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91.
92.
Ronald S. Harwerth Earl L. Smith Dennis M. Levi 《Attention, perception & psychophysics》1980,27(1):43-50
Binocular interactions of suprathreshold grating patterns have been investigated using a reaction time measure of contrast detection. Simple reaction times were determined for monocular and binocular viewing conditions over a contrast range from .63 to near threshold. The results from all subjects showed binocular summation for contrast levels near threshold, but there was considerable variation across subjects for contrast levels above threshold. Some subjects showed summation over the entire contrast range, but other subjects showed either binocular inhibition or binocular facilitation for some range of contrast levels. The pattern of binocular interaction for a given subject was consistent for several spatial frequencies. The differences in types of interaction between subjects, the variation in magnitude of binocular interaction with contrast level for each subject, and the data from experiments involving stimulation of noncorresponding retinal areas show that the binocular interactions found for suprathreshold stimuli cannot be accounted for on the basis of probability, and must, therefore, result from physiological interactions between the two eyes. These interactions have been investigated further under conditions of (1) induced fixation disparity, (2) horizontal gratings, and (3) orthogonally oriented gratings. 相似文献
93.
Developments in television technology have made possible new approaches to the study of the role of visual feedback in motor control. In two experiments using a special videodisc recording and playback system, the effects of delaying for 66 msec a subject's view of his own hand during a target-directed movement was investigated. The observed effects of such visually delayed feedback compared to spatially distorted feedback produced by prisms led to three major conclusions: (a) despite the behavioral similarity (overshooting) induced by the two kinds of altered feedback, the role of each in the visual-motor control loop is different; (b) adaptation to and the after effect of the two kinds of altered feedback are based on different control mechanisms (c) the processing and use of visual information in hand control requires less time than previous experiments have indicated. 相似文献
94.
Bruce L Smith 《Brain and language》1980,10(1):89-97
Audio recordings of the speech of seven patients receiving cortical stimulation during epilepsy surgery were acoustically analyzed, and duration measurements of the sound /s/ under stimulation and nonstimulation conditions were compared. It was found that in the dominant hemisphere, stimulation tended to significantly increase the duration of /s/; but not all stimulation sites were comparably affected. Stimulation of frontal lobe locations was also observed to more frequently result in durational increases than when temporal or parietal sites were stimulated. However, for sites affected, the actual magnitude of durational increase was comparable among the three lobes. 相似文献
95.
Previous work has shown that adults and older children tend to classify multi-dimensional objects by identity on one dimension, whereas children under 8 years of age tend to classify these same objects by a relation of overall similarity. The present study investigated the hypothesis that this developmental trend is restricted to the classification of simple objects that differ only by limited amounts on a few dimensions. The specific hypothesis was that overall-similarity relations structure both adults' and children's classifications of heterogenous objects (objects that differ in a variety of ways). This hypothesis was suggested by the correspondence between the structure of young children's classifications and the structure of natural categories. The result of two experiments supported the hypothesis. When the to-be-classified objects varied simultaneously on relatively many dimensions, adults as well as children constructed classifications that maximized within-category similarity on all varying dimensions. The implications of these results for accounts of the perception of multidimensional relations and classificatory behavior are discussed. 相似文献
96.
I Rock D Smith 《Journal of experimental psychology. Human perception and performance》1981,7(1):19-29
It has been assumed that certain stimulus transformations lead directly to depth effects, that is, that such transformations are the necessary and sufficient conditions for kinetically generated depth perception. An alternative is to view such perception as the preferred solution to the problem posed by the transforming stimulus as to what even in the world is producing that transformation. In several experiments it is shown that when other solutions are supportable by the stimulus, those same transformations will no longer lead to depth perception. These other solutions become preferred on the basis of rejection of certain coincidental features of the stimulus that otherwise would have to be accepted were the kinetic depth solution to be maintained. The findings are interpreted as challenging any theory that perception is simply the direct result of stimulation or of extraction of stimulus information and as supporting the Helmkoltzian rule of perception as a construction of the most reasonable representation. 相似文献
97.
An evaluation is offered of one of the Government's measures to alleviate youth unemployment-the Work Experience Programme (WEP). In a small-scale study conducted in Essex, most of the young people and employers involved in the scheme thought that its benefits considerably outweighed its disadvantages, and this view was shared by careers officers. The scheme helped the young participants to develop confidence in themselves and in their working potential, although at the same time it made them anxious about their ability and/or opportunity to continue this development. As a short-term response to youth unemployment, WEP has considerable value. Without certain improvements, however, it is not adequate for dealing with long-term structural unemployment. 相似文献
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An adaptive up-down tracking procedure was used in combination with a visually reinforced head turn response to examine auditory sensitivity for 500, 2000, and 8000-Hz tone bursts in infants 6 to 18 months of age. Six- and 10-month-old infants were tested with headphone presentation of stimuli, while 10-, 14, and 18-month-olds were tested in sound field. Infant threshold estimates for both headphone and sound field were within 15 dB of adult comparisons for all frequencies and age groups. Six-month-olds were significantly less sensitive to the 8000-Hz tone than to either of the lower frequency stimuli, but older infants demonstrated approximately equal sensitivity for all three frequencies tested. 相似文献