Abstract
Automatic detection of information changes in the visual environment is crucial for individual survival. Researchers use the oddball paradigm to study the brain’s response to frequently presented (standard) stimuli and occasionally presented (deviant) stimuli. The component that can be observed in the difference wave is called visual mismatch negativity (vMMN), which is obtained by subtracting event-related potentials (ERPs) evoked by the deviant from ERPs evoked by the standard. There are three hypotheses to explain the vMMN. The sensory fatigue (or refractoriness) hypothesis considers that weakened neural activity caused by repetition results in decreased ERPs of the standard. The memory trace hypothesis proposes that vMMN results from increased responses to the deviant. The predictive coding hypothesis attributes the difference to enhanced responses for deviants and suppression for standards. However, when distinguishing between these effects, previous researchers did not consider the effect of low-level features on the vMMN. In this experiment, we used face sequences composed of different emotions (e.g., neutral and fearful face) and presented an oddball sequence, a reverse oddball sequence, and an equiprobable sequence to participants. The deviant of the oddball sequence was subtracted from the standard of the oddball sequence, the reverse oddball sequence, and the same type of stimulus of the equiprobable sequence to get oddball-vMMN (vMMN1), reverse oddball-vMMN (vMMN2), and equiprobable-vMMN (vMMN3), respectively. The results showed no significant difference between vMMN2 and vMMN3 in 100–350 ms following stimulus onset, while the vMMN effect was significant, indicating that the probability of the standard did not affect vMMN, which supported the memory trace hypothesis. Additionally, the fearful-related vMMN were more negative than the neutral-related vMMN within the range of 100–150 ms, suggesting a negative bias. We analyzed the source location of different vMMNs. There was no significant difference in brain regions between different vMMNs. Time-frequency analysis showed that the deviant had stronger theta-band oscillatory than the standard (visual mismatch oscillatory responses, vMORs). However, there was no difference between vMORs2 and vMORs3, indicating that vMORs reflect an enhanced response to the deviant in terms of neural oscillation, supporting the memory trace hypothesis.
Highlights
The results showed no significant difference between vMMN2 and vMMN3 in 100–350 ms following stimulus onset, while the visual mismatch negativity (vMMN) effect was significant, indicating that the probability of the standard did not affect vMMN, which supported the memory trace hypothesis
Based on the memory trace hypothesis, we aimed to show that vMMN is not affected by event-related potentials (ERPs) weakening of standard stimuli, so that there would be no significant difference between vMMN2 and vMMN3
Our results suggest that the vMMN effects in the time range of 100–350 ms are not affected by the repetition effect, indicating that vMMN index is an enhanced response to the deviant
Summary
One of the important functions of the human cognitive system is to detect changes in the environment and make a response. One crucial finding is that mismatch negativity (MMN), an ERP component, emerges due to violation of the probability in a sequence of sensory stimuli, reflecting the brain’s automatic detection of information changes (Kimura et al, 2011; Czigler, 2014). Many subsequent studies (Kimura, 2012; Stefanics et al, 2014b) have shown that the phenomenon exists in the visual system, where it is known as visual mismatch negativity (vMMN). The vMMN is an ERP index of automatic processing of unattended visual information, which has been widely used to study the neural mechanism underlying a visual change detection process (Kimura et al, 2011; Stefanics et al, 2011; Li et al, 2012; Czigler, 2014; Kremláèek et al, 2016; Chen et al, 2020)
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