Simon Task
Background
The Simon Task is a classic neuropsychological test of interference resolution and cognitive control. It was developed and published by J. Richard Simon and colleagues in 1963.
In the classic visual Simon Task set up, participants are asked to use a left or right response key based on the color (blue vs. red) of presented squares. The squares can be presented either on the left or the right side of the screen. For example, participants are asked to press the left Shift key for blue squares and press the right Shift key for red squares. Thus, it's the color of the square that determines the correct response button and the screen location of the square is irrelevant for the required responses. Nevertheless, a robust phenomenon can be observed: Even if the location of the stimulus is irrelevant for the required response, people respond faster to stimuli if the spatial locations of stimulus and response buttons match (e.g. blue square is presented on the left side of the screen) than when they do not (e.g. blue square on right side of the screen). This spatial stimulus-response compatibility has become known as the 'Simon Effect'.
Task Procedure
Each trial begins with a fixation cross in the center of the screen that remains visible for 800 ms and is followed by a 250-ms blank interval. At the end of this interval, a red or blue square appears on either the left or the right side of the screen and remains visible until a response is made or for 1,000 ms if there is no response. Participants are instructed to press the left 'A' key (left on QWERTY keyboards) when they see a blue square and the right 'L' key when they see a red square. Response timing begins with the onset of the stimulus, and the response terminates the stimulus. There is a 500-ms blank interval before the onset of the next trial.
A short practice block of 8 trials with error feedback precedes the test block that concludes after 28 trials.
What it Measures
The Simon Task is a classic neuropsychological test of interference resolution and cognitive control.
Psychological domains
- Cognitive Control: Ability to quickly adapt one's thoughts and behavior to current demands
- Inhibitory Control / Response Inhibition: Ability to override automatic responses that interfere with one's goals
- Cognitive Flexibility: Ability to quickly change between different task demands
Main Performance Metrics
- Simon Effect: Difference in accuracy (response times) to incongruent trials and congruent trials = Measure of Interference Resolution and Response Inhibition
Psychiatric Conditions
Performance on the Simon Task can be impaired in the following patient groups:
- Attention Deficit Hyperactivity Disorder (ADHD)
- Parkinson’s Disease (PD)
- Schizophrenia
Test Variations
The Simon task adapted from Bialystok et al (2004).
A short Simon task using mouse or touch input adapted from Bialystok et al (2004).
A variation of the Simon Task using keyboard responding as developed by Davidson et al (2006) measuring working memory and inhibition.
A variation of the Simon Task optimized for mouse/touch responding as developed by Davidson et al (2006) measuring working memory and inhibition.
A child-friendly version of the Simon Task as developed by Davidson et al (2006).
A child-friendly version of the Simon Task s developed by Davidson et al (2006) that is optimized for mouse (or touchscreen).
References
Search Google Scholar for peer-reviewed, published research using the Inquisit Simon Task.
Simon, J. R., and Wolf, J. D. (1963). Choice reaction times as a function of angular stimulus-response correspondence and age. Ergonomics, 6, 99-105.
Simon, J. R. & Rudell, A. P. (1967). Auditory S-R compatibility: the effect of an irrelevant cue on information processing. Journal of applied psychology, 51, 300-304.
Simon, J. R. (1969). Reactions towards the source of stimulation. Journal of experimental psychology, 81, 174-176.
Hommel, B. (1993). Inverting the Simon effect by intention: Determinants of direction and extent of effects of irrelevant spatial information. Psychological Research, 55, 270-279
Bialystok, E., Craik, F.I.M., Klein, R., & Viswanathan, M. (2004). Bilingualism, aging, and cognitive control: Evidence from the Simon task. Psychology and Aging, 19, 290-303.
Wittfoth, M., Buck, D., Fahle, M., Hermann, M. (2006) Comparison of two Simon tasks: Neuronal correlates of conflict resolution based on coherent motion perception. NeuroImage, 32, 921-929.
M.C. Davidson, D. Amso, L.C. Anderson, A. Diamond (2006). Development of cognitive control and executive functions from 4 to 13 years: Evidence from manipulations of memory, inhibition, and task switching. Neuropsychologia 44, 2037–2078
M.C. Davidson, D. Amso, L.C. Anderson, A. Diamond (2006). Development of cognitive control and executive functions from 4 to 13 years: Evidence from manipulations of memory, inhibition, and task switching. Neuropsychologia 44, 2037–2078
Diamond,A., Barnett, W.S., Thomas,J. & Munro, S. (2007). Preschool Program Improves Cognitive Control. SCIENCE, 318, 1387-1388.
Proctor, R. (2011). Playing the Simon game: Use of the Simon task for investigating human information processing. Acta Psychologica, 136, 182-188.
Green, T., Weinberger, R., Diamond, A., Berant, M., Hirschfeld, L., Frisch, A., . . . Gothelf, D. (2011). The Effect of Methylphenidate on Prefrontal Cognitive Functioning, Inattention, and Hyperactivity in Velocardiofacial Syndrome. Journal of Child and Adolescent Psychopharmacology, 21(6), 589-95.
Ursache, A., & Raver, C. (2013). Trait and state anxiety: Relations to executive functioning in an at-risk sample. Cognition & Emotion, 1-11.
Brocki, Karin C., & Tillman, Carin. (2014). Mental Set Shifting in Childhood: The Role of Working Memory and Inhibitory Control. Infant and Child Development, 23(6), 588-604.
Adele Ediamond, & Andy Ewright. (2014). An effect of inhibitory load in children while keeping working memory load constant. Frontiers in Psychology, 5, Frontiers in Psychology, 01 March 2014, Vol.5.
Ursache, A., & Raver, C. (2015). Iowa Gambling Task Performance and Executive Function Predict Low-income Urban Preadolescents' Risky Behaviors. Personality and Individual Differences, 79, 1-6.
Marion Stein, Max Auerswald, & Mirjam Ebersbach. (2017). Relationships between Motor and Executive Functions and the Effect of an Acute Coordinative Intervention on Executive Functions in Kindergartners. Frontiers in Psychology, 8, Frontiers in Psychology, 01 May 2017, Vol.8.