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Task conflict in the Stroop task: When Stroop interference decreases as Stroop facilitation increases in a low task conflict context.

Parris BA - Front Psychol (2014)

Bottom Line: In the present study participants completed two blocks of the Stroop task, one in which the response-stimulus interval (RSI) was 3500 ms and one in which RSI was 200 ms.Such a finding would be problematic for models of Stroop effects that predict these indices of performance should be affected in tandem.A crossover interaction is reported supporting these predictions.

View Article: PubMed Central - PubMed

Affiliation: Psychology Research Centre, Faculty of Science and Technology, Bournemouth University Poole, UK.

ABSTRACT
In the present study participants completed two blocks of the Stroop task, one in which the response-stimulus interval (RSI) was 3500 ms and one in which RSI was 200 ms. It was expected that, in line with previous research, the shorter RSI would induce a low Task Conflict context by increasing focus on the color identification goal in the Stroop task and lead to a novel finding of an increase in facilitation and simultaneous decrease in interference. Such a finding would be problematic for models of Stroop effects that predict these indices of performance should be affected in tandem. A crossover interaction is reported supporting these predictions. As predicted, the shorter RSI resulted in incongruent and congruent trial reaction times (RTs) decreasing relative to a static neutral baseline condition; hence interference decreased as facilitation increased. An explanatory model (expanding on the work of Goldfarb and Henik, 2007) is presented that: (1) Shows how under certain conditions the predictions from single mechanism models hold true (i.e., when Task conflict is held constant); (2) Shows how it is possible that interference can be affected by an experimental manipulation that leaves facilitation apparently untouched; and (3) Predicts that facilitation cannot be independently affected by an experimental manipulation.

No MeSH data available.


Related in: MedlinePlus

Figure showing the effect of modifying the level of task conflict in the Stroop task. In the low task conflict context RTs to incongruent trials and congruent trials are short revealing interference and facilitation effects due to Informational conflict (IConflict) and Informational Convergence (IConver), respectively. In the high task conflict context evidence for response facilitation disappears due to the overriding influence of task conflict (TC). However, from one context to another RTs to incongruent and congruent trials are affected in tandem whilst interference and facilitation effects are affected in opposing directions.
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Figure 1: Figure showing the effect of modifying the level of task conflict in the Stroop task. In the low task conflict context RTs to incongruent trials and congruent trials are short revealing interference and facilitation effects due to Informational conflict (IConflict) and Informational Convergence (IConver), respectively. In the high task conflict context evidence for response facilitation disappears due to the overriding influence of task conflict (TC). However, from one context to another RTs to incongruent and congruent trials are affected in tandem whilst interference and facilitation effects are affected in opposing directions.

Mentions: In an attempt to account for neural loci effects and to find support for the task conflict hypothesis, Goldfarb and Henik (2007; see also Kalanthroff et al., 2013) considered whether the behavioral expression of task conflict was being masked. Goldfarb and Henik (2007) distinguished between informational and task conflict and proposed the existence of a task conflict detector, which if operating quickly enough, could resolve task conflict leaving only informational competition or convergence to determine reaction times. In contrast, if task conflict is not resolved quickly it will be expressed in RTs potentially hiding informational contributions, leading to longer RTs for congruent than neutral trials; a reverse facilitation effect. Goldfarb and Henik (2007) employed a large proportion of repeated letter string (to be referred to as non-word neutral) trials to reduce the recruitment of the task conflict detector since such trials do not have a word dimension that could activate a word reading task set, and observed the predicted reverse facilitation effect. However, when a cue was presented that indicated an upcoming task conflict trial or an upcoming letter string trial, participants were able to prepare appropriate focus on the color identification goal, reducing RTs to congruent trials and eliminating the reverse facilitation effect. The reverse facilitation effect was interpreted as being due to increased task conflict in the absence of the cue. Importantly, in their study interference and facilitation were not affected in tandem but RTs to incongruent and congruent trials with both increasing in response to greater task conflict (although it is unclear whether the former reached significance). If both increase or decrease together whilst the baseline condition remains relatively unaffected it would modify the expression of interference and facilitation effects (see Figure 1).


Task conflict in the Stroop task: When Stroop interference decreases as Stroop facilitation increases in a low task conflict context.

Parris BA - Front Psychol (2014)

Figure showing the effect of modifying the level of task conflict in the Stroop task. In the low task conflict context RTs to incongruent trials and congruent trials are short revealing interference and facilitation effects due to Informational conflict (IConflict) and Informational Convergence (IConver), respectively. In the high task conflict context evidence for response facilitation disappears due to the overriding influence of task conflict (TC). However, from one context to another RTs to incongruent and congruent trials are affected in tandem whilst interference and facilitation effects are affected in opposing directions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202807&req=5

Figure 1: Figure showing the effect of modifying the level of task conflict in the Stroop task. In the low task conflict context RTs to incongruent trials and congruent trials are short revealing interference and facilitation effects due to Informational conflict (IConflict) and Informational Convergence (IConver), respectively. In the high task conflict context evidence for response facilitation disappears due to the overriding influence of task conflict (TC). However, from one context to another RTs to incongruent and congruent trials are affected in tandem whilst interference and facilitation effects are affected in opposing directions.
Mentions: In an attempt to account for neural loci effects and to find support for the task conflict hypothesis, Goldfarb and Henik (2007; see also Kalanthroff et al., 2013) considered whether the behavioral expression of task conflict was being masked. Goldfarb and Henik (2007) distinguished between informational and task conflict and proposed the existence of a task conflict detector, which if operating quickly enough, could resolve task conflict leaving only informational competition or convergence to determine reaction times. In contrast, if task conflict is not resolved quickly it will be expressed in RTs potentially hiding informational contributions, leading to longer RTs for congruent than neutral trials; a reverse facilitation effect. Goldfarb and Henik (2007) employed a large proportion of repeated letter string (to be referred to as non-word neutral) trials to reduce the recruitment of the task conflict detector since such trials do not have a word dimension that could activate a word reading task set, and observed the predicted reverse facilitation effect. However, when a cue was presented that indicated an upcoming task conflict trial or an upcoming letter string trial, participants were able to prepare appropriate focus on the color identification goal, reducing RTs to congruent trials and eliminating the reverse facilitation effect. The reverse facilitation effect was interpreted as being due to increased task conflict in the absence of the cue. Importantly, in their study interference and facilitation were not affected in tandem but RTs to incongruent and congruent trials with both increasing in response to greater task conflict (although it is unclear whether the former reached significance). If both increase or decrease together whilst the baseline condition remains relatively unaffected it would modify the expression of interference and facilitation effects (see Figure 1).

Bottom Line: In the present study participants completed two blocks of the Stroop task, one in which the response-stimulus interval (RSI) was 3500 ms and one in which RSI was 200 ms.Such a finding would be problematic for models of Stroop effects that predict these indices of performance should be affected in tandem.A crossover interaction is reported supporting these predictions.

View Article: PubMed Central - PubMed

Affiliation: Psychology Research Centre, Faculty of Science and Technology, Bournemouth University Poole, UK.

ABSTRACT
In the present study participants completed two blocks of the Stroop task, one in which the response-stimulus interval (RSI) was 3500 ms and one in which RSI was 200 ms. It was expected that, in line with previous research, the shorter RSI would induce a low Task Conflict context by increasing focus on the color identification goal in the Stroop task and lead to a novel finding of an increase in facilitation and simultaneous decrease in interference. Such a finding would be problematic for models of Stroop effects that predict these indices of performance should be affected in tandem. A crossover interaction is reported supporting these predictions. As predicted, the shorter RSI resulted in incongruent and congruent trial reaction times (RTs) decreasing relative to a static neutral baseline condition; hence interference decreased as facilitation increased. An explanatory model (expanding on the work of Goldfarb and Henik, 2007) is presented that: (1) Shows how under certain conditions the predictions from single mechanism models hold true (i.e., when Task conflict is held constant); (2) Shows how it is possible that interference can be affected by an experimental manipulation that leaves facilitation apparently untouched; and (3) Predicts that facilitation cannot be independently affected by an experimental manipulation.

No MeSH data available.


Related in: MedlinePlus