Challenges to attention: A continuous arterial spin labeling (ASL) study of the effects of distraction on sustained attention

Abstract

Maintaining attention and performance over time is an essential part of many activities, and effortful cognitive control is required to avoid vigilance decrements and interference from distraction. Regions at or near right middle frontal gyrus (Brodmann’s area (BA) 9), as well as in other prefrontal and parietal areas, are often activated in studies of sustained attention (e.g., Cabeza & Nyberg, 2000; Kim et al., 2006; Lim et al., 2010). This activation has often been interpreted as representing the engagement of cognitive control processes. However, such studies are typically implemented at one level of task difficulty, without an experimental manipulation of control demands. The present study used the distractor condition sustained attention task (dSAT), which has been used extensively in animals to determine the role of neuromodulator systems in attentional performance, to test the hypotheses that BA 9 is sensitive to changes in the demand for cognitive control and that this sensitivity reflects an increased engagement of attentional effort. Continuous arterial spin labeling (ASL) was used to measure neural activity in sixteen healthy, young adults performing a sustained attention task under standard conditions and under a distraction condition that provided an experimental manipulation of demands on cognitive control. The distractor impaired behavioral performance and increased activation in right middle frontal gyrus. Larger increases in right middle frontal gyrus activity were associated with greater behavioral vulnerability to the distractor. These findings indicate that while right middle frontal gyrus regions are sensitive to demands for attentional effort and control, they may not be sufficient to maintain performance under challenge. In addition, they demonstrate the sensitivity of ASL methods to variations in task demands, and suggest that the dSAT may be a useful tool for translational cross-species and clinical research.

Cortical cholinergic signaling controls the detection of cues

“…The decision to target right mPFC was based on findings indicating that performance of the task used here enhances cholinergic function in the right, but not left, mPFC in mice (21) and activates right prefrontal regions in humans (19,22). The present results support the hypothesis that the ability of cues to guide behavior is mediated by phasic cholinergic signaling.…”

Bidirectional interactions between circadian entrainment and cognitive performance

“…Under these conditions, water maze trials with a fixed platform location across multiple training days may not evoke the same level of attentional effort required by the SAT. The largest time-of-day effects on performance in human subjects have been reported for cognitive tasks that challenge attentional processes or executive functions requiring prefrontal areas (Yoon et al 1999), which the SAT recruits in both humans and rodents (Sarter et al 2005Kozak et al 2006;Parikh et al 2007;Demeter et al 2008Demeter et al , 2011St. Peters et al 2011).…”

The neuroscience of cognitive-motivational styles: Sign- and goal-trackers as animal models.

“…Furthermore, a relatively automatic attraction to, or capture of attention by, salient environmental stimuli characterizes poor attentional control. In our research, the Sustained Attention Task (SAT) has been designed to tax attentional control mechanisms in rodents and humans (Demeter, Hernandez-Garcia, Sarter, & Lustig, 2011; Demeter, Sarter, & Lustig, 2008; St. Peters, Demeter, et al, 2011). …”