Reaction Time to Word Meaning and Ink Color of Laterally-Presented Stroop Stimuli: Effects of Handedness and Sex

Abstract

In two experiments, subjects pressed a key labeled Red or Green in response to a 100 msec duration stimulus presented to the left or right visual field. In Experiment I, subjects responded to the meaning of Stroop words; the stimulus was the word Red or Green printed in red, green, or white ink. In Experiment II, subjects responded to ink color; the stimulus was either the word Red or Green printed in red or green ink or a red or green color patch. In each experiment, there were 20 strongly right-handed subjects and 20 strongly left-handed subjects. Half the subjects in each handedness group were male and half were female. In both experiments, RT was faster when words were presented to the right visual field than to the left visual field, suggesting that both meaning and ink color of Stroop words were processed more quickly in the left hemisphere. Results of both experiments revealed faster reactions when meaning and ink color of the Stroop words were congruent than when they were not. A comparison with baseline trials indicated that the RT difference between responses to congruent and incongruent Stroop words was due to the incongruent cue interfering with information processing rather than to the congruent cue facilitating processing. Hypothesized interactions between stimulus position, congruence, handedness and sex were not significant.

Interactions between stimulus-stimulus congruence and stimulus-response compatibility

“…In other words, the present Exp. 1 fully replicates the major outcome of the studies of Simon et al (1985), Simon and Berbaum (1990), and Kornblum (1994), at least as far as mean RTs are concerned. This result is consistent with the seriality assumption of Kornblum's dimensional-overlap model, but not with the temporal-overlap hypothesis of Hommel's (1993).…”

“…Consistent with the widespread belief that stimulusresponse (S-R) compatibility affects response selection while stimulus-stimulus (S-S) congruence influences a preceding stage (e.g., stimulus identification), most studies on the relationship between these two factors found additive effects (Kornblum, 1994;Simon & Berbaum, 1990;Simon, Paullin, Overmyer, & Berbaum, 1985;Stoffels & Van der Molen, 1988). 1 Along this line, the most comprehensive model of compatibility phenomena to date, suggested by Kornblum (1992Kornblum ( , 1994Kornblum et al, 1990), provides two different sites for congruence and compatibility effects: Conflicts arising from S-S incongruence occur and are solved at a stimulus-identification stage before any stimulus information is passed on to the succeeding response-production stage.…”

“…From this perspective, it is not too surprising to find that previous studies were afflicted by a kind of tradeoff between congruence and compatibility main effects: presence of congruence effects but absence of compatibility effects in the studies of Simon et al (1985) or Simon and Berbaum (1990), and vice versa with Kornblum (1994). In fact, given the temporal dynamics obtained, the size of congruence and compatibility main effects as well as the relationship between them can be expected to depend mainly on particularities of the respective sample and the task.…”

“…However, the congruence main effect was very small in the studies of Simon and colleagues (Simon et al, 1985;Simon & Berbaum, 1990), 27 ms and 30 ms, respectively, and even absent in the Kornblum (1994) experiment. Conversely, the compatibility effect was insignificant in all but the Kornblum study (11 ms, 11 ms, and 36 ms, respectively).…”

Coloring an action: Intending to produce color events eliminates the Stroop effect

“…In order to synchronize novel, response-contingent events with particular responses the vocal utterances would need to be speech-recognized and categorized on-line and rather quickly, because even brief delays between responses and effects can reduce the likelihood of their integration (Elsner & Hommel, in press;Hommel & Elsner, 2000). Fortunately, however, Stroop effects are not restricted to vocal responses but occur with manual responses as well (e.g., Hommel, 1997b;Simon & Berbaum, 1990;Simon, Paullin, Overmyer, & Berbaum, 1985), even though it has been argued that the manual version lacks some aspects of the vocal counterpart (Kornblum et al, 1990). As the manual version allows for an easy way to register responses and to select action-contingent effect accordingly, it was in this study preferred over the vocal version.…”