Does surprise enhancement or repetition suppression

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A long tradition of electrophysiological studies, using oddball sequences, showed that neural responses to a given stimulus differ when the presentation occurs ...

Does surprise enhancement or repetition suppression explain visual mismatch negativity? Catarina Amado

a,

Gyula

a,b Kovács

a

Institute of Psychology, Friedrich-Schiller-University of Jena, 07737 Jena, Germany b DFG Research Unit Person Perception, Friedrich-Schiller-University of Jena, 07743 Jena, Germany

Introduction A long tradition of electrophysiological studies, using oddball sequences, showed that neural responses to a given stimulus differ when the presentation occurs frequently (standards) as compared to rare, infrequent presentations (deviants). This difference is termed as visual mismatch negativity (vMMN, Czigler et al., 2004). Recent studies detected neuronal response decay after the repetition of a given stimulus, i.e. repetition suppression (RS) and RS was suggested as the first explanation for MMN, an explanation currently supported by recent animal studies. However, human studies have also shown that a surprise-related response enhancement, due to the violation of predictions, might also underlie vMMN. Therefore, the aim of the current study is to disentangle which neural mechanism explains vMMN: a surprise response to deviants or repetition suppression related to the standards.

Methods Here we examined the presence of surprise or repetition related responses in vMMN for different stimulus categories (faces, chairs, real and false characters) using a visual oddball paradigm. 21 healthy subjects participated in an EEG experiment.

Results

Table 1 – Percentages and Correlations of vMMN with RS and Surprise Comparison

Faces

Chairs

MMN & RS

41.08% (R=0.9; p=0.01)

51.36% (R=0.89; p=0.02)

MMN & Surprise

0%

0%

Behavioural Results - Accuracy: Mean – 77% (SD:24%); no effects of category or condition (oddball, reversed-oddball or control) - Reaction Times: Mean – 661 ms (SD: 103ms); interaction between category and condition (F4,80=14.38, P

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