Polyaminergic agents modulate contextual fear extinction in rats

Polyamines, such as spermidine and spermine, have been reported to improve memory retention through the activation of N-methyl-d-aspartate receptors (NMDAr). However whether polyamine agonists and antagonists alter extinction remains unclear. In the current study, we investigated whether spermidine and polyamine antagonists that selectively block the NR2B subunit at the NMDAr alter the extinction of contextual conditioned fear in male Wistar rats. The bilateral intra-hippocampal administration of exogenous spermidine (2 nmol/site) immediately after, but not 6 h after extinction training, facilitated the extinction of fear conditioning. The injection of the NMDAr antagonists arcaine (0.2 nmol/site), ifenprodil (20 nmol/site) and traxoprodil (0.2 nmol/site), disrupted fear extinction and, at doses that had no effect per se, reversed the facilitatory effect of spermidine on fear extinction. These results suggest that exogenous and endogenous polyamines facilitate the extinction of contextual conditioned fear through activation of NR2B subunit-containing NMDAr in the hippocampus. Since extinction-based exposure therapy is widely used as treatment for a number of anxiety-related disorders, including phobias and post-traumatic stress, the currently reported facilitation of extinction by polyaminergic agents suggest these compounds as putative candidates for drug development.     

The dynamics of contemporary therapies

Deviations of behavior induced in animals by motivational conflicts can be alleviated by pharmocologic, environmental and dyadic or group retraining procedures analogous to those employed clinically. To be successful in humans, basic therapeutic modalities involving rapport, anamnestic review, cognitive reorientations and guided rehabilitation should resonate with universal and urgent (Ur) aspirations for physical vitality, social security and existential serenity.Adapted from a Plenary Address to the Eighth World Congress of the World Psychiatric Association, Athens, Greece, October, 1989.Past President, American Psychiatric Association and Honorary Life President, World Association for Social Psychiatry.     

A Test of Multiple Achievement Goal Benefits in Physical Education Activities

The independent and combined effects of achievement goals for physical education activities were investigated. Both dispositional goal orientations as well as perceived motivational goal climate were assessed, and the paper evaluated four different hypotheses for multiple goal benefits (additive, interactive, specialized, and selective hypotheses). It was hypothesized that students may benefit most from endorsing both task and ego orientations in their fitness activities, especially depending on their perceptions of the motivational climate. However, benefits of pursuing multiple goal orientations were not found. Instead, students reported putting forth more effort, enjoying their fitness activities more, feeling more competent in the activity, and persisting after the semester when they endorsed a task orientation or perceived the motivational climate to be task oriented.     

A cross-cultural study of the representation of shape: Sensitivity to generalized cone dimensions

Many of the phenomena underlying shape recognition can be derived from an assumption that the representation of simple parts can be understood in terms of independent dimensions of generalized cones, e.g., whether the axis of a cylinder is straight or curved or whether the sides are parallel or nonparallel. What enables this sensitivity? One explanation is that the representations derive from our immersion in a manufactured world of simple objects, e.g., a cylinder and a funnel, where these dimensions can be readily discerned independent of other stimulus variations. An alternative explanation is that genetic coding and/or early experience with extended contours—a characteristic of all naturally varying visual worlds—would be sufficient to develop the appropriate representations. The Himba, a seminomadic people in a remote region of Northwestern Namibia with little exposure to regular, simple artifacts, were virtually identical to western observers in representing generalized-cone dimensions of simple shapes independently. Thus immersion in a world of simple, manufactured shapes is not required for the development of a representation that specifies these dimensions independently.     

The Clinical Application of Phantasy Studies

The role of external genital sensory feedback and sex of S and the effects on copulatory behavior were investigated. The prevention of semen plugs and anesthetization of the vagina had no significant effect on the running times of the female or the number of mounts of the male, when compared to a control group. Anesthetization of the penis and prevention of erection significantly reduced the number of mounts made by the male. Short term changes in external genital sensory feedback were found to be one factor affecting copulation; however, nonsexual factors were also suggested as possible determinants and cited as areas of subsequent research.     

Categorical perception of animal patterns

As part of the more general issue of whether culture can affect perception, the present paper addresses the Whorfian question of whether the language available to describe perceptual experience can influence the experience itself. It investigated the effect of vocabulary on perceptual classification by the study of a remote culture (Himba) which possesses a poor colour vocabulary but a rich vocabulary of animal pattern terms. Thus, the present study examined Categorical Perception (CP) with a type of visual stimulus not previously used to assess the effect of labels on perceptual judgments. For the animal patterns, the Whorfian view predicted that it would only be the Himba who showed superiority for cross‐category decisions as only they have the appropriate labels. The Whorfian view was upheld and confirmed previous findings that linked perceptual differences to labelling differences.     

Face familiarity, distinctiveness, and categorical perception

Four experiments with faces support the original interpretation of categorical perception (CP) as only present for familiar categories. Unlike in the results of Levin and Beale (2000), no evidence is found for face identity CP with unfamiliar faces. Novel face identities were shown to be capable of encoding for immediate sorting purposes but the representations utilized do not have the format of perceptual categories. One possibility explored was that a choice of a distinctive face as an end-point in a morphed continuum can spuriously produce effects that resemble CP. Such morphed continua provided unequal psychological responses to equal physical steps though much more so in a better likeness paradigm than for forced-choice recognition. Thus, researchers doing almost the same experiments may produce very different results and come to radically different conclusions.     

Maximizing noise energy for noise-masking studies

Noise-masking experiments are widely used to investigate visual functions. To be useful, noise generally needs to be strong enough to noticeably impair performance, but under some conditions, noise does not impair performance even when its contrast approaches the maximal displayable limit of 100 %. To extend the usefulness of noise-masking paradigms over a wider range of conditions, the present study developed a noise with great masking strength. There are two typical ways of increasing masking strength without exceeding the limited contrast range: use binary noise instead of Gaussian noise or filter out frequencies that are not relevant to the task (i.e., which can be removed without affecting performance). The present study combined these two approaches to further increase masking strength. We show that binarizing the noise after the filtering process substantially increases the energy at frequencies within the pass-band of the filter given equated total contrast ranges. A validation experiment showed that similar performances were obtained using binarized-filtered noise and filtered noise (given equated noise energy at the frequencies within the pass-band) suggesting that the binarization operation, which substantially reduced the contrast range, had no significant impact on performance. We conclude that binarized-filtered noise (and more generally, truncated-filtered noise) can substantially increase the energy of the noise at frequencies within the pass-band. Thus, given a limited contrast range, binarized-filtered noise can display higher energy levels than Gaussian noise and thereby widen the range of conditions over which noise-masking paradigms can be useful.     

Lasting Effects of Alcohol on the Reduction of Anxiety in Rats

A factor analysis was performed combining HSPQ forms A and B scores from a group of high school males (N = 1504) and a group of high school females (N + 1255). Eight factors were extracted and rotated from each of the two groups. It was found that the resulting factor patterns were both clearer (had better simple structure) and more closely matched the second order factor structure found among adults than previous HSPQ structures. These results supported the contention that (a) there are comparable second order personality factors between adults and high school students, and (b) since the factor pattern was similar to patterns found previously, the primary factors tend to be stable.