Maternal separation exaggerates the toxic effects of 6-hydroxydopamine in rats: implications for neurodegenerative disorders

Many studies have shown that early life stress may lead to impaired brain development, and may be a risk factor for developing psychiatric pathologies such as depression. However, few studies have investigated the impact that early life stress might have on the onset and development of neurodegenerative disorders, such as Parkinson's disease, which is characterized in part by the degeneration of dopaminergic neurons in the nigrostriatal pathway. The present study subjected rat pups to a maternal separation paradigm that has been shown to model adverse early life events, and investigated the effects that it has on motor deficits induced by a unilateral, intrastriatal injection of 6-hydroxydopamine (12 microg/4 microl). The female rats were assessed for behavioral changes at 28 days post-lesion with a battery of tests that are sensitive to the degree of dopamine loss. The results showed that rats that had been subjected to maternal separation display significantly impaired performance in the vibrissae and single-limb akinesia test when compared to normally reared animals. In addition, there was a significant increase in the loss of tyrosine hydroxylase staining in maternally separated rats. Our results therefore suggest that adverse experiences sustained during early life contribute to making dopamine neurons more susceptible to subsequent insults occurring during more mature stages of life and may therefore play a role in the etiopathogenesis of Parkinson's disease.     

Mags and Abs: Media Consumption and Bodily Concerns in Men

Media messages directed toward men increasingly promote the hypermuscular male body, an ideal impossible for most men to achieve. In this study we investigated the association between media consumption and bodily concerns in a sample of 89 college men. Reading male-directed magazines was associated with concerns about muscularity and general fitness, beauty product use, and dietary supplement use to build muscle. Low self-esteem was linked to weight concerns. Men's media exposure was also associated with their standards for women's bodies: the more male-directed magazines a man read and the more movies he saw, the more he valued thinness in women.     

Reducing the threat value of chronic pain: A preliminary replicated single-case study of interoceptive exposure versus distraction in six individuals with chronic back pain

This paper describes a preliminary experimental evaluation of a technique intended to help people suffering from chronic back pain and low pain acceptance to alter the aversiveness or threat value of their persisting pain. Using a multiple baseline cross-over design six individuals with chronic back pain were taught to use a form of interoceptive exposure as well as a relaxation/distraction breathing-based technique in the presence of their pain. Half the participants used one method for three weeks, and then crossed over to the other method for a further three weeks. The other half did the reverse. Assessments were conducted at pre/post treatment and at a three month follow-up. Daily monitoring of pain-related distress was also completed. The results indicated moderately high improvements in pain acceptance across most participants and corresponding declines in pain-related distress. No clear differences occurred between conditions, but the changes on disability and catastrophising scales for most cases were consistent with those reported after more substantial interventions. The study raises some important clinical and methodological issues that could inform future research in this area.     

Simple movement imitation: Are kinematic features sufficient to map perceptions into actions?

The aim of this study was to pinpoint the nature of the visual features used in the automatic mapping of perceived movements into similar executed movements, following the direct matching hypothesis. In Experiment 1 subjects imitated the lifting of one of two fingers, presented with different orientations. As predicted, stimuli which were further rotated away from the posture of the executing hand elicited slower reaction times. In Experiment 2, we verified that this orientation effect was not a purely perceptual effect by presenting the same stimuli but asking subjects to respond verbally. No orientation effect was found using a verbal response. In Experiment 3, we replaced the moving fingers by two arbitrary objects moving with the trajectories of the finger tips of Experiment 1. The same orientation effect as in Experiment 1 was observed. We conclude that in this experiment participants are using purely kinematic features to map perceived into executed movements.     

Gustatory responses during periods of controlled and ad lib cigarette smoking

Three psychophysical methods, differential sensitivity, perceived intensity, and degree of liking, were used to measure gustatory responses among nonsmokers and among smokers who were placed on 2-week schedules of increased and decreased cigarette consumption. Varying the smoking levels had little influence on the smokers’ sensitivity to the tastes of sucrose and sodium chloride. Throughout the experiments, nonsmokers were slightly more sensitive than smokers. Lower intensity ratings were ascribed to both compounds by smokers than by nonsmokers. Degree of liking of the test solutions was unrelated to smoking. A subsequent experiment showed that 45 nonsmokers were slightly, but not significantly, more sensitive than were 45 smokers to the tastes of sucrose, sodium chloride, citric acid, and quinine hydrochloride, with no differences in their sensitivity to the odor of 2-butanone and to the viscosity imparted by carrageenan gum. There was a slight inverse relationship between sensitivity and the number of cigarettes smoked per day. Smokers liked coffee significantly better and drank more cups per day than did nonsmokers. Few changes in body weight were observed, despite the smokers’ subjective assessment that their appetites and food intake were inversely related to the number of cigarettes smoked.     

Scaling of dot numerosity

Subjective impression of numerosity of dots randomly scattered in an area of 19.5 × 24.5 cm, 36≈1,010 in number (?), was scaled by four different methods with five subjects. The absolute identification showed that the number of dots is underestimated if ? > 10. Each of two scales based uponratio judgments is a power function of $ with the exponent of 0.87, and each of two scales based upondifference judgments is also a power function of ? when the origin of the scale is appropriately defined. The relationship between the four scales and comparison with scales in other sense modalities were discussed from the viewpoint of scaling methodology.     

Gender differences in object location memory in a real three-dimensional environment

In this preliminary study we investigate gender differences in object location memory. Our purpose is to extend the results about object location memory obtained in laboratory settings to a real 3-D environment and to further distinguish the specific components involved in this kind of memory by considering the strategies adopted to perform the task. To do this, we join the three-level model of spatial representations (landmark, route, and survey) proposed by Siegel and White (1975) with the three subcomponents of spatial memory (what, where, and what + where) identified by Postma and De Haan (1996). We adopted the object relocation task devised by Postma and De Haan (1996), adapted to a real environment. Seven common objects were placed on the floor of a cylindrical room. Sixty-four males and 64 females were asked to memorize the spatial layout. Next, the experimenter moved the objects to a different position along with seven new objects and the participants had to relocate the original objects to their initial positions. In line with Postma, Izendoorn, and De Haan (1998), we found no gender difference in object recognition, and in recalling absolute distance and categorical spatial relations; however males were better than females in recalling the distance between objects and the size of the layout. Overall, the data show a male advantage in some components of spatial cognition closely linked to the encoding of the metric structure of the spatial relationships at both route and survey level.     

INTER-LANGUAGE COMPARISON OF WORD-ASSOCIATION RESPONSES1

Comparaison des associations verbales dans différentes langues. — Le but du présent article est de comparer, en se basant sur une population polonaise, numé-riquement la plus nombreuse parmi les populations européennes étudiées, la communauté des associations verbales pour des groupes d'étudiants de différents pays, testés selon la méthode de Kent-Rosanoff. De la comparaison des resultats américains, français, allemands et polonais, il apparaît que près de la moitié des associations sont équivalentes sur la base des traductions. La thèse suivant laquelle les associations les plus fréquentes dans une langue donnée auront un contenu analogue aux réponses correspondantes dans une autre langue ne trouve pas de confirmation dans les résultats polonais. d'une comparaison plus détaillée des populations polonaise et americaine, il ressort que la communauté des associations les plus fréquentes est trés inférieure chez les sujets polonais et qu'un stimulus donné évoque davantage de réponses différentes. Les associations les plus fréquentes sont en général paradigmatiques par rapport aux stimuli. Dans les réponses polonaises, outre cette tendance paradigmatique, on observe une assez forte tendance syntagmatique. L'utilisation d'une consigne spéciale affaiblit cette tendance : les résultats polonais se rapprochent alors des résultats americains.