Decoding semantics across fMRI sessions with different stimulus modalities: a practical MVPA study
Decoding semantics across fMRI sessions with different stimulus modalities: a practical MVPA study
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DOI:
10.3389/fninf.2012.00024
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发表时间:
2012-01-01
影响因子:
3.5
通讯作者:
Poesio, Massimo
中科院分区:
文献类型:
--
作者:
Akama, Hiroyuki;Murphy, Brian;Poesio, Massimo
Both embodied and symbolic accounts of conceptual organzation would predict partial sharing and partial differentiation between the neural activations seen for concepts activated via different stimulus modalities. But cross-participant and cross-session variability in BOLD activity patterns makes analyses of such patterns with MVPA methods challenging. Here, we examine the effect of cross-modal and individual variation on the machine learning analysis of fMRI data recorded during a word property generation task. We present the same set of living and non-living concepts (land-mammals, or work tools) to a cohort of Japanese participants in two sessions: the first using auditory presentation of spoken words; the second using visual presentation of words written in Japanese characters. Classification accuracies confirmed that these semantic categories could be detected in single trials, with within-session predictive accuracies of 80-90%. However cross-session prediction (learning from auditory-task data to classify data from the written-word-task, or vice versa) suffered from a performance penalty, achieving 65-75% (still individually significant at p