Impaired Representation of Time in Schizophrenia Is Linked to Positive Symptoms and Cognitive Demand

Abstract

Time processing critically relies on the mesencephalic dopamine system and striato-prefrontal projections and has thus been suggested to play a key role in schizophrenia. Previous studies have provided evidence for an acceleration of the internal clock in schizophrenia that may be linked to dopaminergic pathology. The present study aimed to assess the relationship between altered time processing in schizophrenia and symptom manifestation in 22 patients and 22 controls. Subjects were required to estimate the time needed for a visual stimulus to complete a horizontal movement towards a target position on trials of varying cognitive demand. It was hypothesized that patients – compared to controls – would be less accurate at estimating the movement time, and that this effect would be modulated by symptom manifestation and task difficulty. In line with the notion of an accelerated internal clock due to dopaminergic dysregulation, particularly patients with severe positive symptoms were expected to underestimate movement time. However, if altered time perception in schizophrenia was better explained in terms of cognitive deficits, patients with severe negative symptoms should be specifically impaired, while generally, task performance should correlate with measures of processing speed and cognitive flexibility. Patients underestimated movement time on more demanding trials, although there was no link to disease-related cognitive dysfunction. Task performance was modulated by symptom manifestation. Impaired estimation of movement time was significantly correlated with PANSS positive symptom scores, with higher positive symptom scores associated with stronger underestimation of movement time. The present data thus support the notion of a deficit in anticipatory and predictive mechanisms in schizophrenia that is modulated both by symptom manifestation and by cognitive demand.

Processing of sub- and supra-second intervals in the primate brain results from the calibration of neuronal oscillators via sensory, motor, and feedback processes

“…In a recently published study, schizophrenic patients were found to underestimate anticipatory time intervals during the tracking of the movement of visual stimuli under cognitively challenging conditions (Peterburs et al, 2013). Common basis for the cognitive defect and impairment of interval timing in schizophrenia can be explained with the help of this model.…”

Correlations between exploratory eye movement, hallucination, and cortical gray matter volume in people with schizophrenia

“…It is widely accepted that GMV in certain cortical regions (including the frontal, temporal, and parietal cortices) is negatively correlated with hallucinations [ 44 , 49 – 52 ]. Since the reduction of prefrontal cortical volume and hallucinations are also associated with the susceptibility gene for schizophrenia and schizoaffective disorder, DISC1 [ 49 ], studies of the relationship between behavioral/cognitive deficits and hallucinations of schizophrenia are critical for understanding the pathopsychological processes and the endophenotype of this mental disorder [ 3 , 53 , 54 ].…”

Predictive timing disturbance is a precise marker of schizophrenia

“…Likewise, current neurocognitive and computational theories propose that the positive symptoms of schizophrenia are due to an abnormality in the brain's inference mechanism, such that a failure in the integration and exchange between incoming sensory information and expectations is related to the emergence of delusions and hallucinations ( Adams et al, 2013 ; Fletcher and Frith, 2009 ; Fuchs, 2007 ; Sterzer et al, 2016 ). Indeed, patients appear to have difficulty in predicting events over very short time intervals ( Giersch et al, 2016 ; Lalanne et al, 2012 ) and in efficiently coding events in time suggesting that prediction impairments in patients may concern the prediction of time in particular ( Giersch et al, 2015 ; Peterburs et al, 2013 ; Waters and Jablensky, 2009 ). Predictive timing disturbances in SZ have been mostly inferred from electrophysiological studies ( Todd et al, 2003 , Todd et al, 2008 ; Umbricht and Krljesb, 2005 ) although a recent behavioural investigation has established a link between predictive timing and clinical symptoms of SZ ( Martin et al, 2017 ).…”