Abstract
Goal: In a perceptual learning task in which observers trained with neutral cue and peripheral cue (attention) trials simultaneously, we observed that exogenous attention led to stronger perceptual learning (Carrasco, Giordano & Looser, VSS 07). Here, we compared perceptual learning for observers trained exclusively in either endogenous (sustained) attention, exogenous (transient attention), or a neutral condition. We assessed the effects of training using a speed-accuracy trade-off (SAT) procedure.
Methods: Observers performed a conjunction (orientation X spatial frequency) 2-AFC orientation discrimination task in which a cue preceded a target (3-cpd tilted Gabor) presented with 7 distracters (3-cpd vertical and 2-cpd tilted Gabors) at 8 isoeccentric locations. There were three cue conditions: exogenous (dot adjacent to target location), neutral (central dot) or endogenous (central bar indicating target location). A response tone prompted observers to respond after various lags (40–1500 ms). Observers completed 5 consecutive training sessions (1/day) then completed 3 sessions of a transfer task in which the identity of the target and one of the distracters was switched (target: 2-cpd tilted Gabor; distracters: 2-cpd vertical and 3-cpd tilted Gabors).
Results & Conclusion: In the training task perceptual learning occurred for the neutral condition for both discriminability and temporal dynamics. Exogenous and endogenous attention magnified the benefit, more so for the former than the latter. In the transfer task, performance for the neutral condition shows a decrement in both discriminability and temporal dynamics. However, performance kept improving for discriminability with both transient and sustained attention. With regard to temporal dynamics, transient attention continues to speed processing, whereas sustained attention yields performance that levels off. In conclusion, these results indicate that both types of attention improve perceptual learning, and that exogenous attention yields the strongest benefits, even though it is less effortful than endogenous attention.
Grant: NIH R01 EY016200-01A2.