James Everett

The Selective Attention Deficit in Schizophrenia: Limited Resources or Cognitive Fatigue?

The Stroop Word-Color Test was used to study selective attention deficits in schizophrenic and nonschizophrenic psychiatric patients, compared with nonpsychiatric control subjects. Parts of the Weschler Memory Test and a shortened version of the Stroop Test were administered to test the hypotheses that the attentional deficit could be explained by problems of memory or cognitive fatigue. All patients showed deficits on all of the Stroop scales, but closer analysis of the results permitted discrimination of schizophrenic from nonschizophrenic patients. Schizophrenic patients showed as much difficulty as nonschizophrenic subjects on a limited-duration selective-attention task, but deteriorated significantly more when selective attention had to be maintained. The results could not be attributed to memory problems in the schizophrenic group. The results support the existence of two separable selective attention deficits in schizophrenic patients: a difficulty in selectively attending to the salient aspect of a complex stimulus, a difficulty shared with nonschizophrenic subjects, and a difficulty in maintaining selective attention over time that seems to be more marked in schizophrenic subjects.

Distractibility and Processing Resource Deficit in Major Depression. Evidence for Two Deficient Attentional Processing Models

Performance on the Stroop Color-Word Test is impaired in depression, but it is not clear whether this impairment reflects a distractor inhibition disturbance or a reduction of processing resources. In this study, untreated major depressives were evaluated using a modified computerized Stroop Test composed of three tasks: to name the color of XXXXXs, of nonconflicting words, and of conflicting color words. It was hypothesized that, unlike color words, nonconflicting word distractors would disturb the color naming task only in the presence of a primary distractor inhibition disturbance. The slow reaction time (RT) depressives and normal RT depressives, according to their color naming speed without distractors, were contrasted to distinguish depressives with and without clear signs of resource deficit. It was found that interference produced by nonconflicting words was greater in normal RT depressives than in either slow RT depressives or control subjects, while interference caused by color words was dramatically stronger in slow RT depressives than in other groups. Results suggest the existence of two different attentional deficit patterns in clinical depression: some depressives have a distractor inhibition disturbance while others are deficient in processing resources.

Attention disturbance in clinical depression. Deficient distractor inhibition or processing resource deficit

Cognitive impairments in depression have recently been proposed as secondary to more basic attentional disturbances. Studies have shown that performance on the Stroop Color-Word Test is impaired in depressives, but it is not clear whether this impairment reflects a primary distractor inhibition disturbance or a more global cognitive dysfunction, such as a reduction of processing resources. In the present study, unmedicated clinical depressives were evaluated using a computerized Stroop Color-Word Test and the Visuo-Spatial Interference Test, a selective attention task that makes fewer demands on resources. Compared with normal subjects, depressives presented increased choice reaction times (CRT) and interference in both tests. Correlations were found between CRT and interferences only in depressives, favoring the processing resource hypothesis. Further exploratory analysis comparing the more rapid depressives and the slower normal subjects on CRT revealed that although these subgroups had comparable CRT, rapid depressives still exhibited increased interference on the Visuo-Spatial Interference Test. Thus, in non- or mildly retarded patients, a specific distractor inhibition deficit was observed in absence of resource deficit.

Depression, attention, and time estimation.

Depression is known to affect several cognitive functions, but little is known about the effect of this neuropsychological disorder on timing tasks. In the present experiment, 15 depressed and 20 non-depressed participants, classified on the basis of the Beck Depression Inventory, were tested on attentional and on temporal processing tasks. On the Continuous Performance Test, depressed participants made more omissions, but not more erroneous responses, than non-depressed participants. As well, discrimination of relatively long intervals (1120 vs 1280 ms) was poorer for the depressed group, which was not the case for discrimination of brief durations (80 vs 120 ms, and 450 vs 550 ms). Finally, there was a significant difference between groups regarding the variability of 1- or 10-s interval productions made with continuous series of finger taps. The attentional requirements of long-interval processing seems to be a critical factor in depression-induced deficits of temporal processing.

Inner speech as a mediator of self-awareness, self-consciousness, and self-knowledge: An hypothesis

Abstract Little is known with regard to the precise cognitive tools the self uses in acquiring and processing information about itself. In this article, we underline the possibility that inner speech might just represent one such cognitive process. Duval and Wicklunds theory of self-awareness and the self-consciousness, and self-knowledge body of work that was inspired by it are reviewed, and the suggestion is put forward that inner speech parallels the state of self-awareness, is more frequently used among highly self-conscious persons, and represents an effective, if not indispensable, tool involved in the formation of the self-concept. The possibility is also raised that the extent to which one uses inner speech could partially explain individual differences in self-consciousness and self-knowledge. A selective review of the private and inner speech literature is presented, and some possible ways of testing the hypothesis by using pre-existing techniques are proposed in the hope of stimulating empirical investigations. Some implications are outlined in conclusion.

Pleasure as a Sign of Efficacy of Mental Activity

Previous work has shown that sensory pleasure is both the motor and the sign of optimal behaviors aimed at physiological ends. From an evolutionary psychology point of view it may be postulated tha...

Cognitive effects of psychostimulant medication in hyperactive children

Hyperactive and normal children were given a test of selective attention (Stroop test) and a neurocognitive test sensitive to a functional deficit of prefrontal cortex (Wisconsin Card Sorting Test). Hyperactive children showed significant deficits on both measures. After a year of psychostimulant medication, the hyperactive children all showed clinical and neurocognitive improvement, but continued to show a selective attention deficit compared with normal children. The results indicate a dissociation between the cognitive processes measured by the Wisconsin test and selective attention as measured by the Stroop, and that the selective attention deficit is more resistant to psychostimulant intervention.

Self-awareness and introspective private speech in 6-year-old children

It has been suggested recently that self-awareness is cognitively mediated by inner speech and that this hypothesis could be tested by using the private speech paradigm. This paper describes a study in which the creation of a state of self-awareness was attempted in children to test the viability of a research strategy based on private speech and used to explore the hypothesis of a link between self-awareness and inner speech, and to test directly this hypothesis by comparing the incidence of private speech in self-aware and control conditions. 32 children were asked to evaluate the attractiveness of pictures when in front of a mirror (a widely used self-focusing stimulus) and with no mirror. Reliably more favorable ratings of the images were predicted presuming intensification of affects in self-awareness. Private speech was recorded, with the prediction of a more important incidence of “introspective” self-verbalizations (for example, “Wow! I really like this picture!”) in the self-aware condition. None of these outcomes were obtained. Results are discussed in terms of previous attempts to manipulate self-awareness in children. It is suggested that the private speech paradigm does not appear to be a promising strategy when inner speech and self-awareness are considered.