Compensatory Plasticity in the Lateral Extrastriate Visual Cortex Preserves Audiovisual Temporal Processing following Adult-Onset Hearing Loss

Figure 3

Audiovisual-evoked CSD profiles within the multisensory zone of the V2L cortex in response to 3 different SOAs. Representative CSD profiles (a, c, and e) and extracted CSD waveforms (b, d, and f) at SOAs of (a, b) 0 ms, (c, d) 30 ms, and (e, f) 50 ms in response to a combined audiovisual stimulus. CSD waveforms were extracted from the electrode showing the largest amplitude from each of the individual sinks (denoted by the dashed lines on the CSD images for the supragranular (sSk, red), granular (gSk, green), infragranular upper (iSk-upper, blue), and infragranular lower (iSk-lower, black) responses; sinks are positive, whereas sources are negative. In each of the plots, the horizontal black bar denotes the presentation of the visual stimulus (50 ms LED flash at 15 lux) and the grey horizontal bar shows the timing of the auditory stimulus (50 ms noise burst at 40 dB above click threshold). The black arrow within the CSD waveforms on panels (b,f) shows the location of the visual response, demonstrating that the visual response changes from occurring second at an SOA of 0 ms to occurring first at an SOA of 50 ms.