ABSTRACT
The study of the event-related potentials recorded from the human scalp provides evidence about the neurophysiology of selective information processing that can improve our understanding of human attention. The early components of the sensory evoked potential are unaffected by changes in attention, suggesting an initial stable registration and analysis of incoming information. When attention is directed toward a particular sensory channel, there is enhancement of a negative component in the evoked potential with a peak latency of around 100 msec – https://www.w3.org/1998/Math/MathML"> N 100 ¯ . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003310228/145decb4-863e-4f51-9668-a53fcbdcabf3/content/math3_429_1_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> This effect is based on the simple stimulus attributes that define the selected channel, and it occurs irrespective of the significance of the stimuli within that channel. It reflects a “stimulus set” selection process. The evoked potential to an important signal or target stimulus within an attended channel contains, as well as the enhanced https://www.w3.org/1998/Math/MathML"> N 100 ¯ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003310228/145decb4-863e-4f51-9668-a53fcbdcabf3/content/math3_429_2_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> component, a large late positive wave with a peak latency of near 350 msec – https://www.w3.org/1998/Math/MathML"> P 350 ¯ . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003310228/145decb4-863e-4f51-9668-a53fcbdcabf3/content/math3_429_3_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> This component reflects a “response set” selection process. The https://www.w3.org/1998/Math/MathML"> P 350 ¯ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003310228/145decb4-863e-4f51-9668-a53fcbdcabf3/content/math3_429_4_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> amplitude varies with the amount of meaningful information processed from the signal to appropriate perceptual or motor response. During attention there are long-lasting negative shifts recorded mainly from frontal regions. This negativity possibly represents the exertion of effort in the active organization and control of selective information processing.
