Physiology & behavior
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The purpose of the present study was to determine the effect of the menstrual cycle on dressing behavior in cold exposure. Rectal and skin temperatures, temperature sensation and metabolic rate were measured in seven women during the luteal (L) and the follicular (F) phases of the menstrual cycle, as was their dressing behavior in these two phases. The subjects were instructed to dress so as to feel comfortable when the ambient temperature was decreased from 30 degrees C to 15 degrees C (07:00-09:00). ⋯ They felt cooler in the L phase during the last 30 min of the temperature fall. Rectal and skin temperatures showed significant differences between L and F phases and metabolic rate was significantly higher in the L phase. The results can be interpreted in terms of the establishment of a higher set-point in core temperature during the L phase.
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Physiology & behavior · May 1995
Locomotor activity and melatonin rhythms in rats under non-24-h lighting cycles.
The adjustment of pineal melatonin and locomotor activity rhythms to 10:10-h light:dark (LD) or 14:14-h LD cycles was studied in male Wistar rats. Both lighting conditions were thought to be outside the limits of entrainment of the rest-activity rhythm in this species. We assumed that the rhythm of pineal melatonin synthesis might be more adaptable. ⋯ This melatonin pattern fitted the LD-adjusted activity rhythm. Thus, the melatonin rhythm did not adapt better than the activity rhythm to the exotic LD cycles. Instead, parallel changes were found.
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Physiology & behavior · Feb 1995
Effects of ketamine, a noncompetitive NMDA antagonist, on the acquisition of the lever-press response in rats.
We analyzed the effects of ketamine, a noncompetitive NMDA antagonist, on the acquisition of the lever-press response in the Skinner box and on motor performance both in the open field and in the inclined screen. Ninety-six adult male Wistar rats were assigned at random to eight different groups (n = 12). ⋯ Results showed that ketamine impaired the acquisition of the lever-press response in a dose-dependent manner, with no effects on ambulation in the open field nor on length of stay in the inclined screen. These results suggest that ketamine effects on the acquisition of the lever-press response cannot be attributed to a motor impairment, indicating a possible specific effect of ketamine on the associative learning acquisition.
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Physiology & behavior · Jan 1993
Restrained and nonrestrained eaters' orienting responses to food and nonfood odors.
Dietary restraint was assessed by Stunkard and Messick's (1985) three-factor eating questionnaire, using the restraint subfactor score only in normal-weight college students (n = 41). The subjects were than assessed for skin conductance orienting responses (ORs) to food and nonfood odors when hungry and sated (after a standard breakfast and after an overnight fast). Subjects also rated their hunger and each odorant for pleasantness on separate 7-point scales. ⋯ Finally, nonrestrained subjects rated food and nonfood odors approximately equal in pleasantness, while the restrained eaters rated food odors as more pleasant than the nonfood odors. These results suggest that restrained eaters must certainly process odor stimuli related to foods, but also suggests that orienting to these salient (informative) cues is restricted. Perhaps in defense of the diet, restrained eaters learn methods/responses (cognitive strategies, instructional sets) to block orienting to food related cues such as odors.
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I have examined whether adults can recognize their boyfriends/husbands or girlfriends/wives by stroking either their partner's hand or face. On both trials, subjects were asked to chose their mate from amongst two unfamiliar age- and gender-matched adult foils. During testing, the subject's eyes and nose were covered and auditory cues were masked by ambient noise. ⋯ However, while both women and men were successful at the face-touch-recognition task, only the women were successful at the hand-recognition task. I conclude that tactile cues afforded by stroking skin are sufficiently salient to allow for individual recognition. As for the gender-related difference, women may have an advantage at hand recognition because men's hands are more discriminable than women's hands.