Figure 12.

Concurrent memory load and working memory capacity affect ABRs. The amplitude of Wave V of click-elicited auditory brainstem responses decreases with visual(-verbal) memory load on working memory capacity (WMC). Note SN10 mirrored performance rather better than Wave V: SN10 was reduced by the load of the 3-back relative to the 2-back, indicating performance-limiting processes that are possibly cortical, in turn leading to more error-prone n-back performance (1-back = 2-back < 3-back). On the high-load 3-back task, the higher an individual's WMC, the lower the amplitude of Wave V. Working memory capacity limits a top-down system that corticofugally suppresses to-be-ignored sound. The cortical cholinergic system is such a top-down system. The red line depicts the waveform when participants voluntarily attended the non-target repeated standard clicks, without n-back performance. The relative suppression of SN10 in n-back tasks, particularly the 3-back is consistent with the notion that load suppresses attention during the SN10 time range. Credit: Adapted from Sörqvist et al. (2012); n = 35. Reprinted by permission of MIT Press Journals.