Study: MRI sheds light on introspective qualities
Greater gray matter volume in the anterior pre-cortex of the human brain is a strong indicator of introspective ability and interindividual variation in the process of introspection can be correlated to white matter microstructure connected with this area of the brain, found a study published in the Sept. 17 issue of Science.
Lead author Stephen Fleming, PhD candidate, from the Wellcome Trust Centre for Neuroimaging at University College London, and colleagues said that while the ability to introspect about self-performance and discriminate correct from incorrect perceptual decisions varies across individuals, little is known of the neuroanatomical basis of metacognitive sensitivity and ability.
“We objectively quantified variability in metacognitive sensitivity between individuals and then related these interindividual differences to brain structure measured with MRI,” the authors explained.
The researchers recruited 32 healthy participants for the study and presented them with two screens, each containing six patterned patches. One screen contained a single patch that was brighter than the rest and the participants were asked to designate which screen contained the brighter patch. Then, participants were asked to rate how confident they felt in their answers. The authors explained that the difficulty of the visual judgment was varied on a per-participant basis in order to keep performance to a consistent level.
Fleming and colleagues explained that the task was designed so that participants were never completely sure if their answers were correct and hypothesized that participants good at introspection would be confident after making correct decisions about the patch and less confident when they perceived they were incorrect. After researchers observed participants judging their own decision-making, the subjects underwent MRI scans.
The findings confirmed that despite each participant performing equally well on the task, their introspective abilities varied considerably. The researchers reviewed the MRI scans of each participant's brain to identify a correlation between introspective ability and the amount of gray matter in the right anterior pre-frontal cortex and the structure of neighboring white matter.
The results of the study may help further understanding of how brain injuries can affect introspection and metacognition, offered Fleming, who noted the possibility to improve treatments for stroke or brain trauma patients.
The authors said that the findings may be indicative of innate differences in human anatomy, or alternatively, the physical effects of experience and learning on the brain. In addition, while the findings do establish a correlation between the structure of gray and white matter in the prefrontal cortex and the various levels of introspection that individuals may experience, the researchers stressed that they have not established that individuals with greater volume of gray matter in their right anterior prefrontal cortex have experienced or will experience more introspective thoughts over others.
"We want to know why we are aware of some mental processes while others proceed in the absence of consciousness," concluded Fleming. “If we understand self-awareness at the neurological level by measuring [introspection] and relating it to the brain, then perhaps we can also adapt treatments and develop training strategies for patients."
Lead author Stephen Fleming, PhD candidate, from the Wellcome Trust Centre for Neuroimaging at University College London, and colleagues said that while the ability to introspect about self-performance and discriminate correct from incorrect perceptual decisions varies across individuals, little is known of the neuroanatomical basis of metacognitive sensitivity and ability.
“We objectively quantified variability in metacognitive sensitivity between individuals and then related these interindividual differences to brain structure measured with MRI,” the authors explained.
The researchers recruited 32 healthy participants for the study and presented them with two screens, each containing six patterned patches. One screen contained a single patch that was brighter than the rest and the participants were asked to designate which screen contained the brighter patch. Then, participants were asked to rate how confident they felt in their answers. The authors explained that the difficulty of the visual judgment was varied on a per-participant basis in order to keep performance to a consistent level.
Fleming and colleagues explained that the task was designed so that participants were never completely sure if their answers were correct and hypothesized that participants good at introspection would be confident after making correct decisions about the patch and less confident when they perceived they were incorrect. After researchers observed participants judging their own decision-making, the subjects underwent MRI scans.
The findings confirmed that despite each participant performing equally well on the task, their introspective abilities varied considerably. The researchers reviewed the MRI scans of each participant's brain to identify a correlation between introspective ability and the amount of gray matter in the right anterior pre-frontal cortex and the structure of neighboring white matter.
The results of the study may help further understanding of how brain injuries can affect introspection and metacognition, offered Fleming, who noted the possibility to improve treatments for stroke or brain trauma patients.
The authors said that the findings may be indicative of innate differences in human anatomy, or alternatively, the physical effects of experience and learning on the brain. In addition, while the findings do establish a correlation between the structure of gray and white matter in the prefrontal cortex and the various levels of introspection that individuals may experience, the researchers stressed that they have not established that individuals with greater volume of gray matter in their right anterior prefrontal cortex have experienced or will experience more introspective thoughts over others.
"We want to know why we are aware of some mental processes while others proceed in the absence of consciousness," concluded Fleming. “If we understand self-awareness at the neurological level by measuring [introspection] and relating it to the brain, then perhaps we can also adapt treatments and develop training strategies for patients."