Abstract
Introduction. Conventionally, attentional selection is conceived as an interplay of willful, top-down choices and stimulus-driven, bottom-up demands. We hypothesized a third mode based on learned, context-dependent heuristics; a procedural selection - akin to that which governs skilled motor behavior - that occurs without cognitive supervision, but is still flexible and dynamic. This study contrasted how eye movement patterns in well-practiced versus un-practiced, but formally identical tasks (here, reading text forward versus backwards, respectively), were affected by distraction: when top-down selection is defeated, will the eyes still get to where they need to go? Methods. Four conditions were run blocked: Forward versus Backward reading (from bottom right to top left corner) each with and without a concurrent 1-back auditory tone-matching task (i.e. Dual- versus Single-task). A Tobii eye-tracker monitored reading; in the 1-back task, observers reported matches with a keypress. Nine observers saw six 250-word passages (excerpts from Kant) for each condition; tones were presented over headphones. Results. Our analyses focused on average fixation duration: forward, single-task: 270.2ms (SE 13.4ms); forward, dual-task: 292.8ms (SE 15.0), backward, single-task: 313.6ms (SE 10.5); and backward, dual-task: 361.1ms (SE 17.2). Reading backward or with a concurrent task lengthens fixation duration, but most importantly, the interaction - with the concurrent task disproportionately impairing unpracticed, backwards (as opposed to familiar, forwards) reading, was significant (a paired t-test of dual-task costs, for forward versus backward reading: mean difference: 24.85ms; SE: 6.74; t=3.686; p=0.0062). Performance in the 1-back task was 93% (SE 1.8) and 86% correct (SE 1.7) for forward and backward reading, respectively. Conclusions. We hypothesized that attentional selection during reading has been proceduralized, so puts diminished demands on top-down selection (cf. mind-wandering while reading) while unfamiliar backwards reading requires greater supervision, making it more susceptible to distraction. Our findings support this, suggesting the action of proceduralized attention.
Meeting abstract presented at VSS 2016