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Neural Differences between Healthy Adolescents and Those At Risk for Psychological Disorders: An Analysis of P100 and P300 ERPs Using an Emotional Oddball Paradigm
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- Author / Creator
- Wood, Julia G. A.
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Attention Deficit Hyperactivity Disorder (ADHD), Depression, Anxiety, and Conduct Disorder are Axis 1 Psychological Disorders that can affect adolescents' attention and emotion regulation. In this study, we aimed to compare attentional skills and emotional regulation between at-risk and healthy control groups using a modified version of the emotional oddball paradigm while collecting event-related potentials (ERPs). We hypothesized that significant differences in attention related ERPs, particularly in the P100 and P300, would be observed between the two groups.
We collected data from 33 participants in the Clinical group (recruited from CASA Child and Adolescent Services for All mental health services) (females: n=14, males: n=19). And, we included 17 participants in the Healthy Control group (females: n=11, males: n=6). We conducted a modified version of the emotional oddball paradigm, which was designed to observe both emotional and non-emotional responses. To do this, the paradigm included baseline images (scrambled pictures), infrequent distractors (sad, fearful, and neutral pictures of faces), and infrequent targets (circles). Participants were instructed to make a right-hand button press in response to targets and a left-hand button press to all other stimuli.
The behavioral data showed a significant effect of age on accuracy, where older participants were more accurate. Additionally, the amplitude of P100 in response to the distractors was significantly larger for the control group compared to the CASA group. This effect was observed at two electrode sites (POR and Oz). The results also showed significant effects of sex on the right side of the brain for the distractor stimuli (emotions), with males having larger P300 amplitudes. Furthermore, the CASA group showed longer P300 latencies for the target stimuli. As the P300 reflects top-down, or conscious attention processing, these findings suggest that the CASA group is taking longer to consciously process attentional stimuli, whether because they need to devote more cognitive resources to the task, due to perhaps less efficient processes, or over-attenuating to specific stimuli.
Our study identified significant differences in neural functioning between healthy adolescents and those with Axis 1 Psychological Disorders, particularly at the P100 and P300 ERPs. Group differences at the P100 reflect differences in early attention processes, and group differences at the P300 reflect differences in later, top-down attentional processes. Effects of experimental group occurred mostly where sex was not significant, suggesting sex as a confounding variable. Future research should carefully match for sex and age when analyzing differences between healthy and clinical groups. Our findings suggest the potential usefulness of the emotional oddball paradigm and ERP in detecting and differentiating individuals with psychological disorders from healthy controls.
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- Graduation date
- Fall 2024
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.