Research suggests Alpha oscillations in brain regions with functions not engaged by a current task, must perform processes that inhibit activity in such non-relevant regions, as effective working memory functioning is dependent on inhibition of irrelevant processes. Neural activity during WM delay-test periods (when individuals are shown a black screen) show increased upper alpha power in parieto-occipital electrodes located above areas of the brain responsible to visual processing. A sustained high power of alpha activity is suggested to illustrate suppression of cortical gain, as opposed to low alpha power which reflects increases in gain. Thus high power alpha suggests top-down inhibition of brain region processes that are not relevant to a current task. Increased alpha activity is associated with decreased fMRI blood flow in the visual cortex, demonstrating the suppression of disruptive activity, thusly leading to facilitation of working memory performance.