Poster #: 3
Topic: Attention and distraction
Friday, Sep 11, 2015
Voluntary action modulates the processing of unattended rule-violating events indexed by visual mismatch negativity
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
Visual mismatch negativity (MMN) reflects the automatic processing of rule-violating events embedded in a visual stimulus sequence. To investigate whether the processing of rule-violating events embedded in an unattended visual stimulus sequence is determined in a bottom-up (i.e., stimulus-driven) manner, or can be modulated by top-down control, we examined the effects of the participant’s voluntary action on visual MMN with a dual-task experimental design. As a primary task, the participants were required to detect a sudden change in the size of a central fixation point. As a secondary task, they were required to press one button frequently (about 90%) and another button infrequently (10%) in random order, which produced a visual stimulus sequence at unattended surrounding locations. Frequently-performed button presses triggered rule-conforming stimuli (81%), but occasionally rule-violating stimuli (9%; externally-generated rule violation). In contrast, infrequently-performed button presses triggered rule-violating stimuli (9%; self-generated rule violation), but occasionally rule-conforming stimuli (1%). The results showed that visual MMN was elicited by the externally-generated rule violation, but not by the self-generated rule violation. These results suggest that the processing of rule-violating events embedded in an unattended visual stimulus sequence can be controlled in a top-down manner. This top-down control is considered to play an important role in cancelling out non-significant (i.e., predictable) rule violation that carries no new information and facilitating the selective detection of significant (unpredictable) rule violation that can carry new information.