“Indeed, our inability to simultaneously think deeply about something and listen fully to someone talk is illustrative of the limitations of our attentional systems. If attention is something which truly must be ‘paid,’ then let’s examine what cognitive ‘accounting’ looks like. In this case, we need to note that the total amount of attention that we can devote is limited and largely fixed. Thus if we choose to devote the bulk of our attention to one task, there is very little ‘left over’ for other tasks.
Capacity theories (e.g., Kahneman) often use the analogy of attention as a pie (rather than as a bank account with fixed limits and a strict overdraft policy). Because both internal and external stimuli compete for the same attentional pie, if one piece gets larger (e.g. worries about an ongoing snowstorm outside), there is less ‘pie’ to divide among whatever else requires attention (e.g. the lively party discourse).
Though a number of brain regions are involved in attention, two that are central to attention are the prefrontal cortex and the anterior cingulate cortex (Sturm & Willmes, 2001). These areas help to plan our actions, including upon what and where we will focus our attention at a given moment. Both of these regions have been implicated in decision making and planning (e.g. what to wear to a party in two weeks) in general (Cohen, Botvinick, & Carter, 2000), suggesting the similarities involved in deciding where to consciously direct attention and how to direct one’s life in the long term.
These two regions also ‘mature’ more slowly than other brain regions and have not reached full potential even in late adolescence (Eshel, Nelson, Blair, Pine, & Emst, 2007). Thus challenges with getting teenagers (or younger children) to focus on or think about the long-term ramifications of their actions likely stem from the same developmental ‘lag’ in brain maturation. In contrast, areas responsible for directing attention to external stimuli (e.g. a loud ‘bang’ that grabs our attention), such as the pulvinar nucleus of the thalamus and the superior colliculus (Posner, Cohen, & Rafal, 1982), reach adult levels of functionality relatively early in development (Johnson, 2002).
Though the overall amount of attention that is available at any one time is limited, the demands upon attention, those slices of our attentional pie, are not all the same size nor do they remain the same size. Many factors influence the size of the slices (i.e. demands), including cue salience, motivation, emotions, and practice. When we consciously decide to focus our attention on a given task, we increase the size of that slice relative to the other demands that could be processed, which leaves less total attention for other demands.”
Excerpted from: Rekart, Jerome L. The Cognitive Classroom: Using Brain and Cognitive Science to Optimize Student Success. New York: Rowman & Littlefield Education, 2013.