Abstract
Recent evidence suggests that some cases of learning are supported by improvements in top-down attentional control that transfers across spatial location (e.g. Xiao et al., 2008; Zhang et al., 2013). Since feature-based attention is considered to be spatially global, training feature-based attention could lead to generalized and transferrable improvements in attentional modulations (Byers & Serences, 2012). We conducted two experiments to test whether feature-based attention modulates learning and transfer and the role of hemispheric spatial attentional resources in learning (see Alvarez et al., 2012). In Experiment 1, subjects trained on a 2AFC motion coherence discrimination task, which employed valid and invalid feature cues and 6 motion coherence levels. Subjects trained for four days with the stimuli located either to the left, right, above, or below fixation; on the 5th day, the stimuli switched to the opposite position (e.g. left to right, top to bottom; see Supplemental Figure). Learning, quantified as a leftward shift in the psychometric function, occurred across positions but was only modulated by the attentional cue in subjects who trained in the top/bottom position. To the extent that subjects learned, these improvements also transferred to the untrained spatial position. A follow-up experiment examined interactions between learning and both space- and feature-based attention. Subjects trained on a 2IFC motion coherence detection task and were given a feature cue, a space cue, both cues, or an uninformative neutral cue on each trial. Preliminary data suggest that initial performance was best with the combined cue and the spatial cue and initial performance on feature-cued trials was equivalent to neutral trials. However, performance on the feature-cued trials relative to neutral trials improved with learning and this attention effect transferred across spatial position. Together, these data suggest that training can enhance feature-based attentional modulations and that these enhancements transfer across spatial locations.
Meeting abstract presented at VSS 2014