Dilution of compatibility effects in Simon-type tasks depends on categorical similarity between distractors and diluters

Abstract

1598Performance of choice reaction tasks is influenced by the features of task stimuli, even when those features are irrelevant to response selection. For example, in Stroop tasks, response times (RTs) are longer when task-relevant and -irrelevant stimulus features are incompatible with one another than when they are compatible (Stroop, 1935; see MacLeod, 1991, for a review). In the color-naming version of the Stroop task, this conflict on incompatible trials arises when the ink color is conveyed by a word that spells out an alternative color, such as when trying to name the ink color green in the presence of the word RED. The resulting increase in RTs and errors to words with incompatible colors and meanings, as compared with those with compatible colors and meanings, is referred to as the Stroop effect. Because the Stroop effect reflects the influence of a word's meaning that is irrelevant to performing the task, the Stroop effect is often taken as evidence that word reading is automatic (Keele, 1972;Posner & Snyder, 1975). Stroop DilutionIf word reading is truly automatic in the traditional sense, it must be involuntary and free from attentional demands. However, the idea that word reading occurs without the need for attention has been called into question by the phenomenon of Stroop dilution (Kahneman & Chajczyk, 1983). In the most common Stroop dilution paradigm, participants are to respond to a target color bar by naming its color. In addition to the target stimulus, two other stimuli are presented concurrently: a distractor and a diluter. The distractor is a color word that may interfere with naming the color of the target, thereby leading to a Stroop effect. The diluter is an additional stimulus that does not interfere with color naming but may reduce the influence of the distractor. For example, when responding to the target bar by naming its color, participants' RTs are longer when the color word distractor and target bar indicate different colors rather than the same color. When a neutral word (e.g., talk) is presented simultaneously with the target and distractor, the Stroop effect is diminished, and Stroop dilution has occurred.Brown, Roos-Gilbert, and Carr (1995) summarized three accounts of Stroop dilution. First, dilution may occur at the level of lexical processing. According to this account, Stroop dilution takes place because of a general capacity limit for word processing. When a color word distractor and neutral word diluter are presented concurrently, both words are processed in parallel. Since lexical processing is a limited resource, the meaning of each individual word is only partially activated. Assuming that there is a relation between the level of word activation and the word's influence on behavior, the effect of the distractor is reduced. Kahneman and Chajczyk (1983) tested this possibility using a neutral word or string of Xs as the diluter. If words are read automatically and dilution is a consequence of the finite resources of lexical processing, then the X diluter should not re...

Processing overlap-dependent distractor dilution rather than perceptual target load determines attentional selectivity

“…Results that are compatible with the present findings have also been reported in the context of Stroop (Roberts & Besner, 2005) and Simon effect dilution studies (Miles, Yamaguchi, & Proctor, 2009). For instance, Miles and colleagues (2009) in a word-based Simon task found that a word diluter reduced the compatibility effect produced by a location-word distractor but not that produced by a spatial symbol distractor, thus providing evidence that stimulus-response compatibility effects were susceptible to the presence of diluters that were categorically similar to the distractors.…”

Observed bodies generate object-based spatial codes

“…Alternatively, the abstract shape that accompanied the figure might have inadvertently diluted the spatial compatibility effects, in line with other studies that have introduced irrelevant noise or 'diluter' stimuli (Miles et al, 2009;Proctor & Lu, 1994).…”

Multidimensional vector model of stimulus–response compatibility.

“…For instance, Eimer and Schlaghecken (1998) showed that the spatial compatibility between subliminally primed arrows and responses influenced performance when the target stimuli were also arrows but not when they were letters, suggesting that processing irrelevant subliminal primes depends on what kind of stimuli the observer intends to process. Similarly, Miles, Yamaguchi, and Proctor (2009) demonstrated that the Simon effect can be diluted when a task-irrelevant neutral stimulus is presented, but the dilution occurs only when the neutral stimulus is categorically similar to a task-irrelevant stimulus that produces the Simon effect. This result implies that processing of task-irrelevant stimuli is capacity limited and context dependent.…”