The Effect of Secondary Task on the Power-space Interactions during the Semantic Category Judgment Task

Abstract: There is much evidence suggesting that power is represented as vertical space in our brain, specifically, verbal-spatial coding (amodal representation) and visuospatial coding (modal representation). Both codes are context-dependent, and the activation of which depends on the concurrent task. Studies using the dual-task paradigm have revealed that the explicit power judgment task activates both codes, whereas the semantic category judgment task mainly activates the verbal-spatial codes. However, it is still unclear whether the semantic category judgment task can activate the visuospatial codes when excluding the verbal-spatial codes.  Thus, the aim of the present study is to explore whether the semantic category judgment task can activate the visuospatial codes when excluding verbal-spatial information.

Using the dual-task paradigm, the present study tested the effect of visuospatial and verbal secondary task on the power-space interactions after excluding the verbal-spatial codes. In the experiment, a power word was presented in the center of the screen with two response labels (“human” and “animal”) at the up or down side of the target word. The response labels were mapping to the up and down cursor keys in the keyboard. The locations of the two labels exchanged from trial to trial. This manipulation could exclude the activation of the verbal-spatial codes. Participants were required to judge the semantic category of the word in three task conditions: the single task, the visual dual task, and the verbal dual task. It is hypothesized that the power-space interactions would be affected by the visual secondary task, but not by the verbal secondary task.

Consistent with our prediction, the results showed that the power-space interactions during the semantic category judgment task were affected by the visual secondary task, but not by the verbal secondary task.

The findings suggested that (1) the semantic category judgment task could activate visuospatial codes (modal representations) individually after excluding the verbal spatial-codes and (2) the visuospatial codes were only interfered by the visuospatial secondary task.