The effects of type and workload of internal tasks on voluntary saccades in a target-distractor saccade task

Abstract

When we engage in internally directed cognition, like doing mental arithmetic or mind wandering, fewer cognitive resources are assigned for other activities like reacting to perceptual input—an effect termed perceptual decoupling. However, the exact conditions under which perceptual decoupling occurs and its underlying cognitive mechanisms are still unclear. Hence, the present study systematically manipulated the task type (arithmetic, visuospatial) and workload (control, low, high) of the internal task in a within-subject design and tested its effects on voluntary saccades in a target-distractor saccade task. As expected, engagement in internal tasks delayed saccades to the target. This effect was moderated by time, task, and workload: The delay was largest right after internal task onset and then decreased, potentially reflecting the intensity of internal task demands. Saccades were also more delayed for the high compared to the low workload condition in the arithmetic task, whereas workload conditions had similarly high effects in the visuospatial task. Findings suggests that perceptual decoupling of eye behavior gradually increases with internal demands on general resources and that perceptual decoupling is specifically sensitive to internal demands on visuospatial resources. The latter may be mediated by interference due to eye behavior elicited by the internal task itself. Internal tasks did not affect the saccade latency-deviation trade-off, indicating that while the internal tasks delayed the execution of the saccade, the perception of the saccade stimuli and spatial planning of the saccade continued unaffected in parallel to the internal tasks. Together, these findings shed further light on the specific mechanisms underlying perceptual decoupling by suggesting that perceptual decoupling of eye behavior increases as internal demands on cognitive resources overlap more strongly with demands of the external task.

Preprint: How workload and availability of spatial reference shape eye movement coupling in visuospatial working memory

“…Intentional eye movements require top-down control and cognitive resources. We showed in previous studies, that performing the visuospatial WM task even with the 3x3 matrix interferes with voluntary eye movements required by a parallel task (Korda et al, 2023;Walcher et al, 2023). Hence, it is unlikely that the pattern of internal coupling found in the current study is the result of participants' expectations and intentional manipulation of eye movements.…”

“…Several studies showed that covert shifts of attention can have beneficial effects similar to eye movements (i.e., overt shifts of attention) on retrieving information associated with spatial locations (Godijn & Theeuwes, 2012;Scholz et al, 2018). In a similar vein, previous studies found that when participants had to perform an eye movement task (smooth pursuit, targetdistractor task, or simply maintain fixation, respectively) in parallel to the visuospatial WM task, and hence internal coupling was restricted, performance was still high (Korda et al, 2023(Korda et al, , 2024Walcher et al, 2023). These findings suggest that eye movements follow internal shifts of attention automatically (Huber & Krist, 2004).…”

“…Based on our internal pilots, we expected medium to large effect sizes. We determined the sample size a priori based on our own previous studies which used similar statistical approaches (i.e., within-subject LMM with more than one within-subject factor; Korda et al, 2023Korda et al, , 2024Walcher et al, 2023) and power analysis using G*power version 3.1 (Faul et al, 2009). Based on our previous studies, we expected medium-sized within-subject effects of dz = 0.4 (Annerer- Walcher et al, 2021).…”

“…Data preprocessing followed our previous protocols (Korda et al, 2023;Walcher et al, 2023). Eye tracking data were exported from EyeLink Data Viewer Software (SR Research Ltd., version 4.2.1) and further processed with R (R Version 4.2.2, R Core Team, 2020) using RStudio (Version 2022.12.0, RStudio Team, 2020).…”

Internal Coupling: Eye Behavior Coupled to Visual Imagery

“…For instance, a person might remember the beach they once visited, think of different destinations for their next vacation, or mentally map out the quickest route home. Interestingly, eye behavior was shown to distinguish between external and internal attention focus (Korda et al, 2023(Korda et al, , 2024Walcher et al, 2023a). For example, during periods of internal focus, individuals exhibit increased blink frequency and duration, fewer but longer fixations, and greater variability in pupil diameter (Annerer-Walcher et al, 2018, 2021(Annerer-Walcher et al, 2021;Annerer-Walcher et al, 2018;Hollander & Huette, 2022;Smallwood et al, 2011;Uzzaman & Joordens, 2011).…”