Avoidance of driving in young adults and decreased cognitive functions.

Decrease in cognitive function is known to be the main cause of driving cessation in old age but the same has not been clearly established in young adults. Previous research has implicated a variety of psychological factors related to fear of driving in young adults. Present study focuses on the measure of cognitive skills in such individuals who avoid driving in spite of an opportunity and necessity to do so. Cognitive function tests for two domains – speed and attention were performed in young female non drivers and drivers. Our results show a highly significant decrease in cognitive ability (P<0.05) in non drivers compared to the drivers. Our study indicates that decreased cognitive functions may be the main cause of cessation of driving seen in small but significant group of population.

Digit Ratio (2d4d) and Performance in Indian Swimmers.

It has been suggested that achievement in sports is correlated with a putative measure of prenatal testosterone the 2nd to 4th digit ratio (2D: 4D). It has been shown that digit ratio (2D: 4D) is negatively associated with prenatal testosterone, and it is also negatively associated with ability in sports. This study examined associations between 2D: 4D and performance of both male and female National level Indian swimmers. Age matched non-sports personnel formed the control. Lengths of second and fourth digits were measured after scanning both hands and their ratio calculated. Our results show lower 2D:4D values in males compared to females (P<0.05). Among male, but not female, swimmers had significantly (P<0.05) lower 2D: 4D ratio. Low 2D: 4D in male swimmers suggests they are more prenatally programmed via long-lasting extra genital effects of testosterone. 2D: 4D ratio could be used to identify young sports personnel who have potential to reach high levels of performance.

Gender differences in predator induced pain perception in rats.

Pain is an unpleasant sensation. It warns the living being about the impending damage to the tissues. The perception of pain is influenced by physical and psychological factors. The impact of chronic intermittent psychological stress on pain perception and the differences in antinociceptive responses have been studied in male and anestrous female albino rats. Fifteen rats in each group were subjected to psychological stress, by exposing them to their natural predator--cat, for a duration of 20 min daily for 12 consecutive days. Tail flick response latency to radiant heat was used as a measure to evaluate pain perception. It was observed that both the groups had a relatively high pain threshold at the beginning of exposure schedule due to the modulation of opioid analgesic system by the higher level of circulating testosterone in males and low level of estrogen in anaestrous females. However, the threshold for pain perception showed a gradually declining trend in both the groups over the next 11 days to reach the control values. This increase in sensitivity to pain or decreased pain threshold could be attributed to the phenomenon of habituation.

Predator induced stress and its analgesic potential on estrous and anestrus albino rats.

It has been established that physical stress induces antinociceptive effect. In the present study efforts were made to investigate the role of chronic intermittent psychological stress in the induction of the analgesic effect and the probable role of estrous cycle in modulating the antinociceptive response. Albino rats in regular estrous cycle (n = 15) and those in anestrus (n = 15) were exposed to psychological stress for a period of 20 min each day for 12 consecutive days. The predator (domestic cat) was used to induce the psychological stress. At the end of each session tail flick response time to heat was recorded as a measure of pain perception. It was observed that female estrous rats had a low pain threshold in the beginning but its tolerance increased gradually reaching a peak by 6th to 7th day and returned to control level by 11th day. The anestrus female had higher pain threshold at the beginning and showed a gradual decline to reach the control level as estrous females by 12th day. These results suggest that the ovarian hormones and the corticosterone may modulate the impact of stressor on endogenous pain inhibition and other stress responsive systems.