Dots Task
Background
The Dots Task is a variant of the classic Simon Task, a test of interference resolution and cognitive control, with higher demands on working memory.
While the classic Simon Task uses simple response key rules ('if a 'blue' shape then left key'), the Dots Task uses rules that are inherently tied to the stimulus's location (Same-side vs. Opposite-side): If the red shape appears, use the key on the same side. If the blue shape appears, use the key on the opposite side. Thus, the Dots Task not only requires people to hold the response rule in 'passive' short-term memory storage but also requires them to actively manipulate the rule in working memory to determine the correct response key in any given trial.
The Dots Task is specifically used to assess executive function in children (see Hearts and Flowers Task) and adults because it forces the participant to switch between rules in a mixed block, which adds a layer of "cognitive flexibility" not typically measured in a standard Simon procedure.
The task can be run with touch/mouse input or with keyboard responses.
Task Procedure
Each trial begins with a fixation cross in the center of the screen that remains visible for 1000 ms. At the end of this interval, a red or blue dot appears on either the left or the right side of the screen and remains visible until a response is made or for 1750 ms if there is no response. Participants are instructed to press the response button on the same side if the red dot appears, but use the opposite response button if the blue dot appears. In the touchscreen version, participants need to press the 'home button', located in between the two response buttons to start the next trial. This ensures that the response finger is located in a neutral response position before the next stimulus appears.
Participants work through a short practice block of 8 trials with error feedback. If they respond to at least 75% of the trials correctly, they move on to the testblock that concludes after 20 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
- Working Memory: Ability to manipulate information in short-term-memory storage
Main Performance Metrics
- Simon Effect: Difference in accuracy (response times) to incongruent trials and congruent trials = Measure of Interference Resolution and Response Inhibition
- Switch Accuracy/Speed: Measure of Cognitive Flexibility
Psychiatric Conditions
Performance on the Dot's Task can be impaired in the following patient groups:
- Attention Deficit Hyperactivity Disorder (ADHD)
- Parkinson’s Disease (PD)
- Schizophrenia
Test Variations
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.
References
Search Google Scholar for peer-reviewed, published research using the Inquisit Dots Task.
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