Recognition memory for source and occurrence: The importance of recollection

Previous recognition memory studies indicate that when both recollection and familiarity are expected to contribute to recognition performance (e.g., discriminating studied items from nonstudied items) the dual-process and the unequal-variance signal detection models provide comparable accounts of performance. When familiarity is not expected to be useful (e.g., when items from two equally familiar sources are discriminated between), the dual-process model provides a significantly better account of performance. In the present study, source recognition was tested under conditions in which familiarity could have been used to perform a list-discrimination task; participants were required to discriminate between strong studied items, weak studied items, and new items. The dual-process model provided a better account of performance than did the unequal-variance model. Moreover, the results indicated that the unequal-variance assumption in a single-process signal detection model was not a valid substitution for recollection and that recollection was used to make recognition judgments even when assessments of familiarity were useful.     

The relationship between social anxiety and social support in adolescents: a test of competing causal models

This study compared the strength of competing causal models in explaining the relationship between perceived support, enacted support, and social anxiety in adolescents. The social causation hypothesis postulates that social support causes social anxiety, whereas the social selection hypothesis postulates that social anxiety causes social support. The reciprocal model combines the two hypotheses by arguing that the causal relationship between social support and social anxiety is largely reciprocal. This study tests a modification of the reciprocal model by specifying perceptions of support as a mediating construct. Two waves of data with an interval of three months were collected on 357 college students. Structural equation modeling was used to compare the reciprocal and mediated reciprocal causal models. The study found some support for the mediated reciprocal model, but the magnitude of the relationships were weaker than expected. Limitations and suggestion for future research are discussed.     

Accuracy of self-reports of alcohol offenders in a rural midwestern county

Self-reports of drinking are of doubtful accuracy as heavy drinkers tend to underreport consistently amounts drunk as well as other alcohol-related data. A sample of 60 people cited for DWI in a rural midwestern county in southeast Nebraska during routine alcohol-dependency evaluations indicated that 10% underreported their Breath Alcohol Content at the time of arrest and 38% their previous number of DWI citations. Subjects were grouped by age (over and under 30) and by accuracy (accurate and inaccurate reporters). A 2 x 2 analysis of variance of later DWI arrests was significant as younger subjects showed greater risk. Those who underreported number of past DWI citations were significantly lower on their self-reported BAC at the time of arrest than accurate reporters. Age and underreporting alcohol-related data are as important for practitioners to attend to as scores on the Michigan Alcoholism Screening Test or SCID measuring alcoholic tendencies.     

Outcome and epidemiological research on personality disorders: implications for classification

The construct of personality disorder has an overall definition that describes chronicity. However, the findings of outcome research indicate that while many patients stop meeting criteria for specific categories of disorder over time, they often continue to suffer from dysfunctional traits. One can also interpret epidemiological findings on personality disorders as overestimating disorders due to a failure to distinguish them from traits. Taken together, these findings point to the need for a revision of the classification of personality disorders that would separate enduring traits from reversible symptoms.     

Neurobiological dimensional models of personality: a review of the models of Cloninger, Depue, and Siever

Neurobiological dimensional models of personality aim to account for the structure of personality traits and disorders through links to neurotransmitter systems. Three such models are reviewed: those of Cloninger, Depue, and Siever. While these proposals have heuristic value, none of them has obtained strong empirical support. Our current understanding of neurobiology is insufficient to develop a model of personality on this basis. At this point, dimensions of personality should be derived from factor analysis rather than from neurobiological theories.     

Acetylcholine release in the hippocampus and striatum during place and response training

These experiments examined the release of acetylcholine in the hippocampus and striatum when rats were trained, within single sessions, on place or response versions of food-rewarded mazes. Microdialysis samples of extra-cellular fluid were collected from the hippocampus and striatum at 5-min increments before, during, and after training. These samples were later analyzed for ACh content using HPLC methods. In Experiment 1, ACh release in both the hippocampus and striatum increased during training on both the place and response tasks. The magnitude of increase of training-related ACh release in the striatum was greater in rats trained on the response task than in rats trained on the place task, while the magnitude of ACh release in the hippocampus was comparable in the two tasks. Experiment 2 tested the possibility that the hippocampus was engaged and participated in learning the response task, as well as the place task, because of the availability of extra-maze cues. Rats were trained on a response version of a maze under either cue-rich or cue-poor conditions. The findings indicate that ACh release in the hippocampus increased similarly under both cue conditions, but declined during training on the cue-poor condition, when spatial processing by the hippocampus would not be suitable for solving the maze. In addition, high baseline levels of ACh release in the hippocampus predicted rapid learning in the cue-rich condition and slow learning in the cue-poor condition. These findings suggest that ACh release in the hippocampus augments response learning when extra-maze cues can be used to solve the maze but impairs response learning when extra-maze cues are not available for use in solving the maze.     

Maladaptive conflict monitoring as evidence for executive dysfunction in children with chromosome 22q11.2 deletion syndrome

Using an adaptation of the Attentional Networks Test, we investigated aspects of executive control in children with chromosome 22q11.2 deletion syndrome (DS22q11.2), a common but not well understood disorder that produces non-verbal cognitive deficits and a marked incidence of psychopathology. The data revealed that children with DS22q11.2 demonstrated greater difficulty than controls in locating and processing target items in the presence of distracters. Importantly, children with DS22q11.2 showed a deficit in the ability to monitor and adapt to stimulus conflict. These data provide evidence of inadequate conflict adaptation in children with DS22q11.2, a problem that is also present in schizophrenia. The findings of specific executive dysfunction in this group may provide a linkage between particular genetic abnormalities and the development of psychopathology.     

Interference with spatial working memory: An eye movement is more than a shift of attention

In the present experiments, we examined whether shifts of attention selectively interfere with the maintenance of both verbal and spatial information in working memory and whether the interference produced by eye movements is due to the attention shifts that accompany them. In Experiment 1, subjects performed either a spatial or a verbal working memory task, along with a secondary task requiring fixation or a secondary task requiring shifts of attention. The results indicated that attention shifts interfered with spatial, butnot with verbal, working memory, suggesting that the interference is specific to processes within the visuospatial sketchpad. In Experiment 2, subjects performed a primary spatial working memory task, along with a secondary task requiring fixation, an eye movement, or an attention shift executed in the absence of an eye movement. The results indicated that both eye movements and attention shifts interfered with spatial working memory. Eye movements interfered to a much greater extent than shifts of attention, however, suggesting that eye movements may contribute a unique source of interference, over and above the interference produced by the attention shifts that accompany them.     

Neuropsychological executive functioning in children at elevated risk for alcoholism: findings in early adolescence

One component of individual risk for alcoholism may involve cognitive vulnerabilities prodromal to alcoholism onset. This prospective study of 198 boys followed between 3 and 14 years of age evaluated neurocognitive functioning across three groups who varied in familial risk for future alcoholism. Measures of intelligence, reward-response, and a battery of neuropsychological executive and cognitive inhibitory measures were used. Executive functioning weaknesses were greater in families with alcoholism but no antisocial comorbidity. IQ and reward-response weaknesses were associated with familial antisocial alcoholism. Executive function effects were clearest for response inhibition, response speed, and symbol-digit modalities. Results suggest that executive deficits are not part of the highest risk, antisocial pathway to alcoholism but that some executive function weaknesses may contribute to a secondary risk pathway.