Response time as a proxy of ongoing mental state: A combined fMRI and pupillometry study in Generalized Anxiety Disorder

Abstract

In Generalized Anxiety Disorder (GAD), fluctuations in ongoing thoughts (i.e., mind-wandering) often take the form of rigid and intrusive perseverative cognition, such as worry. Here, we sought to characterize the neural correlates of mind-wandering and perseverative cognition, alongside autonomic nervous system indices of central arousal, notably pupil dilation. We implemented a protocol incorporating the dynamic delivery of thought-probes within a functional neuroimaging task. Sixteen individuals with GAD and sixteen matched healthy controls (HC) underwent functional magnetic resonance imaging with concomitant pupillometry. Participants performed a series of low-demand tracking tasks, responding to occasional changes in a target stimulus. Such a task is typically accompanied by self-generated, off-task thinking. Thought-probes were triggered based on an individual's response time (RT) when responding to the change in the target. Subjective reports showed that long RT predicted off-task thinking/mind-wandering. Moreover, long RT and mind-wandering were also associated with larger pupil diameter. This effect was exaggerated in GAD patients during perseverative cognition. Within brain, during both pre-target periods and target events, there were distinct neural correlates for mind-wandering (e.g., anterior cingulate and paracingulate activation at target onset) and perseverative cognition (e.g., opposite patterns of activation in posterior cingulate and cerebellum at target onset in HC and GAD). Results suggest that not only attention systems but also sensory-motor cortices are important during off-task states. Interestingly, changes across the 'default mode network' also tracked fluctuations in pupillary size. Autonomic expression in pupillary changes mirror brain activation patterns that occur during different forms of repetitive thinking.

Within-person increase in pathological worry predicts future depletion of unique executive functioning domains

“…Results that rise in GAD severity predicted elevated inhibition and shifting latencies as well as MCs might mean that increased GAD leads to more inefficiencies or uncertainty about responses over time. The long-term effect of chronic worry on allostatic load might impact biomarkers that reinforce the GAD severity-slower latencies relationship and raise the tendency to mind wander (Makovac et al, 2019). Further, results fit with other studies using LCS models and showing that decreased sense of well-being predicted larger decline in perceptual speed across 13 years in older adults (Gerstorf, Lövdén, Röcke, Smith, & Lindenberger, 2007).…”

Testing the construct validity of competing measurement approaches to probed mind-wandering reports

“…In 2006, Smallwood and Schooler published their seminal review of the emerging scientific literature on mind wandering. The next decade and a half saw rapid growth in mind-wandering research, particularly within cognitive psychology and neuroscience (see Callard et al, 2013), but also across such diverse contexts as aeronautics and astronautics (e.g., Casner & Schooler, 2014;Gontier, 2017), education (e.g., , human factors (e.g., Burdett et al, 2019;Walker & Trick, 2018), lifespan development (e.g., Jackson & Balota, 2012;Soemer et al, 2019;Stawarczyk et al, 2014), personality (e.g., Perkins et al, 2015;, philosophy (e.g., Irving, 2016;Metzinger, 2013), and psychopathology (e.g., Chen et al, 2021;Hoffmann et al, 2018;Lanier et al, 2021;Makovac et al, 2019). And, despite a research pace and impact that has supported numerous reviews and theoretical commentaries (e.g., Klinger, 2013;Mildner & Tamir, 2019;Mittner et al, 2016;Smallwood & Andrews-Hanna, 2013;Smallwood & Schooler, 2015), little published work has focused on the validity of subjects' selfreported mind-wandering experiences.…”

How Reliably Do Eye Parameters Indicate Internal Versus External Attentional Focus?

“…Pupil diameter (also referred to as tonic, baseline, or median pupil diameter) is the parameter most commonly used as an indicator of internal versus external focus of attention, both in research and application (e.g., Franklin et al, 2013;Konishi et al, 2017;Palinko et al, 2010;. Studies found larger (Benedek et al, 2017;Ceh et al, 2020;Franklin et al, 2013;Jubera-García et al, 2020;Konishi et al, 2017;Makovac et al, 2019;Pelagatti et al, 2018;Smallwood et al, 2011;Walcher et al, 2017) and smaller pupil diameter (Annerer- Grandchamp et al, 2014; during internal compared to external attentional focus direction. Furthermore, some studies found no effect of attentional focus on pupil diameter (Jubera-García et al, 2020;.…”

“…Several eye parameters were found to discriminate between internal and external cognition, but findings were not fully consistent across studies (Annerer‐Walcher, Körner, & Benedek, 2018; Benedek, Stoiser, Walcher, & Körner, 2017; Ceh et al., 2020; Franklin, Broadway, Mrazek, Smallwood, & Schooler, 2013; Grandchamp, Braboszcz, & Delorme, 2014; Huang et al., 2019; Johansson, Holsanova, & Holmqvist, 2006; Jubera‐García, Gevers, & Van Opstal, 2020; Konishi et al., 2017; Makovac et al., 2019; Palinko et al., 2010; Pelagatti, Binda, & Vannucci, 2018; Piquado, Isaacowitz, & Wingfield, 2010; Salvi et al., 2015; Smallwood et al., 2011; Smilek, Carriere, & Cheyne, 2010; Unsworth & Robison, 2018; Walcher et al., 2017). One reason for the observed inconsistencies could be that eye parameters are sensitive to specific characteristics of the employed internal and external cognition tasks.…”