Attention can vary in intensity (strength) and selection (sharpness). Attention can wane when one is sleepy or distracted by something else. It is one of the most researched topics in psychology and cognitive neuroscience. Of the various cognitive processes in the human brain (decision making, memory, emotions, etc.), attention is considered the most concrete because it has a lot to do with perception. Attention is thus the gateway to the rest of cognition.
These frequencies can improve attention and improve focus as a result.
