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171.
Reports that the dihydropyridine Ca2+ channel antagonists may facilitate memory led to the present study of the behavioral effects of nifedipine. Ninety-two 4-day-old male chicks received 0, 100 nM, 100 microM, or 10 mM nifedipine. Drugs were administered in volumes of 2 microliters into the fourth cerebral ventricle 5 min before training on a visual discrimination task. Nifedipine did not produce any detectable changes in behavior during acquisition trials. Retention, however, was impaired 24 h after training in the 100 nM and 100 microM nifedipine-treated chicks, which made significantly more errors than controls. Nifedipine did not affect the amount of time required to complete the task. No effects on body weight gain were detected, suggesting that the memory impairment was not due to a change in feeding behavior. These data are discussed in terms of the role of calcium-dependent processes in memory.  相似文献   
172.
The hypothesis that representation of projective shape is preattentive whereas representation of objective shape in three-dimensional space requires allocation of attention was tested in 2 visual search and 2 precuing experiments. In the visual search experiments, the slope for projective shape search was expected to approach 0 and that for objective shape search was expected to be a positive monotonic function of set size. In the precuing experiments, the effects of precuing were expected to be largely limited to the task requiring representation of objective shape. The overall pattern of results conformed to expectations. The findings are interpreted in the context of a model of shape-at-a-slant processing set out by Epstein and Lovitts (1985) and Epstein and Babler (1989, 1990).  相似文献   
173.
According to a conditioning analysis of the orientation-contingent color aftereffect (McCollough effect, ME), orientation stimulus (grids) become associated with color. Contrary to this interpretation are reports that simple forms cannot be used to elicit illusory color and that the ME is not degraded by decreasing the grid-color correlation. The present results indicate: (a) Form stimuli can contingently elicit color aftereffects; (b) even a non-patterned stimulus--the lightness of a frame surrounding a colored area--can contingently elicit color aftereffects; (c) this frame lightness-contingent aftereffect, like the ME, persists for at least 24 hr; and (d) the frame lightness-contingent aftereffect can be used to demonstrate that correlational manipulations affect the ME, as they affect other types of conditional responses.  相似文献   
174.
Remembering pictures: pleasure and arousal in memory.   总被引:17,自引:0,他引:17  
Incidental memory performance for pictures that varied along the affective dimensions of pleasantness and arousal was assessed. For both an immediate and delayed (1 year later) free-recall task, only the arousal dimension had a stable effect on memory performance: Pictures rated as highly arousing were remembered better than low-arousal stimuli. This effect was corroborated in a speeded recognition test, in which high-arousal materials encoded earlier in the experiment produced faster reaction times than their low-arousal counterparts. Pleasantness affected reaction time decisions only for pictures not encoded earlier. These results suggest that whereas both the dimensions of pleasantness and arousal are processed at initial encoding, long-term memory performance is mainly affected by arousal.  相似文献   
175.
The essential activity of group therapy consists of members taking an interest in each other by asking questions, showing concern, and conveying understanding. When members have not done this it has often been taken as a sign of resistance. A review of the research on helping suggests that there are four social factors that affect assistance giving in groups: 1) ambiguity-often people fail to give help because they are uncertain about who should give it, what should be done, and how it should be done; 2) often help is not given because of the way in which problems are presented; 3) the social comparisons that individuals make affect help-giving; and 4) there are costs associated with providing assistance. This discussion suggests that leaders can facilitate interaction among group members as teachers who clarify and as indirect helpers who redirect concerns back to group members.  相似文献   
176.
This study explored patterns emerging in videotaped sessions of group psychotherapy with seven outpatients of a large mental health facility. The 22 sessions spanned the 12th to 27th months of the group's existence. Group members had long histories (25–50 years) of symptoms characteristic of schizophrenia. Each session was rated on the Group Environment Scale. One session from a group in its earlier stages was also rated on the same instrument to give some indication of baseline patterns. Analyses of changes across the 15 months were not statistically significant. However, some GES subscales, including Cohesion, Independence, and Self-Discovery, showed relatively high mean levels across the 15-month period. These elevations are discussed as suggesting the codevelopment of orientations that have sometimes been viewed as incompatible and unattainable for schizophrenics. Interpreted clinically, the GES patterns help to elaborate recent findings about the relatively good success of long-term group therapy with such populations. The study, although merely suggestive, illustrates the potential for gleaning solid and clinically useful data from group psychotherapy research.The authors would like to thank Drs. Jill Rierdan, Nina Fieldsteel, Joseph Christy, and an anonymous reviewer for their suggestions, Kendra Bryant for serving as the reliability rater, and Janet Eltinge for her skilled videotaping.  相似文献   
177.
In a conditional-discrimination task (matching-to-sample), we assessed similarities among figures consisting of 2 elemental figures through the choice reaction time, nonmetric multidimensional scaling, and hierarchical cluster analysis data from chimpanzees (Pan troglodytes) and humans (Homo sapiens). Humans also rated similarities among figures. The results of the 3 experiments clearly indicated that the reaction time data obtained from chimpanzees' performances were useful measures of the similarities among figures. The results suggested that chimpanzees and humans perceived the complex figures similarly. The outer-contour elements were perceived most dominantly by both species, and the straight-line elements were perceived least dominantly. Both species showed the same perceptual hierarchy or dominance among perceptual categories, as determined by the similarity of simple elements, on the basis of transformational invariances.  相似文献   
178.
Much of the methodology in stress research focuses on stress manifestation and organismic reactions to life’s crises. In contrast, the present study sought to identify the major sources of stress and the nature of those sources. The results revealed a consistent pattern in high and low stressors throughout the 3-year period of the study, and differences only of intensity between males and females, not type of stress. Except for individuals’ temporal variations in critical events, the highest stressors for the groups were external, primarily financial and time management. Internal sources, such as personal relationships and self-absorption, were typically the lowest concerns. Everyday problems arising from current life styles seem to be significant sources of stress.  相似文献   
179.
This study sought to investigate the effects of mild head injury on a particular type of cognitive ability, verbal analogical reasoning. The performance of 19 individuals with head injuries was compared to a group of 30 control subjects matched for age, education, and gender on 100 verbal analogies. Solution times and error rates were modeled. Unstandardized regression weights for individual subjects were correlated with subjects’ performance on a number of standardized ability tests. Results showed that compared to the control subjects, the head injured subjects: (a) were significantly slower to solve the analogies, and were particularly slow to perform certain processes: encoding/inference and comparison; (b) tended to show greater variability in performance; and (c) had data that had a poorer componential model fit. The data suggest that analogical reasoning is affected by a head injury, and that certain information processes may be responsible for performance deficits.  相似文献   
180.
The authors used a correlated motion paradigm to investigate the effects of aging and gender on motion sensitivity. In 2 experiments with a total of 50 elderly and 50 young subjects, motion thresholds were significantly higher for elderly women. The correlated motion signal, which was embedded in random motion, may have been coherent to subjects in much the same way a form is in Witkin's Embedded Figures Test (EFT). In Experiment 2, EFT scores were obtained. A significant positive relationship between motion thresholds and EFT performance was found within each age group. Although gender-related perceptual style differences may contribute to motion perception effects, the authors argue that a common neural factor contributes to performance on both the EFT and the correlated motion task.  相似文献   
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