Might Cortical Hyper-Responsiveness in Aging Contribute to Alzheimer’s Disease?
Figure 3
Frequency spectra of scalp recorded electrical activity.
Stimulus specific frequency spectra of cortical responses to superimposed optic flow at 1.11 Hz and words at 1.57 Hz during the flow (red) or word (blue) button press tasks. A. Task effects are seen for all groups, with larger responses at the frequency of the task-relevant stimulus. B. Spectral density scalp maps with prominent occipital/posterior activation of the word (left) and flow (right) responses, substantially more evident in ONs than YNs or ADs. C. Bar graphs of spectral power (ordinate, mean +/− sem) show task effects for the word (left) and flow (right) stimuli at the fundamental frequencies, during the flow (red) and word (blue) push button tasks, for the three subject groups (abscissa).