Study 1a: cross-modality time course of speeded word recognition (21 participants)
Method: visual, auditory and audiovisual lexical decision task and event-related potentials (ERPs)
Results:
1) lexical access starts earlier in the visual than in the auditory modality
2) more negative ERP amplitudes predict slower speed of responding across modalities.
Conclusions:
1) a written stimulus presented all at once provides an advantage over its auditory counterpart when recognizing words both at the behavioral (speed of responding) and neurophysiological level
2) the speeded LDT tapped into both lexical access and response processes. However, in order to properly tease both processes apart we conducted study 1b, explained below.
Dissemination: 2018 International Meeting of the Psychonomic Society, Amsterdam, The Netherlands.
Manuscript in preparation: López Zunini, R.A. Samuel, A. G., Baart, M., & Armstrong, B. C. The temporal dynamics of visual and auditory word recognition: Insights from behavioral and neural measures.
Study 1b: cross-modality time course of delayed word recognition (21 participants)
Methods: visual, auditory and audiovisual lexical decision task and event-related potentials (ERPs)
Results:
1) lexical access starts earlier in the visual than in the auditory modality
2) re-instantiation of the lexicality effect at the time of responding
3) more negative ERP amplitudes at the time of responding predict slower speed of responding across modalities.
Conclusions:
1) replication of result 1 in study 1a
2) the re-instantiation effect suggest there is re-activation of the stimuli in memory and the time of responding
3) the predictive ERP amplitudes were shifted toward the post-response time window, indicating that such amplitudes are related to post-lexical response processes rather than to lexical access itself.
Dissemination: 2018 International Meeting of the Psychonomic Society, Amsterdam, The Netherlands.
Manuscript in preparation: López Zunini, R.A. Samuel, A. G., Baart, M., & Armstrong, B. C. The temporal dynamics of visual and auditory word recognition: Insights from behavioral and neural measures.
Study 2: cross-modality word recognition in young and older adults (20 young adults and 21 older adults)
Method: visual, auditory and audiovisual delayed lexical decision task and event-related potentials (ERPs)
Results:
1) right-lateralization of lexicality effect across modalities in older adults
2) the lexicality effect post-response was larger in older adults when compared to young adults
3) larger lexicality effect in older than young adults in the audiovisual modality.
Conclusions:
1) the right-laterization of the effect in older adults suggest that they process semantic information qualitatively different from young adults. It seems older adults have a more focused lexico-semantic system
2) the larger post-response effect may reflect a compensatory mechanism that may help older adults keep up with young adult-like accuracy at the time of responding
3) older adults benefit more from multisensory information than young adults, perhaps by relying more on internal semantic knowledge rather than the physical characteristics of visual or auditory stimulus.
Dissemination: 2018 10th Annual Meeting of the Society for the Neurobiology of Language, Quebec City, QC, Canada.
Manuscript in preparation: López Zunini, R.A. Samuel, A. G., Baart, M., & Armstrong, B. C. The temporal dynamics of visual and auditory word recognition in the ageing brain: An Event-Related Potential study.
