Stimulus competition in affective and relational learning

Evaluative learning theory states that affective learning, the acquisition of likes and dislikes, is qualitatively different from relational learning, the learning of predictive relationships among stimuli. Three experiments tested the prediction derived from evaluative learning theory that relational learning, but not affective learning, is affected by stimulus competition by comparing performance during two conditional stimuli, one trained in a superconditioning procedure and the other in a blocking procedure. Ratings of unconditional stimulus expectancy and electrodermal responses indicated stimulus competition in relational learning. Evidence for stimulus competition in affective learning was provided by verbal ratings of conditional stimulus pleasantness and by measures of blink startle modulation. Taken together, the present experiments demonstrate stimulus competition in relational and affective learning, a result inconsistent with evaluative learning theory. (C) 2001 Academic Press.

Does affective learning exist in the absence of contingency awareness?

The proposal that affective learning, the learning of likes and dislikes, can exist in the absence of contingency awareness, whereas signal learning, the learning of stimulus relationships, cannot, was investigated in a differential conditioning paradigm that was embedded in a visual masking task. Startle magnitude modulation and changes in verbal ratings served as measures of affective learning, whereas skin conductance was taken to reflect signal learning. Awareness was assessed online with an expectancy dial and in a postexperimental questionnaire. Both between-subject comparisons of verbalizers and nonverbalizers and within-subject comparisons of verbalizers before and after verbalization failed to reveal any evidence for learning, whether affective or otherwise, in the absence of knowledge of the stimulus contingencies. (C) 2001 Academic Press.

Cognitive behaviour therapy for the management of obsessive-compulsive disorder

Current research reflects conflict regarding best practice in the treatment of obsessive-compulsive disorder (OCD). The. present study reports on the psychological treatment of a 54-year-old woman diagnosed with OCD, and follows the implementation of pharmacological treatment. The study utilises both exposure and response prevention (ERP) and cognitive therapy (CT), although there was no attempt to compare these approaches in an experimental design. Measures of avoiding and neutralising behaviours were taken on three occasions across treatment. Measures were also taken of intrusive thoughts, appraisal of responsibility, and effective challenging, both across treatment and at follow-up. The results indicate that gains were made in addition to those reported following the implementation of medication. The results also suggest that the addition of CT to exposure and response prevention facilitates the extinction of neutralising behaviours.

Relationship of glycosaminoglycan and matrix changes to vascular smooth cell phenotype modulation in rabbit arteries after acute injury

Purpose: The phenotype of vascular smooth muscle cells (SMCs) is altered in several arterial pathologies, including the neointima formed after acute arterial injury. This study examined the time course of this phenotypic change in relation to changes in the amount and distribution of matrix glycosaminoglycans. Methods: The immunochemical staining of heparan sulphates (HS) and chondroitin sulphates (CS) in the extracellular matrix of the arterial wall was examined at early points after balloon catheter injury of the rabbit carotid artery. SMC phenotype was assessed by means of ultrastructural morphometry of the cytoplasmic volume fraction of myofilaments. The proportions of cell and matrix components in the media were analyzed with similar morphometric techniques. Results: HS and CS were shown in close association with SMCs of the uninjured arterial media as well as being more widespread within the matrix. Within 6 hours after arterial injury, there was loss of the regular pericellular distribution of both HS and CS, which was associated with a significant expansion in the extracellular space. This preceded the change in ultrastructural phenotype of the SMCs. The glycosaminoglycan loss was most exaggerated at 4 days, after which time the HS and CS reappeared around the medial SMCs. SMCs of the recovering media were able to rapidly replace their glycosaminoglycans, whereas SMCs of the developing neointima failed to produce HS as readily as they produced CS. Conclusions: These studies indicate that changes in glycosaminoglycans of the extracellular matrix precede changes in SMC phenotype after acute arterial injury. In the recovering arterial media, SMCs replace their matrix glycosaminoglycans rapidly, whereas the newly established neointima fails to produce similar amounts of heparan sulphates.

The future of cognitive and behavioral therapies in the prevention and early management of psychosis: Opportunities and risks

Behavioral and cognitive interventions for people with psychosis have a long and distinguished history, although the evidence for their application to young people remains limited. We anticipate that the next decades will show substantial research into psychological intervention for this population. Important targets will include the management of environmental stressors, reduction of substance misuse, and promotion of early treatment. Psychological management of positive symptoms, depression, and suicidal behavior will continue to be critical objectives. Important secondary prevention goals will be the retention of cognitive functioning, vocational options, social skills, and social network support, including appropriate family support. We expect primary prevention to include both universal programs and interventions for adolescents at particularly high risk. Technical innovations will include increasing use of Internet-based intervention and behavior cueing devices. Pressures for intervention brevity will continue, as will problems with the systematic delivery of effective procedures.

Outpatient cognitive behavioural therapy programme for alcohol dependence impact of naltrexone use on outcome

Objective: Cognitive-behavioural therapy (CBT) has been effectively used in the treatment of alcohol dependence. Clinical studies report that the anticraving drug naltrexone, is a useful adjunct to treatment. Currently, few data are available on the impact of adding this medication to programmes in more typical, outpatient, and rehabilitation settings. The objective of this study was to examine the impact on outcome of adding naltrexone to an established outpatient alcohol rehabilitation program which employed CBT. Method: Fifty patients participated in an established 12-week, outpatient, 'contract'-based alcohol abstinence programme which employed CBT. They also received naltrexone 50 mg orally daily (CBT + naltrexone). Outcomes were compared with 50 historical, matched controls, all of whom participated in the same programme without an anticraving medication (CBT alone). All patients met DSM-IV criteria for alcohol dependence. Results: Programme attendance across the eight treatment sessions was lower in the CBT alone group (p < 0.001). Relapse to alcohol use occurred sooner and more frequently in the CBT alone group (p < 0.001). Rehabilitation programme completion at 12 weeks was 88% (CBT + naltrexone) compared with 36% for (CBT alone) (p < 0.001). Alcohol abstinence at 12 weeks was 76% (CBT + naltrexone) compared with 18% (CBT alone) (p < 0.001). Conclusion: When employing the same outpatient rehabilitation programme and comparing outcomes using matched historical controls, the addition of naltrexone substantially improves programme attendance, programme completion and reported alcohol abstinence. In a typical outpatient programme, naltrexone addition was associated with significantly improved programme participation, better outcomes and was well tolerated.

Lexical decision in Parkinson's disease: A reply to Brown, McDonald, and Spicer (1999)

Recent semantic priming investigations in Parkinsons disease (PD) employed variants of Neelys (1977) lexical decision paradigm to dissociate the automatic and attentional aspects of semantic activation (McDonald, Brown, Gorell, 1996; Spicer, Brown, Gorell, 1994). In our earlier review, we claimed that the results of Spicer, McDonald and colleagues normal control participants violated the two-process model of information processing (Posner Snyder, 1975) upon which their experimental paradigm had been based (Arnott Chenery, 1999). We argued that, even at the shortest SOA employed, key design modifications to Neelys original experiments biased the tasks employed by Spicer et al. and McDonald et al. towards being assessments of attention-dependent processes. Accordingly, we contended that experimental procedures did not speak to issues of automaticity and, therefore, Spicer, McDonald and colleagues claims of robust automatic semantic activation in PD must be treated with caution.

Semantic priming in Alzheimer's dementia: Evidence for dissociation of automatic and attentional processes

The nature of the semantic memory deficit in dementia of the Alzheimer's type (DAT) was investigated in a semantic priming task which was designed to assess both automatic and attention-induced priming effects. Ten DAT patients and 10 age-matched control subjects completed a word naming semantic priming task in which both relatedness proportion (RP) and stimulus-onset asynchrony (SOA) were varied. A clear dissociation between automatic and attentional priming effects in both groups was demonstrated; however, the DAT subjects pattern of priming deviated significantly from that of the normal controls. The DAT patients failed to produce any priming under conditions which encouraged automatic semantic processing and produced facilitation only when the RP was high. In addition, the DAT group produced hyperpriming, with significantly larger facilitation effects than the control group. These results suggest an impairment of automatic spreading activation in DAT and have implications for theories of semantic memory impairment in DAT as well as models of normal priming. (C) 2001 Academic Press.

Modulation of the adrenocortical stress response in marine turtles (Cheloniidae): evidence for a hormonal tactic maximizing maternal reproductive investment

The relationships between reproductive condition, level of reproductive investment and adrenocortical modulation to capture stress in marine turtles form the basis of this study. When subjected to either capture or ecological stressors, nesting marine turtles have demonstrated adrenocortical responses that are both small in magnitude, and slow in responsiveness. These observations were further investigated to determine whether this minimal stress response was a physiological strategy to maximize reproductive investment in adult green Chelonia mydas and hawksbill Eretmochelys imbricata turtles. Female green and hawksbill turtles exhibited a decrease in adrenocortical responsiveness with progressive reproductive condition. Breeding turtles exhibited most suppression of their adrenocortical response to capture compared to both non-breeding and pre-breeding female counterparts. Nesting green turtles maintained a suppressed adrenocortical response to capture throughout the nesting season despite decreased reproductive investment. In contrast, male green and hawksbill turtles were less able to modulate their corticosterone (B) response to acute capture stress. During breeding, male turtles possessed significantly greater adrenocortical responses to capture than females. These results could indicate that the large reproductive investment necessary for female marine turtle reproduction might underlie the marked decrease in adrenocortical responsiveness. This hormonal mechanism could function as one strategy by which female marine turtles maximize their current reproductive event, even though under certain situations this mechanism could entail costs to female survival.

Phylogenetic classification of Eudorylini (Diptera: Pipunculidae)

The phylogenetic relationships of members of Eudorylini (Diptera: Pipunculidae: Pipunculinae) were explored. Two hundred and fifty-seven species of Eudorylini from all biogeographical regions and all known genera were examined. Sixty species were included in an exemplar-based phylogeny for the tribe. Two new genera are described, Clistoabdominalis and Dasydorylas. The identity of Eudorylas Aczél, the type genus for Eudorylini, has been obscure since its inception. The genus is re-diagnosed and a proposal to stabilize the genus and tribal names is discussed. An illustrated key to the genera of Pipunculidae is presented and all Eudorylini genera are diagnosed. Numerous new generic synonyms are proposed. Moriparia nigripennis Kozánek & Kwon is preoccupied by Congomyia nigripennis Hardy when both are transferred to Claraeola, so Cla. koreana Skevington is proposed as a new name for Mo. nigripennis.