Learned Value Magnifies Salience-Based Attentional Capture

Visual attention is captured by physically salient stimuli (termed salience-based attentional capture), and by otherwise task-irrelevant stimuli that contain goal-related features (termed contingent attentional capture). Recently, we reported that physically nonsalient stimuli associated with value through reward learning also capture attention involuntarily (Anderson, Laurent, & Yantis, PNAS, 2011). Although it is known that physical salience and goal-relatedness both influence attentional priority, it is unknown whether or how attentional capture by a salient stimulus is modulated by its associated value. Here we show that a physically salient, task-irrelevant distractor previously associated with a large reward slows visual search more than an equally salient distractor previously associated with a smaller reward. This magnification of salience-based attentional capture by learned value extinguishes over several hundred trials. These findings reveal a broad influence of learned value on involuntary attentional capture

The emergence of saliency and novelty responses from Reinforcement Learning principles

© Suomen työnohjaajat ry.fi=vertaisarvioimaton|en=nonPeerReviewed

Reward predictions bias attentional selection

Attention selects stimuli for perceptual and cognitive processing according to an adaptive selection schedule. It has long been known that attention selects stimuli that are task relevant or perceptually salient. Recent evidence has shown that stimuli previously associated with reward persistently capture attention involuntarily, even when they are no longer associated with reward. Here we examine whether the capture of attention by previously reward-associated stimuli is modulated by the processing of current but unrelated rewards. Participants learned to associate two color stimuli with different amounts of reward during a training phase. In a subsequent test phase, these previously rewarded color stimuli were occasionally presented as to-be-ignored distractors while participants performed visual search for each of two differentially rewarded shape-defined targets. The results reveal that attentional capture by formerly rewarded distractors was the largest when both recently received and currently expected reward were the highest in the test phase, even though such rewards were unrelated to the color distractors. Our findings support a model in which value-driven attentional biases acquired through reward learning are maintained via the cognitive mechanisms involved in predicting future rewards

Valuable orientations capture attention

Visual attention has long been known to be drawn to stimuli that are physically salient or congruent with task-specific goals. Several recent studies have shown that attention is also captured by stimuli that are neither salient nor task relevant, but that are rendered in a colour that has previously been associated with reward. We investigated whether another feature dimension—orientation—can be associated with reward via learning and thereby elicit value-driven attentional capture. In a training phase, participants received a monetary reward for identifying the colour of Gabor patches exhibiting one of two target orientations. A subsequent test phase in which no reward was delivered required participants to search for Gabor patches exhibiting one of two spatial frequencies (orientation was now irrelevant to the task). Previously rewarded orientations robustly captured attention. We conclude that reward learning can imbue features other than colour—in this case, specific orientations—with persistent value

Behavioral Results for the Test Phase of Experiment 1.

<p>Mean response time ± within-subjects s.e.m. for each distractor condition over the course of the test phase. The difference in RT on trials containing a high-value vs. a low-value distractor represents the effect of learned value on salience-driven attentional capture.</p

Response times (in milliseconds) and error rates by distractor condition for Experiments 1 and 2.

<p>Error terms, in parentheses, reflect the within-subjects standard error of the mean (s.e.m.).</p

Behavioral Results for the Training Phase of Experiment 1.

<p>Mean response time ± within-subjects s.e.m. for high- and low-reward targets over the course of the training phase. Only the main effect of trial block was significant [<i>F</i>(9,153) = 4.92, <i>p</i><.001, η<i>_p</i>² = .224].</p

Behavioral Results for the Test Phase of Experiment 2.

<p>Mean response time ± within-subjects s.e.m. for each distractor condition over the course of the test phase.</p

Behavioral Task.

<p>Sequence of events and time course for a trial during training (<i>a</i>) and at test (<i>b</i>) in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0027926#s2" target="_blank">Experiment 1</a>.</p