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851.
The present study is a replication of Schofield's findings (1978) in the use of the Draw-A-Person as a measure of racial identity acceptance. Unlike Schofield's study, the present investigation involved an adolescent sample of blacks and whites, and race of figure drawn was determined by judges' consensus rather than an objective scoring system. The findings generally supported those of Schofield and the racial identity and preference literature as a whole in revealing blacks to be less accepting of their racial identity than whites.  相似文献   
852.
853.
Three pigeons learned to peck four colors in a particular sequence, regardless of how these colors were positioned on four response keys and without feedback following each response. This demonstrates that serial learning is possible in subprimate animals.  相似文献   
854.
Temporal control of behavior and the power law   总被引:9,自引:9,他引:0       下载免费PDF全文
The performance of rats and pigeons under fixed-interval schedules was studied in two experiments. The duration of postreinforcement pause was a declining proportion of fixed-interval duration. For pigeons this was true both when the duration of the reinforcer was fixed and when it was increased in direct proportion to increases in fixed-interval duration; the longer reinforcer durations did, however, lengthen the postreinforcement pause at higher schedule values. A quantitative analysis of data from Experiments 1 and 2 and from other studies showed that fractional exponent power functions described the relationship between postreinforcement pause and fixed-interval value; similar functions have previously been observed in studies of temporal differentiation. It was concluded that power functions reflect a direct causal, rather than artifactual, relationship between performance and the temporal requirements of reinforcement schedules.  相似文献   
855.
Three types of oculomotor programming disturbances are described in patients with the dementia syndrome. This report describes two of these abnormalities, poorly regulated gaze patterns and a programming type of gaze perseveration. All patients showed poorly regulated gaze patterns in contrast to the normal controls, whereas on the whole only the moderately affected patients showed the programming type of gaze perseveration. The third type of oculomotor programming disturbance is efferent perseveration of gaze (a hypokinetic, "staring" type of gaze pattern) and can be seen with severe dementia. The possible significance of these findings is discussed.  相似文献   
856.
857.
To assess the concurrent validity of the Fruit Distraction Test, the Stroop Color-Word Test and the Fruit Distraction Test were administered to two groups of boys aged 12 yr. (N = 63) and 8 yr. (N = 52). Partial correlations, with IQ controlled, based on time and error scores derived from both tests, provided no convincing evidence that the Fruit Distraction Test is a valid downward extension of the Stroop.  相似文献   
858.
Electromyographic (EMG) recordings of masseter muscle tension during conversational speech by six adult stutterers were compared to EMG levels of 6 normal speakers. Stutterers' and normal speakers' tension levels were significantly different; however, there was no correlation found between level of tension and severity of stuttering.  相似文献   
859.
860.
In Experiment 1, pictures were presented to subjects two, five, or eight times, and subjects were asked to imagine each pciture two, five, or eight times. Subsequently, subjects estimated the number of times each picture had been presented. Their estimates of the frequency of these external events were influenced by imagination trials; this effect was greater for good imagers than for poor imagers. Experiment 2 involved a similar design in which subjects were asked either to imagine the same referent for a word or to imagine a different referent for a word on successive imagination trials. Consistency (same referent) did not increase the influence of imaginations on immediate judgments of external frequency. Thus, the results of Experiment 1 were attributed to the greater accuracy (as opposed to greater consistency) of good imagers' internal generations of the stimuli. Furthermore, variation (imagining different referents), like greater accuracy, increased the effects of imagination trials on immediate but not on delayed judgments of frequency. Possible mechanisms underlying these effects are discussed. In general, the two studies show that qualitative characteristics of completely covert generations influence their impact on estimates of the frequency of external events.  相似文献   
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