Tool-use Extends Peripersonal Space Boundaries in Schizophrenic Patients

Area of Science:

• Neuroscience
• Psychiatry
• Perception

Background:

• Schizophrenia (SCZ) is characterized by disruptions of the bodily self.
• Inefficient multisensory integration in peripersonal space (PPS) may underlie these self-disorders.
• The plasticity of PPS, the space surrounding the body, is altered in SCZ but has not been studied.

Purpose of the Study:

• To investigate the plasticity of peripersonal space (PPS) in schizophrenia patients.
• To examine how motor training with a tool influences PPS boundaries in SCZ.
• To explore the relationship between PPS alterations and schizophrenia symptoms.

Main Methods:

• Twenty-seven SCZ patients and 32 healthy controls (HC) performed an audio-tactile task to assess PPS boundaries.
• PPS was measured before and after a motor training task involving tool use.
• Key parameters estimated included PPS size and the slope of the psychometric function.

Main Results:

• SCZ patients exhibited a narrower PPS extent compared to HC.
• Both groups showed PPS expansion after tool-use training, demonstrating preserved PPS plasticity in SCZ.
• A shallower PPS slope in SCZ patients at baseline correlated with negative symptoms, but this steepened after training.

Conclusions:

• This study reveals preserved peripersonal space (PPS) plasticity in schizophrenia patients.
• Motor training with tools can enhance the demarcation of bodily boundaries in SCZ.
• Findings support exploring multisensory and motor rehabilitation for self-disorders in schizophrenia.