EEG and MEG dynamics give clues as to the role of macrodynamics (producing EEG and MEG records) in brain function. Here, a cluster of lateral occipital independent component processes (from a group of subjects performing in a modified Sternberg visual letter working memory task), produce both the triphasic ERP (see 4-back single-subject slide) but also ‘crisp’ changes in alpha power time locked to experimental events. Here, the ERP image plots the time course of alpha power in single trials (rather than potential). Not the sudden increase in alpha power following the auditory feedback (second curving black line) marking the end of the trial. This and other experiments associate alpha activity in sensory areas with a decrease in level of sensory attention.