Lin, Mei-Heng, authorDavies, Patricia, advisorBielak, Allison, committee memberGavin, William, committee memberMalcolm, Matthew, committee member2018-09-102020-09-062018https://hdl.handle.net/10217/191472The overarching goal of this dissertation is to explore the relationship between cognitive functions and occupational performance in neurotypical children, neurotypical adults, and adults with attention-deficit/hyperactivity disorder (ADHD). Electroencephalography (EEG)/event-related potential (ERP) techniques were used to measure the neural processes while participants performed a speeded computer-based task for the three studies conducted in this dissertation. The first study examined the test-retest reliability on the amplitudes of two ERP components associated with performance monitoring, the error-related negativity (ERN) and error-positivity (Pe), in 53 neurotypical adults and 118 neurotypical children aged 8-12-year-old. The findings indicated that the test-retest reliability of these measures was moderate for children (rERN = 0.55, rPe = 0.62), and was moderate to strong for adults (rERN = 0.69, rPe = 0.75). Moreover, the adaptive Woody filter was implemented to adjust for the trial-to-trial variation in latency (i.e., latency jitter) when measuring the ERN and Pe amplitudes. The findings showed that adjusting for the latency jitter did not improve the reliability of ERN and Pe amplitudes for both groups, suggesting that the latency variability may be a trait-like variable which systematically occurred across sessions. Furthermore, the test-retest reliability of stimulus-locked ERP components on correct trials was higher compared to the reliability of response-locked ERPs for children and adults, confirming that both children and adults generally attended to the task consistently across sessions. The second study demonstrated the feasibility of utilizing the structural equation modeling (SEM) approach to model the complicated inter-relationship between neural processes and simple task behaviors (e.g., response times) in 143 children with typical development aged 8-12 years. The findings from the latent models indicated that the brain-and-behavior relationships were significant on correct trials but were not significant on incorrect trials after controlling for trait and state factors. Moreover, both models demonstrated different patterns of relationship among latent variables to response time, yet both models yielded excellent model fit indices. This finding suggested that our conceptual models were valid in terms of detecting the distinct patterns of neural processes leading to opposite behavioral outcomes (e.g., correct and incorrect). The final model demonstrated that the post-error adjustment in the stream of neural processes provided an adaptive effect on the early neural processing of the stimulus on correct trials. To our knowledge, this is the first study demonstrating how the post-error adjustment occurs at the level of neural processing. The third study (1) compared the group differences (children, adults, and adults with ADHD) on neural and occupational performance measures, (2) examined the inter-relationship between these measures for each group, and (3) investigated which measures can best differentiate three groups. The findings suggested that adults with ADHD demonstrated significantly lower quality of occupational performance particularly on the motor aspect of the activities of daily living (ADL). Moreover, for neurotypical children, larger ERN amplitudes were associated with lower quality of social interaction. For adults with ADHD, larger N2 amplitude was associated with lower quality of social interaction. Lastly, discriminant analyses demonstrated that the combination of neural and occupational performance measures differentiated children, adults, and adults with ADHD with 93.2% classification accuracy. Taken together, this dissertation demonstrated significant brain-and-behavior relationships especially for neurotypical children and adults with ADHD by relating the neural measures (e.g., ERP components) to behaviors obtained from the computer-based task (e.g., response times), and to the quality of occupational performance (e.g., social interaction and ADL). Moreover, this dissertation demonstrated that having both neural and occupational performance measures is beneficial to obtain a comprehensive understanding of dimensions of maturation and disability.born digitaldoctoral dissertationsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.error positivityoccupational performancestructure equation modelingerror-related negativityattention deficit hyperactivity disorderperformance monitoringText