Action monitoring and perfectionism in anorexia nervosa

To study action monitoring in anorexia nervosa, behavioral and EEG measures were obtained in underweight anorexia nervosa patients (n=17) and matched healthy controls (n=19) while performing a speeded choice-reaction task. Our main measures of interest were questionnaire outcomes, reaction times, error rates, and the error-related negativity ERP component. Questionnaire and behavioral results indicated increased perfectionism in patients with anorexia nervosa. In line with their perfectionism and controlled response style patients made significantly less errors than controls. However, when controlling for this difference in error rates, the EEG results demonstrated a reduced error-related negativity in the patient group. These seemingly contradictory outcomes of improved performance and reduced error monitoring are discussed in relation with indications of anterior cingulate cortex hypoactivity in anorexia nervosa patients.     

The contingent negative variation laterality and dynamics in antisaccade task in normal and unmedicated schizophrenic subjects

Contingent negative variation (CNV) topography, hemispheric asymmetry and time-course were investigated in healthy subjects and non-medicated paranoid schizophrenic patients in two antisaccade paradigms with the short (800-1000 ms) and long (1200-1400 ms) durations of the fixation period. EEG and electrooculogram (EOG) were recorded. Saccade characteristics and mean amplitudes of slow cortical potentials time-locked to peripheral target were analyzed in 23 healthy volunteers and 19 schizophrenic patients. Compared to healthy control subjects, schizophrenic patients had significantly slower antisaccades and committed significantly more erroneous saccades in the both antisaccade tasks. The prolongation of the fixation period resulted in noticeable decrease of error percent in patients group. The analysis of CNV time-course has revealed two distinct stages in both groups. The early CNV stage was represented by a negative wave with the maximal amplitude over midline fronto-central area, and the late stage was characterized by increased CNV amplitude at the midline and left parietal electrode sites. In healthy subjects the simultaneous activation of frontal and parietal areas was observed in the paradigm with the shorter fixation interval; the increase of the fixation period produced consecutive activation of these areas. Schizophrenic patients' CNV amplitude was generally smaller than that of healthy subjects. The most pronounced between-group differences of the negative shift amplitude were revealed at frontal electrode sites during the early CNV stage in both modifications of the antisaccade task. The deficit of frontal activation revealed in patients at the early stage of antisaccade preparatory set in both antisaccadic paradigms may be related to pathogenesis of paranoid schizophrenia.     

Hemispheric processing deficits in patients with paranoid schizophrenia

The purpose of the present study was to investigate hemispheric deficits in individuals with paranoid schizophrenia on four kinds of tasks: dichoptic viewing tasks involving verbal and nonverbal visual stimuli, and dichotic listening tasks involving verbal and nonverbal auditory stimuli. As dependent measures, both accuracy and speed of (correct) responding were measured. The sample recruited for this study consisted of 18 patients with paranoid schizophrenia, 15 outpatients with anxiety disorders, and 20 controls with no history of psychiatric disorders. Results indicated that, relative to the controls, the paranoid schizophrenic patients were less accurate and less efficient on auditory-verbal tasks requiring right hemisphere processing. Unlike the controls the paranoid schizophrenic patients manifested a lateralized left hemisphere advantage.     

Paranoia and Power Anxiety

Several previous studies of paranoid schizophrenia have provided only scattered support for Freud's notion that homosexual wishes and fears are the root of the difficulty. The present study was designed as a partial test of the broader theory that paranoid schizophrenia in men involves severe anxiety over aggression or assertion. The subjects were men and women in three categories: paranoid schizophrenic, nonparanoid schizophrenic, and people without any history of psychiatric trouble. Using a set of TAT cards portraying various situations of anger and aggression, it was found, as predicted, that paranoid schizophrenic men, and only paranoid schizophrenic men, show a defensive response. These findings are discussed in the context of traditional gender roles and other evidence about the paranoid style.     

Lateralized lexical decision in schizophrenia: hemispheric specialization and interhemispheric lexicality priming

Reports of left-hemisphere dysfunction and abnormal interhemispheric transfer in schizophrenia are mixed. The authors used a unified paradigm, the lateralized lexical decision task, to assess hemispheric specialization in word recognition, hemispheric error monitoring, and interhemispheric transfer in male, right-handed participants with schizophrenia (n=34) compared with controls (n=20). Overall, performance and error monitoring were worse in patients. However, patients like controls showed left-hemisphere superiority for lexical processing and right-hemisphere superiority for error monitoring. Only patients showed selective-interhemispheric lexicality priming for accuracy, in which performance improved when the lexical status of target and distractor stimuli presented to each hemifield was congruent. Results suggest that schizophrenia is associated with impaired monitoring and with increased interhemispheric automatic information transfer rather than with changed hemispheric specialization for language or error monitoring.     

Hemispheric Processing Deficits in Patients with Paranoid Schizophrenia

The purpose of the present study was to investigate hemispheric deficits in individuals with paranoid schizophrenia on four kinds of tasks: dichoptic viewing tasks involving verbal and nonverbal visual stimuli, and dichotic listening tasks involving verbal and nonverbal auditory stimuli. As dependent measures, both accuracy and speed of (correct) responding were measured. The sample recruited for this study consisted of 18 patients with paranoid schizophrenia, 15 outpatients with anxiety disorders, and 20 controls with no history of psychiatric disorders. Results indicated that, relative to the controls, the paranoid schizophrenic patients were less accurate and less efficient on auditory-verbal tasks requiring right hemisphere processing. Unlike the controls, the paranoid schizophrenic patients manifested a lateralized left hemisphere advantage.     

A study of blocking and other response variables in psychotic, brain-damaged and personality-disturbed patients

An experiment was conducted on the hypothesis that the differences in personality and behaviour of various groups of psychiatric patients would be reflected in a serial visuo-motor task. The patients' errors, blocks and RT variability were ascertained and significant differences emerged between the groups. All of the experimental groups—chronic schizophrenic, brain-injured psychotics, brain-injured non-psychotics—differed from the disturbed, non-psychotic control group on all of the variables tested. A group of paranoid schizophrenic patients, however, differed from the controls in only two respects, i.e. variability and number of responses per minute. The paranoid schizophrenic group produced a strikingly different performance from that of the chronic schizophrenic group. The latter group exceeded all other groups in both the frequency and duration of blocks.     

Response-monitoring dysfunction in schizophrenia: an event-related brain potential study

Error-monitoring abnormalities may underlie positive symptoms of schizophrenia. Response-synchronized event-related potentials during picture-word matching yielded error- and correct-response-related negativity (ERN, CRN) and positivity (Pe, Pc) and preresponse lateralized readiness potentials (LRP) from 18 schizophrenic patients and 18 controls. Both groups responded faster to matches than nonmatches, although patients were generally slower and made more errors to nonmatches. Compared with controls, patients, particularly with paranoid subtype, had smaller ERNs and larger CRNs, which were indistinguishable. LRPs showed evidence of more response conflict before errors than before correct responses in controls but not patients. Despite ERN/CRN abnormalities, post-error slowing and Pe were normal in patients, suggesting a dissociation of ERN and error awareness. Anterior cingulate and dorsolateral prefrontal cortical dysfunction in schizophrenia are implicated.     

Comparison of Beck Depression Inventories-IA and-II in Psychiatric Outpatients

The study of mental representations on projective tests such as the Rorschach has made substantial contributions to our understanding of psychopathology. It is not clear, however, whether the representations of paranoid schizophrenics can be differentiated from those of normals and whether the Rorschach is the best test for such comparison. Object representations on the Rorschach and a role-playing (Johnson & Quinlan, 1980, 1985) test were studied in groups of normal (n = 31) and schizophrenic subjects (divided into paranoid [n = 16], intermediate [n = 11], and nonparanoid groups [n = 16]). Developmental levels of representation on both tests were measured with the widely used system of Blatt, Brenneis, Schimek, and Glick (1976), derived from Werner's concepts of differentiation, articulation, and integration. Generally the groups were not differentiated on these measures on the Rorschach. The role-playing test showed greater discriminatory power than the Rorschach, possibly due to its explicit demand to produce representations of humans in interaction. Results of the role-playing test showed differentiation and integration scores were negatively correlated with measures of psychotic symptoms. Nonparanoids differed from the other three groups on differentiation measures, and paranoid and normal groups scored higher on integration measures than did the intermediate and nonparanoid groups. Paranoid subjects scored higher than nonparanoids on functional articulation and higher than intermediates on perceptual articulation; however, paranoid subjects were not differentiated from normals on any developmental measure. Differences between the schizophrenic sample and normals were explained entirely by the nonparanoid subgroup, supporting the paranoid-nonparanoid distinction and raising questions regarding the nature of the deficit in paranoid schizophrenia.     

Alexithymia in schizophrenia: an exploratory study.

This study assessed a relationship between alexithymia and schizophrenia suggested by reports based on small samples of patients. Here, 50 outpatients with a diagnosis of paranoid schizophrenia were compared with 50 pair-matched healthy subjects. Alexithymia was measured by the Polish version of the Toronto Alexithymia Scale-20. The mean total score was significantly higher in the schizophrenia group (M = 52.3, SD = 13.47) than in the healthy controls (M = 45.8, SD = 11.39, p < .02). This replicates earlier findings showing that a group of patients with paranoid schizophrenia have higher scores on alexithymia scales than healthy controls. There seems a need for a comprehensive examination of relations between alexithymia and other concepts denoting pathology of affect in schizophrenia.     

Flanker compatibility effects in patients with Parkinson's disease: impact of target onset delay and trial-by-trial stimulus variation

Parkinson’s disease (PD) patients and healthy controls were administered a flanker task that consisted of the presentation of colored targets and distractors. Participants were required to attend to the center target and identify its color. The stimulus displays were either congruent (i.e., the target and flankers were the same color) or incongruent. The time between the onset of the flanker and the target color (the target onset delay) was either short or long. Results indicated that PD patients and controls did not differ in the magnitude of the flanker effect within individual trials in that both groups demonstrated a typical flanker effect at the short target onset delay and neither group demonstrated a flanker effect at the longer delay. However, when performance was examined on a trial-by-trial basis, PD patients demonstrated a slowing of reaction time relative to controls when having to make the same response across consecutive trials at longer inter-trial intervals when the flankers were incongruent across consecutive trials and the display on the second of two trials was incongruent. These results indicate that PD patients are impaired in inhibiting the distractors over an extended delay and that this deficit may impact motor responding in these patients, suggesting that the basal ganglia contribute to the interface of attention and action.     

Response-selection processes in paranoid and nonparanoid schizophrenia

Previous research (Marshall, 1973) has shown that the most pronounced component of deficit on a choice reaction time task among a mixed schizophrenic sample involved response-selection processes. Other evidence has indicated that paranoids may be more deficient in this respect than nonparanoids. Hence, it was hypothesized that the former subgroup of schizophrenics would display response-selection deficit while the latter subgroup would display either less or no deficit. Response-selection processes were re-examined using the CRT paradigm with comparisons carried out among paranoid and nonparanoid schizophrenics and a group of nonschizophrenic controls. Results indicated that only the paranoid schizophrenics displayed abnormally retarded response-selection operations, the nonparanoid schizophrenics being nonsignificantly discriminable from the controls. It was suggested that past evidence of CRT response-selection deficit among mixed schizophrenics might have been attributable primarily to the performance of the paranoids, whose performance appears to be adversely affected by an increase in the number of dimensions relevant to response selection.     

Random number generation deficit in early schizophrenia

Random number generation with a written response mode provides a potentially appealing marker for executive processes. Impaired performance on written random number generation tasks has been reported in chronic schizophrenic patients. However, no study has investigated whether such a deficit occurs in early schizophrenia and whether its profile and severity are similar to those in patients with chronic illness. This study investigated the ability to generate random numbers in patients with early schizophrenia (n = 44) and a healthy control group (n = 48). Patients were less able to maintain several production strategies and generated more stereotyped response sequences, whereas their abilities to identify randomness with an even-handed treatment of digits and to monitor the equality of occurrence of single digits appeared to remain intact. These results provide evidence that some aspects of the deficits in random number generation among chronic schizophrenic patients are also present at early psychotic episode, while some other aspects are relatively less affected in the early years.     

Revisiting the suitability of antisaccade performance as an endophenotype in schizophrenia

Poor performance on the antisaccade task has been proposed as a candidate endophenotype in schizophrenia. Caveats to this proposal, however, include inconsistent findings in first-degree relatives of individuals with schizophrenia, and substantial heterogeneity in individuals with the disorder. In this study, we examined antisaccade performance in patients and relatives, and sought to establish whether antisaccade measures could differentiate between two patients clusters identified in the Western Australian Family Study of Schizophrenia with either pervasive cognitive deficits (CD) or cognitively spared (CS). Ninety-three patients (CD = 47, CS = 46), 99 relatives and 62 healthy controls carried out a standard antisaccade task. Results showed: (i) significantly greater error rate, and prolonged latencies to correct responses and self-correction saccades in patients compared with controls; (ii) high error rates in relatives of poorly performing patients; (iii) longer latencies of self-correction saccades in relatives compared to controls; and (iv) higher error rate and longer latencies of self-correction saccades in the CD subgroup compared with CS. Unaffected relatives as a group were unimpaired in error rate as compared to healthy controls. These findings suggest that the antisaccade error rate and latency of self-correction saccades are useful measures in specific applications of genetic research in schizophrenia, without fully meeting endophenotype co-familiality requirements.     

Priming effects in perceptual classification

Priming stimuli that spatially flank a fixated target stimulus may cause either facilitation or interference with target classification, depending on experimental context. Two experiments demonstrated distinct effects of response compatibility and semantic congruity between flankers and target. Response competition occurred when targets were flanked by context stimuli associated with the opposite response, but this effect diminished when the target was delayed relative to the flankers. Facilitative priming by response-compatible flankers, in contrast, required prior exposure of the flankers, and was strongly influenced by the semantic congruity of flankers and targets. These differing time courses suggest that perceptual priming encompasses a variety of distinct underlying cognitive and motor events.     

Evidence for early selection: precuing target location reduces interference from same-category distractors

In this study, we evaluated whether uncertainty about target location and category overlap between the target and the flankers played a role in recent findings (Miller, 1987) of semantic interference of irrelevant stimuli. In each of four testing conditions, subjects were required to identify a target letter surrounded by irrelevant flankers whose identity predicted the correct response. We varied (1) whether or not the target location was precued, and (2) the flanker's category (digits vs. letters). We found a substantial effect of letter flankers when subjects were uncertain of the precise target location. However, this effect was greatly attenuated when attention was predirected to the target location. Similarly, a reduced flanker effect was observed when the flankers (digits) belonged to a different semantic category than the target. However, when the target location was precued, no effect of the semantic congruity of target and flankers was found. Coupled with previous research, these findings converge in establishing that both failures to maintain attention on the target location and the semantic congruity of target and flankers modulate the size of the effects from irrelevant stimuli. These results are discussed in the context of early and late selection views of selective attention.     

Implicit and explicit self-esteem discrepancies in paranoia and depression

The main purpose of the present study was to examine implicit and explicit self-esteem (SE) in patients with persecutory delusions. In samples of paranoid patients, depressed patients, and healthy controls, implicit SE was assessed using the experimental go/no-go association task, whereas explicit SE was measured using 2 self-reporting questionnaires: the self-worth subscale of the World Assumption Scale (Janoff-Bulman, 1989) and the self-acceptance subscale of the Scales of Psychological Well-Being (Ryff & Keyes, 1995). Our analysis revealed that depressed patients showed lower explicit SE than did paranoid and healthy control participants. However, participants with persecutory delusions had significantly lower implicit SE scores than did healthy controls. We interpret the discrepancies observed between overt and covert measures in the paranoid group as psychological defense mechanisms. The present study stresses the clinical and theoretical importance of the use of implicit measures in psychopathology.     

Empirically and clinically useful decision making in psychotherapy: differential predictions with treatment response models

In the delivery of clinical services, outcomes monitoring (i.e., repeated assessments of a patient's response to treatment) can be used to support clinical decision making (i.e., recurrent revisions of outcome expectations on the basis of that response). Outcomes monitoring can be particularly useful in the context of established practice research networks. This article presents a strategy to disaggregate patients into homogeneous subgroups to generate optimal expected treatment response profiles, which can be used to predict and track the progress of patients in different treatment modalities. The study was based on data from 618 diagnostically diverse patients treated with either a cognitive-behavioral treatment protocol (n = 262) or an integrative cognitive-behavioral and interpersonal treatment protocol (n = 356). The validity of expected treatment response models to predict treatment in those 2 protocols for individual patients was evaluated. The ways such a procedure might be used in outpatient centers to learn more about patients, predict treatment response, and improve clinical practice are discussed.     

Smooth-pursuit eye tracking in first-episode psychotic patients and their relatives.

We wished to determine the specificity of smooth-pursuit eye tracking dysfunction to schizophrenia and the prevalences of dysfunction among functionally psychotic and normal individuals. Therefore, we investigated pursuit tracking in a large sample of psychotic patients, normal subjects, and first-degree relatives (N = 482). Patients were recruited as part of an epidemiological study of first-episode psychosis that used a broadly based referral network to identify all cases in a major metropolitan area over a 2 1/2-year period. Patients received diagnoses of schizophrenia, schizophreniform disorder, psychotic mood disorder, and paranoid or other psychotic disorder based on the third edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1980). The distribution of tracking performance was bimodal for the schizophrenic patients and their relatives, perhaps reflecting major gene action. Moreover, poor tracking ran in families. Pursuit tracking dysfunction was relatively specific to schizophrenic patients and their relatives and occurred infrequently in other psychotic patients and normal subjects.     

Performance monitoring in obsessive–compulsive disorder: A temporo-spatial principal component analysis

Hyperactive performance monitoring is a robust finding in obsessive–compulsive disorder (OCD). Patients show increased amplitudes of the error-related negativity (ERN) and correct-related negativity (CRN). Recently, two temporo-spatial factors were shown to contribute to both ERPs in healthy individuals. In the present study, it was investigated whether the factor structure underlying ERN and CRN is similar in OCD and which factors differ between groups. A principal component analysis (PCA) was employed to investigate the temporo-spatial factor structure of ERN and CRN. Twenty-six OCD patients and 26 healthy controls conducted a flanker task. EEG data were analyzed as conventional ERP components and as factor scores derived from temporo-spatial PCA. ERP results showed expected increases in ERN and CRN amplitudes in OCD patients. For both groups, the PCA confirmed the assumed factor structure of a central and a fronto-parietal factor contributing to ERN and CRN. Factor scores of both factors were differently affected by response correctness in OCD. Alterations in factor scores indicate increased activity in both an outcome-independent monitoring process and an error-sensitive process, contributing to overactive performance monitoring in OCD.