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201.
This study investigated the second-decade effects of the Buffalo Creek dam collapse and flood that occurred in West Virginia in 1972. One hundred twenty-one survivors who had participated in an earlier lawsuit against the coal company that built the collapsed dam were compared to 78 nonlitigant survivors on self-reported symptoms, clinical ratings, and diagnoses. A nonexposed sample from a geographically and culturally similar neighborhood was investigated as well. Findings showed no differences between the litigant and nonlitigant survivor groups. The survivor groups together showed higher rates of anxiety, depression, and hostility symptoms and diagnoses than the nonexposed sample. The findings were discussed in the context of the nature of the traumatic event, social and cultural influences on recovery, and the constellation of symptoms which differentiated the groups.  相似文献   
202.
It has been frequently suggested that the ability to analyze spoken words into phonemes facilitates children’s learning of spelling-sound rules. This research attempts to demonstrate that link by showing that phonemic-analysis training helps children take advantage of spelling sound rules in learning to read. In two experiments, preschool and kindergarten prereaders participated in an analysis condition and a control condition on each of 4 test days. In the analysis condition, children learned to segment (and in Experiment 2, also to blend) selected spoken syllables. In the control condition, they merely repeated syllables. Children were then introduced to printed items that corresponded to the spoken syllables with which they had worked. The pronunciation of the “related” item could be deduced from those of other printed items in the set; the pronunciation of the “unrelated” item could not be so deduced. Both experiments revealed a significant interaction between condition (analysis vs. control) and item type (related vs. unrelated). In the control condition, children tended to make more errors on the related item than on the unrelated item; in the analysis condition, they tended to make fewer errors on the related item than on the unrelated item. These results suggest a causal link between the ability to analyze spoken syllables and the ability to benefit from spelling-sound relations in reading.  相似文献   
203.
Young adult humans pressed a key to obtain money. When responding was punished by presentation of a stimulus signifying that money was lost, response frequencies decreased and response latencies increased. Since these changes did not increase relative earnings, the aversive properties of loss of reinforcement were manifested independently or reinforcement gain. When loss punishment was delayed for either 10, 20, or 40 sec the extent of suppression was found to vary inversely with the response-punishment interval. Subsequent manipulations indicated that the effectiveness of delayed punishment was increased when the response also produced immediate conditioned punishment, i.e., a stimulus paired with the delayed loss stimulus. Instructions about the response-punishment contingency had similar effects. The findings were consistent with animal studies of delayed shock punishment, insofar as a similar delay-of-punishment gradient was observed, and with studies of delayed positive reinforcement, insofar as mediation through conditioned punishment (or instructions) increased the effectiveness of delayed punishment.  相似文献   
204.
A purported universal of language is the generalization of distinctive features, for example, in phonology and semantics, within a language or an individual. This could be due to a tendency either to use or to ignore a feature depending on whether or not it has previously been distinctive. This mechanism is shown to operate in retrieval of well-learned artificial concept names. Several simple models of performance cannot account for this effect. The apparent inefficiency of possible mechanisms which could account for this result suggests that it may reflect a special predisposition.  相似文献   
205.
Five rats were trained on a two-component multiple schedule with each component consisting of a two-link chain schedule. Differential response suppression in the initial links of the chain schedules was used as a measure of the relative aversiveness of events introduced into the subsequent terminal links. When unsignalled shock was scheduled in one terminal link and signalled shock in the other (in addition to equal numbers of food reinforcers), responding was suppressed to a greater degree in the initial link preceding the unsignalled-shock condition. Reversing the terminal-link positions of unsignalled shock and signalled shock led to a reversal of the differential response suppression in the initial links. These results confirm previous findings that signalled shock is less aversive than unsignalled shock and extend the generality of this phenomenon from choice measures to rate measures of aversiveness.  相似文献   
206.
Ss were asked to make two forced-choice discriminations on each trial: in Experiment I, they had to tell on which side of the display a latter pair appeared and whether or not its members were identical; in Experiment II, to say where the pair appeared and whether it consisted of Xs or Os; in Experiment III, to say where a letter appeared and whether it rhymed with E; and in Experiment IV, to say whether a letter pair was presented and whether it was a word. In Experiment III, and for some Ss in Experiment I, the second discrimination was dependent on the first; that is, when the S was wrong on the first, he performed at chance level on the second. In Experiment IV, when Ss indicated that nothing was presented (with confidence), they performed at chance level on the recognition task; thus, recognition was dependent upon some information about the detection task. It is argued that perceptual dependence implies that a threshold state, a state in which the S has no information, exists for the dependent discrimination. One explanation of dependence assumes mediation of the dependent discrimination by a processing stage which succeeds stages mediating the other task.  相似文献   
207.
208.
Two experiments were conducted to examine the influence of ambient temperature upon physical aggression. In the first, male subjects received either a positive or negative evaluation from a confederate and were then provided with an opportunity to agress against this person by means of electric shock. On the basis of previous research, it was predicted that high ambient temperatures (92-95 degrees F) would facilitate aggression by those receiving positive evaluations but actually inhibit such behavior by those receiving negative assessments. Results confirmed both of these predictions and also indicated that more moderate but still uncomfortably warm temperatures (82-85 degrees F) produced similar effects. The second experiment employed procedures similar to the first and examined the suggestion that administration of a cooling drink would reduce the impact of high ambient temperatures upon overt aggression. This prediction, too, was confirmed. The possible mediating role of negative affect with respect to the influence of ambient temperature and other environmental factors upon aggression was discussed.  相似文献   
209.
210.
Rats repeatedly acquired the performance of selecting only the four baited arms in an automated eight-arm radial maze, with the arms containing food pellets randomly assigned prior to each session. During each 14-trial (trial: obtain all four pellets) daily session, the number of errors (selecting nonbaited arms or repeating arm selections) showed a within-session decline, and choice accuracy for the first four arm selections showed a positive acceleration across trials for all rats. An index-of-curvature statistic, calculated for total errors, was used to quantify both the within- and between-session improvement of performance. Scopolamine (0.03 to 0.3 mg/kg, ip), but not methylscopolamine (0.3 mg/kg), reduced the accuracy of the first four selections of each trial and increased total within-session errors for all rats. Session times also were increased by scopolamine. An examination of within-session accuracy showed only slight signs of improvement at the higher dosages of scopolamine. The results indicate that behavior in transition states maintained by reinforcement contingencies in the radial maze is similar to that maintained by extended chained schedules, despite the fact that some of the stimuli controlling behavior in the maze are absent at the moment behavior is emitted.  相似文献   
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