Fractal fluctuations in gaze speed visual search

Abstract

Visual search involves a subtle coordination of visual memory and lower-order perceptual mechanisms. Specifically, the fluctuations in gaze may provide support for visual search above and beyond what may be attributed to memory. Prior research indicates that gaze during search exhibits fractal fluctuations, which allow for a wide sampling of the field of view. Fractal fluctuations constitute a case of fast diffusion that may provide an advantage in exploration. We present reanalyses of eye-tracking data collected by Stephen and Mirman (Cognition, 115, 154-165, 2010) for single-feature and conjunction search tasks. Fluctuations in gaze during these search tasks were indeed fractal. Furthermore, the degree of fractality predicted decreases in reaction time on a trial-by-trial basis. We propose that fractality may play a key role in explaining the efficacy of perceptual exploration.

Transfer of calibration between hand and foot: Functional equivalence and fractal fluctuations

“…Previous research has documented such findings in the context of exploratory movements by the hand or by the eye (Stephen & Anastas, 2011;. The predictive power of fractality for capturing differences in information detection supports a view of perception-action as the evolving transaction of an organism with the patterned energy distribution in the environment (Gibson, 1966;Wagman & Miller, 2003) without depending on a simple psychophysical correspondence (cf.…”

“…Sensitivity to events across such a wide variety of scales makes search behavior more thorough and effective (Bartumeus, Catalan, Fulco, Lyra, & Viswanathan, 2002;Reynolds, 2010). Indeed, temporally fractal fluctuations in exploratory movements (by the hand and eye) facilitate the detection of information in perceptual tasks (Dixon, Stephen, Boncoddo, & Anastas, 2010;Stephen & Anastas, 2011;Stephen, Boncoddo, Magnuson, & Dixon, 2009). Most relevant to the present article, temporally fractal fluctuations in wielding movements promote accuracy in judgments during dynamic touch by the hand .…”

Cue predictability changes scaling in eye-movement fluctuations

“…However, the relation between task difficulty and scaling in eye movements is not straightforward. For example, although Stephen and Anastas (2011) showed that faster completion of a visual search task corresponded to increases in scaling exponents, results by Wallot, O'Brien, Coey, and Kelty-Stephan (2015) showed that increases in text difficulty in a reading task also led to an increase of scaling exponents in eye movement fluctuations. While the former finding seems to indicate that a reduction in task difficulty during visual search goes together with higher scaling exponents, the latter finding seems to indicate that an increase in task difficulty during reading goes together with higher scaling exponents.…”

“…Recent studies have shown fluctuations across fixations and saccades are intimately connected, suggesting that eye movements of all sizes are governed by fundamentally interdependent processes (e.g., Stephen & Mirman, 2010;Wallot, Coey, & Richardson, 2015;Wallot & Kelty-Stephen, 2014). More specifically, like many other kinds of behavioral and physiological measures (see Van Orden, Kloos, & Wallot, 2011 for a review), eye movements display complex patterns of fluctuations that conform to power-law scaling relations (e.g., Aks, Zelinsky, & Sprott, 2002;Coey, Wallot, Richardson, & Van Orden, 2012;Mirman, Irwin, Stephen, 2012;Stephen & Anastas, 2011).…”

“…Moreover, the previous research has also demonstrated that the scaling relations in eye movements are predictive of task performance. For instance, Stephen and Anastas (2011) found that individual differences in scaling predicted speed differences of participants in two visual search tasks. Similarly, Mirman and colleagues (2012) showed that children with autism spectrum disorder differed from typically developing children in the scaling of eye movements during a visual speech perception task.…”