Auditory enhancement of visual phosphene perception: the effect of temporal and spatial factors and of stimulus intensity

Citation:

Merabet LB, Pascual-Leone A, Maravita A, Senna I, Bolognini N. Auditory enhancement of visual phosphene perception: the effect of temporal and spatial factors and of stimulus intensity. Neuroscience letters. 2010;477 :109-14. Copy at https://tinyurl.com/ybryw8ad

Date Published:

Jun 25

Abstract:

Multisensory integration of information from different sensory modalities is an essential component of perception. Neurophysiological studies have revealed that audiovisual interactions occur early in time and even within sensory cortical areas believed to be modality-specific. Here we investigated the effect of auditory stimuli on visual perception of phosphenes induced by transcranial magnetic stimulation (TMS) delivered to the occipital visual cortex. TMS applied at subthreshold intensity led to the perception of phosphenes when coupled with an auditory stimulus presented within close spatiotemporal congruency at the expected retinotopic location of the phosphene percept. The effect was maximal when the auditory stimulus preceded the occipital TMS pulse by 40 ms. Follow-up experiments confirmed a high degree of temporal and spatial specificity of this facilitatory effect. Furthermore, audiovisual facilitation was only present at subthreshold TMS intensity for the phosphenes, suggesting that suboptimal levels of excitability within unisensory cortices may be better suited for enhanced crossmodal interactions. Overall, our findings reveal early auditory-visual interactions due to the enhancement of visual cortical excitability by auditory stimuli. These interactions may reflect an underlying anatomical connectivity between unisensory cortices.

Notes:

Bolognini, NadiaSenna, IreneMaravita, AngeloPascual-Leone, AlvaroMerabet, Lotfi BK23-EY016131/EY/NEI NIH HHS/K24 RR018875/RR/NCRR NIH HHS/UL1 RR025758/RR/NCRR NIH HHS/IrelandNeurosci Lett. 2010 Jun 25;477(3):109-14. Epub 2010 Apr 27.

Website