Alterations in Connectivity Patterns by Cognitive State and Mental Disorder Status May Suggest Different Neural Patterns of Consciousness Isaac Christian , Michael Liuzzi, B.A.; Qiongru Yu, MA; Christopher S. Monk, Ph.D.; Jillian Lee Wiggins, Ph.D.; (Psychology, San Diego State University, San Diego, CA ) C19
Prior literature suggests that alterations in brain connectivity patterns may indicate differences in cognitive state (Ma, et al, 2017). Statements about 'hyper-connectivity' or 'hypo-connectivity' implicated in the pathophysiology of mental disorders could be more nuanced by observing potential differences in brain activity during task vs. resting states. Exploring such differences would grant a broader view of how the neural patterns of consciousness differ depending on cognitive state or psychological diagnosis, ultimately contributing to a more holistic understanding of brain function. Autism spectrum disorder (ASD) is an ideal test case for this, as differences in connectivity in ASD youth have been documented during rest and during an emotional faces task (albeit with inconsistent results), but the two states have not yet been directly compared within individuals. Our study therefore seeks to provide clarity as to how the brain processes emotional information by state and disorder status.
We predict two possible outcomes for our study. First, if amygdala-prefrontal connectivity alterations in ASD differ in the socio-emotional task versus rest, this would provide evidence that connectivity alterations are an evoked phenomenon that is neither maladaptive or adaptive but rather context-dependent. Conversely, if the same alterations in connectivity are found across contexts, this would suggest a pervasive task-independent brain disturbance in ASD. Support for either of these hypotheses would yield critical insight into understanding how the brain processes social information and signify neural patterns which perhaps create differences in conscious experience.
To investigate this, we collected fMRI data from 43 youth with autism and 71 typically developing individuals at rest and during an emotional faces task, calculating whole-brain connectivity of the right and left amygdala following typical resting data preprocessing procedures. The resulting r-coefficients were converted to z-scores and inserted into a group analysis using AFNI's 3dMVM function.
Our results indicate alterations in brain connectivity based on Cognitive State, Diagnosis, and the interaction of Cognitive State x Diagnosis. Relative to controls, the ASD group has weaker amygdala-dorsomedial connectivity during resting state, and greater connectivity during task (Cognitive State x Diagnosis). Furthermore, across both cognitive states, ASD youth had greater connectivity in the left insula, yet decreased connectivity in the parahippocampal region, and across both diagnosis statuses, all participants showed connectivity alterations in superior/inferior temporal, bilateral middle frontal, inferior parietal, and cingulate regions during rest verse task.
These results support that connectivity alterations in ASD are an evoked, context-dependent phenomenon. Relative to controls, the increased connectivity ASD youth exhibit during task may represent abnormal modulation of the amygdala in socio-emotional processing; conversely, the decreased connectivity ASD youth exhibit during rest may reflect abnormal emotion integration in the absence of social/emotional stimuli like faces. Alterations in connectivity based on state and diagnosis indicate that brain regions interact differently in a wide range of conditions, providing evidence that consciousness may have alternate neural patterns in both neurodevelopmental disorders and cognitive states. Further studies contrasting neural patterns in a variety of conditions including state and disorder status are needed to better understand how the brain creates conscious experience.