Summary of the research on Self vs. Other Processing in Psychosis
This research investigated how individuals with psychosis experience the difference between sensations caused by their own actions (self-touch) adn sensations caused by others (other-touch). The study found notable differences in how people with psychosis process these sensations compared to healthy controls, suggesting a disruption in the fundamental ability to distinguish ”self” from “other.”
Here’s a breakdown of the key findings:
* Spinal Cord Level Differences: Healthy individuals show a measurable difference in the timing of neural signals at the spinal cord when experiencing self-touch versus other-touch.This difference was significantly reduced in patients with psychosis, indicating a potential disruption in this basic processing level.
* Tactile Sensitivity: Healthy controls are less sensitive to touch when touching themselves (a form of sensory dampening for predictable sensations). Patients with psychosis did not show this reduced sensitivity during self-touch, suggesting a problem with sensory filtering.
* Interoception (Internal Body Awareness): Patients with psychosis where less accurate at detecting their own heartbeat without feeling for a pulse, but performed equally well detecting a recorded heartbeat. This points to a specific difficulty in perceiving internal signals.
* brain Response to Heartbeat: Patients with psychosis showed a reduced brain response to signals from their own heartbeat.
* Correlation with Symptoms: The degree of alteration in touch-related measures was linked to the severity of psychotic symptoms. Brain activity during self-touch coudl accurately predict whether someone was in the patient or control group.
Overall Implications:
The study suggests that psychosis may involve a fundamental disruption in how the brain processes self-generated sensations, impacting the sense of self. This disruption isn’t just happening in the brain, but appears to begin at the spinal cord level. The researchers believe understanding these mechanisms could lead to new therapies for psychosis.
Limitations:
* Medication: Patients were taking medication, which could have influenced the results (though analyses didn’t show a clear effect).
* Patient Group: The patient group had varying levels of symptoms and included individuals with different psychotic disorders.
Future Research:
The researchers plan to investigate these mechanisms in individuals earlier in the illness or before treatment begins. They are also exploring the sense of self in other conditions like autism,ADHD,anorexia,and grief.
