Visual Demands of Walking Are Reflected in Eye-Blink-Evoked EEG-Activity

Abstract

Blinking is a natural user-induced response which paces visual information processing. This study investigates whether blinks are viable for segmenting continuous electroencephalography (EEG) activity, for inferring cognitive demands in ecologically valid work environments. We report the blink-related EEG measures of participants who performed auditory tasks either standing, walking on grass, or whilst completing an obstacle course. Blink-related EEG activity discriminated between different levels of cognitive demand during walking. Both behavioral parameters (e.g., blink duration or head motion) and blink-related EEG activity varied with walking conditions. Larger occipital N1 was observed during walking, relative to standing and traversing an obstacle course, which reflects differences in bottom-up visual perception. In contrast, the amplitudes of top-down components (N2, P3) significantly decreased with increasing walking demands, which reflected narrowing attention. This is consistent with blink-related EEG, specifically in Theta and Alpha power that, respectively, increased and decreased with increasing demands of the walking task. This work presents a novel and robust analytical approach to evaluate the cognitive demands experienced in natural work settings, which precludes the use of artificial task manipulations for data segmentation.

Eye-blink patterns reflect attention to continuous speech

“…As has been argued before, eye blinks are more prevalent when the processing of a chunk of information has been completed (Wascher et al, 2022). The fact that we observed particularly more eye blinks during pauses in the attended speech stream and that the pauses most likely constituted breakpoint within speech provide further evidence for this view.…”

“…It is therefore reasonable that people tend to refrain from blinking when they expect relevant information to occur. For example, blinks are more likely to occur once relevant visual information has been revealed (Nakano et al, 2009;Wascher et al, 2022). Recently it has been shown that eye blinks also occur systematically in response to auditory stimuli.…”

Tracking drivers’ minds: Continuous evaluation of mental load and cognitive processing in a realistic driving simulator scenario by means of the EEG

“…Firstly, bERPs have a similar waveform as regular eventrelated potentials (ERPs) following visual stimuli; positive and negative deflections after the event can be interpreted in terms of event-related changes in cognitive processing. This was shown in the laboratory (Wascher et al, 2014) as well as in outside environments (Wascher et al, 2022;Wunderlich & Gramann, 2021). Changes in ERP components (namely P1, N1, P2 etc.)…”

“…Based on ICA decomposition, eye blinks were identified by gaussian fits (see Wascher et al, 2022). Saccades were detected by searching for maximal velocity in the IC identified to reflect horizontal eye movements.…”

“…Here, eye activity such as blinks and/or saccades was found to be useful. By analyzing blink-evoked event-related potentials (bERPs) and blink-evoked event-related spectral perturbations (bERSPs) during different natural tasks (in particular walking), insights into visual processing, and visual and cognitive demands of natural behavior were provided without experimental manipulation of the (visual) scene (Wascher et al, 2014(Wascher et al, , 2022. This technique could also be applied to driving scenarios, although car driving may be more complex than walking in terms of eye behavior.…”