A new method of monitoring motor activity in baboons

Movement activity of a normal baboon and of a baboon with induced Parkinsonism by unilateral administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was recorded by the Walter Reed Activity Monitor (or actigraph). Mean activity in the lesioned baboon was 41% less than that of the nonlesioned baboon measured over a 14-day period. In addition, the daily maximum activity value was significantly less in the MPTP-treated baboon. Moreover, resting and sleeping periods were 30% greater in the lesioned animal. The akinesia and resting and sleeping periods were displayed by the lesioned baboon throughout the day, whereas the control baboon showed them only at night. The data representing summarized movement activity are in accordance with observations of bradykinesia, hypokinesia, and akinesia of the MPTP-treated baboon. The actigraph was well tolerated by the animal because its small size and weight made it largely unobtrusive. We suggest that the actigraph is an appropriate device for measuring motor activity in nonhuman primates.     

Comparison of lingual vibrotactile suprathreshold numerical responses in men and women: effects of threshold shift during magnitude-estimation scaling

The purpose of this study was to investigate differences in tactile sensory system function between men and women. This task was accomplished by studying the effects of possible tactile threshold shifts occurring during magnitude-estimation scaling of vibratory stimuli presented to the dorsal surface of the tongue. 12 men (M age = 19.7 yr.) and 12 women (M age = 19.3 yr.) participated. Analysis suggested that men and women have tactile sensory systems that operate similarly at both threshold and suprathreshold levels of stimulation. Men and women do, however, choose to use consistently different numerical responses to suprathreshold stimuli, suggesting that environmental and/or cultural-educational influences may be involved in numerical decision-making aspects of the scaling process.     

The effects of verbal labeling on short-term and incidental memory: A cross-cultural and developmental study

Effects of induced verbal labeling on short-term and incidental memory were studied in Yucatan, Mexico. The 208 subjects, evenly divided by sex, were selected from four age groups (7–8, 10–11, 13–15, 20–21 years) from a large public school. Stimuli were cards depicting both animals and objects familiar to all subjects, and were presented over 14 trials. Short-term memory was tested with a probed serial recall task on each trial; incidental memory was tested following the 14 trials. Several results conformed to findings with earlier studies using American subjects: short-term memory improved with age; primacy and recency recall were influenced by both age and labeling; and the typical inverted U-shaped incidental memory function was found. Verbal labeling apparently aided recall by focusing attention on the relevant items, but such overt labeling also impeded the strategy of verbal rehearsal used by older subjects. Cultural factors appeared to play a limited role in the present study; the common element of formal schooling, among both American and Yucatecan subjects, was hypothesized as a possible explanation of such cross-cultural similarities.     

Daily and major life events: A test of an integrative model of psychosocial stress

The hypothesis that negative daily events mediate the relationship between major negative events and psychological symptomatology was tested using a three-wave, three-variable panel design. Measures of major and daily life events and psychological symptomatology were administered to 58 older adolescents at three time points during the transition from high school to college. The results indicated that the pathways from major life events to daily events and from daily events to psychological symptomatology were significant at each of the time points, but that the direct pathways from major events to psychological symptomatology were not significant at any time point. Thus, the hypothesis was fully supported. The findings are discussed in light of their implications for an integrative theory of the process by which major and daily events have an effect on psychological symptomatology.