3.3.3 LPC time window (500-800 ms) As shown in Fig. 6a and b, the late positive component (LPC) was elicited from a broader distribution of brain regions in older adults, extending to more frontal brain sites, compared to younger adults where it was mainly restricted to posterior brain regions (main effect of age: = 8.49, = .007, = .25, and = 33.58, < .001, = .73), and x F(1,26) p η2 region: F(2,25) p η2 age interaction: = 8.34, = .002, = .40). Specifically, younger adults show region F(2,25) p η2 negative amplitude in the anterior regions (M = -2.69, = .68), which gets positive at the SE central (M = .22, = .72) and especially posterior regions (M = 2.90, = .92), while older SE SE adults show a broad positivity in all regions (anterior: = 1.23, = .61), especially central (M M SE = 3.08, = .61) and posterior (M = 3.78, = .55). Furthermore, ERP responses to unexpected SE SE melodies were shown to be more positive in left brain sites compared to expected melodies (marginal x interaction: = 3.16, = .060, = .20). These melodic expectancy laterality F(2,25) p η2 results clearly indicate that the neural system for processing melodic expectancy is differently localized depending on age group: it is largely located in posterior regions in younger adults but is broadly distributed in older adults extending to more frontal regions. Fig. 6 Here 4. Discussion To review, our main purpose here was to investigate whether lifetime exposure to music would lead to age-related differences in behavioral and neural responses to unexpected endings in melodies. Because the melodies were newly composed, we were not investigating the detection of a change in a memory representation, but rather the on-line computation of expectations. This dynamic computation consumes resources, which might have resulted simply in overall reduction of responses (lower goodness-of-fit ratings and smaller EEG amplitudes) in
3.3.3 LPC time window (500-800 ms) As shown in Fig. 6a and b, the late positive component (LPC) was elicited from a broader distribution of brain regions in older adults, extending to more frontal brain sites, compared to younger adults where it was mainly restricted to posterior brain regions (main effect of age: F(1,26) = 8.49, p = .007, η2 = .25, and region: F(2,25) = 33.58, p < .001, η2 = .73), and age x region interaction: F(2,25) = 8.34, p = .002, η2 = .40). Specifically, younger adults show negative amplitude in the anterior regions (M = -2.69, SE = .68), which gets positive at the central (M = .22, SE = .72) and especially posterior regions (M = 2.90, SE = .92), while older adults show a broad positivity in all regions (anterior: M = 1.23, SE = .61), especially central (M = 3.08, SE = .61) and posterior (M = 3.78, SE = .55). Furthermore, ERP responses to unexpected melodies were shown to be more positive in left brain sites compared to expected melodies (marginal melodic expectancy x laterality interaction: F(2,25) = 3.16, p = .060, η2 = .20). These results clearly indicate that the neural system for processing melodic expectancy is differently localized depending on age group: it is largely located in posterior regions in younger adults but is broadly distributed in older adults extending to more frontal regions. Fig. 6 Here 4. Discussion To review, our main purpose here was to investigate whether lifetime exposure to music would lead to age-related differences in behavioral and neural responses to unexpected endings in melodies. Because the melodies were newly composed, we were not investigating the detection of a change in a memory representation, but rather the on-line computation of expectations. This dynamic computation consumes resources, which might have resulted simply in overall reduction of responses (lower goodness-of-fit ratings and smaller EEG amplitudes) in
Brain%26Cognition2017_AcceptedVersion.docx