Self and time in individuals with schizophrenia: A motor component?

Area of Science:

• Cognitive psychology
• Neuroscience
• Psychiatry

Background:

• Schizophrenia is associated with disruptions in the subjective experience of time and sense of self.
• Temporal expectations link present experiences to future events and are known to be fragile in schizophrenia patients.
• Previous research indicates a connection between temporal expectation deficits and disorders of self in schizophrenia.

Purpose of the Study:

• To investigate if the impaired performance in schizophrenia patients persists when motor responses can be prepared in advance.
• To examine the impact of foreperiod duration on response preparation and performance in schizophrenia.
• To explore the relationship between the benefit of temporal passage and disorders of self in schizophrenia.

Main Methods:

• Two experiments were conducted with 41 patients with schizophrenia and 43 neurotypical controls.
• Participants responded to visual targets presented after a warning signal with a variable foreperiod.
• The EASE scale was used to measure the sense of self in Experiment 1. Analysis focused on trials with consistent foreperiods to isolate the passage of time effect.

Main Results:

• Both groups showed a general benefit from longer foreperiods, indicating better preparation over time.
• However, the benefit of longer foreperiods compared to shorter ones was present in controls but absent in patients with schizophrenia.
• This diminished benefit of temporal passage in patients remained even when motor preparation was possible.

Conclusions:

• The ability to benefit from the passage of time for response preparation is impaired in schizophrenia.
• This impairment is linked to disorders of the sense of self, even when motor preparation is facilitated.
• Findings suggest a non-verbal cognitive impairment underlies the disorders of self experienced by individuals with schizophrenia.