Detection Task

Background

The Detection Task (DET), part of the Cogstate Brief Battery (CBB), is a simple computerized response time test to measure psychomotor function and information processing speed. The task is described in the 2009 article published by Paul Maruff and colleagues in which they studied the validity of the CBB. In addition to the Detection Task, the Millisecond library also provides implementations of the CBB's 'Identification Task', 'The One-Card Learning Task' and the 'NBack Task - Touchscreen' (aka the 'One-Back Task' of the CBB). All Millisecond implementations are based on the publicly available information (e.g. Maruff et al, 2009). All tasks of the CBB use a similar card-game user interface and are designed to run on touchscreens. Nevertheless, Millisecond's implementations will adapt to mouse-use on non-touchscreens.

Task Procedure

Participants learn about the task in a brief tutorial that includes a short practice. In addition, the entire tutorial can be repeated as often as necessary before starting the test phase.

The interface of the DET consists of a 'deck' of joker cards presented in the center of the screen, a 'YES' response button and a circle-shaped home button on which the response finger rests until a joker card is turned over. The home button is implemented to ensure that response fingers are roughly equally distanced from the 'YES' response button for each trial. Once a joker card is turned over, participants are asked to press the 'YES' response button as fast as possible. After the response is made, a card-animation is started that 'returns' the card back to the stack.

By default, the task runs 1 test block with 35 trials, using the same joker card for every trial. Should researchers run the script with more than one block, the script provides a brief, self-paced rest trial in between test blocks. During each trial, the joker is turned over randomly with a 500-5000ms delay after the home button is pressed. A reminder to press the home button is presented after 2 seconds. Pressing the home button starts the random delay period. If the home button is released during this period for more than 250ms (this period is implemented to account for possible, short tremors), the trial is terminated, participants are asked to return to the home button, and a new random delay is selected for the interrupted trial. After the YES-button has been successfully pressed, the response finger can return to the home button immediately. In this case, the next trial starts immediately after the 1-second card animation has concluded.

What it Measures

The Detection Task (DET) is a measure of psychomotor function and information processing speed

Psychological domains

• Sustained Attention: Maintaining consistent focus on a monotonous task over an extended period of time
• Processing Speed: Speed with which stimuli get processed and responded to

Main Performance Metrics

• Response Times: mean (raw and log10 transformed) and median response times (in ms) to stimulus presentation; main measure of processing speed
• Response Times Variability: response time variability across the task (raw standard deviation and log10 transformed standard deviation)

Psychiatric Conditions

The following patient groups are routinely assessed with the DET

• Mild Cognitive Impairment (MCI)
• Alzheimer’s Disease (AD)
• Parkinson’s Disease (PD)
• Huntington’s Disease (HD)
• Multiple Sclerosis (MS)
• Stroke Patients
• Traumatic Brain Injury (TBI)

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Detection Task.

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Maruff P, Thomas E, Cysique L, Brew B, Collie A, Snyder P, Pietrzak RH. Validity of the CogState brief battery: relationship to standardized tests and sensitivity to cognitive impairment in mild traumatic brain injury, schizophrenia, and AIDS dementia complex. Arch Clin Neuropsychol. 2009 Mar;24(2):165-78