solution

According to the popular press, some kinds of thinking (visual tasks) are “right-brained,” whereas others (verbal tasks) are “left-brained.” There is a fair amount of scientific support for this theory. For example, one experiment invented by L. R. Brooks involves two kinds of tasks. [Source: L. R. Brooks, “Spatial and Verbal Components of the Act of Recall,” Canadian Journal of Psychology 22 (1968): 349–68.] The verbal task was to scan a sentence such as “The pencil is on the desk” and decide whether each word is or is not a noun. (The correct response is “No Yes No Yes.”) The visual task was to scan a block letter like the F shown here, starting at the arrow and moving clockwise, and decide whether each corner is an outside corner. (The correct response is “Yes No Yes No Yes.”)

Brooks also devised two ways to report, one verbal and one visual. To report verbally, you would simply say “Yes” or “No” out loud; to report visually, you would point in sequence to “Yes” or “No” on a piece of paper. The theory predicted that when the task and the report were of the same kind, they would interfere with each other in memory and slow the response time. If visual and verbal tasks are handled independently, then a visual task with a verbal report or a verbal task with a visual report would be easier and so would take less time than a verbal task with a verbal report or a visual task with a visual report.

Display 9.49 (on the next page) shows the data from a version of the experiment run by a psychology lab at Mount Holyoke College.