Visual Motion Area MT+/V5 Responds to Auditory Motion in Human Sight-Recovery Subjects

Abstract

Using functional magnetic resonance imaging, we found that cortical visual motion area MTϩ/V5 responded to auditory motion in two rare subjects who had been blind since early childhood and whose vision was partially recovered in adulthood. Visually normal control subjects did not show similar auditory responses. These auditory responses in MTϩ were specific to motion compared with other complex auditory stimuli including frequency sweeps and speech. Thus, MTϩ developed motion-specific responses to nonvisual input, suggesting that cross-modal plasticity can be influenced by the normal functional specialization of a cortical region. Regarding sight recovery after early blindness, our results further demonstrate that cross-modal responses coexist with regained visual responses within the visual cortex.

Neural correlates of motion processing through echolocation, source hearing, and vision in blind echolocation experts and sighted echolocation novices

“…Previous behavioral research has shown that people are sensitive to echo-motion (Rosenblum et al 2000;Thaler et al 2011), and in a previous functional magnetic resonance imaging (fMRI) study, we found that echoes from moving compared with stationary surfaces elicited an increase in activation in temporal-occipital cortex in blind echolocation experts (Thaler et al 2011). Human temporal-occipital cortex harbors visual-motion area MTϩ, as well as areas sensitive to auditory source-motion (Saenz et al 2008), however. Consequently, here we addressed the question of how neural substrates of echo-motion, auditory source-motion, and visualmotion in temporal-occipital cortex are related.…”

“…With regard to the functional properties of visual-and source-motion areas, there is an ongoing debate as to what degree visual-motion area MTϩ is sensitive to sound-motion. While some evidence supports the idea of an auditory motion response in area MTϩ (Poirier et al 2005(Poirier et al , 2006, other evidence does not (Saenz et al 2008). It has been suggested that seemingly contradictory results may be due to differences in data analysis, i.e., analysis of spatially averaged data vs. ROI analysis (Saenz et al 2008).…”

“…*P Ͻ 0.05, **P Ͻ 0.01, ***P Ͻ 0.005. , 2006Saenz et al 2008). With regard to the functional properties of visual-and source-motion areas, there is an ongoing debate as to what degree visual-motion area MTϩ is sensitive to sound-motion.…”

“…It has been suggested that seemingly contradictory results may be due to differences in data analysis, i.e., analysis of spatially averaged data vs. ROI analysis (Saenz et al 2008). In our present study, we used functional localizer methods and ROI analyses similar to those used by Saenz et al (2008), and, consistent with their results, we also found that sighted participants' visual-motion areas in temporal-occipital cortex were not driven by auditory motion (Fig. 4, top right panel).…”

Functional specialization for auditory–spatial processing in the occipital cortex of congenitally blind humans

“…Alternatively, another perspective on dorsal and ventral visual processing streams rather considers them to be involved in the control of object-directed actions and object recognition, respectively (12). Interestingly, recent studies in CB have reported task-specific responses in ventral (13)(14)(15)(16) and dorsal (17)(18)(19)(20)(21)(22) occipital streams in response to "what" and "where" nonvisual processing. For example, Renier et al (22) have recently found that the middle occipital gyrus (MOG) is preferentially activated by the spatial processing of nonvisual inputs.…”