Attention is a complex construct, and the neural network controlling attention is distributed along different areas of the brain (Banich, 2004, pp. 253-268). Attention depends on complex interactions among different parts of the brain, including the reticular activating system (RAS), the superior collicus, the thalamus, the parietal lobe, the anterior cingulate cortex and the frontal lobe (Banich, 2004, p. 254).
The RAS is in charge of the most basic category of attention, alertness and arousal: the levels that allow us to “extract information from the environment or to select a particular response” (Banich, 2004, p. 254). The superior collicus is in charge of directing attention, moving it to new objects or places (Banich, 2004, p. 255). The thalamus helps modulate the levels of arousal in the cortex, and helps select foci of attention (control of selective attention through selectively relaying information early in processing) (Banich, 2004, p. 258). The parietal lobe is responsible for visual and spatial aspects of attention, such as directing spatial attention, and binding different visual features together (e. g., color and shape) (Banich, 2004, pp. 259, 260). The anterior cingulate cortex is responsible for selecting a response to the stimuli the brain receives, especially among multiple or novel possible responses (Banich, 2004, p. 261). The frontal lobe is in charge of the more complex selection of information, such as selecting specific words or information to be held in memory, as well as “selecting, initiating, and inhibiting motor responses” (Banich, 2004, p. 262). The latter are part of the executive functions, those that coordinate mental processes (Swanson et al., 1998, p. 447), allow for planning of actions, and in general accounts for strategic action (Rose & Meyer, 2002, p. 22). Not surprisingly, brain imaging studies have found abnormalities (reduced sizes) in the right frontal regions, the anterior cingulate, right parietal regions (Swanson et al., 1998, pp. 451-455), and malfunctions in prefrontal cortex, the cerebellum (which is hypothesized to have a role in motivation), and the basal ganglia (Barkley, 1998, p. 66; Raz, 2004, p. 42).