Attentional Focus Manipulations Affect Naming Latencies of Neutral But Not of Incongruent Stroop Trials

Abstract

People are slower and more error-prone when indicating the color of incongruent color words compared to that of neutral stimuli. This Stroop effect results from the concurrent semantic analysis of the word stimulus. It has long been considered a prime example of the automaticity of semantic activation. However, coloring as well as cuing only a single letter both reduce the Stroop effect to the point of being absent. Proposed underlying mechanisms include the blocking of semantic activation, an improved selectivity between the interfering stimulus dimensions, and slowed color processing. In order to test the validity of these differing accounts of the single-letter Stroop effect, we compared vocal responses to standard and single-letter Stroop stimuli in two experiments. Irrespective of whether participants maintained a wide (Experiment 1) or a narrow (Experiment 2) attentional focus, both single-letter coloring and single-letter cuing increased reaction times to neutral Stroop stimuli but left those to incongruent stimuli unaffected. Both curtailed semantic activation and improved selection for action should, however, speed up reactions to incongruent stimuli. Our data thus support an explanation of the single-letter Stroop phenomenon in terms of impeded color processing, possibly as a result of color-color interference.

Is There Semantic Conflict in the Stroop Task?

“…It is, however, noteworthy that two colors are still present in our SLCC condition (a color from the response set and white) – making it plausible that an additional color–color interference still occurs in SLCC as compared to ALCC. Its known lengthening effect on color-neutral items (e.g., Küper & Heil, 2012; Monahan, 2001) might be canceled in the RTs by the concomitant shift in attentional focus toward the relevant color dimension in SLCC, which in turn reduces the task conflict. In sum, future studies – which should include a direct measure of task conflict – need to address these possibilities directly, perhaps with a more fine-grained measures than RTs (e.g., Hershman & Henik, 2019).…”

“…8An additional color–color interference occurs when remaining letters are colored in other (incongruent) colors from the response set. Since this is known to increase RTs on color-neutral trials in the SLCC condition (e.g., Küper & Heil, 2012; Monahan, 2001), it might inflate the SLCC-induced reduction of both standard and semantic Stroop interferences (e.g., Manwell et al, 2004). …”

Activation of lexical and semantic representations without intention along GPC-sublexical and orthographic-lexical reading pathways in a Stroop paradigm.

“…They reasoned that when CWAs are compared to a neutral baseline, the results should provide evidence of a semantically based Stroop effect, as opposed to just a standard Stroop effect (i.e., comparison of CWs to a neutral baseline). As a result, some researchers (e.g., Besner et al, 1997; Küper & Heil, 2012) have entirely eliminated the use of congruent trials and replaced them with a neutral baseline, arguing that inclusion of congruent trials can inflate the size of Stroop effects. These researchers argue that when congruent trials are used, it is unclear whether the responses of participants are due to naming the color of the word or reading the word.…”

“…Participants were shown CWs, CPHs, and neutral controls, and asked to identify the color of the letter string. Both experiments found Stroop effects for the CPHs, indicating that GPC in the sublexical route of reading is difficult to control, although Besner and Stolz suggested that this finding does not imply that phonological computation itself is automatic as other contexts, such as the single letter cuing and coloring paradigm, have found decreased Stroop effects for CWs and CWAs (Besner, Stolz, & Boutilier, 1997; Küper & Heil, 2012; Manwell, Roberts, & Besner, 2004; we note, however, the limitations in ecological validity that are intrinsic to studies that focus attention on a single letter in a word). Furthermore, Besner and Stolz suggested it might be possible for individuals to control GPC to a certain extent.…”

A brief review of three manipulations of the Stroop task focusing on the automaticity of semantic access

“…Thus, the observed decrease of the Stroop interference could probably be due to an increase RT in the control condition rather than a decrease in the incongruent condition. More recently, Küper and Heil (2012) used the same procedure as Manwell et al (2004). Like Monahan (2001), in their first experiment they observed that the decrease of the Stroop effect in the SLC condition was due to an enhancement of the RT for neutral words and not a decrease of RT for classical incongruent words.…”