Uncontrollable shock proactively increases sensitivity to response-reinforcer independence in rats

Learned helplessness theory predicts that animals exposed to inescapable shock acquire an expectancy of response-reinforcer independence, which proactively interferes with learning of response-reinforcer dependence. The theory also predicts that this expectancy can increase sensitivity to subsequent instances of response-reinforcer independence. These experiments test the latter prediction in a paradigm that minimizes the confounding effects of shock-induced activity deficits. Rats were trained to respond for food, then given either escapable, inescapable, or no shock. Subsequently, they received two sessions of response-contingent food followed by sessions of noncontingent food deliveries. During this phase, inescapably shocked animals decreased responding faster than did controls. Experiment 2 replicated this finding with a different schedule of food delivery and a procedure that more directly minimized the possibility that the outcome is due to either direct or indirect shock-induced activity changes. These results support the prediction that uncontrollable aversive events can increase an animal's sensitivity to noncontingent response-reinforcer relationships.     

Information processing abilities in twins reared apart

A battery of information processing measures and psychometric tests of specific and general cognitive abilities was administered to a sample of 105 individuals which included 34 monozygotic and 13 dizygotic reared apart twin pairs or triplets. Correlations between information processing parameters and psychometric abilities as well as twin resemblances for the information processing parameters were examined. In a principal components analysis of the information processing parameters, three components were identified which accounted for 67% of the total variation; Overall Speed of Response (OSR), Speed of Information Processing (SIP), and Speed of Spatial Processing (SSP). OSR was significantly correlated with WAIS IQ, and psychometric measures of verbal reasoning, spatial ability, and perceptual speed and accuracy. SIP was significantly correlated with WAIS IQ, measures of verbal reasoning, and one of the perceptual speed and accuracy measures. SSP was significantly correlated with measures of both spatial ability and perceptual speed and accuracy. Due to the small size of the dizygotic twin sample, no strong conclusions could be drawn regarding the magnitude of their resemblance. The correlation between component scores of reared apart monozygotic twins was significant for OSR, but not for SIP or SSP.     

Teachers do not Deal in Widgets

Although the use of merit pay, incentive pay, bonus pay, and job promotion are well-established measures in the private or corporate sector of American society, few examples of successful teacher merit pay systems exist. In 1983, the Eastern Washington University Department of Education surveyed six major private corporations to determine whether corporate merit pay programs could be applied to teachers and educational institutions. Survey findings suggest several reasons why merit pay programs for teachers will probably fail: (a) lack of monetary goals; (b) the necessity for subjective evaluation, which requires multiple measurement devices, extensive supervision, and time; (c) the absence of a many-tiered corporate structure in most educational institutions; and (d) increased supervisory direction that could stifle creativity and flexibility.     

Vasopressin prolongs bradycardiac response during orientation

Adult male rats were implanted with transcutaneous ECG electrodes and habituated to a dark chamber with elevated background noise levels. ECG was recorded prior to, immediately after, and 3 min after sudden elimination of background noise. The orienting response to the stimulus offset was accompanied by transient bradycardia. Neither AVP (1 microgram/rat) nor oxytocin (1 microgram/rat) injected subcutaneously 1 hr prior to testing altered baseline heart rate or the immediate bradycardiac response to stimulus offset. However, AVP, and to a lesser extent oxytocin, prolonged the bradycardia induced by stimulus offset. The results show that neurohypophyseal peptide hormones enhance the cardiovascular component of orienting to stimulus change.     

Working memory theory of hippocampal function needs qualification

To compare the predictive value of "cognitive map" and "working memory" theories of hippocampal function, the performance of rats with dorsal hippocampal lesions was compared to that of control rats in a series of experiments. In Experiment I, experimental rats learned a spatial alternation task with normal ease, but in Experiment II, they were significantly impaired on an elevated 8-arm radial maze. In Experiment III, the performance of the same experimental and control rats was compared on two versions of a 16-arm enclosed radial maze. In the first version, carpet inserts served as cues to mark eight unbaited arms and each of the remaining arms contained one food pellet. While both experimental and control rats successfully avoided the set of cued arms, experimental rats reentered uncued baited arms more frequently than did control rats. In the second version no intramaze cues were provided, but the spatial distribution of baited and unbaited arms remained the same as that used in the first version. In this uncued version, experimental rats both entered unbaited arms and reentered baited arms more frequently than did control rats, i.e., they were impaired in both "reference" and "working" memory. These findings are compatible with the hypothesis that hippocampal lesions result in an impaired capacity to form cognitive maps but they are not compatible with the working memory hypothesis. Furthermore, twelve separate evaluators classed experimental rats as using fewer mapping and more orientation strategies than control rats in the 8-arm maze.     

Pictorial rehearsal

Subjects were presented with a sequence of picture-word items. The pictures were line drawings of common objects, and the words were the names of the objects. Half of the items were followed quickly by the next item, and the other half by a 15-sec “rehearsal interval.” The subjects were told to use these intervals to rehearse the item just presented, either by saying the word over and over to themselves or by maintaining the picture before the mind’s eye. There followed a test in which each item from the study list was cued with a fragment of either the picture or the name. Consistent with previous findings, identification was more probable for fragments of items that had been followed by a rehearsal interval. In addition, this advantage was found to be greater when the type of cue matched the mode of rehearsal that the subject had been instructed to adopt; there was in fact little, if any, advantage of rehearsal when cue and mode of rehearsal mismatched. This pattern of results suggests functionally distinct pictorial and verbal modes of rehearsal that serve not only to maintain information in conscious mind but also to build up memory proper.     

Altering information to gain action control: Functional aspects of human information processing in decision making

In recent approaches to social judgment, information distortion has been discussed primarily as a violation of individual rationality, due to unintentionally occurring biases. In contrast to this view, it is argued that frequently individuals make purposive use of selective changes in information processing in order to avoid indecisiveness. In this sense, selective changes in information processing may be considered a functional requirement of a volitional process which protects the current intention (or tentative decision) from being replaced by competing behavioral tendencies. On the basis of J. Kuhl's theory of action control (1981, Journal of Personality and Social Psychology, 40, 155–170; 1982, in W. Hacker, W. Volpert, & M. von Cranach, Eds., Cognitive and Motivational Aspects of Action, Amsterdam: North-Holland, 1984, in B. A. Maher, Progress in Experimental Personality Research, Vol. 13, New York: Academic Press) it was predicted that subjects having a high score on the action-control scale (i.e., action-oriented subjects) should show a stronger tendency to increase the attractiveness rating of a tentatively preferred decision during the process of decision making than subjects scoring low on that scale (i.e., state-oriented subjects). To test this assumption, students searching for an apartment were offered 16 apartments along with a list containing information about the alternatives. The subjects had to rate the attractiveness of each apartment twice before they were asked to indicate which apartments they would like to rent. The results confirmed the predictions. It was found that action-oriented subjects increased the divergence of their attractiveness ratings from the first to the second point of evaluation, whereas state-oriented subjects did not.     

Telephone counseling and crisis intervention: A review

The empirical research pertaining to the effectiveness of telephone counseling and referral systems personnel was critically reviewed. The assessment was organized according to several evaluation strategies that researchers have utilized to evaluate effectiveness. These strategies included, for example, client self-reports, client "shows" versus "no-shows" following referral, data pertaining to suicide rates, counselor ratings of personal effectiveness, and phone workers' ability to offer empathy to clients. It was concluded that discussions of effectiveness should be constrained by a careful consideration of the specific index of efficacy chosen by investigators as well as methodological issues associated with current research in this area. There is reason to believe that the availability of telephone crisis services may be related to reduced suicide rates among young white females. Also, there is a significant need to empirically associate counseling technique and indices of effectiveness with substantive measures of client outcome in future research. Additional topics reviewed include the probable differential effectiveness of lay workers with various presenting problems of clients, and the role that training and maturity seem to play in successful interventions. Guidelines for the use of evaluation techniques which coincide with service goals are also offered.     

The temporal structure of motivation. V. A within-episodes analysis of priming and provocation

Rats provided with chronic, continuous access to intracranial self-stimulation (ICS) exhibit discrete episodic response patterns. Response episodes under two conditions were examined for systematic trends in the spacing of times between successive responses (interresponse times; IRTs) to better identify the motivational bases of ICS. Three trends were observed in self-initiated and experimenter-provoked episodes. First, initial responses of spontaneous episodes typically had declining interresponse times. Second, this trend was not present when responses were provoked rather than spontaneous. Third, absolute times between responses varied across conditions, with provoked behavior having significantly lower initial IRTs. The findings suggest that for spontaneously initiated responding a transient facilitatory process cumulates at the beginning of ICS episodes. For provoked responding, it is possible that a manipulation which increased the initial probability of responding over time may have done so by maximizing an initial phasic priming process. At their onset, spontaneous and provoked episodes may be characterized by quantitatively differing motivational profiles.     

Postsurgical enrichment aids adult hemidecorticate rats on a spatial navigation task

The effect of environmental enrichment on normal rats, rats that received hemidecortication at birth, and rats that received hemidecortication when adult was studied in the Morris water task, which is a spatial navigation task requiring the use of distal cues for successful performance. Enrichment was achieved by housing the rats for 90 days in a large outdoor compound that was designed to model a natural environment. Adult hemidecorticated lab-raised rats were severely impaired in the acquisition of the task but neonatally hemidecorticated rats, although also impaired, showed significant sparing. Postsurgical, but not presurgical, enrichment of adult hemidecorticated rats significantly enhanced their recovery. Enrichment had little effect on neonatally decorticated rats or on normal rats. Although there were no gross anatomical changes associated with enrichment, the paradigm provides both a robust phenomena and a cortically dependent task that is ideal for investigating the processes in the remaining intact hemisphere that must support recovery.