-point scale) for the ninth than the first course. Agreeableness predicted changes in motivation to learn such that motivation decreased at a steeper rate for highly agreeable trainees across courses. The results suggest that there is a dynamic interplay among motivational constructs over time, and motivation should be examined from a systems perspective to understand carryover effects across training courses.     

Mutual influences between the implicit and explicit self-concepts: The role of memory activation and motivated reasoning

Whereas previous research has predominantly focused on dissociations between the explicit and implicit self-concepts, the current research investigates how these aspects of self-representation come into correspondence through the activation of information about the self in memory. Experiment 1 provides evidence for a “bottom-up” process of self-construal in which information activated in the implicit self-concept produces congruent changes in the explicit self-concept. Experiment 2 provides evidence for a “top-down” process of self-construal in which the motivated assertion of a propositional belief in the explicit self-concept leads, via a process of confirmatory hypothesis testing, to the activation of substantiating information in the implicit self-concept. These two processes of self-concept change are integrated within a framework that specifies how the explicit and implicit self-concepts are related within an overall, dynamic self-system. Possibilities for expanding the framework to account for self-concept dissociations are discussed.     

To escape blame, don't be a hero—Be a victim

In situations where people (or their lawyers) seek to escape blame for wrongdoing, they often use one of two strategies: frame themselves as a hero (hero strategy) or as a victim (victim strategy). The hero strategy acknowledges wrongdoing, but highlights previous good deeds to offset blame. The victim strategy also acknowledges wrongdoing, but highlights the harms suffered by the perpetrator to deflect blame. Although commonsense suggests that past good deeds can offset blame from transgressions, moral typecasting (Gray & Wegner, 2009) suggests otherwise. Despite past good deeds, heroes remain blameworthy as moral agents. On the other hand, victims are moral patients and thus incapable of blame. Three studies found that victim strategy consistently reduced blame, while the hero strategy was at best ineffectual and at worst harmful. This effect appeared to stem from how the minds of victims and heroes are perceived.     

Alcohol First Use and Attitudes Among Young Children

We describe the attitudes and first use of alcohol by children, grades 3-6, who participated in the Bogalusa Heart Study, 1993-94. Questionnaire data reflected that more than one-third of the children had experimented with alcohol at the time of the study. The dominant environmental factor in experimentation was family modeling, and the dominant personal factor was curiosity, regardless of race, gender, or grade. Most children believed that alcohol use can lead to accidents, that drinking has negative social consequences, and that alcohol use hurts only if done to excess. Indications are that young children generally have negative attitudes regarding alcohol use, and that public and family alcohol education efforts need to be more specific about deleterious effects of even low levels of alcohol use in the young.