Category learning in the color-word contingency learning paradigm

International audienceIn the typical color-word contingency learning paradigm, participants respond to the print color of words where each word is presented most often in one color. Learning is indicated by faster and more accurate responses when a word is presented in its usual color, relative to another color. To eliminate the possibility that this effect is driven exclusively by the familiarity of item-specific word-color pairings, we examine whether contingency learning effects can be observed also when colors are related to categories of words rather than to individual words. To this end, the reported experiments used three categories of words (animals, verbs, and professions) that were each predictive of one color. Importantly, each individual word was presented only once, thus eliminating individual color-word contingencies. Nevertheless, for the first time, a category-based contingency effect was observed, with faster and more accurate responses when a category item was presented in the color in which most of the other items of that category were presented. This finding helps to constrain episodic learning models and sets the stage for new research on category-based contingency learning

Response Modality and the Stroop Task: Are there phonological Stroop effects with manual responses?

A long-standing debate in the Stroop literature concerns whether the way we respond to the color dimension determines how we process the irrelevant dimension, or whether word processing is purely stimulus driven. Models and findings in the Stroop literature differ in their predictions about how response modes (e.g., responding manually vs. vocally) affect how the irrelevant word is processed (i.e., phonologically, semantically) and the interference and facilitation that results, with some predicting qualitatively different Stroop effects. Here, we investigated whether response mode modifies phonological facilitation produced by the irrelevant word. In a fully within-subject design, we sought evidence for the use of a serial print-to-speech prelexical phonological processing route when using manual and vocal responses by testing for facilitating effects of phonological overlap between the irrelevant word and the color name at the initial and final phoneme positions. The results showed phoneme overlap leads to facilitation with both response modes, a result that is inconsistent with qualitative differences between the two response modes

Comparing Word Processing Times in Naming, Lexical Decision, and Progressive Demasking: Evidence from Chronolex

We report performance measures for lexical decision (LD), word naming (NMG), and progressive demasking (PDM) for a large sample of monosyllabic monomorphemic French words (N = 1,482). We compare the tasks and also examine the impact of word length, word frequency, initial phoneme, orthographic and phonological distance to neighbors, age-of-acquisition, and subjective frequency. Our results show that objective word frequency is by far the most important variable to predict reaction times in LD. For word naming, it is the first phoneme. PDM was more influenced by a semantic variable (word imageability) than LD, but was also affected to a much greater extent by perceptual variables (word length, first phoneme/letters). This may reduce its usefulness as a psycholinguistic word recognition task

Do Task Sets Compete in the Stroop Task and Other Selective Attention Paradigms?

Task sets have been argued to play an important role in cognition, giving rise to the notions of needing to switch between active task sets and to control competing task sets in selective attention tasks. For example, it has been argued that Stroop interference results from two categories of conflict: informational and task (set) conflict. Informational conflict arises from processing the word and is resolved by a late selection mechanism; task conflict arises when two task sets (i.e., word reading and colour identification) compete for activation and can be construed as involving an early selection mechanism. However, recent work has argued that task set control might not be needed to explain all of the switching cost in task switching studies. Here we consider whether task conflict plays a role in selective attention tasks. In particular, we consider whether S-R associations, which lead to informational conflict, are enough on their own to explain findings attributed to task set conflict. We review and critically evaluate both the findings that provided the original impetus for proposing task conflict in selective attention tasks and more recent findings reporting negative facilitation (longer RTs to congruent than to neutral stimuli) – a unique marker of task conflict. We then provide a tentative alternative account of negative facilitation based on poor control over informational conflict and apply it to a number of paradigms including the Colour-Object interference and Affordances tasks. It is argued that invoking competition between task sets in selective attention tasks might not be necessary

EXPRESS: Onset complexity and task conflict in the Stroop task

The present study examined the extent to which a key marker of task conflict, negative facilitation, is modified by onset complexity. Negative facilitation, slower RTs to congruent stimuli than to non-lexical neutral stimuli in the Stroop task, is thought to reflect competition between the task sets of colour naming and word reading in the Stroop task (also known as task conflict). That is, it reflects competition between whole task sets, over and above any competition between specific responses associated with a stimulus. An alternative account of negative facilitation argues that it reflects the specific phonological processing differences between pronounceable (e.g., congruent) and non-pronounceable (e.g., xxxx) stimuli that are magnified by the specific task contexts that produce negative facilitation (a mostly non-lexical trial context). Here we used onset complexity to manipulate pronounceability of the irrelevant words in the Stroop task to test this alternative account. However, before applying manipulations that produce negative facilitation, we initially tested whether there was an effect of onset complexity on Stroop task performance. The results from Experiment 1 (and 3) showed that complex onsets led to larger positive facilitation and congruency effects relative to simple onsets, but did not modify incongruent or neutral word RTs. Experiment 2 directly tested whether onset complexity modifies negative facilitation and provided strong evidence for no effect of onset complexity, contrary to the alternative account predictions. The implications of the results for task conflict theory, selective attention and phonological processing in the manual response Stroop task are discussed

A mouse-tracking study of the composite nature of the Stroop effect at the level of response execution.

By forcing selection into response execution processes, the present mouse-tracking study investigated whether the ongoing process of response selection in the colour-word Stroop task is influenced by conflict and facilitation at both the level of response and stimulus. Mouse-tracking measures including partial errors provided credible evidence that both response and semantic conflict (i.e., distinct constituents of interference) contribute to the overall Stroop interference effect even after a response has been initiated. This contribution was also observed for the overall facilitation effect (that was credibly decomposed into response and semantic components in response times but not in mouse deviation measures). These results run counter to the dominant single-stage response competition models that currently fail to explain: 1) the expression of Stroop effects in measures of response execution and; 2) the composite nature of both interference and facilitation. By showing that Stroop effects-originating from multiple levels of processing-can cascade into movement parameters, the present study revealed the potential overlap between selection and execution process. It therefore calls for further theoretical efforts to account for when, where and under what conditions Stroop effects originating from different loci are controlled

The influence of response modality (manual vs. vocal) in the Stroop task

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Influence de la présentation bicolore des mots sur l’effet Stroop

First letter coloring and the Stroop effect Manwell, Roberts, and Besner (2004) recently reported the absence of a semantically based Stroop effect (i. e., slower color naming latencies for color-associated words than for colorneutral words) when a single letter was spatially precued and appeared in a different color from the rest of the word displayed as compared to condition where all letters in the display were precued and appeared in a homogeneous color. In contrast to the latter results, two experiments in the present work showed a semantically based Stroop effect in both singleletter coloring when participants were instructed to focus their attention on the first letter of the display only and to name its color. This single letter was colored differently from the rest of the word displayed in Experiment 1a, and was the only letter colored while the rest of the word displayed in grey in Experiment 1b. These different results are interpreted in a new general framework suggesting that semantic information is always automatically activated but not systematically used in visual word recognition.Manwell, Roberts et Besner (2004) ont montré récemment une absence de l’effet Stroop associé (i. e., latences de dénomination plus longues pour les mots associés aux couleurs que pour les mots neutres) lorsqu’une seule lettre était spatialement indicée et apparaissait dans une couleur différente du reste du mot. À l’inverse, les deux expériences présentées ici montrent l’effet Stroop associé lorsque les participants doivent focaliser leur attention sur la première lettre uniquement et en dénommer la couleur. Cette première lettre était colorée différemment du reste du mot dans l’Expérience 1a, et était la seule lettre colorée alors que le reste du mot apparaissait en gris dans l’Expérience 1b. Ces différents résultats sont interprétés dans un nouveau cadre théorique suggérant que l’information sémantique est toujours automatiquement activée mais pas systématiquement utilisée lors de la reconnaissance visuelle des mots.Augustinova Maria, Ferrand Ludovic. Influence de la présentation bicolore des mots sur l’effet Stroop. In: L'année psychologique. 2007 vol. 107, n°2. pp. 163-179

The influence of mere social presence on Stroop interference: New evidence from the semantically-based Stroop task

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