#MINIMAL LEVELATOR FUNCTION EYES DRIVER#

We first performed a univariate fMRI analysis to identify brain regions that were activated by both visual and auditory stimuli, and these regions corresponded well with those found in previous studies. In the present study, we used multivariate pattern analysis (MVPA) of functional magnetic resonance imaging (fMRI) data to probe multimodal regions for neural representations that were both content specific and modality invariant. First, are the neural patterns established in these multimodal brain regions content specific? In other words, do they reflect the identity of a sensory stimulus rather than a more general aspect of the perceptual process? Second, are the neural patterns modality-invariant? In other words, does an object evoke similar neural response patterns when it is apprehended through different modalities?

These observations alone, however, do not address two important questions.

#MINIMAL LEVELATOR FUNCTION EYES DRIVER#

Calvert, 2001, Amedi et al., 2005 Beauchamp, 2005 Doehrmann and Naumer, 2008 Driver and Noesselt, 2008). Recent functional neuroimaging studies in humans are in line with the anatomical and electrophysiological evidence and have located areas of multisensory integration in the lateral prefrontal cortex, premotor cortex, posterior parietal cortex, and the pSTS region (for review, see e.g. Also, electrophysiological studies have identified bimodal and trimodal neurons in the pSTS ( Benevento et al., 1977 Bruce et al., 1981 Hikosaka et al., 1988). Lesion and tracer studies have shown that the pSTS region not only receives projections from visual, auditory, and somatosensory association cortices, but returns projections to those cortices as well ( Seltzer and Pandya, 1991 Barnes and Pandya, 1992). Neuroanatomists have long identified areas of multisensory convergence in the monkey brain, for instance in the lateral prefrontal and premotor cortices, the intraparietal sulcus, the parahippocampal gyrus, and the posterior part of the superior temporal sulcus (pSTS) ( Seltzer and Pandya, 1978, 1994). The fact that we are able to do so independently of the perceptual channel through which we were stimulated suggests that the information provided by different channels converges, at some stage, into modality-invariant neural representations of the object. Upon recognition, we are able to access the wide conceptual knowledge we possess about bells and we use this knowledge to generate motor behaviors and verbal reports. Whether we see a bell swing back and forth or instead hear its distinctive dingdong, we easily recognize the object in both cases. This region thus appears to play an important role in our ability to recognize objects in our surroundings through multiple sensory channels and to process them at a supramodal (i.e., conceptual) level. While several areas became activated in response to both auditory and visual stimulation, only the neural patterns recorded in a region around the posterior part of the superior temporal sulcus displayed both content specificity and modality invariance. In this functional magnetic resonance imaging study of human subjects, we first identified brain areas that responded to both visual and auditory stimuli and then used crossmodal multivariate pattern analysis to evaluate the neural representations in these regions for content specificity (i.e., do different objects evoke different representations?) and modality invariance (i.e., do the sight and the sound of the same object evoke a similar representation?). This suggests that information from different sensory channels converges somewhere in the brain to form modality-invariant representations, i.e., representations that reflect an object independently of the modality through which it has been apprehended. People can identify objects in the environment with remarkable accuracy, regardless of the sensory modality they use to perceive them.

Minimal levelator function eyes