Context-processing deficits in schizophrenia: diagnostic specificity, 4-week course,and relationships to clinical symptoms

Previous research on schizophrenia suggests that context-processing disturbances are one of the core cognitive deficits present in schizophia. However, it is not clear whether such deficits are specific to schizophrenia as compared with other psychotic disorders. To address this question, the authors administered a version of the AX Continuous Performance Test designed to assess context processing in a sample of healthy controls, patients with schizophrenia, and patients with other psychotic disorders. Participants were tested at index (when medication naive and experiencing their first contact with psychiatric services) and 4 weeks later, following medication treatment. At index, patients with schizophrenia and the psychotic comparison group demonstrated similar impairments in context processing. However, context-processing deficits improved in the psychotic comparison group at 4 weeks but did not improve in patients with schizophrenia.     

Do age of onset and course of illness define biologically distinct groups within atypical depression?

Illness course separates patients with atypical depression into tricyclic responders and nonresponders as does perceptual asymmetry. The authors therefore investigated whether the course-of-illness parameters would define groups within atypical depression differing in brain laterality. Patients with atypical depression were assessed for illness course and brain laterality. Two patient groups were defined, 1 with onset prior to age 20 plus a very chronic course, and a 2nd group having later onset or less chronic illness. Patients reporting early onset of very chronic dysphoria showed significantly less right-ear (left-hemisphere) accuracy and also differed in characteristic perceptual asymmetry when compared to patients with later onset or less chronicity. Course of illness may usefully define more homogeneous depressive subgroups within atypical depression.     

Interidentity amnesia for neutral,episodic information in dissociative identity disorder

Interidentity amnesia is considered a hallmark of dissociative identity disorder (DID) in clinical practice. In this study, objective methods of testing episodic memory transfer between identities were used. Tests of both recall (interference paradigm) and recognition were used. A sample of 31 DID patients was included. Additionally, 50 control subjects participated, half functioning as normal controls and the other half simulating interidentity amnesia. Twenty-one patients subjectively reported complete one-way amnesia for the learning episode. However, objectively, neither recall nor recognition scores of patients were different from those of normal controls. It is suggested that clinical models of amnesia in DID may be specified to exclude episodic memory impairments for emotionally neutral material.     

What response times tell of children's behavior on the balance scale task

Analysis of accuracy of responses to balance scale problems gives a global idea of the cognitive processes that underlie problem-solving behavior on this task. We show that response times (RTs) provide additional detailed information about the kind and duration of these processes. We derive predictions about the RTs from Siegler's (1981) model for the balance scale task, including the counterintuitive prediction that young adults are slower than children in solving particular balance scale problems. The predictions were tested in a study in which 191 6- to 22-year-old participants were presented with a computerized balance scale task. RTs were analyzed with regression models. In addition to qualitative differences between items, we also modeled quantitative differences between items in the regression models. Analyses supported the predictions and provided additional knowledge on the rules. Rule II was reformulated as a rule that always involves the encoding, but not always the correct application of the distance cue. RTs provided evidence for the use of a buggy-rule and not an addition-rule. Finally, a relation between rule inconsistency and increased RT was found.     

Flanker and negative flanker effects in letter identification

In a speeded choice reaction time task, responses to centrally presented letter targets can be altered by the identity of surrounding task-irrelevant letters (flankers). In the standard flanker effect, flankers associated with the same response as the target lead to faster and more accurate responses, whereas flankers associated with a different response lead to slower and more error-prone responses. B. A. Eriksen and C. W. Eriksen (1974, pp. 143-149) have argued that these flanker effects occur through response competition. We present data from a novel version of the Eriksen task, in which some targets and flankers consist of letter forms that are morphed versions of target letters. In this paradigm, flankers induce classic flanker effects on well-formed targets. But flankers induce an opposite effect, termed a negative flanker effect on morphed letter targets. For example, targets that are morphs between the letters "A" and "H" are more likely to be identified as an "A" when flanked by an "H." The interpretation advanced here is that there are two distinct kinds of flanker effects contrast enhancement in perceptual processes and response competition in response selection processes.     

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Authors Index

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Using response times to detect aberrant responses in computerized adaptive testing

A lognormal model for response times is used to check response times for aberrances in examinee behavior on computerized adaptive tests. Both classical procedures and Bayesian posterior predictive checks are presented. For a fixed examinee, responses and response times are independent; checks based on response times offer thus information independent of the results of checks on response patterns. Empirical examples of the use of classical and Bayesian checks for detecting two different types of aberrances in response times are presented. The detection rates for the Bayesian checks outperformed those for the classical checks, but at the cost of higher false-alarm rates. A guideline for the choice between the two types of checks is offered.This study received funding from the Law School Admission Council (LSAC). The opinions and conclusions contained in this paper are those of the authors and do not necessarily reflect the policy and position of LSAC. The authors are most indebted to Wim M. M. Tielen for his computational assistance and to the US Defense Manpower Data Center for the permission to use the ASVAB data set in the empirical examples.     

When stereotypes get in the way: stereotypes obstruct stereotype-inconsistent trait inferences

There is a growing body of evidence indicating that people spontaneously make trait inferences while observing the behavior of others. The present article reports a series of 5 experiments that examined the influence of stereotypes on the spontaneous inference of traits. Results consistently showed weaker spontaneous trait inferences for stereotype-inconsistent behavioral information than for stereotype-consistent and stereotype-neutral information. Taken together, the current results suggest that specific spontaneous trait inferences become obstructed by inhibitory processes when behavior is inconsistent with an already activated stereotype. These findings are discussed in relation to stereotype maintenance processes and recent models of attribution in social judgment.     

It takes two to mimic: behavioral consequences of self-construals

The present studies demonstrated the moderation of self-construal orientation on mimicry. Recent research has indicated that an interdependent self-construal is associated with assimilation of the other to the self whereas an independent self-construal is associated with minimizing the influence of others on the self (H. R. Markus & S. Kitayama, 1991; D. Stapel & W. Koomen, 2001). Therefore, the authors hypothesized that an interdependent self-construal would be associated with more mimicry than an independent self-construal. When self-construal orientations were experimentally primed, as in Studies 1 and 2, independent self-construals produced less nonconscious mimicry than interdependent self-construals. When self-construals were examined as cultural differences with either a chronically dominant independent (Americans) or interdependent (Japanese) construal of the self, these results were replicated.