| Summary: | Visual mismatch negativity (vMMN) is recognized to represent human precognitive non-attended visual processing in the visual cortical and prefrontal areas. VMMN is an event-related potential (ERP) component of visual change detection recorded in the visual cortex. The aim of this thesis was to study whether there is a connection between long-term leisure time physical activity and precognitive visual processing in healthy young males. This connection was also studied between active and inactive monozygotic twin brothers. Second aim was to study if there is any relationship between body composition and vMMN.
VMMN was recorded with electroencephalography (EEG) from 32 healthy young males, recruited from a cohort twin study. Among them 9 monozygotic twin pairs (n=18) were identified to be discordant in their leisure time physical activity. VMMN recording was conducted with a passive oddball paradigm with visual bars. Standard (90 %) and deviant (10 %) stimuli in different orientations were presented randomly as the subject’s attention was directed to a radio play. The difference waves from the standard and deviant responses were calculated. The vMMN peak latencies were measured from the difference waves and data was rectified and integral value (area under curve) calculated within the time window from 100 to 300 ms. The participants were divided into active group according to their leisure time physical activity from the past three years (3-year mean leisure time MET index).
Active group had shorter vMMN latencies compared to inactive group in occipital electrodes. There were no significant differences in the difference wave integral values. There was a trend for significance in occipital electrode 71, suggesting that the integral value was larger in active group. Subgroup analysis did not provide any further significant results of the discordant twins. However, the results were in the same direction as in the first analysis. In the subgroup analysis a smaller fat percentage predicted a bigger difference wave integral value in occipital electrode 76. No further associations between body composition and vMMN were found. Physically active participants showed faster processing of the deviant stimulus compared to inactive individuals. There was a trend for more synchronized precognitive visual processing in the active twins but the results did not quite reach significance. There are no prior studies connecting physical activity and vMMN. These results indicate that precognitive non-attended visual processing is sensitive to long-term leisure time physical activity.
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