Motivation and learning: Neurophysiological mechanisms in a “model” system

The neurophysiological mechanisms underlying behavioral motivation and associative learning are described in an invertebrate “model” system, the carnivorous marine mollusc Pleurobranchaea. Feeding motivation can be controlled via nutritional history and is represented centrally in the feeding motor network as a change in the balance of synaptic excitation and inhibition at the level of interneurons that initiate feeding behavior, i.e., feeding “command” interneurons. Associative learning, induced by avoidance conditioning of feeding behavior, manifests identically at the level of the command interneurons, but is distinguished from non-associative motivational changes by processes that occur in identified neurons and pathways presynaptic to the command interneurons. Motivation and learning are therefore linked mechanistically by convergent neurophysiological mechanisms at the level of central neurons that initiate behavior.     

Perceptions of unresponsive others: Attributions,attraction, understandability,and memory of their utterances

Analyses of the rules governing conversation have frequently pointed to the existence of a rule dictating that responses to others' communications should be relevant. Unfortunately, there have been few systematic theoretical analyses of the consequences of violations of the response relevance rule. The present research was designed to extend our previous analyses of the consequences of responsiveness in dyadic interaction to examine in detail the effects of irrelevant response on processing and retention of response content, and attributions concerning the speaker. It was argued that irrelevant responses will be processed and retained more poorly, because the preceding utterance will provide a less adequate context for their interpretation. In addition, it was argued that unresponsiveness will generally be attributed to the lack of one or more of four factors previously suggested to facilitate responsiveness: attention to the other, understanding of the preceding communication, adequate response repertoire, or motivation to be responsive—along with situational (e.g., distraction) or dispositional (e.g., incompetence) reasons for their absence. These processes were examined in the context of a political debate, in which the relevance of candidates' answers to the questions was varied. As expected, response relevance was shown to facilitate processing (as indexed by ratings of clarity and organization) and retention (both recall and recognition memory) of response content. Further, the unresponsive speaker was perceived to have less clearly understood the questions asked, to possess less knowledge of the facts and understanding of the issues concerning the questions raised, and to be less motivated to discuss the issues raised (as opposed to facilitating his self-presentational goals). Moreover, those attributions were accompanied by attributions of dispositional incompetence. Finally, the unresponsive candidate was perceived as less attractive than the responsive candidate.     

Strength of the nervous system and augmenting-reducing: Paradox lost

Two conflicting viewpoints were identified regarding the relationship between sensation seeking and subjective response to stimulation: (a) that sensory augmenters are high sensation seekers compared with sensory reducers (the view of Zuckerman and Buchsbaum); and (b) that it is the reducer rather than the augmenter who is the high sensation seeker (the view of Petrie and Vando). Proponents of the first approach measure Augmenting-Reducing through the use of the average cortical-evoked response, while advocates of the second position use Petrie's version of the Kinaesthetic Figural Aftereffects Test or Vando's Reducer-Augmenter Scale. It is argued that the disagreement is semantic and results from the differences in method of measurement. It is further argued that most, if not all, of the research findings may be accommodated within the framework of strength-of-the-nervous-system theory which distinguishes between two dimensions,sensitivity andfunctional endurance. The implications for future research are pointed out.     

Autocontingencies: Suppressive and accelerative effects of pairs of shocks superimposed on a positively reinforced operant baseline

Previous research has shown that unsignaled shock may accelerate positively reinforced operant responding if each shock signals a subsequent shock-free period. In order to explore the boundary conditions of this effect, two experiments were performed. In Experiment 1, pairs of unsignaled shocks separated by 15, 30, 60, or 120 seconds resulted in suppressed responding during the briefest intershock interval, and in accelerated responding during the longer intervals. When the second shock in each pair signaled a shock-free period of at least 3 minutes, accelerated responding also followed offset of the second shock in all but the 30-second condition. In Experiment 2, the addition of a conditioned stimulus prior to each pair of shocks restored baseline responding, and eliminated accelerative control following the second shock only under the briefest inter-shock interval. The results are discussed in terms of the similarity between autocontingencies (shock/no-shock relations; Davis, Memmott, & Hurwitz, 1975) and recent modifications of the feature-positive procedure (e.g., Reberg & Memmott, 1979), which stress stimulus control by shock/no-shock relationships.     

Contextual sensitivity in young children's drawings

Previous research has examined the characteristic errors made by young children when drawing from a three-dimensional array. The aim of the present research was to investigate the influence of context in copying tasks. In a series of three experiments children between the ages of 4 and 7 years were presented with contrasting models to copy. These included cups and sugar bowls in various combinations and orientations. In each experiment the children's copies were scored for inclusion or omission of the occluded handle on the model. The results showed that nearly one third of the children did not respond consistently by either copying accurately or by always including the occluded handle. Instead the findings pointed to a large group of children whose responses were directed by the type of context present within the arrays.     

Sex differences in adjustment correlates of locus of control dimensions

This study investigated the hypothesis that dimensions of locus of control are differentially predictive of adjustment criteria for males and females. Two samples of undergraduates completed the Reid-Ware Three-Factor Locus of Control Scale and either the Texas Social Behavior Inventory or the Zander and Thomas version of the Barron ego strength scale. For both males and females, internals reported greater self-esteem and ego strength. However, for males, the fatalism dimension was the strongest predictor for each adjustment correlate. The social system control dimension was not predictive for males in either case. For females, the social system control dimension was predictive for each adjustment correlate, although it was not consistently the strongest predictor. The results are consistent with research on sex differences in parental antecedents of locus of control. Methodological implications of the differential predictiveness of locus of control dimensions are also addressed.     

The effects of dispositional empathy on emotional reactions and helping: A multidimensional approach

Recent research indicates that an affective state termed empathic emotion, and characterized by feelings of sympathy and compassion for another, is associated with altruistic responding. That is, persons experiencing high levels of empathic emotion offer help to another even when escape from the situation is easy. Persons experiencing high levels of another emotional state—personal distress—help much less when escape from the situation is easy. A study was conducted to test two related hypotheses. The first was that individual differences in empathy can influence empathic emotion and personal distress, above and beyond the influence of situational factors. The second hypothesis was that this effect of individual differences is due to variation in emotional and not cognitive empathy. The results provide support for both hypotheses. Regarding hypothesis 1, a significantly greater proportion of the variance in emotional reactions was accounted for when individual difference factors were included as predictors. Hypothesis 2 was also supported: It was found that a dispositional measure of emotional empathy was clearly related, and a dispositional measure of cognitive empathy was clearly unrelated, to these emotional reactions. The results provide support for a multidimensional view of empathy.     

Contiguity and contingency in the acquisition and maintenance of an operant

Three experiments compared the effects of nondifferential and differential reinforcement of response location on a circular dimension. Rats were required to operate a vertical joystick to produce food. When food was delivered immediately after responses, but independent of response location, the spatial concentration of responding was low and no progressive changes were observed. Traditional and percentile schedules of differential reinforcement for response location produced highly reliable acquisition of spatially concentrated responding. Once concentrated responding had been established, nondifferential reinforcement was sufficient to maintain it in some subjects. Since only the differential reinforcement schedules established a contingency with respect to response location, it was concluded that this relationship was necessary for acquisition, but that response-reinforcer contiguity may be sufficient for maintenance. This conclusion is consistent with the view that operant conditioning is a contiguity-based process, but that contingencies are required to produce reliable contiguity between reinforcers and particular responses.