Mechanisms of Sustained Selective Attention in 3- to 5-year-old Children: Evidence from a New Object Tracking Task

Mechanisms of Sustained Selective Attention in 3- to 5-year-old Children: Evidence from a New Object Tracking Task Anna V. Fisher (fisher49@andrew.cmu.edu) Department of Psychology, 5000 Forbes Avenue Pittsburgh, PA 15213 USA Abstract Sustained selective attention is a crucial component of many higher-order cognitive processes; yet there is little research into the mechanisms of this ability early in development. One of the challenges in investigating mechanisms of sustained selective attention in young children is lack of appropriate experimental paradigms. This paper reports findings from a novel paradigm designed to investigate mechanisms of sustained selective attention in young children - the Object Tracking task. Results of two experiments with 3- to 5-year- old children provided support to the notion that development of the endogenous component of selective sustained attention lags behind the development of the exogenous component of this process. Importantly, the Object Tracking paradigm allowed investigating both of these components within the same task, thereby making it possible to attribute changes in performance to different mechanisms of attentional control rather than to differences in the level of motivation and engagement in different tasks. Keywords: Selective attention; Sustained attention; Focused Attention; Cognitive Development. Introduction The ability to selectively sustain attention is crucially important because it is an essential component of most higher-order cognitive processes, such as categorization, language comprehension, reasoning, and problem solving. For example, it takes preverbal infants as little as 500 ms to locate a target object among eight distracters (Adler & Orprecio, 2006), whereas it takes them approximately twenty times longer to categorize a single object (Quinn & Eimas, 1996). Similar latency differences between simple visual search tasks and higher-order categorization tasks are also present in older children and adults (Fisher, in press; Gerhardstein & Rovee-Collier, 2002; Trick & Enns, 1998). However, development of the mechanisms of sustained selective attention, also referred to as focused attention, has been sparsely investigated. The goal of the research presented below was to investigate mechanisms of sustained selective attention in 3- to 5-year-old children. When several objects are present in a scene and one needs to focus attention on a single object, how is the competition resolved? One of the paradigms that has been widely used to explore this question in the domain if visual attention is the visual search paradigm pioneered by Treisman and Gelade (1980). The classic finding from this paradigm is that when adults are asked to search a visual array for a target object defined by a conjunction of features (e.g., color and shape), their reaction time increases with the increase in the number of distracter objects in the display. However, when displays contain target objects defined by a single feature (e.g., color) visual search reaction times remain constant regardless of the number of distracters, as the target object seems to instantly “pop-out” from the display. While there is no consensus on the mechanisms of visual search, many theories distinguish between two broad ways in which competition between multiple objects in a scene can be resolved. One way has been characterized as stimulus-driven, effortless, bottom-up, and passive, whereas the other way has been characterized as participant-driven, effortful, top-down, and active (Lavie, 2005; Lavie & Tsal, 1994; Kastner & Undergleider, 2000; Norman & Shallice, 1986; Schneider and Shiffrin, 1977; Schneider & Chein, Research on the development of selective attention indicates that even newborns are not indifferent to what they attend to, and prefer to attend to some stimuli over others (Colombo, 2001; Fantz, 1963). However, this selectivity has been characterized as stimulus-driven or automatic (i.e., driven by exogenous factors), rather than participant-driven or voluntary (i.e., driven by endogenous factors). In particular, selective attention in newborns and young infants is driven to a large degree by the properties of the stimulus, such as its frequency and duration (for auditory stimuli) and intensity and brightness (for visual stimuli), rather than by infants’ intentions (Bornstein, 1990; Ruff & Rothbart, By the time infants reach seven months of age, their allocation of attention is driven by a complex interaction of exogenous and endogenous factors (Oakes, Kannass, & Shaddy, 2002). For instance, exogenous factors, such as stimulus brightness and complexity still exert a strong pull on attention allocation; however, reorientation to salient distracters is less likely when infants are in a state of focused attention (i.e., concentrating on a particular toy or activity) than when infants are in a state of casual attention – suggesting that internal state of an infant (an endogenous factor) plays a role in how attention is allocated (Tellinghuisen, Oakes, & Tjebkes, 1999). Considerable evidence suggests that when several objects compete for attention and one of these objects is defined by a unique feature, similar to adults, infants as young as 3 ½- months of age exhibit the “pop-out” effect (Adler & Orprecio, 2006; Gerhardstein & Rovee-Collier, 2002; Treisman & Gelade 1980). Search for objects defined by a conjunction of features has not been studied with preverbal infants, however findings with 12- to 36-month old toddlers