Task difficulty affects the predictive process indexed by visual mismatch negativity.

Motohiro Kimura,Yuji Takeda

doi:10.3389/fnhum.2013.00267

Abstract

Visual mismatch negativity (MMN) is an event-related brain potential (ERP) component that is elicited by prediction-incongruent events in successive visual stimulation. Previous oddball studies have shown that visual MMN in response to task-irrelevant deviant stimuli is insensitive to the manipulation of task difficulty, which supports the notion that visual MMN reflects attention-independent predictive processes. In these studies, however, visual MMN was evaluated in deviant-minus-standard difference waves, which may lead to an underestimation of the effects of task difficulty due to the possible superposition of N1-difference reflecting refractory effects. In the present study, we investigated the effects of task difficulty on visual MMN, less contaminated by N1-difference. While the participant performed a size-change detection task regarding a continuously-presented central fixation circle, we presented oddball sequences consisting of deviant and standard bar stimuli with different orientations (9.1 and 90.9%) and equiprobable sequences consisting of 11 types of control bar stimuli with different orientations (9.1% each) at the surrounding visual fields. Task difficulty was manipulated by varying the magnitude of the size-change. We found that the peak latencies of visual MMN evaluated in the deviant-minus-control difference waves were delayed as a function of task difficulty. Therefore, in contrast to the previous understanding, the present findings support the notion that visual MMN is associated with attention-demanding predictive processes.

Highlights

PREDICTIVE PROCESSES INDEXED BY VISUAL MISMATCH NEGATIVITY The ability to extract sequential rules embedded in the temporal structure of sensory events and to predict upcoming sensory events based on the extracted sequential rules is crucial for successful adaptation to the external environment (e.g., Mumford, 1992; Friston, 2003, 2005)
The elicitation of visual mismatch negativity (MMN) is not limited to such physically deviant stimuli, but rather includes a variety of stimuli that violate concrete or abstract sequential rules (e.g., Czigler et al, 2006; Kimura et al, 2010b, 2012; Stefanics et al, 2011). This leads to the notion that visual MMN emerges when a current visual event is incongruent with visual events that are predicted on the basis of extracted sequential rules
We examined the effects of task difficulty on visual MMN as well as deviant-related negativity (DRN) and N1-difference, and investigated whether or not the predictive processes reflected by visual MMN are truly attention-independent

Summary

Introduction

PREDICTIVE PROCESSES INDEXED BY VISUAL MISMATCH NEGATIVITY The ability to extract sequential rules embedded in the temporal structure of sensory events and to predict upcoming sensory events based on the extracted sequential rules is crucial for successful adaptation to the external environment (e.g., Mumford, 1992; Friston, 2003, 2005). Visual MMN is a negative-going ERP component with a posterior scalp distribution that usually emerges at around 150–400 ms after the onset of visual events. The elicitation of visual MMN is not limited to such physically deviant stimuli, but rather includes a variety of stimuli that violate concrete or abstract sequential rules (e.g., Czigler et al, 2006; Kimura et al, 2010b, 2012; Stefanics et al, 2011) This leads to the notion that visual MMN emerges when a current visual event is incongruent with visual events that are predicted on the basis of extracted sequential rules (i.e., prediction error account of visual MMN; Kimura et al, 2011; Kimura, 2012)

Methods

Results

Conclusion