Conditioned memory modulation, freezing, and avoidance as measures of amygdala-mediated conditioned fear

Three conditioned aversive responses were used to infer the existence of an unobservable central state of "conditioned fear," and the roles of certain amygdala subregions in producing these responses were investigated. Rats received tone-shock pairings in one compartment of a shuttle box and no tones or shocks in the other, distinctive, compartment. They were then trained to find food in one arm of a Y-maze. After the final training trial they were exposed to different sets of stimuli in the shuttle box with no shock. Twenty-four hours later rats that had received immediate posttraining exposure to the conditioned stimuli (in the shock-paired compartment) made significantly more correct responses on the Y-maze than rats that had been exposed to the neutral stimuli (in the no-shock compartment) or rats that had received delayed posttraining exposure to the conditioned stimuli. This constitutes a demonstration of posttraining memory modulation by conditioned aversive stimuli. Freezing increased during posttraining exposure to the conditioned stimuli compared to the neutral stimuli. When subsequently allowed to move freely between the two compartments, the rats in all groups also showed significant conditioned avoidance of the compartment containing the conditioned stimuli. In a second experiment the effects of lesions confined to specific parts of the amygdala on the three conditioned responses (memory modulation, freezing, avoidance) were tested. Lesions of the central nucleus impaired all three conditioned responses; lesions of the medial nucleus impaired conditioned modulation and avoidance. These lesions had no effect on freezing during the training trials. Lesions of the lateral and basolateral nuclei attenuated freezing during both training and testing. The findings suggest that the central and medial nuclei of the amygdala may be important parts of neural circuits mediating conditioned responses that constitute conditioned aversive states, but that conditioned freezing may be mediated independently.     

Open Space

Abstract

The Emotional Needs of Young Children and Their Families: Using Psychoanalytic Ideas in the Community, Judith Trowell and Marion Bower, London: Routledge, 1995, 320 pp., £45 hb., £14.99 pb.

The Evolution of the Emotion-Processing Mind, Robert Langs, London: Karnac, 1996, 223 pp., £18.95 pb.

The Influence of Race and Racial Identity in Psychotherapy, Robert T. Carter, New York: Wiley Interscience, 1995, 312 pp., £29.95 hb.

Counselling in Criminal Justice, Brian Williams, Buckingham: Philadelphia, 1996, 176 pp., £12.99 pb.

Thinking about Children, D.W. Winnicott, eds Ray Shepherd, Jennifer Johns and Helen Taylor Robinson, London: Karnac, 1996, 343 pp., £19.95 pb.

That Why Child: Problems in Psychotherapy and Counselling, Carol Jeffrey, London: Free Association Books, 1996, 127 pp., £13.95 pb.

Desire and the Female Therapist: Engendered Gazes in Psychotherapy and Art Therapy, Joy Schaverien, London: Routledge, 1995, 233 pp., £45 hb, £17.99 pb.     

The counsellor and the GP: The gulf and the isthmus - or the dilemmas of difference

Research supervision in the field of counselling and psychotherapy is a fruitful area for investigation in view of the fact that the research supervisory relationship is powerful and highly charged, whether consciously acknowledged or not. Researchers trained as counsellors and psychotherapists possess the skills to facilitate the emergence of, and work creatively with, impasses and crises, both in the research itself and the supervisory relationship, as a result of their training and experience in dealing with crisis and catharsis in clinical work. This paper will demonstrate these points using a case vignette from my work as a supervisor of research dissertations undertaken by students on a Masters in Therapeutic Counselling course. Drawing on narrative analysis, clinical supervision theory and discursive analysis it will look at the strengths and weaknesses of a ‘psychotherapeutic’ approach to research supervision.     

Semantic Elaboration through Integration: Hints Both Facilitate and Inform the Process

Semantic knowledge can be extended in a variety of ways, including self-generation of new facts through integration of separate yet related episodes. We sought to promote integration and self-generation by providing “hints” to help 6-year-olds (Experiment 1) and 4-year-olds (Experiment 2) see the relevance of separate episodes to one another. Varying the timing of presentation of the hints—whether provided between episodes or before test—afforded insights into the processes responsible for self-generation of new semantic knowledge through integration. In both experiments, hints provided immediately before testing facilitated performance relative to a control condition. In contrast, hints provided between episodes did not. The findings imply that integration of distinct experiences is not an automatic process set into motion based on shared elements. Even when integration is primed through a hint that a prior episode is relevant to a forthcoming experience, shared elements apparently are not sufficient to promote self-generation of new semantic knowledge. Instead, the process seems to occur upon demand, such as in response to a question. These findings can be used to guide interventions designed to promote enrichment of semantic memory and also further our understanding of the basic cognitive processes involved in extension of knowledge.     

Visual impressions of penetration in the perception of objects in motion

Observers viewed visual stimuli in which one object moved to a position of partial occlusion by another. The objects were presented as two-dimensional profiles moving in an undefined space, so the partial occlusion supports several different physical interpretations. In fact some stimuli reliably gave rise to a perceptual impression that the moving object penetrated or pierced the stationary one. This kind of interaction impression has not previously been reported. The impression was maximized by rapid deceleration to a halt with minimal occlusion. If the object decelerated more slowly, so that it was completely occluded or projected from the far side of the stationary object, it was perceived as moving behind the stationary object. The shape of the moving object and its speed prior to occlusion had significant but small effects.     

Is the perceived present a predictive model of the objective present?

ABSTRACT

Processing latencies for coherent, high level percepts in vision are at least 100?ms and possibly as much as 500?ms. Processing latencies are less in other modalities, but still significant. This seems to imply that perception lags behind reality by an amount equal to the processing latency. It has been proposed that the brain can compensate for perceptual processing latencies by using the most recent available information to extrapolate forward, thereby constructing a model of what the world beyond the senses is like now. The present paper reviews several lines of evidence relating to this hypothesis, including the flash-lag effect, motion-induced position shifts, representational momentum, static visual illusions, and motion extrapolation at the retina. There are alternative explanations for most of the results but there are some findings for which no competing explanation has yet been proposed. Collectively, the evidence for extrapolation to the present is suggestive but not yet conclusive. An alternative account of compensation for processing latencies, based on the hypothesis of rapid emergence of percepts, is proposed.     

Talkativeness in Cognitively Normal Women at Genetic Risk for Alzheimer’s Disease

Previous research has suggested a correlation between some linguistic patterns and the risk for Alzheimer’s disease (AD). There is increasing clinical need to identify factors that can be used alone or in combination to predict the onset of AD. The purpose of the present study was to explore the association of language skills and genetic risk for Alzheimer’s disease. Oral and written language samples of cognitively normal women with a susceptibility gene for AD (ApoE e4) were compared to those of noncarriers on measures of grammatical complexity, topic relevance, and talkativeness by observers unaware of participant genotypes. Participants included 29 ApoE e4 carriers 49-73 years of age, and 29 e4 noncarriers 48-76 years of age, most of whom had a first-degree relative with AD. Carriers and noncarriers were group matched for age, educational level, and estimated IQ. Participant groups did not differ significantly in language complexity or topic relevance. However, the ApoE e4 group was significantly more talkative than the noncarrier group (p < .05).     

An examination of career indecision and application to dispositional authenticity

Authenticity has been viewed as a dimension related to life satisfaction, but we propose that authenticity is related to career outcomes. In this study, we examined the relation between authenticity and career indecision. Authenticity was assessed by the Authenticity Scale and it was found to be moderately related to different indices of career indecision in a sample of 537 undergraduate university students. Results are discussed in terms of their clinical and research implications and encourage a broader perspective in conceptualizing vocational concerns.     

Mismatch negativity and P300 to behaviorally perceptible and imperceptible frequency and intensity contrasts

Mismatch negativity and the P300 have been investigated as electrophysiological indices of behavioral auditory discrimination of duration. Using an oddball paradigm, responses were evoked to stimuli that had been behaviorally demonstrated to be either perceptible or imperceptible. The results indicated P300 events were present with the perceptible contrast but absent for the imperceptible contrast with all participants, while mismatch negativities were present in approximately 80 and 20% of participants to the perceptible and imperceptible contrasts, respectively. The present study extended the findings by applying the same paradigm to the discrimination of spectral and amplitude contrasts. 10 young adults with normal hearing were participants. Assuming that auditory assessment should involve representation and processing in all acoustic domains (i.e., temporal/duration, spectral/frequency, and amplitude/intensity), the effects seen with temporal contrasts were predicted to be similar for spectral and amplitude contrasts. The findings generally illustrated that the P300 was more accurate than the mismatch negativity in reflecting behavioral discrimination. Together, these studies challenge the use of mismatch negativity as an electrophysiological correlate for behavioral discrimination of auditory perceptible contrasts.