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941.
    
The light-emitting diode (LED) is becoming increasingly popular as a luminance source in behavioral research. We describe a simple, inexpensive LED driver circuit that produces luminances almost linearly proportional to an input voltage. Negative feedback provides a stable output. Unlike previous designs, the LED is ground referenced.  相似文献   
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In a mental rotation task, participants must determine whether two stimuli match when one undergoes a rotation in 3-D space relative to the other. The key evidence for mental rotation is the finding of a linear increase in response times as objects are rotated farther apart. This signature increase in response times is also found in recognition of rotated objects, which has led many theorists to postulate mental rotation as a key transformational procedure in object recognition. We compared mental rotation and object recognition in tasks that used the same stimuli and presentation conditions and found that, whereas mental rotation costs increased relatively linearly with rotation, object recognition costs increased only over small rotations. Taken in conjunction with a recent brain imaging study, this dissociation in behavioral performance suggests that object recognition is based on matching of image features rather than on 3-D mental transformations.  相似文献   
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This study evaluated laterality in scratching by chimpanzees (n = 89) during socially arousing circumstances. Hand use and the side of the body scratched was recorded during a baseline and experimental condition. In the experimental condition, chimpanzees were shown a video of other conspecifics sharing, fighting over, and consuming a watermelon. Self-touches were categorized as either rubs or scratches. The chimpanzees showed a significant right hand bias for rubbing and also significantly directed the rubs to the right side of the body. For scratching, the chimpanzees showed no hand preference but a significant bias for scratching on the left side of the body. These results support the view that the right hemisphere regulates the autonomic nervous system during arousal.  相似文献   
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Rhesus monkeys (Macaca mulatta) with bilateral ibotenic acid-produced lesions of the amygdala were compared with controls in several novel situations, including exposures to metal objects, toy animals, and a person. Early in testing, the monkeys with lesions showed reduced inhibitions on responsiveness compared with controls. With continuing exposures, differences between groups diminished sharply as inhibitions waned in the controls. This outcome is consistent with the hypothesis that the amygdala mediates caution in initial reactions to ambiguous or threatening novel situations, which, in the absence of adverse consequences, diminishes with repetition. Consistency of individual responsiveness across different situations, including pairing with other monkeys, was substantial in lesioned and normal monkeys, suggesting that stable qualities of temperament influenced the results in both groups.  相似文献   
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