Neural Correlates of Multisensory Spatial Attention: A Computational Modelling Study

Mechanisms of selective attention are vital for directing neural resources to the most behaviorually relevant events. In daily life, spatial attention often needs to be coordinate across different modalities. Cross-modal links have been observed either when attention is directed voluntarly (endogenous) or involuntarly (exogenous). The neural basis of cross-modal attention presents a significat challenge to cognitive neuroscience. Here, we used a neural network model to elucidate the possible neural correlates of visual-tactile interactions in endogenous and exogenous spatial attention. The model is composed of two networks (one per hemisphere), each including two unimodal (visual and tactile) areas of neurons connected with a bimodal area. The two hemispheres communicate via inhibitory synapses. The model is able to explain cross-modal facilitation both in exogenous and endogenous attention, ascribing it to an advantaged activation of the bimodal area on the attended side, with concomitant supramodal inhibition towards the opposite side. The model suggests that the same neural substrates may mediate both forms of attention. Model predictions may help interpretation of behavioural and neuroimaging results on spatial attention and cross-modal construction of space.