The maturation of eye movement behavior: Scene viewing characteristics in children and adults

Abstract

While the close link between eye movements and visual attention has often been demonstrated, recently distinct attentional modes have been associated with specific eye movement patterns. The ambient mode-serving the localization of objects and dominating early scene inspection-is expressed by short fixations and large saccade amplitudes. The focal mode-associated with the identification of object details and dominating later stages of scene exploration-is indicated by longer fixations embedded in short saccades. The relationship between these processing modes and eye movement characteristics has so far only been examined in adults. While studies in children revealed a maturation of oculomotor behavior up to adolescence, developmental aspects of the processing modes are still unknown. Here we explored these mechanisms by comparing eye movements during the inspection of naturalistic scenes. Therefore, gaze behavior from adults and children in four different age groups (2, 4-6, 6-8, 8-10years old) was examined. We found a general effect of age, revealing that with age fixation durations decrease and saccade amplitudes increase. However, in all age groups fixations were shorter and saccades were longer at the beginning of scene inspection but fixations became longer and saccades became shorter over time. While saliency influenced eye guidance in the two youngest groups over the full inspection period, for the older groups this influence was found only at the beginning of scene inspection. The results reveal indications for ambient and focal processing strategies for as early as 2 years of age.

Effects of salience are both short- and long-lived

“…the time from stimulus onset to a saccade is made to the target, with short-latency saccades being primarily salience driven and longlatency saccades being primarily top down driven (Donk & van Zoest, 2008;Goschy et al, 2013;Van Zoest & Donk, 2006;Van Zoest et al, 2004). Although these studies suggest that the effect of salience dissipate after the first saccade, a second group of studies in which eye movements have been measured over a longer time window suggest a slower decay in the effect of salience (Foulsham & Underwood, 2007;Fuchs, Ansorge, Redies, & Leder, 2011;Helo, Pannasch, Sirri, & Raemae, 2014;Parkhurst, Law, & Niebur, 2002;Tatler et al, 2005). These studies are not necessarily at odds with the timing account seeing that the effect of salience typically wanes within the first 10-20 fixations to the scene.…”

Your gaze betrays your age

“…An horizontal bias is also observed whatever the age, but is more pronounced when getting older [10]. Finally, the fixation durations decrease with age [8].…”

“…Fixations shorter than 90 ms and fixations around blinks were discarded. For all the results reported in this paper, the first fixation has been removed (more details are available in [8]). …”

“…This development as well as aging influence saccade parameters. Saccade frequency, amplitude, and mean velocity are reduced and the velocity/amplitude distribution as well as the velocity profile become less skewed [9], [8]. An horizontal bias is also observed whatever the age, but is more pronounced when getting older [10].…”

“…As we are getting older, the function of the visual system appears to deteriorate. Helo et al [8] provided evidence of age-related differences in viewing patterns during natural scene perception. This development as well as aging influence saccade parameters.…”