Cognitive and Neurological Sign Features of Intense Blinkers in Chronic Schizophrenia

Abstract

Blink rate seems to be a marker for schizophrenia and other psychotic disorders. Previous studies suggest that significant difference exists between patients with schizophrenia and normal controls in a resting or relaxing condition, but not cognitively active condition. Given the common neural substrates of blink rate, neurological signs, and some of the neurocognitive functions, it is surprising relatively few studies have been specifically designed to investigate their relationships. This study aimed to explore the relationships among cognitive functions, neurological signs, and clinical symptoms in a group of chronic schizophrenia patients, intense blinkers in particular. A sample of 90 chronic schizophrenic patients was recruited. Blink rate was recorded when participants were in a resting and relaxing condition. The mean blink rate was 24.49 count/min (SD = 18.15). Significant correlations were only found between blink rate and global psychopathology of psychotic symptoms (r = -.3, p = .009), and disinhibition subscale of soft signs (r = .26, p = .021). When the group was further divided into two sub-groups by taking the lower and upper quartiles of their blink rate, i.e., intensive blinker (>75th %ile; n = 23) and rare blinker (<25th %ile; n = 23), intense blinkers exhibited significantly more disinhibition signs than rare blinkers (z = 2.224, p = .026). There was also a trend for the intense blinkers to commit more error in a sustained attention task ( p < .1, effect size = .38). These findings suggest that blink rate is associated with disinhibition signs among chronic schizophrenia.