In the Stroop task, congruency effects (i.e., the color-naming latency difference between incongruent stimuli, e.g., the word BLUE written in the color red, and congruent stimuli, e.g., RED in red) ...are smaller in a list in which incongruent trials are frequent than in a list in which incongruent trials are infrequent. The traditional explanation for this pattern is that a conflict-monitoring mechanism adjusts attention to task-relevant versus task-irrelevant information in a proactive fashion based on list-wide conflict frequency. More recently, however, multiple alternative explanations have been advanced that could explain the pattern without invoking this form of proactive control: Individuals might only adapt to conflict frequency specific to individual items (as opposed to list-wide conflict frequency), they could learn word-color contingencies (e.g., how often a particular word and color are paired), or they could adapt attention based on whether the words are informative of the color (even if many word-color pairings are incongruent) in the list as a whole. To examine this issue, we designed a new paradigm that should eliminate any impact of these alternative mechanisms. In that paradigm, the proportion of neutral (e.g., XXX in red) and incongruent stimuli was manipulated across lists. Paralleling the results in the original paradigm, there was a smaller latency difference between incongruent and neutral stimuli in a list in which incongruent trials were frequent than in a list in which incongruent trials were infrequent, suggesting that proactive control in response to list-wide conflict frequency is a process humans can and do use.
In the standard Proportion-Congruent (PC) paradigm, performance is compared between a list containing mostly congruent (MC) stimuli (e.g., the word RED in the color red in the Stroop task; Stroop, ...1935) and a list containing mostly incongruent (MI) stimuli (e.g., the word BLUE in red). The PC effect, the finding that the congruency effect (i.e., the latency difference between incongruent and congruent stimuli) is typically larger in an MC list, has been interpreted by the popular conflict-monitoring account (Botvinick et al., 2001) as reflecting a proactive process whereby attention to task-relevant information is adapted based on how frequently conflict from task-irrelevant information arises. Recently, however, alternative accounts of the PC effect have emerged that assume either that the PC effect reflects processes other than proactive conflict adaptation (e.g., stimulus-response contingency learning) or that proactive conflict adaptation is only engaged as a last resort (e.g., when contingency learning cannot be used to minimize interference). We examined these ideas in three experiments in which proactive conflict adaptation could be evaluated independently from processes that are normally confounded with it in the PC paradigm, while still allowing those processes, particularly contingency learning, to be used to minimize interference. Consistent with the conflict-monitoring account of the PC effect, but inconsistent with all the alternative accounts of the PC effect, evidence for proactive conflict adaptation emerged in all experiments. Although multiple processes may be engaged in the PC paradigm, this paradigm remains a valid tool for examining proactive conflict adaptation, its typical use.
Previous masked translation priming studies, especially those with different-script bilinguals, have shown that cognates provide more priming than noncognates, a difference attributed to cognates' ...phonological similarity. In our experiments employing a word naming task, we examined this issue for Chinese-Japanese bilinguals in a slightly different way, using same-script cognates as primes and targets. In Experiment 1, significant cognate priming effects were observed. The sizes of the priming effects were, however, statistically not different for phonologically similar (e.g., 信赖/xin4lai4/-信頼/shiNrai/) and dissimilar cognate pairs (e.g., 保证/bao3zheng4/-保証 /hoshoR/), suggesting no impact of phonological similarity. In Experiment 2, using exclusively Chinese stimuli, we demonstrated a significant homophone priming effect using two-character logographic primes and targets, indicating that phonological priming is possible for two-character Chinese targets. However, priming only emerged for pairs that had the same tone pattern (e.g., 守卫/shou3wei4/-首位/shou3wei4/), suggesting that a match in lexical tone is crucial for observing phonologically based priming in that situation. Therefore, Experiment 3 involved phonologically similar Chinese-Japanese cognate pairs in which the similarity of their suprasegmental phonological features (i.e., lexical tone and pitch-accent information) was varied. Priming effects were statistically not different for tone/accent similar pairs (e.g., 关心/guan1xin1/-関心/kaNsiN/) and dissimilar pairs (e.g., 满足/man3zu2/-満足/maNzoku/). Our results indicate that phonological facilitation is not involved in producing cognate priming effects for Chinese-Japanese bilinguals. Possible explanations, based on underlying representations of logographic cognates, are discussed.
Conflict-induced control refers to humans’ ability to regulate attention in the processing of target information (e.g., the color of a word in the color-word Stroop task) based on experience with ...conflict created by distracting information (e.g., an incongruent color word), and to do so either in a proactive (preparatory) or a reactive (stimulus-driven) fashion. Interest in conflict-induced control has grown recently, as has the awareness that effects attributed to those processes might be affected by conflict-unrelated processes (e.g., the learning of stimulus-response associations). This awareness has resulted in the recommendation to move away from traditional interference paradigms with small stimulus/response sets and towards paradigms with larger sets (at least four targets, distractors, and responses), paradigms that allow better control of non-conflict processes. Using larger sets, however, is not always feasible. Doing so in the Stroop task, for example, would require either multiple arbitrary responses that are difficult for participants to learn (e.g., manual responses to colors) or non-arbitrary responses that can be difficult for researchers to collect (e.g., vocal responses in online experiments). Here, we present a spatial version of the Stroop task that solves many of those problems. In this task, participants respond to one of six directions indicated by an arrow, each requiring a specific, non-arbitrary manual response, while ignoring the location where the arrow is displayed. We illustrate the usefulness of this task by showing the results of two experiments in which evidence for proactive and reactive control was obtained while controlling for the impact of non-conflict processes.
A robust finding in the Stroop literature is that congruency effects (i.e., the color-naming latency difference between color words presented in incongruent vs. congruent colors) are larger for color ...words presented most often in their congruent color than for color words presented most often in incongruent colors. However, the cause of this item-specific proportion congruent (ISPC) effect is unclear, as it might be produced by either a conflict-adaptation strategy (e.g., prepare for conflict when the word RED appears) and/or a more general learning mechanism of stimulus-response contingencies (e.g., prepare to respond blue when the word RED appears). Thus far, attempts to directly dissociate the two processes appear to indicate no role for conflict adaptation, at least in situations in which contingency learning is also possible. We re-examined this conclusion in a Stroop task in which contingency learning and item-specific conflict frequency were manipulated partially independently. In addition to a contingency-learning effect emerging for stimuli matched on conflict frequency, a conflict-adaptation effect also emerged for stimuli matched on contingency. The two effects also had different time courses, with the contingency-learning effect emerging early and remaining stable throughout the experiment and the conflict-adaptation effect arising later in the experiment. These results challenge not only the contingency-learning account of the ISPC effect, an account that denies the existence of a conflict-adaptation process, but also control accounts that assume that, although conflict-adaptation processes do exist, they are not used when contingency learning is also possible.
In interference tasks (e.g., Stroop, 1935), congruency effects are larger following a congruent versus an incongruent trial. This "congruency sequence effect" has been traditionally explained in ...terms of a conflict-monitoring mechanism that focuses attention toward relevant information when conflict has recently been experienced. More recently, it has been suggested that effects of this sort result from differences in the temporal expectancies formed following congruent trials (fast responding) versus incongruent trials (slow responding). Evidence supporting this "temporal-learning" account was recently reported for a similar effect, the finding that congruency effects are larger in a mostly congruent list than in a mostly incongruent list. That is, consistent with the idea that this "proportion-congruent effect" is based on different temporal expectancies following congruent versus incongruent trials in interference tasks, the proportion-congruent effect was eliminated on normal (i.e., immediate-response) trials when temporal expectancies were equated by requiring a delayed response on the prior trial. In two experiments, we examined whether this delayed-response procedure would have a similar impact on the congruency sequence effect. Consistent with the temporal-learning account (but not inconsistent with conflict-monitoring accounts), the congruency sequence effect on immediate-response trials was eliminated when the previous trial required a delayed response. However, no evidence supporting the temporal-learning account emerged from reanalyses of experiments requiring only immediate responses in which the response latency in the previous trial functioned as the temporal-expectancy index. Overall, the present results and analyses do not provide much evidence favoring the temporal-learning account over conflict-monitoring accounts of the congruency sequence effect.
Public Significance Statement
The "congruency sequence effect" is an effect that has traditionally been interpreted as evidence for people's ability to adapt their attention based on whether they recently had to deal with distraction. The present research examines an alternative interpretation according to which that effect depends on the point in time at which people expect to be able to make a response to a stimulus. Although this alternative interpretation gained support from one of the lines of research that we pursued, it gained no support from other lines of research.
Using two-character Chinese word targets in a masked priming lexical-decision task, Gu and colleagues (2015) demonstrated a significant transposed character (TC) priming effect. More importantly, the ...priming effect was the same size for single-morpheme words and multiple-morpheme words, suggesting that TC priming effects are not influenced by morphemic structure. In Chinese, there are, however, two types of single-morpheme words, single-morpheme simple words (e.g., 哆嗦 similar to practice in English) and single-morpheme complex words (e.g., 烂漫 similar to carpet in English in that both components are words themselves and, hence, when presented in transposed order, may activate morphological information reflecting the individual components rather than the word itself), a contrast that Gu et al. did not examine. In Experiment 1, we replicated Gu et al.'s finding of equal TC priming effects for their single- and multiple-morpheme words, although our priming effects were noticeably smaller than theirs. In Experiment 2, we split the single-morpheme condition in order to examine the TC priming effects for single-morpheme simple words, single-morpheme complex words and multiple-morpheme words. The results showed that the single-morpheme complex words produced the smallest priming effect, indicating that transposed morphemes can influence masked priming in Chinese; however, apparently only in an inhibitory fashion.
Transposing two words in a sentence (e.g. "cat" and "was" in "the white cat was big") creates a sequence that is harder to classify as ungrammatical than control sequences (e.g. "the white was cat ...slowly"), suggesting that word position coding is noisy and can be affected by syntactic expectations. In the present research, this transposed-word effect was examined more closely using Rapid Serial Visual Presentation (RSVP) formats which provided either clear temporal cues to word order but no spatial cues, or both types of cues. Compared to when all words were presented simultaneously, the two RSVP formats reduced the transposed-word effect to the same degree while having no parallel impact on another ungrammatical comparison condition involving no transposition. These results are discussed in the context of serial and parallel models of reading as well as models that propose a later processing stage for the locus of the transposed-word effect.
In interference tasks (e.g., Stroop, 1935), the difference between congruent and incongruent latencies (i.e., the "congruency" effect) is larger in trial blocks containing mostly congruent trials ...than in trial blocks containing mostly incongruent trials (the proportion-congruent PC effect). Although the PC effect has typically been interpreted as reflecting adjustments in attention toward/away from the task-irrelevant dimension (i.e., a conflict-adaptation strategy), recent research has suggested alternative accounts based on the learning of either contingencies (i.e., distractor-response associations) or of temporal expectancies (i.e., the typical response speed on previous trials), accounts in which conflict adaptation plays no role. Using the picture-word interference paradigm, we report data from two PC manipulations in which contingency learning was made impossible by using nonrepeated distractors (Experiment 1A) or both nonrepeated distractors and responses (Experiment 1B). The classic PC effect emerged in both experiments. In addition, learning of temporal expectancies could not explain the present PC effects either, as results from trial-level analyses of Experiments 1A and 1B and a nonconflict version of Experiment 1B (Experiment 2) were inconsistent with the predictions of the temporal learning account of PC effects. These results suggest that conflict adaptation remains a credible explanation for PC effects.
Public Significance Statement
This study shows that people can adapt their attention to deal with situations in which there is frequent distraction, and it rules out alternative interpretations for this behavior.
Perceptual learning accounts of orthographic coding predict that transposed-letter (TL) priming effects should be smaller when the prime and target stimuli are not presented in their canonical ...(left-to-right horizontal in English) orientation (Dehaene, Cohen, Sigman, & Vinckier, 2005; Grainger & Holcomb, 2009). In contrast, abstract letter unit accounts would propose that TL priming effects should be essentially unaffected by presenting stimuli in most unfamiliar text orientations (Witzel, Qiao, & Forster, 2011). In the present experiments, we examined masked TL priming effects with primes and targets presented in 3 different text orientations (e.g., 0°, as well as 90° and 180° rotations). Results revealed that the magnitude of the TL priming effect with native English readers was equivalent for stimuli presented in these three orientations, providing support for abstract letter unit accounts of orthographic coding.
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