Anticipatory eye movements when approaching a curve on a rural road depend on working memory load

Abstract

Where do drivers look when approaching curves on a winding road? Existing models on visual processes in curve driving have focused on path-controlling behaviour. Another aspect in curve driving is the visual anticipation of potential oncoming vehicles, obstacles and road alignment. We define the occlusion point of a curve as the nearest point where the view of the road is blocked by some obstacle (e.g. vegetation). Monitoring the occlusion point is relevant for safe driving because potential oncoming vehicles or obstacles on the road will come into view on the occlusion point. In the current on-road study, ten participants drove an instrumented car at their own pace on a low standard rural road while their eye-movements were recorded. We investigated anticipatory glances towards the occlusion point while approaching open sight curves and how anticipatory glances are affected by a cognitive secondary task without explicit visuospatial or motor components. The results demonstrate that drivers indeed look at the occlusion point while approaching open curves on rural roads, and that working memory load leads to a significant decrease in visual anticipation. Previously, it has been shown that cognitive secondary tasks lead to reduction of looking at the speedometer and mirrors and of safety critical visual scanning at street crossings. We show that the effect is also present in the anticipation of road curvature and hazards on rural roads.

Driving context and visual-manual phone tasks influence glance behavior in naturalistic driving

“…While turning, %EONR was significantly higher during baseline driving, and MaxGD significantly lower during the phone tasks. This behavior is probably driven by the higher visual demand while turning, and suggests that the driver anticipates potential hazards such as oncoming vehicles (Land & Lee, 1994;Lehtonen et al, 2012). The results are in line with previous simulator studies demonstrating that drivers' glance behavior is influenced by road curvature during visual-manual tasks (Tsimhoni & Green, 2001;Victor et al, 2005).…”

Look-ahead fixations in curve driving

“…The approach phase of curve R1 was also studied in Lehtonen et al (2012) with different data and method. In order to compare the results, fixation parameters were calculated along a 100 m segment in the approach of R1 (550-650 m) with available data and averaged condition-wise for each subject.…”

“…Common to them is that drivers look towards the direction of travel with a lead time of 1-2 s. While it is recognised that drivers also look further up the road, through the curve (Land and Horwood 1996, *Corresponding author. Email: esko.lehtonen@helsinki.fi Ergonomics 2012, 1-11, iFirst article Underwood et al 1999, Kandil et al 2010, Lehtonen et al 2012, relatively little quantitative research has been done on this behaviour.…”

“…We will examine where the look-ahead fixations occur and what parts of the road they target, and how cognitive load affects them. Especially, we examine whether drivers look as far along the road as they can see, to the occlusion point of a curve (the nearest point where the view of the road is occluded, and where the oncoming vehicle would first emerge from: Lehtonen et al 2012), or whether they select some other point on the visible road. Finally, we discuss how the concepts of guiding and look-ahead fixations can be applied to other driving situations than curve driving.…”

Effect of verbal working memory load during the oculomotor activity in visual search

“…№ 2 Нагрузка на рабочую память может приводить не только к изменениям показателей эффективности выполнения различных когнитивных задач (таких, как задача зрительного поиска), но и к специфическим изменениям глазодвигательной активности (Lehtonen et al, 2012;MacNamara et al, 2012). Например, было показано, что при управлении автомобилем на дороге с поворотами нагрузка на рабочую память приводит к снижению вероятности антици-пирующих движений глаз, направленных на мониторинг точек окклюзии -ближайших к во-дителю точек дороги, за которыми дорога скрыта от наблюдения (Lehtonen et al, 2012). Таким образом, нагрузка на рабочую память приводит к повышению экономичности движений глаз, известному обеднению их динамики, их концентрации на элементах, непосредственно необ-ходимых для выполнения текущей задачи (в данном примере -на элементах, мониторинг ко-торых необходим для поддержания оптимальной траектории движения).…”