Subjectivity of the Anomalous Sense of Self Is Represented in Gray Matter Volume in the Brain.
Noriaki Kanayama, Tomohisa Asai, Takashi Nakao, Kai Makita, Ryutaro Kozuma, Takuto Uyama, Toshiyuki Yamane, Hiroshi Kadota, Shigeto Yamawaki
Frontiers in human neuroscience January 1, 2017 Peer reviewed DOI: 10.3389/fnhum.2017.00232 via PubMed
Summary
A negative correlation was found between ownership malfunction and gray matter volume in the insular cortex among 96 healthy adults. Participants completed the Embodied Sense of Self Scale (ESSS) to measure malfunctions in three self functions: agency, ownership, and narrative self. Brain structure was assessed using MRI and voxel-based morphometry. Only the ownership subscale showed a significant relationship with brain structure, suggesting that feelings of ownership are linked to distinct neural substrates.
Study at a glance
| Design | observational cohort |
|---|---|
| Sample size | 96 |
| Population | healthy people |
| Key finding | Ownership malfunction negatively correlated with insular cortex gray matter volume. |
Abstract
The self includes complicated and heterogeneous functions. Researchers have divided the self into three distinct functions called "agency," "ownership," and "narrative self". These correspond to psychiatric symptoms, behavioral characteristics and neural responses, but their relationship with brain structure is unclear. This study examined the relationship between the subjectivity of self-related malfunctions and brain structure in terms of gray matter (GM) volume in 96 healthy people. They completed a recently developed self-reported questionnaire called the Embodied Sense of Self Scale (ESSS) that measures self-related malfunctions. The ESSS has three subscales reflecting the three distinct functions of the self. We also determined the participants' brain structures using magnetic resonance imaging (MRI) and voxel-based morphometry (VBM). Multiple regression analysis revealed a significant negative correlation between ownership malfunction and the insular cortex GM volume. A relationship with brain structure could thus only be confirmed for the ESSS "ownership" subscale. This finding suggests that distinct brain structures feel ownership and that the ESSS could partly screen for distinct brain structures.