Identifying Distinct Metacognitive Phenotypes Following Traumatic Brain Injury
Restricted (Penn State Only)
- Author:
- Grossner, Emily
- Graduate Program:
- Psychology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 20, 2022
- Committee Members:
- Sarah Rajtmajer, Outside Unit & Field Member
Michele Diaz, Major Field Member
Frank Hillary, Chair & Dissertation Advisor
Peter Arnett, Major Field Member
Kristin Buss (she/her), Program Head/Chair - Keywords:
- Neuropsychology
Traumatic brain injury (TBI)
Metacognition
Neuroimaging - Abstract:
- Longstanding evidence has shown that there are common cognitive deficits that occur following traumatic brain injury (TBI), specifically in the domain of executive functioning. One executive functioning ability is metacognition, defined as thinking about one’s own cognitive processes. Deficits in metacognition have been documented following TBI, but what remains unclear is precisely the nature of metacognitive deficits following TBI and why this occurs after injury. Broadly, I hypothesized that there would be a deficit in basic “in-the-moment” detection of errors as well as in higher level evaluative processes following brain injury and that these deficits would be associated with damage to frontal and parietal regions of the brain. In Paper 1, we attempted to dissociate separate processes of metacognition, specifically “error detection” and “performance evaluation.” Results demonstrated that individuals sustaining TBI performed worse on an error detection task than a healthy control group, but performance on a performance evaluation task was equivalent between the two groups (although individuals in the TBI group performed worse on this task in Paper 2). Additionally, the performance evaluation task was associated with neurocognitive tasks of executive functioning and the error detection task was not, lending further support to the evidence that these tasks measure distinct cognitive processes that comprise metacognition. In Paper 2, we examined neural substrates and their association to performance evaluation using both structural and functional neuroimaging. Findings revealed an association between metacognitive deficit and increased connectivity within the default mode network, a functional network comprised of frontal and posterior brain regions that is associated with self-referential thoughts. Lastly, Paper 3 examined potential predictors of metacognitive deficit using a machine learning algorithm. We found that performance on neurocognitive tasks of attention and executive functioning, age, and gray matter volume of posterior brain regions best predicted metacognitive deficit following TBI. Overall, the results of these studies demonstrate that there is commonly a deficit in metacognition following brain injury, and this deficit likely occurs during “in-the-moment” processing, as well as during retrospective evaluation of performance. Damage to both frontal and posterior brain regions is associated with metacognitive deficit following injury, and individuals with damage to these regions who are older and also have additional cognitive deficits in attention and executive functioning are likely to display deficits in metacognition after sustaining a TBI. These findings are important to developing targeted rehabilitation and points of intervention for individuals sustaining brain injuries.