In this article, I describe a method for presenting multiple bit-mapped images on video displays under precise temporal control. The method makes use of the color-table animation technique that can be used with color-lookup-table display devices. The principal challenge in applying this technique to the display of multiple stimuli lies in dealing efficiently with the problem of overlapping displays. The solution described here is to allocate separate bit slices of screen memory to stimuli that overlap and to allocate sequential color-table indices to stimuli that are disjoint. Software is described that automatically computes the location of a stimulus on the screen, allocates color indices appropriately, transfers bit images to screen memory efficiently, and manipulates the color lookup table to present a given stimulus to the viewer. These operations are handled transparently; the user simply draws the stimuli and then turns them on or off under program control. 相似文献
A differential conditioning study examined whether an acoustic startle probe, presented during extinction of an aversively conditioned visual stimulus, potentiated the reflex eyeblink response in humans and whether this potentiation varied with the change in affective valence of the conditioned stimulus. Sixty college students were randomly assigned to view a series of two slides, depicting either unpleasant/highly arousing, unpleasant/moderate arousing, neutral/calm, pleasant/moderate arousing or pleasant/highly arousing scenes and objects (duration: 8 sec). During preconditioning (8 trials) and extinction (24 trials) acoustic startle probes (white noise bursts [50 ms; 95 dBA] were administered during and between slide presentation). During acquisition (16 trials) CS+ was reinforced by an electric shock. Startle response magnitudes significantly increased from preconditioning to extinction and were substantially larger to CS+. Conditioned startle reflex augmentation linearly increased with the pleasantness of the slides. Furthermore, subjects showed a greater post-conditioning increase of judged aversiveness to slides that they had previously reported to be more pleasant, exactly paralleling the startle reflex results.
Early infantile autism was found to be associated with an atypical pattern of cerebral lateralization. Based on EEG measures of hemispheric activation during cognitive processing, it was found that 7 of the 10 autistic individuals tested showed a pattern of hemispheric specialization rarely seen in the normal population; namely, a “reversal” in lateralization reflective of a lack of left-hemisphere specialization for linguistic functions. Furthermore, the autistic individuals' pattern of cognitive strengths and weakness is suggestive of a selective impairment of the left cerebral hemisphere. 相似文献
Within the last few years, considerable attention has been devoted to the possibility that the amelioration of stuttering in many novel speaking conditions is a function of vocal changes with or without accompanying modifications in prosodic expression. These formulations have made reference primarily to conditions in which stutterers were induced into one or another novel speech pattern by an external stimulus such as masking noise, a rhythmic cue, or by instructions to sing, or read in unison with another speaker. In contrast, far less attention has been paid to other ameliorative conditions that lack a novel external stimulus or special instructions that direct the stutterer to speak in some unique manner. Speaking or reading to a child is an example of this latter type of condition. The present study was conducted to see if nine adult stutterers and a matched group of nonstutterers would evince vocal changes as they read aloud to another adult, a child, and a child and adult together. There was also a fourth control condition wherein the subjects read to one of the experimenters. Dependent measures of disfluency and stuttering, fundamental frequency, fundamental frequency deviation, fluent reading rate, and peak vocal sound pressure level were made and treated statistically. The major findings of this study indicated that, relative to the control condition, both subject groups exhibited several vocal changes when reading to a child alone and to a child and adult together. In addition, the stutterers experienced a reduction in disfluency, but only when reading to the child alone. The normal speakers exhibited too few disfluencies in the control condition for any meaningful change to occur in that dependent variable. The fact that the stutterers evinced vocal changes in both experimental conditions but a significant drop in disfluency in just one bears importantly on hypotheses that emphasize vocal changes in conditions that ameliorate stuttering. 相似文献
An 8-month-old infant with a developmental quotient of months was given response-contingent stimulation using a pressure-sensitive pillow which turned an overhead mobile. The subject learned to control the mobile by kicking the pillow, and concurrently began smiling at both the mobile and her mother for the first time. After mastering three contingencies on arm, head, and leg movement, she displayed what appeared to be a Piagetian coordinated secondary circular reaction, in which one response provided 4 seconds of access to another contingency. Although the subject remains severely retarded, the results suggest that some forms of developmental delay may be treated at least in part as a failure to develop contingency awareness. 相似文献
The behavioural treatment of auditory hallucinations in three chronic schizophrenic patients is reported. Two treatment conditions, one in which white noise followed hallucinations and a second in which white noise was presented during reported hallucinations, were contrasted in a crossover design with a control condition where white noise was presented randomly. All three patients improved, although reported reductions in hallucinations were more marked in two cases than in the third. Some generalization of treatment effects was observed in all three patients. White noise presented concurrently with hallucinatory reports appeared to be the most effective. The implication of these findings for a theory of auditory hallucinations is discussed. 相似文献
This research examined gender differences in orientations toward autonomous and social achievement. Three independent samples of subjects (total N= 359 males and 574 females) completed measures of achievement orientation (including Strumpfer's [1975] Autonomous Achievement Values and Social Achievement Values scales) and relevant cognitive, affective, and behavioral variables. Correlational and factor analyses clearly identified distinct autonomous and social achievement factors for both men and women in each of the samples. Examination of the correlates of achievement orientation indicated that whereas an autonomous achievement orientation is similarly expressed in males and females, there are considerable sex differences in the expression of an orientation toward social achievement. In particular, a social achievement orientation was associated with concerns over social approval and responsiveness to social influence among males, but was generally unrelated to these factors among females. Findings are discussed in terms of several recent hypotheses concerning the effects of sex role norms on the development and expression of achievement needs in men and women. 相似文献
This paper presents the second part of a two-part study on axiomatizations of perceived risk. The first part (P. C. Fishburn, Foundations of risk measurement, I. Risk as probable loss. Mimeo., Bell Laboratories, 1981) focussed on risk as probable loss. The second part considers measures of risk that include effects of gains on perceived risk. It adopts the position that increased gains can reduce the risk of fixed probable losses without completely negating this risk. Moreover, every prospect that has no chance of yielding a loss is presumed to have no risk. Several numerical measures of risk are axiomatized. The more specialized are separable in gains and losses. Further specializations isolate the effects of loss and gain probabilities. 相似文献