The switching and visualizing components of figural fluency

The problem. The purpose of the study was to demonstrate the two nonverbal components required in the performance of figural fluency that govern the executive functions of the frontal lobe: the switching or ability to shift cognitive set flexibly and the visualizing, planning ability to generate new patterns. To demonstrate the above components of figural fluency, dual attention tasks were utilized. It was predicted that a sequential finger tapping task that makes demands upon the prefrontal lobe would interfere with the switching, and a visual sequential imagery task that makes demands upon the right parietal lobe would interfere with the visualizing.;Method. Thirty normal subjects between the ages of 20 and 35 were recruited. A within-subjects multivariate analysis of variance was conducted to determine the effects of interference on the switching and visualizing aspects of figural fluency under five different interference conditions which represent independent variables that include: (1) Sequential Finger Tapping to simulate a right prefrontal lobe lesion, (2) Finger Tapping serving as control of Sequential Finger Tapping, (3) Visual Sequential Imagery to simulate a right parietal lobe lesion, (4) Serial Naming as control of Visual Sequential Imagery, and (5) no interference. Two dependent variables were measured: (1) switching--the number of perseverations made, and (2) visualizing--the number of strategies utilized. Both switching and visualizing were also measured by the number of unique designs generated. Independent variables were counterbalanced to control for practice effects. Multiple paired comparisons were used to differentiate the specific effects of switching and visualizing components.;Results. Both Sequential Finger Tapping and Visual Sequential Imagery interfered with design production, and both did so more than their respective control tasks. Sequential Finger Tapping produced an increase in the percentage of perseverative responses but Visual Sequential Imagery did not. Both interference tasks reduced the number of strategies used. It was concluded that the production of designs is disrupted by demands on attention while perseverative responses reflect disruption of a frontally based switching component of the task.