Value-driven attentional capture

It has long been known that the control of attention in visual search depends both on voluntary, top-down deployment according to context-specific goals, and on involuntary, stimulus-driven capture based on the physical conspicuity of perceptual objects. Recent evidence suggests that pairing target stimuli with reward can modulate the voluntary deployment of attention, but there is little evidence that reward modulates the involuntary deployment of attention to task-irrelevant distractors. We report several experiments that investigate the role of reward learning on attentional control. Each experiment involved a training phase and a test phase. In the training phase, different colors were associated with different amounts of monetary reward. In the test phase, color was not task-relevant and participants searched for a shape singleton; in most experiments no reward was delivered in the test phase. We first show that attentional capture by physically salient distractors is magnified by a previous association with reward. In subsequent experiments we demonstrate that physically inconspicuous stimuli previously associated with reward capture attention persistently during extinction--even several days after training. Furthermore, vulnerability to attentional capture by high-value stimuli is negatively correlated across individuals with working memory capacity and positively correlated with trait impulsivity. An analysis of intertrial effects reveals that value-driven attentional capture is spatially specific. Finally, when reward is delivered at test contingent on the task-relevant shape feature, recent reward history modulates value-driven attentional capture by the irrelevant color feature. The influence of learned value on attention may provide a useful model of clinical syndromes characterized by similar failures of cognitive control, including addiction, attention-deficit/hyperactivity disorder, and obesity.

Previous research demonstrated that associating a stimulus with value (e.g., monetary reward) can increase its salience and induce a value-driven attentional capture when it becomes a distractor in visual search. Here we investigate to what extent this value-driven attentional capture is affected by the perceptual salience of the stimulus and the type of value attached to the stimulus. We showed that a color previously associated with monetary gain or loss impaired subsequent search for a unique shape target (Experiment 1), but a shape that was previously associated with gain or loss did not affect search for a unique color target (Experiments 2A and 2B), indicating that the associative learning of value and the effect of value-driven attentional capture are modulated by the perceptual salience of a stimulus. The value-based attentional capture recurred when the shape distractor was paired more strongly with monetary loss (Experiment 2C) or was paired with pain stimulation (Experiment 3), indicating that when the value is significant enough to an organism, it can render a perceptually less salient stimulus capable of capturing attention in visual search. These results suggest that value interacts with perceptual salience to modulate the value-based attentional capture, and the extent of value information capturing attention depends on the biological significance of the value attribute.

Despite being physically nonsalient and task-irrelevant, objects rendered in a color that once signaled monetary reward reflexively capture attention during visual search, a phenomenon known as value-driven attentional capture (VDAC). However, it remains a subject of empirical controversy whether learned reward associations are necessary to driving subsequent attentional capture: VDAC-like effects have been observed when accuracy-based feedback alone was used during the VDAC training phase, resulting in attentional capture by objects that were never associated with monetary reward; perplexingly, the presence of these VDAC-like effects in the literature conflicts with those of a number of control studies in which no such capture has been observed, leaving the issue currently unresolved. In this Registered Report, we present new empirical evidence of attentional capture by unrewarded former targets following limited accuracy-based training. We proposed to replicate these results in an independent sample and to test an empirically derived hypothesis concerning a methodological difference between the studies that have shown VDAC-like effects with accuracy-based feedback and those that have not. In short, we found no evidence that this methodological difference accounts for the inconsistencies in the literature, but our replication efforts were overwhelmingly successful, thus reinvigorating debate about the role that selection history may play in value-driven attentional capture.

Feature-reward association elicits value-driven attentional capture (VDAC) regardless of the task relevance of associated features. What are the necessary conditions for feature-reward associations in VDAC? Recent studies claim that VDAC is based on Pavlovian conditioning. In this study, we manipulated the temporal relationships among feature, response, and reward in reward learning to elucidate the necessary components of VDAC. We presented reward-associated features in a variety of locations in a flanker task to form a color-reward association (training phase) and then tested VDAC in a subsequent visual search task (test phase). In Experiment 1, we showed reward-associated features in a task display requiring response selection and observed VDAC, consistent with most previous studies. In Experiment 2, features presented at a fixation display before a task display also induced VDAC. Moreover, in Experiment 3, we reduced the time interval between features and rewards so that features appeared after a task display and we obtained marginally significant VDAC. However, no VDAC was observed when features and rewards were simultaneously presented in a feedback display in Experiments 4 and 5, suggesting that a direct association between feature and reward is not sufficient for VDAC. These results are in favor of the idea that response selection does not mediate feature-reward association in VDAC. Moreover, the evidence suggests that the time interval of feature and reward is flexible with some restriction in the learning of feature-reward association. The present study supports the hypothesis that theories of Pavlovian conditioning can account for feature-reward association in VDAC.

Attention priority of reward history, also called value-driven attentional capture (VDAC), is different from that of saliency or contingency. The magnitude of VDAC was found to be correlated with working memory capacity, but how cognitive control interacts with the attentional allocation of reward association is not clear. Here, we examined whether the distraction by learned color-reward association would change under different working memory load conditions. Participants were first trained with color-reward associations by searching a green/red circle with low/high reward. Then, during the test session, participants needed to search a unique shape while a green/red shape was either presented as a distractor or not shown at all. To manipulate the working memory load in the test, a digital memory task was integrated with the visual search task in half of the trials (memory load condition), but not in the other half (no-load condition). Consistent results were found in two experiments that the magnitude of attentional capture caused by low-value distractors was larger under memory load condition than under no-load condition, while there was no enough evidence supporting the influence of memory load on attentional capture by high-value distractors. These results suggested that working memory load, which occupied part of cognitive resources, reduced the priority of target information and might also modulate the strength of reward association holding in working memory. These findings extend the knowledge regarding the influence of working memory load on attentional capture of reward and suggest that reward-induced distraction is dynamic and could be modulated by cognitive control.

Studies of selective attention typically consider the role of task goals or physical salience, but attention can also be captured by previously reward-associated stimuli, even if they are currently task irrelevant. One theory underlying this value-driven attentional capture (VDAC) is that reward-associated stimulus representations undergo plasticity in sensory cortex, thereby automatically capturing attention during early processing. To test this, we used magnetoencephalography to probe whether stimulus location and identity representations in sensory cortex are modulated by reward learning. We furthermore investigated the time course of these neural effects, and their relationship to behavioral VDAC. Male and female human participants first learned stimulus–reward associations. Next, we measured VDAC in a separate task by presenting these stimuli in the absence of reward contingency and probing their effects on the processing of separate target stimuli presented at different time lags. Using time-resolved multivariate pattern analysis, we found that learned value modulated the spatial selection of previously rewarded stimuli in posterior visual and parietal cortex from ∼260 ms after stimulus onset. This value modulation was related to the strength of participants' behavioral VDAC effect and persisted into subsequent target processing. Importantly, learned value did not influence cortical signatures of early processing (i.e., earlier than ∼200 ms); nor did it influence the decodability of stimulus identity. Our results suggest that VDAC is underpinned by learned value signals that modulate spatial selection throughout posterior visual and parietal cortex. We further suggest that VDAC can occur in the absence of changes in early visual processing in cortex.SIGNIFICANCE STATEMENT Attention is our ability to focus on relevant information at the expense of irrelevant information. It can be affected by previously learned but currently irrelevant stimulus–reward associations, a phenomenon termed “value-driven attentional capture” (VDAC). The neural mechanisms underlying VDAC remain unclear. It has been speculated that reward learning induces visual cortical plasticity, which modulates early visual processing to capture attention. Although we find that learned value modulates spatial signals in visual cortical areas, an effect that correlates with VDAC, we find no relevant signatures of changes in early visual processing in cortex.

Human visual attention is strongly influenced by rewards, affecting both top-down and bottom-up attentional processes. The value-driven attentional capture (VDAC) paradigm, introduced by Anderson et al. (2011b), has had a significant impact on the field of visual attention. In particular, it has facilitated scientific understanding of how a previously task-irrelevant stimulus (e.g., a red circle) paired with monetary or social rewards can capture attention when presented as a distractor (e.g., red) in subsequent non-reward shape-search tasks (e.g., diamond). However, recent work using the traditional VDAC paradigm has produced controversial research findings. The present systematic review, including 23 publications (52 experiments), investigated whether a) reward-associated features might influence attentional capture subsequently, and b) the VDAC paradigm provides a reliable experimental approach to examine the reward-attention relationship. The analysis of these VDAC experiments has revealed methodological concerns, including history-selection confounds, issues with color-reward associations, color-luminance effects and preferences, and low statistical power. Reward-associated features influence attentional capture, however, the current VDAC paradigm provides weak experimental effects. Critically, the literature review provides a concise evaluation of the VDAC paradigm and offers potential directions for further experimental research.

Findings from an increasingly large number of studies have been used to argue that attentional capture can be dependent on the learned value of a stimulus, or value-driven. However, under certain circumstances attention can be biased to select stimuli that previously served as targets, independent of reward history. Value-driven attentional capture, as studied using the training phase-test phase design introduced by Anderson and colleagues, is widely presumed to reflect the combined influence of learned value and selection history. However, the degree to which attentional capture is at all dependent on value learning in this paradigm has recently been questioned. Support for value-dependence can be provided through one of two means: (1) greater attentional capture by prior targets following rewarded training than following unrewarded training, and (2) greater attentional capture by prior targets previously associated with high compared to low value. Using a variant of the original value-driven attentional capture paradigm, Sha and Jiang (Attention, Perception, and Psychophysics, 78, 403-414, 2016) failed to find evidence of either, and raised criticisms regarding the adequacy of evidence provided by prior studies using this particular paradigm. To address this disparity, here we provided a stringent test of the value-dependence hypothesis using the traditional value-driven attentional capture paradigm. With a sufficiently large sample size, value-dependence was observed based on both criteria, with no evidence of attentional capture without rewards during training. Our findings support the validity of the traditional value-driven attentional capture paradigm in measuring what its name purports to measure.

Recent research reported that task-irrelevant colors captured attention if these colors previously served as search targets and received high monetary reward. We showed that both monetary reward and value-independent mechanisms influenced selective attention. Participants searched for two potential target colors among distractor colors in the training phase. Subsequently, they searched for a shape singleton in a testing phase. Experiment 1 found that participants were slower in the testing phase if a distractor of a previous target color was present rather than absent. Such slowing was observed even when no monetary reward was used during training. Experiment 2 associated monetary rewards with the target colors during the training phase. Participants were faster finding the target associated with higher monetary reward. However, reward training did not yield value-dependent attentional capture in the testing phase. Attentional capture by the previous target colors was not significantly greater for the previously high-reward color than the previously low or no-reward color. These findings revealed both the power and limitations of monetary reward on attention. Although monetary reward can increase attentional priority for the high-reward target during training, subsequent attentional capture effects may not be reward-based, but reflect, in part, attentional capture by previous targets.

Recent evidence shows that distractors that signal high compared to low reward availability elicit stronger attentional capture, even when this is detrimental for task-performance. This suggests that simply correlating stimuli with reward administration, rather than their instrumental relationship with obtaining reward, produces value-driven attentional capture. However, in previous studies, reward delivery was never response independent, as only correct responses were rewarded, nor was it completely task-irrelevant, as the distractor signaled the magnitude of reward that could be earned on that trial. In two experiments, we ensured that associative reward learning was completely response independent by letting participants perform a task at fixation, while high and low rewards were automatically administered following the presentation of task-irrelevant colored stimuli in the periphery (Experiment 1) or at fixation (Experiment 2). In a following non-reward test phase, using the additional singleton paradigm, the previously reward signaling stimuli were presented as distractors to assess truly task-irrelevant value driven attentional capture. The results showed that high compared to low reward-value associated distractors impaired performance, and thus captured attention more strongly. This suggests that genuine Pavlovian conditioning of stimulus-reward contingencies is sufficient to obtain value-driven attentional capture. Furthermore, value-driven attentional capture can occur following associative reward learning of temporally and spatially task-irrelevant distractors that signal the magnitude of available reward (Experiment 1), and is independent of training spatial shifts of attention towards the reward signaling stimuli (Experiment 2). This confirms and strengthens the idea that Pavlovian reward learning underlies value driven attentional capture.

Recent evidence shows that distractors that signal high compared to low reward availability elicit stronger attentional capture, even when this is detrimental for task-performance. This suggests that simply correlating stimuli with reward administration, rather than their instrumental relationship with obtaining reward, produces value-driven attentional capture. However, in previous studies, reward delivery was never response independent, as only correct responses were rewarded, nor was it completely task-irrelevant, as the distractor signaled the magnitude of reward that could be earned on that trial. In two experiments, we ensured that associative reward learning was completely response independent by letting participants perform a task at fixation, while high and low rewards were automatically administered following the presentation of task-irrelevant colored stimuli in the periphery (Experiment 1) or at fixation (Experiment 2). In a following non-reward test phase, using the additional singleton paradigm, the previously reward signaling stimuli were presented as distractors to assess truly task-irrelevant value driven attentional capture. The results showed that high compared to low reward-value associated distractors impaired performance, and thus captured attention more strongly. This suggests that genuine Pavlovian conditioning of stimulus-reward contingencies is sufficient to obtain value-driven attentional capture. Furthermore, value-driven attentional capture can occur following associative reward learning of temporally and spatially task-irrelevant distractors that signal the magnitude of available reward (Experiment 1), and is independent of training spatial shifts of attention towards the reward signaling stimuli (Experiment 2). This confirms and strengthens the idea that Pavlovian reward learning underlies value driven attentional capture.

Values learned through previous experiences of reward can later modulate attentional capture if associated with a distractor in singleton search tasks (value-driven attentional capture; VDAC). Moreover, it has been shown that re-encountering distractor features can facilitate performance or reduce attentional capture (sequential effects). However, little is known about how sequential effects and attentional capture are jointly modulated by learned distractor value. Here, we examined the role of learned reward in sequential modulation of attentional capture. In two experiments we used a VDAC paradigm, varying the type of reward (monetary vs. sustainability-related). After associating letter colors with a high or low reward, or none at all, in a flanker task (learning phase), in a subsequent singleton task (test phase) we manipulated the effects of distractor value of the present and of the previous trial on attentional capture. In both experiments repetition of the same distractor value from trial N-1 to trial N was associated with faster responses, and reward value did not modulate this facilitation. In addition, attentional capture by rewarded, compared with unrewarded, distractors was observed when the preceding trial was unrewarded. Value-signaling distractors, if re-encountered, reduced attentional capture in the current trial, and this happened even for rewarded distractors of different values (e.g., high value followed by low value, and vice versa). These results suggest that, for different forms of incentives, repetition of previously rewarded distractors and attentional capture by the current reward interact in modulating the processing of learned values.

Attention and working memory (WM) have previously been shown to interact closely when sensory information is being maintained. However, when non-sensory information is maintained in WM, the relationship between WM and sensory attention may be less strong. In the current study, we used electroencephalography to evaluate whether value-driven attentional capture (i.e., allocation of attention to a task-irrelevant feature previously associated with a reward) and its effects on either sensory or non-sensory WM performance might be greater than the effects of salient, non-reward-associated stimuli. In a training phase, 19 participants learned to associate a color with reward. Then, participants were presented with squares and encoded their locations into WM. Participants were instructed to convert the spatial locations either to another type of sensory representation or to an abstract, relational type of representation. During the WM delay period, task-irrelevant distractors, either previously-rewarded or non-rewarded, were presented, with a novel color distractor in the other hemifield. The results revealed lower alpha power and larger N2pc amplitude over posterior electrode sides contralateral to the previously rewarded color, compared to ipsilateral. These effects were mainly found during relational WM, compared to sensory WM, and only for the previously rewarded distractor color, compared to a previous non-rewarded target color or novel color. These effects were associated with modulations of WM performance. These results appear to reflect less capture of attention during maintenance of specific location information, and suggest that value-driven attentional capture can be mitigated as a function of the type of information maintained in WM.

Value-driven attentional capture (VDAC) refers to a phenomenon by which stimulus features associated with greater reward value attract more attention than those associated with smaller reward value. To date, the majority of VDAC research has revealed that the relationship between reward history and attentional allocation follows associative learning rules. Accordingly, a mathematical implementation of associative learning models and multiple comparison between them can elucidate the underlying process and properties of VDAC. In this study, we implemented the Rescorla-Wagner, Mackintosh (Mac), Schumajuk-Pearce-Hall (SPH), and Esber-Haselgrove (EH) models to determine whether different models predict different outcomes when critical parameters in VDAC were adjusted. Simulation results were compared with experimental data from a series of VDAC studies by fitting two key model parameters, associative strength (V) and associability (α), using the Bayesian information criterion as a loss function. The results showed that SPH-V and EH- α outperformed other implementations of phenomena related to VDAC, such as expected value, training session, switching (or inertia), and uncertainty. Although V of models were sufficient to simulate VDAC when the expected value was the main manipulation of the experiment, α of models could predict additional aspects of VDAC, including uncertainty and resistance to extinction. In summary, associative learning models concur with the crucial aspects of behavioral data from VDAC experiments and elucidate underlying dynamics including novel predictions that need to be verified.

Stimuli associated with monetary reward can become powerful cues that effectively capture visual attention. We examined whether such value-driven attentional capture can be induced with monetary feedback in the absence of an expected cash payout. To this end, we implemented images of U.S. dollar bills as reward feedback. Participants knew in advance that they would not receive any money based on their performance. Our reward stimuli-$5 and $20 bill images-were thus dissociated from any practical utility. Strikingly, we observed a reliable attentional capture effect for the mere images of bills. Moreover, this finding generalized to Monopoly money. In two control experiments, we found no evidence in favor of nominal or symbolic monetary value. Hence, we claim that bill images are special monetary representations, such that there are strong associations between the defining visual features of bills and reward, probably due to a lifelong learning history. Together, we show that the motivation to earn cash plays a minor role when it comes to monetary rewards, while bill-defining visual features seem to be sufficient. These findings have the potential to influence human factor applications, such as gamification, and can be extended to novel value systems, such as the electronic cash Bitcoin being developed for use in mobile banking. Finally, our procedure represents a proof of concept on how images of money can be used to conserve expenditures in the experimental context.