Comparing EEG Analyses with Different Epoch Alignments in an Auditory Lexical Decision Experiment

Louis ten Bosch, Kimberley Mulder, Lou Boves
2020 Interspeech 2020  
In processing behavioral data from auditory lexical decision, reaction times (RT) can be defined relative to stimulus onset or relative to stimulus offset. Using stimulus onset as the reference invokes models that assumes that relevant processing starts immediately, while stimulus offset invokes models that assume that relevant processing can only start when the acoustic input is complete. It is suggested that EEG recordings can be used to tear apart putative processes. EEG analysis requires
more » ... e kind of time-locking of epochs, so that averaging of multiple signals does not mix up effects of different processes. However, in many lexical decision experiments the duration of the speech stimuli varies substantially. Consequently, processes tied to stimulus offset are not appropriately aligned and might get lost in the averaging process. In this paper we investigate whether the time course of putative processes such as phonetic encoding, lexical access and decision making can be derived from ERPs and from instantaneous power representations in several frequency bands when epochs are time-locked at stimulus onset or stimulus offset. In addition, we investigate whether time-locking at the moment when the response is given can shed light on the decision process per sé.
doi:10.21437/interspeech.2020-2450 dblp:conf/interspeech/BoschMB20 fatcat:sv4k2atwwba77facishlooc7ey