Evidence for Enhanced Multisensory Facilitation with Stimulus Relevance: An Electrophysiological Investigation

Abstract

Currently debate exists relating to the interplay between multisensory processes and bottom-up and top-down influences. However, few studies have looked at neural responses to newly paired audiovisual stimuli that differ in their prescribed relevance. For such newly associated audiovisual stimuli, optimal facilitation of motor actions was observed only when both components of the audiovisual stimuli were targets. Relevant auditory stimuli were found to significantly increase the amplitudes of the event-related potentials at the occipital pole during the first 100 ms post-stimulus onset, though this early integration was not predictive of multisensory facilitation. Activity related to multisensory behavioral facilitation was observed approximately 166 ms post-stimulus, at left central and occipital sites. Furthermore, optimal multisensory facilitation was found to be associated with a latency shift of induced oscillations in the beta range (14–30 Hz) at right hemisphere parietal scalp regions. These findings demonstrate the importance of stimulus relevance to multisensory processing by providing the first evidence that the neural processes underlying multisensory integration are modulated by the relevance of the stimuli being combined. We also provide evidence that such facilitation may be mediated by changes in neural synchronization in occipital and centro-parietal neural populations at early and late stages of neural processing that coincided with stimulus selection, and the preparation and initiation of motor action.

Oscillatory signatures of crossmodal congruence effects: An EEG investigation employing a visuotactile pattern matching paradigm

“…On the one hand, we expected modulations in preparatory neuronal activity related to task requirements, especially in alpha-and beta-frequencies (Mazaheri et al, 2014;van Ede et al, 2011van Ede et al, , 2014. On the other hand and in line with previous studies on crossmodal interactions and low frequency modulations (Barutchu et al, 2013;Doesburg et al, 2009;Gleiss and Kayser, 2014a,b;Hummel and Gerloff, 2005;van Ackeren et al, 2014;van Driel et al, 2014), we expected post-stimulus modulations below 30 Hz related to crossmodal stimulus congruence. In order to investigate the integration of information in visuotactile networks on the level of cortical sources, we performed EEG source reconstruction using eLORETA.…”

Oscillatory signatures of crossmodal congruence effects: An EEG investigation employing a visuotactile pattern matching paradigm

“…On the one hand, we expected modulations in preparatory neuronal activity related to task requirements, especially in alpha- and beta-frequencies (Mazaheri et al, 2014; van Ede et al, 2011; van Ede et al, 2014). On the other hand and in line with previous studies on crossmodal interactions and low frequency modulations (Barutchu et al, 2013; Doesburg et al, 2009; Gleiss and Kayser, 2014a; Gleiss and Kayser, 2014b; Hummel and Gerloff, 2005; van Ackeren et al, 2014; van Driel et al, 2014), we expected post-stimulus modulations in different frequency bands below 30 Hz, possibly reflecting different constituent factors of the complex process of multisensory integration. In order to further differentiate between subcomponents of visual-tactile interactions on a spatial scale, we reconstructed neuronal sources of frequency-band specific power using non-adaptive linear spatial filters (eLORETA).…”

The interactions of multisensory integration with endogenous and exogenous attention

“…The effect of multisensory integration on behavioral performance can be attenuated or even eliminated under conditions of modality-specific selective attention (Mozolic et al, 2008; Wu et al, 2012a). Multisensory facilitation of response times and accuracy was also found to be optimal when both auditory and visual stimuli were targets (Barutchu et al, 2013). Furthermore, relative to conditions in which attention is focused on a single specific modality, when attention is distributed across modalities, sensory gating can be modulated (Anderson and Rees, 2011; Talsma et al, 2007) such that multisensory integration occurs earlier, e.g., within 100 ms after stimulus onset (the P50 component) (Giard and Peronnet, 1999; Talsma et al, 2007).…”