High-fat diets impair spatial learning in the radial-arm maze in mice

It has been suggested that hyperglycemia and insulin resistance triggered by energy-dense diets can account for hippocampal damage and deficits of cognitive behaviour. We wonder if the impairment of learning and memory processes detected in diet-induced obese (DIO) mice is linked to diet composition itself. With this purpose we have evaluated learning performance in mice undergoing a short-term high-fat (HF) treatment, which leads to a pre-obese state characterized by increased adiposity without significant changes of glucose and insulin plasma levels. C57BL/6J mice were fed either a HF (45 kcal% from fat) or control diet (10 kcal% from fat) during 8 weeks. Learning performance was evaluated by using the four-arm baited version of the eight-arm radial maze test (RAM). Mice were trained to learn the RAM protocol and then memory was tested at different time-points. Time spent to consume food placed in baited arms and errors committed to find them were measured in all sessions. DIO mice significantly spent more time in learning the task and made a greater number of errors than controls. Moreover, retention tests revealed that both working and total memory errors were also more numerous in DIO mice. The current results show that short-term DIO impairs spatial learning and suggest that impairment of hippocampal learning elicited by HF diets might be perceptible before metabolic alterations linked to obesity develop.     

Intra-female aggression in the mouse (Mus musculus domesticus) is linked to the estrous cycle regularity but not to ovulation

Intraspecific communication between mice takes place mainly via urinary chemosignals or "pheromones". Pheromones can influence aggressive and reproductive behavior as well as the neuroendocrine condition of the recipient female mice via their olfactory system. In this study, reproductively cyclic mice in the estrus phase were used to test intraspecific agonistic aggressive behavior. Data were obtained also on the count of the eggs shed in the oviducts. The results showed that (i) individually housed female mice are more aggressive toward an intruder female mouse than grouped mice, (ii) mice in which the vomeronasal organ was removed show aggressive behavior intermediate between individually housed and grouped mice, and (iii) a within group analysis did not show a positive correlation between aggression and presence of shed eggs in the oviducts.     

Perceptual visual skills in young highly skilled basketball players

A simple method was designed to evaluate visual abilities such as disance visual acuity, binocular horizontal visual field, simple and choice visual reaction times, and stereoscopic vision in skilled 11- to 13-yr.-old basketball players participating in a 15-day summer training camp. On a test battery, visual abilities were monitored in 473 players of the Spanish Basketball Federation over a 5-yr. period. The players showed outstanding scores on distance visual acuity and stereoscopic vision, and good visual reaction times and horizontal visual fields. When scores were compared by sex and age, significant differences on certain visual measures were observed. Many layers showed crossed eye-hand dominance. Visual screening programs may help promote visual health among junior basketball players and could be used for performance training.     

Expert-novice differences in cognitive and execution skills during tennis competition

This study deals with decision and execution behavior of tennis players during competition. The study is based on the expert-novice paradigm and aims to identify differences between both groups in the decision-making and execution variables in serve and shot actions in tennis. Six expert players (elite Spanish tennis players) and six novice players (grade school tennis players) took part in this study. To carry out this study, the observation protocol defined by McPherson and Thomas in 1989, in which control, decision-making and execution variables were included, was used, where it was applied to the performance of the tennis player in a real match situation. In the analysis, significant differences between experts and novices in decision-making and execution variables are found wherein it can be observed that experts display a greater ability to make the appropriate decisions, selecting the most tactical responses to put pressure on the opponent. Expert tennis players were also able to carry out forceful executions to their opponent with greater efficiency, making the opponent's response to a large extent more difficult. These findings are in accordance with those of McPherson and colleagues.     

Mental number line disruption in a right-neglect patient after a left-hemisphere stroke

A right-neglect patient with focal left-hemisphere damage to the posterior superior parietal lobe was assessed for numerical knowledge and tested on the bisection of numerical intervals and visual lines. The semantic and verbal knowledge of numbers was preserved, whereas the performance in numerical tasks that strongly emphasize the visuo-spatial layout of numbers (e.g. number bisection) was impaired. The behavioral pattern of error in the two bisection tasks mirrored the one previously described in left-neglect patients. In other words, our patient misplaced the subjective midpoint (numerical or visual) to the left as function of the interval size. These data, paired with the patient's lesion site are strictly consistent with the tripartite organization of number-related processes in the parietal lobes as proposed by Dehaene and colleagues. According to these authors, the posterior superior parietal lobe on both hemispheres underpins the attentional orientation on the putative mental number line, the horizontal segment of the intraparietal sulcus is bilaterally related to the semantic of the numerical domain, whereas the left angular gyrus subserves the verbal knowledge of numbers. In summary, our results suggest that the processes involved in the navigation along the mental number line, which are related to the parietal mechanisms for spatial attention, and the processes involved in the semantic and verbal knowledge of numbers, are dissociable.     

Managing stress and managing illness: Survival and quality of life in chronic disease

Interest has been steadily building in the impact of stress on psychological and physiological functioning, in particular on immune system responses, furthering the concept of a strong connection between the mind and the body. Implications for prevention of disease onset or treatment of stress-induced illness or immunocompromised conditions have been explored through the implementation of stress management techniques. Cognitive behavioral stress management interventions, biofeedback, relaxation, guided imagery, hypnosis, individual and group psychotherapy, aerobic exercise, and guided self-efficacy treatment are briefly reviewed to identify possible treatment mechanisms that may affect immune function and promote quality of life. The application of behavioral techniques to reduce distress and sharpen coping skills has great promise in reducing the costs associated with chronic disease and in enhancing quality of life among those afflicted.Presented at the APA Presidential Miniconvention, To Your Health: Psychology Through the Life Span, Session VIII, Assuring a Healthy Lifestyle: Psychology Delivers. Chair: Diane J. Willis, Ph.D. The third author received partial funding through the Terry Fox Research Fellowship 5257, National Cancer Institute of Canada.     

CER suppression, passive-avoidance learning, and stress-induced suppression of drinking in the Syracuse high- and low-avoidance strains of rats (Rattus norvegicus)

The Syracuse strains of Long-Evans rats were selectively bred for good (SHA) or poor (SLA) avoidance learning in a two-way shuttle box, which resulted in a phenotypic difference that is correlated with behavior patterns indicative of emotional reactivity, SLA animals showing evidence of greater emotional reactivity than SHA animals. The first three experiments examined conditioned suppression of bar pressing and compared paired and unpaired conditioned- and unconditioned-stimulus presentations to evaluate the influence of conditioning versus primary aversive stimulation on baseline responding. SLA animals acquired conditioned suppression faster than SHA animals and also showed greater suppression of baseline responding than SHA animals. In Experiment 4, SLA animals learned a passive-avoidance task faster than SHA animals. In Experiment 5, SLA animals showed greater stress-induced suppression of drinking a weak quinine solution than SHA animals. These data are consistent with the hypothesis that SLA animals are more emotionally reactive than SHA animals.     

Sex stereotypes and implicit personality theory. II. A trait-inference approach to the assessment of sex stereotypes

Two experiments were conducted to assess sex stereotypes using the trait-inference method originated by Asch (1946). In both, subjects were asked to make inferences about the personality of a male or a female stimulus target who was introduced by a brief list of traits. In Experiment 1 this trait list described the target as either good or bad in intellectual activities and as either warm or cold while in Experiment 2 the introductory list comprised traits which are relatively neutral in terms of evaluation. Subjects rated the stimulus persons on adjective scales selected to reflect dimensions of personality perception reported in previous research. In both studies, male targets were rated significantly higher than females in terms of the Intellectual Desirability dimension. In addition, female targets tended to be rated higher on Communion in Experiment 1 (p<.06), and lower than males on Potency in Experiment 2 (p<.07). No differences as a function of stimulus sex were obtained for Social Desirability, Activity, and Agency. The results suggest that the dimension of implicit personality theory most closely associated with perceived sex differences is a combination of Intellectual Desirability and Potency. The male end of this dimension is relatively well defined by traits which convey a hard-headed, rational approach to problem solving. The female end is much less elaborated and consists of traits reflecting soft-heartedness.     

A pilot study of the effects of expressive writing on psychological and behavioral adjustment in patients enrolled in a Phase II trial of vaccine therapy for metastatic renal cell carcinoma.

Forty-two patients with metastatic renal cell carcinoma who were participating in a Phase II clinical trial were randomly assigned to an expressive writing (EW) or neutral writing (NW) group. Patients in the EW group wrote about their cancer, and patients in the NW group wrote about health behaviors. No statistically significant group differences were found in symptoms of distress, perceived stress, or mood disturbance, except for the Vigor subscale of the Profile of Mood States. However, patients in the EW group reported significantly less sleep disturbance, better sleep quality and sleep duration, and less daytime dysfunction compared with patients in the NW group. The results suggest that EW may have sleep-related health benefits in terminally ill cancer patients.