The relative attractiveness of distractors and targets affects the coming and going of item-specific control: Evidence from flanker tasks

The role of spatial uncertainty in the context-specific proportion congruency effect

The prime-probe version of the Stroop task has been predominantly used to demonstrate the context-specific proportion congruency (CSPC) effect. In this version, the location of the color is not known until its presentation, creating a spatial uncertainty for the color dimension. We propose that spatial uncertainty plays an important role in observing the CSPC effect. In this study, we investigated the role of spatial uncertainty with two experiments. In Experiment 1 (N = 53), we used a spatially separated version of the Stroop task having spatial uncertainty on the color dimension, and observed a significant CSPC effect. For Experiment 2, we conducted a preregistered prime-probe CSPC experiment with a considerably large sample (N = 128), eliminating the uncertainty of only the color dimension in one condition and both the color and the word dimensions in the other. Results showed that the CSPC effect was not observed in the first condition, while it was very small yet significant in the second condition. The Bayesian approach confirmed frequentist analyses of Experiment 1 and the first condition of Experiment 2. However, in the second condition of Experiment 2, there was no evidence regarding the existence of the CSPC effect. These findings support our claim that the spatial uncertainty of the color dimension, inherent in the prime-probe version Stroop task, contributed to the CSPC effect.

Dissociating selectivity adjustments from temporal learning-introducing the context-dependent proportion congruency effect

The list-level proportion congruency effect (PCE) and the context-specific PC (CSPC) effect are typical findings in experimental conflict protocols, which competing explanations attribute to different mechanisms. Of these mechanisms, stimulus-unspecific conflict-induced selectivity adjustments have attracted the most interest, from various disciplines. Recent methodological advances have yielded an experimental procedure for entirely ruling out all stimulus-specific alternatives. However, there is a stimulus-unspecific alternative-temporal learning-which cannot even be ruled out as the sole cause of either effect with any established experimental procedure. That is because it is very difficult to create a scenario in which selectivity adjustments and temporal learning make different predictions-with traditional approaches, it is arguably impossible. Here, we take a step towards solving this problem, and experimentally dissociating the two mechanisms. First, we present our novel approach which is a combination of abstract experimental conditions and theoretical assumptions. As we illustrate with two computational models, given this particular combination, the two mechanisms predict opposite modulations of an as yet unexplored hybrid form of the list-level PCE and the CSPC effect, which we term context-dependent PCE (CDPCE). With experimental designs that implement the abstract conditions properly, it is therefore possible to rule out temporal learning as the sole cause of stimulus-unspecific adaptations to PC, and to unequivocally attribute the latter, at least partially, to selectivity adjustments. Secondly, we evaluate methodological and theoretical aspects of the presented approach. Finally, we report two experiments, that illustrate both the promise of and a potential challenge to this approach.

Transfer of learned cognitive control settings within and between tasks

Cognitive control is modulated based on learned associations between conflict probability and stimulus features such as color. We investigated whether such learning-guided control transfers to novel stimuli and/or a novel task. In Experiments 1 and 2, participants experienced an item-specific proportion congruence (ISPC) manipulation in a Stroop (Experiment 1) or Flanker (Experiment 2) task with mostly congruent (MC) and mostly incongruent (MI) colors in training blocks. During a transfer block, participants performed the same task and encountered novel transfer stimuli paired with MC or MI colors. Evidencing within-task transfer, in both experiments, responses were faster to incongruent transfer stimuli comprising an MI color compared with an MC color. In Experiment 3, we investigated between-task transfer from Stroop to Flanker. After training with an ISPC manipulation in the Stroop task, a Flanker task was completed with the same colors but without an ISPC manipulation (i.e., 50% congruent). Responses were faster to incongruent transfer stimuli paired with the previously-MI colors compared with the previously-MC colors. Additionally, transfer was evident in the first half of the Flanker task but not the second half. The evidence for within-task transfer, in combination with the novel evidence for between-task transfer, suggests learned control settings are flexibly retrieved and executed when predictive cues signaling these control settings are encountered in novel stimuli or a novel task. Theoretical implications are discussed alongside potential neural mechanisms mediating transfer of learning-guided control.

The dominance of item learning in the location-specific proportion congruence paradigm

Prior research has shown that various cues are exploited to reactively adjust attention, and such adjustments depend on learning associations between cues and proportion congruence. This raises the intriguing question of what will be learned when more than one cue is available, a question that has implications for understanding which cue(s) will dominate in guiding reactive adjustments. Evidence from a picture-word Stroop task demonstrated that item learning dominated over location learning in a location-specific proportion congruence (LSPC) paradigm, a pattern that may explain the difficulty researchers have faced in replicating and reproducing the LSPC effect. One goal was to reproduce this pattern using a non-overlapping two-item set design that more closely matched prior studies, and another goal was to examine generalisability of the pattern to two other tasks. Using a prime-probe, colour-word Stroop task (Experiment 1), and a flanker task (Experiment 2), we again found clear dominance of item learning. In Experiment 3, we attempted to disrupt item learning and promote location learning by using a counting procedure that directed participants' attention to location. Once again, we found the same pattern of item dominance. In addition, in none of the experiments did we find evidence for conjunctive (location-item) learning. Collectively, the findings suggest item learning is neither design- or task-specific; rather, it is robust, reliable, and not easily disrupted. Discussion centres on factors dictating dominance of item- over location-based adjustments and implications for the broader literature on LSPC effects.

Both task-irrelevant and task-relevant information trigger reactive conflict adaptation in the item-specific proportion-congruent paradigm

Adapting attention flexibly is a fundamental ability of the human control system. In the color-word Stroop task, for example, congruency effects are typically smaller for colors and words that appear mainly in incongruent stimuli (mostly-incongruent items) than for colors and words that appear mainly in congruent stimuli (mostly-congruent items). At least part of this item-specific proportion-congruent (ISPC) effect is due to a process of reactive conflict adaptation that affords higher selectivity (i.e., more efficient selection of task-relevant information) when a specific stimulus is presented that is frequently associated in the experiment with conflicting task-irrelevant information. What is unclear, however, is whether, normally, this stimulus-specific adaptation is triggered by the task-relevant component, the task-irrelevant component, or both components of the stimulus. In two experiments, using modified color-word (Experiment 1) and spatial (Experiment 2) Stroop tasks that allowed task-relevant and task-irrelevant triggering processes to be dissociated, we found that the two processes have approximately equivalent impacts. Because these results were obtained in experiments imposing no limitations on the processes potentially contributing to the ISPC effect, these results challenge claims that the ISPC effect involves conflict-adaptation processes only in special situations. The ISPC effect may involve conflict-adaptation processes in most situations, with both task-relevant and task-irrelevant information triggering such processes.

Peripheral vision in real-world tasks: A systematic review

Peripheral vision is fundamental for many real-world tasks, including walking, driving, and aviation. Nonetheless, there has been no effort to connect these applied literatures to research in peripheral vision in basic vision science or sports science. To close this gap, we analyzed 60 relevant papers, chosen according to objective criteria. Applied research, with its real-world time constraints, complex stimuli, and performance measures, reveals new functions of peripheral vision. Peripheral vision is used to monitor the environment (e.g., road edges, traffic signs, or malfunctioning lights), in ways that differ from basic research. Applied research uncovers new actions that one can perform solely with peripheral vision (e.g., steering a car, climbing stairs). An important use of peripheral vision is that it helps compare the position of one’s body/vehicle to objects in the world. In addition, many real-world tasks require multitasking, and the fact that peripheral vision provides degraded but useful information means that tradeoffs are common in deciding whether to use peripheral vision or move one’s eyes. These tradeoffs are strongly influenced by factors like expertise, age, distraction, emotional state, task importance, and what the observer already knows. These tradeoffs make it hard to infer from eye movements alone what information is gathered from peripheral vision and what tasks we can do without it. Finally, we recommend three ways in which basic, sport, and applied science can benefit each other’s methodology, furthering our understanding of peripheral vision more generally.

Meaningful boundaries create boundary conditions for control

Recent research demonstrated that control states learned via experience in inducer locations were retrieved in novel, unbiased (i.e., diagnostic) locations positioned nearby. Such transfer has been observed even in the presence of a visual boundary (a line) separating inducer and diagnostic locations. One aim of the present study was to assess whether a meaningful boundary might disrupt retrieval of control states in diagnostic locations. Supporting this possibility, in Experiment 1 learned control states did not transfer from inducer locations superimposed on a university's quad to diagnostic locations superimposed on buildings outside the quad. Similarly, in Experiment 2 transfer was not observed for diagnostic locations positioned on a track outside of the field where inducer locations were positioned; however, transfer was also not observed for diagnostic locations on the field (inside the boundary). The latter finding helped motivate Experiments 3a and 3b, which tackled the second aim by examining whether a meaningful boundary might attenuate learning of control states for inducer locations within the boundary. Consistent with this hypothesis, a CSPC effect was observed only when a meaningful boundary was not present. Taken together, the findings provide evidence that meaningful boundaries influence how conflict experiences are organized during a task thereby impacting learning and transfer of context-specific control states.

List-level control in the flanker task

Current theories posit multiple levels of cognitive control for resolving conflict, including list-level control: the global or proactive biasing of attention across a list of trials. However, to date, evidence for pure list-level control has largely been confined to the Stroop task. Our goals were twofold: (a) test the generality of theoretical accounts by seeking evidence for list-level control in the letter flanker task, using an established method involving diagnostic items, and investigating the conditions under which list-level control may and may not be observed and (b) develop and test a potential solution to the challenge of isolating list-level control in tasks with a relatively limited set of stimuli and responses such as arrow flanker. Our key findings were that list-level control was observed for the first time in a letter flanker task on diagnostic items (Experiment 1), and it was not observed when the design was altered to encourage learning and use of simple stimulus–response associations (Experiment 2). These findings support the generalisability of current theoretical accounts positing dual-mechanisms or multiple levels of control, and the associations as antagonists to control account positing that list-level control may be a last resort, to conflict tasks besides Stroop. List-level control was also observed in the arrow flanker task using a modified design (Experiment 3), which could be extended to other conflict tasks with limited sets of stimuli (four or fewer), although this solution is not entirely free of confounds.

Evidence against conflict monitoring and adaptation: An updated review

One of the most influential ideas in recent decades in the cognitive psychology literature is conflict monitoring theory. According to this account, each time we experience a conflict (e.g., between a colour word and print colour in the Stroop task), attentional control is upregulated to minimize distraction on subsequent trials. Though influential, evidence purported to support this theoretical model (primarily, proportion congruent and congruency sequence effects) has been frequently criticized. Furious debate has centered on whether or not conflict monitoring does or does not occur and, if so, under which conditions. The present article presents an updated review of this debate. In particular, the article considers new research that either (a) seems particularly damaging for the conflict monitoring view or (b) seems to provide support for the theory. The author argues that new findings of the latter sort are still not compelling, several of which have already-demonstrated confounds and others which are plausibly confounded. Further progress has, to a greater extent than not, provided even stronger support for the position that conflict monitoring is merely an illusion. Instead, the net results can be more coherently understood in terms of (relatively) simpler learning/memory biases unrelated to conflict or attention that confound the key paradigms.

Contingency learning is reduced for high conflict stimuli

Recent theories have proposed that contingency learning occurs independent of control processes. These parallel processing accounts propose that behavioral effects originally thought to be products of control processes are in fact products solely of contingency learning. This view runs contrary to conflict-mediated Hebbian-learning models that posit control and contingency learning are parts of an interactive system. In this study we replicate the contingency learning effect and modify it to further test the veracity of the parallel processing accounts in comparison to conflict-mediated Hebbian-learning models. This is accomplished by manipulating conflict to test for an interaction, or lack thereof, between conflict and contingency learning. The results are consistent with conflict-mediated Hebbian-learning in that the addition of conflict reduces the magnitude of the contingency learning effect.

Attentional control transfers beyond the reference frame

Much research has shown that humans can allocate attentional control differentially to multiple locations based on the amount of conflict historically associated with a given location. Additionally, once established, these control settings can transfer to nearby locations that themselves have no conflict bias. Here we examined if these control settings also extend to nearby locations that are presented outside of the original frame of reference of biased stimuli. During training, participants first responded to biased flanker stimuli that were likely high conflict in one location and low conflict in another location. Then they were exposed to two sets of unbiased stimuli presented in novel transfer locations outside of the established reference frame of biased stimuli. Across three experiments, attentional control settings transferred beyond the reference frame including when there was a visual border (Experiment 2) or meaningful categorical distinction (Experiment 3) delineating training and transfer locations. These novel findings further support the idea that stimulus-driven attention control can be flexibly allocated, perhaps in a categorical manner.

Spatial proximity as a determinant of context-specific attentional settings

People implicitly encode the history of conflict associated with particular contexts and use this information to modulate attention to distractors. This manifests as a reduction in the compatibility effect in mostly incompatible locations compared to mostly compatible locations, a difference termed the context-specific proportion compatibility (CSPC) effect. CSPC effects are explained by an episodic retrieval account positing that abstract attentional settings bind to contextual cues-allowing rapid, context-driven modulation of attention. The current study interrogated this binding process by testing the influence of relative spatial proximity on the association of attentional settings with particular locations. In Experiment 1, like typical CSPC paradigms, biased locations appeared near top (e.g., mostly compatible) and bottom (e.g., mostly incompatible) edges of the screen. A novel feature was the addition of two mostly compatible (above fixation) and two mostly incompatible (below fixation) locations placed within close proximity at the middle of the screen. A CSPC effect was found for outer but not middle mostly compatible and mostly incompatible locations, suggesting the attentional setting bound to the middle locations reflected the average history of conflict (i.e., 50 % compatible) for the group of middle locations. In Experiment 2, distance between middle locations was increased, allowing middle locations to group with outer locations. The CSPC effect was found for outer and middle mostly compatible and mostly incompatible locations. Results support the relative proximity hypothesis, positing that attentional settings bound to a particular location are influenced by experience within a location and relatively close neighboring locations.

Congruency precues moderate item-specific proportion congruency effects

The item-specific proportion congruency (ISPC) effect refers to the reduction in the Stroop effect for items (e.g., words) that mostly appear in an incongruent format, as compared to items that mostly appear in a congruent format. It is thought to demonstrate reactive control of word-reading processes. In the present study, we tested the hypothesis that using explicit, trial-by-trial congruency precues to proactively guide attention during a color-word Stroop task could reduce the otherwise robust ISPC effect. In Experiment 1, the precueing manipulation was employed alongside a manipulation traditionally thought to influence proactive control of word-reading processes (i.e., list proportion congruence [list PC]). Precueing participants with 100 %-valid precues eliminated both the ISPC effect and the list PC effect. In Experiment 2, we used 70 %-valid congruency precues to direct participants to generally expect conflict or congruence on a given trial. ISPC effects were selectively reduced when the participants expected conflict. These results suggest that precueing influences engagement in proactive control and, as a result, reduces the impact of item-specific and list-based tendencies to direct attention toward or away from word reading.

Properties of context-driven control revealed through the analysis of sequential congruency effects

The context specific proportion congruent (CSPC) effect refers to the reduction in the size of the congruency effect at locations with a high proportion of incongruent trials compared to locations with a high proportion of congruent trials. The CSPC effect is commonly taken as evidence for context-driven modulation of cognitive control. Current models of context-driven control suggest that variations in the efficiency of control across locations are due to variations in the occurrence of conflict across locations (context). Moreover, these models predict that control settings are updated on a trial-to-trial basis. In Experiment 1, we investigated this prediction. If variations in conflict drive variations in the efficiency of control, and these location-based control settings are updated on each trial, then the occurrence of conflict at one location should lead to more efficient processing when the location repeats, but not when the location switches. Consistent with this prediction, we observed a sequential congruency effect when the location repeats, but not when the location switches. In Experiment 2, we looked for evidence of sequential congruency effects within and between locations in a manipulation in which an equal proportion of congruent and incongruent trials appear at each location. In contrast to the results of Experiment 1, we observed sequential congruency effects both when location repeated and when location switched. Thus, location appears to be a salient dimension on which to implement control settings when it is used in conjunction with variations in the proportion of congruent and incongruent trials.

Cognitive effort is modulated outside of the explicit awareness of conflict frequency: Evidence from pupillometry

Classic theories of cognitive control conceptualized controlled processes as slow, strategic, and willful, with automatic processes being fast and effortless. The context-specific proportion compatibility (CSPC) effect, the reduction in the compatibility effect in a context (e.g., location) associated with a high relative to low likelihood of conflict, challenged classic theories by demonstrating fast and flexible control that appears to operate outside of conscious awareness. Two theoretical questions yet to be addressed are whether the CSPC effect is accompanied by context-dependent variation in effort, and whether the exertion of effort depends on explicit awareness of context-specific task demands. To address these questions, pupil diameter was measured during a CSPC paradigm. Stimuli were randomly presented in either a mostly compatible location or a mostly incompatible location. Replicating prior research, the CSPC effect was found. The novel finding was that pupil diameter was greater in the mostly incompatible location compared to the mostly compatible location, despite participants' lack of awareness of context-specific task demands. Additionally, this difference occurred regardless of trial type or a preceding switch in location. These patterns support the view that context (location) dictates selection of optimal attentional settings in the CSPC paradigm, and varying levels of effort and performance accompany these settings. Theoretically, these patterns imply that cognitive control may operate fast, flexibly, and outside of awareness, but not effortlessly. (PsycINFO Database Record

Context-Specific Proportion Congruency Effects: An Episodic Learning Account and Computational Model

In the Stroop task, participants identify the print color of color words. The congruency effect is the observation that response times and errors are increased when the word and color are incongruent (e.g., the word “red” in green ink) relative to when they are congruent (e.g., “red” in red). The proportion congruent (PC) effect is the finding that congruency effects are reduced when trials are mostly incongruent rather than mostly congruent. This PC effect can be context-specific. For instance, if trials are mostly incongruent when presented in one location and mostly congruent when presented in another location, the congruency effect is smaller for the former location. Typically, PC effects are interpreted in terms of strategic control of attention in response to conflict, termed conflict adaptation or conflict monitoring. In the present manuscript, however, an episodic learning account is presented for context-specific proportion congruent (CSPC) effects. In particular, it is argued that context-specific contingency learning can explain part of the effect, and context-specific rhythmic responding can explain the rest. Both contingency-based and temporal-based learning can parsimoniously be conceptualized within an episodic learning framework. An adaptation of the Parallel Episodic Processing model is presented. This model successfully simulates CSPC effects, both for contingency-biased and contingency-unbiased (transfer) items. The same fixed-parameter model can explain a range of other findings from the learning, timing, binding, practice, and attentional control domains.