Eye fixation scanpaths of younger and older drivers in a hazard perception task

Abstract

Our previous research has shown that observing patterns of eye fixations is a successful method of establishing differences in underlying cognitive processes between groups of drivers. Eye movements recorded from drivers in a laboratory while they watch film clips recorded from a driver's perspective can be used to identify scanpaths and search patterns that reveal ability differences. In the present study 12 older subjects (60-75 years) and 12 younger subjects (30-45 years) watched clips for potential hazards such as other road users appearing on an intersecting trajectory. Acuity and visual field differences between the two groups were eliminated through screening, so that only age-related differences would emerge. Eye fixations were analysed on a frame-by-frame basis to generate sequences of codes representing the location and object of the viewer's interest, before and during the appearance of a hazard. These codes were analysed for the existence of two fixation scanpaths using Markov Matrices. Unique scanpaths were identified for each group of drivers before and during the hazard. Evidence from the inspection of different objects and from the spread of the search indicated that both groups of driver were sensitive to attentional capture by the appearance of the hazard. Detection of the hazards - both speed and accuracy - was similar for older and younger drivers, although the older drivers perceived the films as being more hazardous in general. There is little evidence in this study of an age-related decline in the search of the scene when detecting hazards.

Observing other pedestrians: Investigating the typical distance and duration of fixation

“…However, the three data sets do not appear to be associated; the collision avoidance distances reported by Fujiyama et al 28 using stop distance are greater than their comfort distances at all illuminances, and these in turn are greater than the comfort distances reported by Adams and Zuckerman. 27 Neither Distance and duration of fixation on pedestrians 553 related 32,33 to the extent that a study investigating pedestrians' fixations in a virtual environment found that specific tasks could be predicted from fixation data. 34 Clearly there are caveats associated with the interpretation of distance and duration from eyetracking data.…”

Visual information search in simulated junction negotiation: Gaze transitions of young novice, young experienced and older experienced drivers

“…This was less pronounced in the young experienced group, for whom transitions were distributed more evenly. Underwood, Phelps, Wright, Van Loon and Galpin (2005) also looked at sequence patterns for younger and older experienced drivers during a hazard detection task, however, few age-related differences were found.…”

Using eye-tracking to identify pedestrians’ critical visual tasks. Part 2. Fixation on pedestrians

“…One approach to identifying critical visual tasks is to find out what pedestrians look at, and eye-tracking offers one method for establishing the objects fixated. There is reason to have some confidence that distribution of gaze and cognitive processes are related [4][5][6] to the extent that a study investigating pedestrians' fixations in a virtual environment found that specific tasks could be predicted from fixation data. 7 Two studies used eye-tracking to record fixations on other pedestrians in laboratory trials.…”