ATTENTION, CONCENTRATION, AND INFORMATION PROCESSING

The processes of attention, concentration, and information processing are often central concerns for any patient with a medical condition involving the brain (28). In many ways, they form the basis on which the other component processes occur. Overall performance on other tests looking at other domains of cognitive functioning is significantly impacted by attention and information processing.

Attention has been conceptualized in a number of ways, generally relating to an organism's receptivity to incoming stimuli. Most do regard the issues of automatic attention processes versus deliberate/voluntary as central dimensions. Other characteristics include sustained, purposeful focus—often referred to as concentration— and the ability to shift attention as required by a stimulus. Being able to ward off distractions is usually seen as part of concentration (28). Vigilance is conceptualized as maintaining attention on an activity for a period of time. There are the needs to respond to more than one aspect of a stimulus or competing stimulus—the capacity to divide attention—alternating with shifts in focus.

The multitude of processes subsumed in the concept of attention is necessary because of the overall effect. Most notable is the developmental nature of attention in childhood and adolescence. Increasing demands in school participation are seen in the shifting requirements throughout the academic process. In the early grades, a child is more directly engaged by the teacher, but as the years progress, the capacity for independent (ie, voluntary/deliberate) processes grows. This capacity is matched with growing expectation and demands for independent work as a child progresses through grades. Attentional processes are a central aspect of the changing capacity of typical development. Attention's vulnerability to normal variation, as with fatigue or anxiety, is a part of typical functioning. Attentional processes require a certain "tone" to the brain's functioning; attention and its concomitants are often affected in brain disorders. Furthermore, with acquired deficits in the disordered brain, the demands are higher, as an individual struggles with recognizing the need to attend along with implementing a specific compensatory task.

Lezak and colleagues (21) note that underlying many attention problems is slowed cognitive processing. This can be misinterpreted as a memory disorder (29), as competing stimuli in normal activity interrupt the processing of the immediately preceding stimuli and something is "forgotten," in common parlance. The discernment of this specific problem is important, as strategies alleviating the effects of slowed processing would be different from those for memory per se. All of these aspects warrant examination, notably in those with a brain disorder, due to the overall effect on functioning and the demand for acquisition of academic and adaptive behaviors throughout childhood. The effects of anxiety about an illness process, its treatment, and demands for coping can all affect attention, and in a competent diagnosis are differentiated from primary brain disruption.

Due to the issue of time in competent attention processes, computerized testing has real utility to control for calibration of presentation and response. In the absence of a fully computerized administration, the use of taped auditory stimulus in attention testing allows for standardized presentation increments. Typically, the computerized tasks involve visual stimulus and the taped presentations involve auditory ones. This differentiation between verbal and nonverbal, or auditory versus visual, is necessary to capture these two central aspects of stimulus processing; there may be a distinct difference in one's ability to maintain visual attention versus auditory attention. This has significant implication with one's ability to learn and absorb information.

The recent development of a battery of attention tasks for children, the Test of Everyday Attention-Children, will be described next. It attempts to cover a number of aspects of attention processes and for the comparison of subtest scores to allow for relative differentiation of components.

Inattention, slowness of cognitive processing, and poor concentration have a wide-ranging effect on competent cognitive and adaptive functioning. Other processes may be quite competent, but attention and its aspects can be a primary "rate limiting" factor. These should be addressed in even a screening of functioning, whether at the bedside or in the clinic, both as an overall indicator of current cognitive activity and as a harbinger for developmental problems to come, signaling the need for more stringent monitoring. Commonly used tests are described in Table 3.1.

TABLE 3.1 TESTS OF ATTENTION AND SPEED OF PROCESSING