Slow Fluctuations in Attentional Control of Sensory Cortex

Abstract

Top-down control of visual sensory cortex has long been tied to the orienting of visual spatial attention on a rapid, moment-to-moment basis. Here, we examined whether sensory responses in visual cortex are also modulated by natural and comparatively slower fluctuations in whether or not one is paying attention to the task at hand. Participants performed a simple visual discrimination task at fixation as the ERPs to task-irrelevant probes in the upper visual periphery were recorded. At random intervals, participants were stopped and asked to report on their attentional state at the time of stoppage-either "on-task" or "off-task." ERPs to the probes immediately preceding these subjective reports were then examined as a function of whether attention was in an on-task versus off-task state. We found that sensory-evoked responses to the probes were significantly attenuated during off-task relative to on-task states, as measured by the visual P1 ERP component. In two additional experiments, we replicated this effect while (1) finding that off-task sensory attenuation extends to the auditory domain, as measured by the auditory N1 ERP component, and (2) eliminating state-dependent shifts in general arousal as a possible explanation for the effects. Collectively, our findings suggest that sensory gain control in cortex is yoked to the natural ebb and flow in how much attention we pay to the current task over time.

When “It” Becomes “Mine”: Attentional Biases Triggered by Object Ownership

“…Likewise, one might argue that the reduction in P1 amplitude for the visual probes following "self " cues could reflect cue-dependent shifts in more general attentional states rather than a specific narrowing of visual spatial attention. For instance, when we naturally drift into a mind wandering state, where oneʼs thoughts become more internally focused, there is a concomitant reduction in the degree of sensory processing in both the visual and auditory domains (Kam et al, 2011)-effects directly analogous to what we observed in our P1 data. Accordingly, if "self" cues triggered a greater degree of internal reflection relative to "other" cues, then that could explain our P1 results from Experiment 2.…”

The Decoupled Mind: Mind-wandering Disrupts Cortical Phase-locking to Perceptual Events

“…P1 ERP contrasts were evaluated with repeated-measures ANOVA (factors Task Focus [FOCUS] and Location [LOC]) of peak deflections over parietal and parieto-occipital electrodes with corresponding 10-20 equivalents (GSN channel 61 (P1), 78 (P2), 60 (PO3), 85 (PO4)), where P1 amplitude tends to be maximal (Kam et al, 2011;Handy & Khoe, 2005;Handy, Soltani, & Mangun, 2001). The time window for detecting peak amplitude of the P1 component was 50-150 msec (e.g., Klimesch, Hanslmayr, Sauseng, Gruber, & Doppelmayr, 2007).…”

“…One well-documented aspect of these experiences (often referred to as mind-wandering or task-unrelated thought) is that their occurrence corresponds to periods of time when external input is neglected (for reviews, see Smallwood, 2013;Schooler et al, 2011). Evidence using a variety of measures of task-unrelated thought and using a variety of different measures of cortical processing indicates that these periods are accompanied by an attenuation of the processing of perceptual input, a phenomenon that has been termed "perceptual decoupling" (Barron, Riby, Greer, & Smallwood, 2011;Kam et al, 2011;Smallwood, Brown, Baird, & Schooler, 2011;Smallwood, Brown, Tipper, et al, 2011).…”

“…Kam et al (2011) recently demonstrated that this decoupling already occurs at the early phase of sensory processing: Early cortical processing in both the visual and auditory domain, indexed by the visual P1 and auditory N1 ERPs, is reduced before reports of taskunrelated thought compared with states of task focus. This finding suggests that task-unrelated thoughts induce a form of endogenous distractor comparable to the standard effect of selective attention on sensory gating by an external distractor (Hillyard, Hink, Schwent, & Picton, 1973).…”

Mind-wandering and falls risk in older adults.

“…We determined the rate of mindwandering for each participant via subjective reports of participants current attentional state (on-task versus mind-wandering), collected at regular but unpredictable intervals (see below). The SART is a widely-used paradigm in mind-wandering studies, where participants are required to respond to frequently presented targets, while inhibiting responses to infrequent targets (e.g., Kam et al, 2011;Smallwood et al, 2008). The SART is thought to measure sustained attention -which is influenced by the moment-to-moment efficacy of attentional control mechanisms (Manly, Robertson, Galloway, & Hawkins, 1999).…”