Extinction-induced immobility in the water maze and its neurochemical concomitants in aged and adult rats: a possible model for depression?

Extinction of escape behavior in the water maze due to the removal of the platform, was hypothesized to induce a negative state, including the development of immobility, which is held to reflect a state of "despair" when measured in the forced swimming test. 27 aged and 8 adult animals (26 and 3 months old Wistar rats, respectively) were tested in the water maze during nine days with a platform hidden, followed by 7 days of extinction trials with the platform absent. As expected, both age groups developed immobility over the extinction trials, with the aged showing more than the adults. To examine whether the age difference in immobility was related to performance differences during acquisition, the aged were subdivided into superior, intermediate and inferior learners (n = 9 per group) on the basis of overall times to platform during acquisition, and compared with each other and the adults. Results showed that the aged inferior learners displayed the highest levels of immobility among the aged. Immobility scores were then correlated with post-mortem neurotransmitter contents in the hippocampus and ventral striatum. In the ventral striatum, levels of immobility were correlated with levels of acetylcholine, dopamine and the metabolite dihydroxyphenylacetic acid in the aged, and with norepinephrine in the adults. The data support the hypothesis that multiple extinction trials in the water maze result in immobility that may indicate "behavioral despair," and that striatal neurotransmitter systems correlate with the degree of its expression. The concept of extinction-induced despair is held to provide the promise of a conceptual and empirical model of human depression that is the consequence of loss of reinforcers.     

Neighbourhood effects on error rates in speech production

Models of speech production differ on whether phonological neighbourhoods should affect processing, and on whether effects should be facilitatory or inhibitory. Inhibitory effects of large neighbourhoods have been argued to underlie apparent anti-frequency effects, whereby high-frequency default features are more prone to mispronunciation errors than low-frequency nondefault features. Data from the original SLIPs experiments that found apparent anti-frequency effects are analysed for neighbourhood effects. Effects are facilitatory: errors are significantly less likely for words with large numbers of neighbours that share the characteristic that is being primed for error ("friends"). Words in the neighbourhood that do not share the target characteristic ("enemies") have little effect on error rates. Neighbourhood effects do not underlie the apparent anti-frequency effects. Implications for models of speech production are discussed.     

Three views of organ procurement policy: moving ahead or giving up?

The supply of organs for transplant remains inadequate to meet the needs of waiting patients, in spite of many programs and approaches to increase rates of donation. Over the years there have been numerous proposals to introduce schemes that would move toward the outright sale of organs. Three articles in this issue of the Journal propose methods for increasing organ supply--two by moving toward a market approach and the third by advocating a change in social culture. All three suffer from shortcomings, including the endorsement and encouragement of the exploitation of those who may offer organs. Although the shortage of organs must be addressed, the social price of a market in organs is too high, and proposals to encourage a rethinking of social responsibility are unlikely to be effective.     

The role of working memory in motor learning and performance

Three experiments explore the role of working memory in motor skill acquisition and performance. Traditional theories postulate that skill acquisition proceeds through stages of knowing, which are initially declarative but later procedural. The reported experiments challenge that view and support an independent, parallel processing model, which predicts that procedural and declarative knowledge can be acquired separately and that the former does not depend on the availability of working memory, whereas, the latter does. The behaviour of these two processes was manipulated by providing or withholding visual (and auditory) appraisal of outcome feedback. Withholding feedback was predicted to inhibit the use of working memory to appraise success and, thus, prevent the formation of declarative knowledge without affecting the accumulation of procedural knowledge. While the first experiment failed to support these predictions, the second and third experiments demonstrated that procedural and declarative knowledge can be acquired independently. It is suggested that the availability of working memory is crucial to motor performance only when the learner has come to rely on its use.     

The Pavlov Department of Physiology: a scientific history

The scientific adventure of the Ivan Pavlov Department of Physiology is traced from Pavlov's and his students pioneer work on "psychic salivation" to the times of the Biological Station at Koltushi. The development of the Department after Pavlov's death is described and the research trends of the three present laboratories (Neurobiology of Integrative Brain Functions, Psychophysiology of Emotions, and Neurodynamic Correction of Psycho Neurological Pathology) are discussed.     

Facts,values, and policies: a comment on Howard H. Kendler (2002)

In a recent article, Howard H. Kendler (2002) criticized Kenneth B. Clark and the other social scientists who worked in Brown v. Board of Education for polluting their science with value judgments. This article argues that Kendler's critique is misguided because it conflates a policy judgment with a value judgment. In addition, Kendler inconsistently applied his own standard of objectivity when he examined in the social science used in Brown.     

Cognitive-behavioral therapy for social anxiety disorder: supporting evidence and future directions

The present paper examines the role of cognitive-behavioral therapy (CBT) in the treatment of social anxiety disorder (SAD). A cognitive-behavioral model of SAD is first presented. Different modalities of CBT for SAD are then described, including exposure, cognitive restructuring, relaxation training, and social skills training, and evidence supporting their efficacy is reviewed. The comparative and combined impact of CBT and pharmacotherapeutic interventions is also explored. CBT appears to be an efficacious treatment for SAD. However, the overall efficacy CBT may be increased by closer examination of the active ingredients of treatment. Such analyses may also enable more successful integration of the different CBT techniques and of CBT and pharmacotherapy in the treatment of SAD.     

Journey to the center of the category: the dissociation in amnesia between categorization and recognition

The authors' theoretical analysis of the dissociation in amnesia between categorization and recognition suggests these conclusions: (a) Comparing to-be-categorized items to a category center or prototype produces strong prototype advantages and steep typicality gradients, whereas comparing to-be-categorized items to the training exemplars that surround the prototype produces weak prototype advantages and flat typicality gradients; (b) participants often show the former pattern, suggesting their use of prototypes; (c) exemplar models account poorly for these categorization data, but prototype models account well for them; and (d) the recognition data suggest that controls use a single-comparison exemplar-memorization process more powerfully than amnesics. By pairing categorization based in prototypes with recognition based in exemplar memorization, the authors support and extend other recent accounts of cognitive performance that intermix prototypes and exemplars, and the authors reinforce traditional interpretations of the categorization-recognition dissociation in amnesia.     

Dynamic analyses of mother-child interactions in functional and dysfunctional dyads: a synergetic approach

Describes the application of a new analytical approach (derived from synergetics, a complex dynamic systems theory) to home observational data of mother–child interactions in average dyads and dyads with children referred for disruptive behavior problems at home and school (n = 11 in each group). Results show that (1) the two groups differed in their daily interactions in predictable ways, and (2) the most frequent patterns of interactions observed in the two groups brought them back repeatedly to behave in similar ways toward each other. The findings are in keeping with a body of literature on mother–child interactions. However, they add to it by providing multivariate, graphical representations of these interactions and by offering a conceptual framework within which to move from an observational to an inferential level of analysis. At that level, the transactional processes that are characteristic of functional and dysfunctional relationships may become apparent.     

The connubial crucible: newlywed years as predictors of marital delight, distress, and divorce

This study showed that couples' newlywed marriages and changes in their union over the first 2 years foreshadow their long-term marital fate after 13 years. Consistent with the enduring dynamics model, differences in the intensity of newlyweds' romance as well as the extent to which they expressed negative feelings toward each other predicted (a) whether or not they were happy 13 years later (among those who stayed married) and (b) how long their marriage lasted prior to separation (for those who divorced). The results provide little support for the idea that emergence of distress (e.g., increasing negativity) early in marriage leads to marital failure but instead show that disillusionment--as reflected in an abatement of love, a decline in overt affection, a lessening of the conviction that one's spouse is responsive, and an increase in ambivalence--distinguishes couples headed for divorce from those who establish a stable marital bond.