Show Reference: "Dimensional overlap accounts for independence and integration of stimulus-response compatibility effects"

Dimensional overlap accounts for independence and integration of stimulus–response compatibility effects In Attention, Perception, & Psychophysics, Vol. 72, No. 6. (2010), pp. 1710-1720, doi:10.3758/app.72.6.1710 by Xun Liu, Yunsoo Park, Xiaosi Gu, Jin Fan
    abstract = {Extensive studies have been conducted to examine various attentional control effects that stem from stimulus— stimulus ({S—S}) and stimulus-response ({S—R}) incompatibility. Among these behavioral paradigms, the best-known are the Stroop effect, the Simon effect, and Posner's cue validity effect. In this study, we designed two behavioral tasks incorporating these effects ({Simon—color-Stroop} and {Simon-spatial-Stroop}) guided by a general framework of {S—R} ensemble, the dimensional overlap theory. We analyzed various attentional effects according to dimensional overlaps among {S—S} and {S—R} ensembles and their combinations. We found that behavioral performance was independently affected by various dimensional overlaps in the {Simon—color-Stroop} task, whereas different sources of dimensional overlap in the {Simon—spatial-Stroop} task interacted with each other. We argue that the dimensional overlap theory can be extended to serve as a viable unified theory that accounts for diverse attentional effects and their interactions and helps to elucidate neural networks subserving attentional control.},
    author = {Liu, Xun and Park, Yunsoo and Gu, Xiaosi and Fan, Jin},
    booktitle = {Attention, Perception, \& Psychophysics},
    citeulike-article-id = {13502963},
    citeulike-linkout-0 = {},
    citeulike-linkout-1 = {},
    doi = {10.3758/app.72.6.1710},
    keywords = {biology, conflict, cortex},
    number = {6},
    pages = {1710--1720},
    posted-at = {2015-01-28 13:46:16},
    priority = {2},
    publisher = {Springer-Verlag},
    title = {Dimensional overlap accounts for independence and integration of stimulus-response compatibility effects},
    url = {},
    volume = {72},
    year = {2010}

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In the Simon task, subjects are required to respond to a stimulus with a response that is spatially congruent or incongruent to that stimulus: They have, for example, to press a button with the left hand in response to a stimulus which is presented either on the left or on the right. Congruent responses (stimulus on the left—respond by pressing a button with the left hand) is usually faster than an incongruent response.

Simon task and Stroop task are similar. A main difference is that the conflict is between a dimension of the response and a task-irrelevant stimulus dimension in the Simon task, while it is between a task-irrelevant dimension of the stimulus, the task-relevant dimension of the stimulus, and a dimension of the response, in the Stroop task.

Attention is necessary to perform the Stroop and Simon tasks.

The dimensional overlap framework can be used to classify overlap and interference between relevant (features of) stimuli and (features of) responses in psychological stimulus-response paradigms. In particular it can be used to classify types of conflict between relevant and irrelevant dimensions of stimuli and response.

In Stroop-type experiments, there is usually conflict between an irrelevant stimulus dimension, the relevant stimulus dimension, and a dimension of the response, for example the color of ink $C_I$ in which a word is written, the meaning of the word (a different color) $C_R$, and the response (saying the name of that color $C_R$).

In Simon-type experiments, there is usually conflict only between an irrelevant stimulus dimension and a dimension of the response, for example the task-irrelevant location of a stimulus and the hand with which to respond.

Liu et al. hypothesize that conflicts between stimulus dimensions and between stimulus and response dimensions are detected by different mechanisms, but resolved by the same executive control mechanism.

Liu et al. found support for their model of two conflict detection mechanisms and one conflict resolution mechanism: In their experiments, compatibility effects between stimulus dimensions and between stimulus dimensions and response dimensions were additive when both types of conflicts occurred (or both were congruent) and they canceled out when one type of conflict and one type of congruency occurred.

The frontoparietal network seems involved in executive control and orienting.

Stroop presented color words which were either presented in the color they meant (congruent) or in a different (incongruent) color. He asked participants to name the color in which the words were written and observed that participants were faster in naming the color when it was congruent than when it was incongruent with the meaning of the word.