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Using different warning signals and threshold stimuli, the thresholds, as determined by a method of limits, were found to rise monotonically as the interval between warning signal and threshold stimulus increased from I to 9 sec. It was found that the variability of the threshold did not increase as the threshold increased. Similar results were obtained for phosphene and auditory thresholds and with visual and auditory warnings; therefore the effect was considered to be central. Motokawa's finding of a minimum in the phosphene threshold 2 sec. after a flash of white light was not repeated. The rise in threshold was not obtained when the warning intervals were randomized and so seemed to depend on the use of fixed warning intervals. A model was developed relating threshold level to accuracy of anticipation of the end of the warning interval. 相似文献
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Fighting cocks were conditioned to emit a key-pecking response on a fixed ratio reinforcement schedule leading to the visual image of another fighting cock. In addition, the relative reinforcing properties of the visual reinforcer were compared with food and water reinforcers in a three-choice, non-reversible option situation. The relative reinforcing effects of mirror presentation and another rooster visually presented through a window, were compared. The mirror maintained a relatively lower response output. 相似文献
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Background and Objectives: In this research, we tested the role of cognitive appraisals in explaining why harmonious and obsessive passion dimensions are related to distinct forms of coping and explored if performance was impacted by these appraisal and coping processes. Design: Undergraduate students (N = 489) participated in a longitudinal study and completed three surveys throughout the course of an academic year. Methods: Participants completed assessments of both passion dimensions (Time 1), reported how they were appraising and coping with the mid-year examination period (Time 2), and provided consent to obtain their final grade in Introductory Psychology (Time 3). The hypothesized model was tested using structural equation modeling. Results: Harmonious and obsessive passion dimensions were linked with approach and avoidant coping responses, respectively. Cognitive appraisals, particularly appraisals of challenge and uncontrollability, played an indirect role in these relationships. In addition, both appraisals and coping responses had an indirect effect in the relationship between passion dimensions and final grade. Conclusions: These results identify cognitive appraisal as a reason why passion dimensions are linked with distinct coping tendencies and demonstrate the role of appraisal and coping processes in the journey to passionate goal attainment. 相似文献
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Martha I. Zapata Roblyer Joseph G. Grzywacz Richard C. Cervantes Michael J. Merten 《Journal of child and family studies》2016,25(2):475-487
Families in which one or more members are undocumented immigrants experience unique hardships. Yet, little is known about stress and substance use among adolescents growing up in these families. The present study examined associations between two sources of adolescent stress (i.e., low parental involvement due to contextual constraints and family economic insecurity) and lifetime alcohol, cigarette, and marijuana use among adolescents in families with undocumented members. The sample was comprised of 102 adolescents (10–18 years old) and one of his or her parents. Participants responded a survey in English or Spanish. Adolescent lifetime use of alcohol, cigarette, and marijuana was 51, 32.4, and 37.3 %, respectively. Chi-square analyses found no significant gender differences in lifetime substance use. Logistic regression models showed that adolescent stress due to hindered parental involvement increased the odds of both lifetime cigarette and marijuana use after controlling for gender, age, linguistic acculturation, familism, parental control, and negative peer affiliation. Being a girl increased the odds of lifetime alcohol use. Family economic stress was not associated with lifetime substance use. Results suggest that hindered parental involvement might be a stressor and a risk factor for cigarette and marijuana use among adolescents growing up in families with undocumented members. Because parents in these families are likely to be undocumented, policies that allow immigrants to apply for legal status could improve parents’ working conditions and facilitate parental involvement; in turn, such policies could decrease the risk for adolescent substance use among children of Latino immigrants. 相似文献