Related Experiment Video
Updated: Aug 19, 2026

A Neuroscientific Approach to the Examination of Concussions in Student-Athletes
Published on: December 8, 2014
Symptomatic and neuropsychological components of defect states
Abstract:
The distinction between positive and negative symptoms has gained prominence in schizophrenia research, but the construct has not been unequivocally validated. The authors report preliminary findings of investigations in which symptomatic and neuropsychological assessments were conducted in a sample of 32 chronic schizophrenic inpatients. Three distinct clusters of symptoms were identified in correlative analyses. One cluster of symptoms (alogia, attentional impairment, positive formal though disorder, and bizarre behavior) appeared to reflect primarily a disorganization of though independent of current definitions of the positive/negative symptom construct. A second cluster of symptoms (affective flattening, avolition/apathy, and anhedonia) appeared to reflect predominantly blunting of affect and volition. A third cluster (delusions, hallucinations, and "breadth of psychosis") seemed to represent only the florid psychotic features. The first and (to a lesser extent) second clusters of symptoms were selectively associated with neuropsychological impairment. The patterns of neuropsychological deficits correlated with the first cluster of symptoms appeared to be consistent with a process characterized by failure in the development of a normal repertoire of cognitive abilities. It is suggested that the "defect state" may not be a monothetic construct, and that within the domain of "type II" schizophrenia, disturbances of thought may be distinguished from those of affect and motivation.
Related Concept Videos
Disorders of the Nervous Tissue
Homeostatic Imbalances:
Alzheimer's disease manifests as a gradual decline in memory and cognitive abilities, attributed to the buildup of amyloid plaques and neurofibrillary tangles in the brain.
Parkinson's disease arises from the...
Alzheimer's Disease: Overview
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau...
Negative and Cognitive Symptoms of Schizophrenia
Negative Symptoms
Negative symptoms of schizophrenia manifest as deficits in normal emotional and behavioral functioning, profoundly impacting daily life. Individuals with schizophrenia often display a flat affect, characterized by a near-total absence of emotional expression,...
Alzheimer Disease l: Introduction
Alzheimer Disease ll: Pathophysiology
Dementia l: Introduction

