A horse of a different color: Stroop interference patterns with transformed words

Journal of Experimental Psychology Human Perception & Performance (Impact Factor: 3.36). 11/1984; 10(5):622-39. DOI: 10.1037/0096-1523.10.5.622
Source: PubMed


Four experiments investigated Stroop interference using geometrically transformed words. Over experiments, reading was made increasingly difficult by manipulating orientation uncertainty and the number of noncolor words. As a consequence, time to read color words aloud increased dramatically. Yet, even when reading a color word was considerably slower than naming the color of ink in which the word was printed, Stroop interference persisted virtually unaltered. This result is incompatible with the simple horse race model widely used to explain color-word interference. When reading became extremely slow, a reversed Stroop effect--interference in reading the word due to an incongruent ink color--appeared for one transformation together with the standard Stroop interference. Whether or not the concept of automaticity is invoked, relative speed of processing the word versus the color does not provide an adequate overall explanation of the Stroop phenomenon.

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Available from: Kevin Niall Dunbar
    • "Because word reading is faster than color naming, the word information arrives at the response buffer before the color information and thus competes with the color for output. However, explanations only in terms of the difference in speed between word reading and color naming are now viewed as inadequate in light of studies that have manipulated the relative speed and practice for the relevant and irrelevant dimensions of the stimulus.[1819] "
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    ABSTRACT: The Stroop paradigm evaluates susceptibility to interference and is sensitive to dysfunction in frontal lobes and drug effects. The aim of the present study was to establish a simple and reliable computerized version of Stroop color-word test, which can be used for screening of various psychotropic drugs. The standardized method was followed in all cases, by recording the reaction time (RT) in msec in 24 healthy participants using computerized version of Stroop color-word test. Reproducibility of the test procedure was evaluated by recording the RTs by a single experimenter on two sessions (interday reproducibility). Validity of the model was further tested by evaluating the psychotropic effect of Zolpidem 5 mg, Caffeine 500 mg, or Placebo on 24 healthy subjects in a randomized, double blind three-way crossover design. The method was found to produce low variability with coefficient of variation less than 10%. Interday reproducibility was very good as shown by Bland-Altman plot with most of the values within ±2SD. There was a significant increase in RTs in Stroop performance with Zolpidem at 1 hr and 2 hrs; in contrast, caffeine significantly decreased RTs in Stroop performance at 1 hr only compared to placebo. The Stroop color-word recording and analysis system is simple, sensitive to centrally acting drug effects, and has potential for future experimental psychomotor assessment studies.
    No preview · Article · Apr 2013 · Indian Journal of Psychological Medicine
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    • "It does appear that models which place the primary interference toward the far end of 12 We cannot further expand on our ideas within the confines of this study or address several seemingly inconsistent results that come to mind from the vast Stroop literature. For instance, Dunbar and MacLeod (1984) found that the Stroop effect was unaffected when the words were presented in a transformed typography and/or in a vertical spatial position (both of which slowed down reading). Consequently, the authors questioned the relative speed of processing account of the Stroop effect. "
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    ABSTRACT: A huge set of focused attention experiments show that when presented with color words printed in color, observers report the ink color faster if the carrier word is the name of the color rather than the name of an alternative color, the Stroop effect. There is also a large number (although not so numerous as the Stroop task) of so-called "redundant targets studies" that are based on divided attention instructions. These almost always indicate that observers report the presence of a visual target ('redness' in the stimulus) faster if there are two replications of the target (the word RED in red ink color) than if only one is present (RED in green or GREEN in red). The present set of four experiments employs the same stimuli and same participants in both designs. Evidence supports the traditional interference account of the Stroop effect, but also supports a non-interference parallel processing account of the word and the color in the divided attention task. Theorists are challenged to find a unifying model that parsimoniously explains both seemingly contradictory results.
    Full-text · Article · Oct 2009 · Cognition
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    • "The original Stroop experiment consisted of incongruent and neutral trials (Stroop 1935), however since the introduction of the congruent condition (Dalrymple-Alford and Budayer 1966), many experiments use this condition as a baseline (Pardo et al. 1990, Carter et al. 1995, Posner et al. 2002) for calculating the Stroop effect. Since the facilitation effect is still debatable [viewed sometimes as a byproduct of faster color reading (in congruent condition) than color naming (in neutral condition)] (Dunbar and MacLeod 1984), and minimal compared to interference effect, and since the functional experiments using neutral and congruent conditions as baseline give virtually the same results of Stroop effect, for the sake of experiment simplicity we decided to use congruent and incongruent conditions to calculate " Stroop effect " as a difference between incongruent and congruent reaction times. Subjects were asked to name the ink color of colored words (e.g., RED in blue ink). "
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    ABSTRACT: Attention and memory deficits are among the most prominent cognitive disturbances observed in schizophrenia. It has been suggested that a disruption in anatomical connectivity between areas involved in attentional control might be responsible for these abnormalities. We used Diffusion Tensor Tractography and Color Stroop/Negative Priming(NP) paradigm to investigate integrity of the Cingulum Bundle(CB), the main white matter tract interconnecting these regions, and its relationship with executive functions in patients with schizophrenia and matched controls. The Fractional Anisotropy(FA), was calculated along the CB pathways, and correlated with reaction times for each Stroop item, and both Stroop, and NP effects. Patients with schizophrenia demonstrated decreased CB integrity and diminished NP effect, compared with controls, but both groups showed Stroop effect. For patients only, reaction times for every item, as well as for Stroop effect, correlated with left CB FA. These findings suggest that CB integrity disruptions might compromise the executive processes in schizophrenia.
    Full-text · Article · Jun 2009 · Brain Imaging and Behavior
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