Fig. 4: Impact of aging on the cingulate gyrus, ventromedial prefrontal cortex and inferior frontal gyrus responses during recognition of musical sequences.

The red graphs in the second row highlight that the VMPFC produced a weaker activity indexing prediction error for the older (n = 39) versus young (n = 37) adults for conditions NT1 and NT3, in an analogous manner to the right hippocampal and inferior temporal regions shown in Fig. 3. Notably, while these two brain regions also showed a decreased activity for the M condition for older versus young adults, this did not happen for the VMPFC. Finally, the last row of this figure shows a much stronger activity originated in the right inferior frontal gyrus of the young versus older adults. This was particularly evident for the M sequences and consisted of a negative component peaking approximately 250 ms after the onset of each musical tone. Note that the figure shows the source localised brain activity illustrated for each experimental condition (M, NT1, NT3) in four ROIs (medial cingulate gyrus, ventromedial prefrontal cortex [VMPFC], left and right inferior frontal gyrus). Grey areas show the statistically significant differences of the brain activity between young (solid red line) and older adults (solid blue, shading indicates standard error in both cases), while red and blue graphs highlight neural components of particular interest. The sketch of the musical tones represents the onset of the sounds forming the musical sequences. The brain templates illustrate the spatial extent of the ROIs.