Repeated exposure on a visual perceptual task renders performance improvements on that task known as perceptual learning (PL). However, no current consensus exists with regard to whether features of PL are specific or generalizable, the brain locus of PL, and the mechanisms underlying task-relevant PL (TR-PL). However, a recent theory posits that PL may actually occur in different stages revealing two types of learning plasticity and may actually encompass discrepant PL findings (Shibata, Sagi & Watanabe, 2014). To experimentally dissociate these two types of learning, the type of attention must be considered as the type of attention has been shown to differentially modulate perceptual processes. Using this framework, the current study investigates the role of exogenous attention using oriented gabor patches embedded in white Gaussian noise in a 2-alternative forced choice TR-PL task. We did a between-groups manipulation of exogenous attention by manipulating effectiveness of the attentional cue during training (cue validity); 100% valid, 50% valid, neutral cue, and no cue. Pre- and post- training noise thresholds of trained and untrained orientation were obtained. It was found that training with attentional cues facilitated PL with greater improvement for 100% valid cue condition as compared to no cue condition for trained orientations but not for untrained, suggesting that learning may occur in lower-level visual processing. Although learning was found based on validity of the cue, there was no difference between groups after training. Our findings suggest that manipulation of exogenous attention modifies PL at lower levels of visual processing in the cortex.
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