Older adults often display postoperative cognitive decline (POCD) after surgery, yet it is unclear to what extent functional connectivity (FC) alterations may underlie these deficits. We examined for postoperative voxel-wise FC changes in response to increased working memory load demands in cardiac surgery patients and nonsurgical controls.

Limited information exists on the effects of temporary functional deafferentation (TFD) on brain activity after peripheral nerve block (PNB) in healthy humans. Increasingly, resting-state functional connectivity (RSFC) is being used to study brain activity and organization. The purpose of this study was to test the hypothesis that TFD through PNB will influence changes in RSFC plasticity in central sensorimotor functional brain networks in healthy human participants.

Spatial attention to a visual stimulus that occurs synchronously with a task-irrelevant sound from a different location can lead to increased activity not only in the visual cortex, but also the auditory cortex, apparently reflecting the object-related spreading of attention across both space and modality (Busse et al., 2005). The processing of stimulus conflict, including multisensory stimulus conflict, is known to activate the anterior cingulate cortex (ACC), but the interactive influence on the sensory cortices remains relatively unexamined. Here we used fMRI to examine whether the multisensory spread of visual attention across the sensory cortices previously observed will be modulated by whether there is conceptual or object-related conflict between the relevant visual and irrelevant auditory inputs. Subjects visually attended to one of two lateralized visual letter-streams while synchronously occurring, task-irrelevant, letter sounds were presented centrally, which could be either congruent or incongruent with the visual letters. We observed significant enhancements for incongruent versus congruent letter-sound combinations in the ACC and in the contralateral visual cortex when the visual component was attended, presumably reflecting the conflict detection and the need for boosted attention to the visual stimulus during incongruent trials. In the auditory cortices, activity increased bilaterally if the spatially discordant auditory stimulation was incongruent, but only in the left, language-dominant side when congruent. We conclude that a conflicting incongruent sound, even when task-irrelevant, distracts more strongly than a congruent one, leading to greater capture of attention. This greater capture of attention in turn results in increased activity in the auditory cortex.