Time Wall Estimation Task
Background
The Time Wall Estimation Task (TWET) is a computerized behavioral assessment used to measure time perception and motion estimation. The TWET was made public by Englund et al. (1987) as part of the Unified Tri-Service Cognitive Performance Assessment Battery (UTC-PAB), developed for military use to measure an individual's ability to predict the movement of a target over a specified distance after it becomes obscured. Research by Vaiva Sutnikieneshow and colleagues from 2025 show scores on the TWET are highly sensitive to mild cognitive impairments and supports the task's diagnostic utility for identifying early Alzheimer's.
The Time Wall presents participants with 10 trials in which a circular object falls at constant speed from the top of the screen towards a wall with a wall opening that is located at the bottom of the screen. At somet point the object disappears behind the wall and the participant is asked to press the spacebar to indicate at what time the object would be visible through the wall opening.
Task Procedure
By default, 10 estimation tasks are run or the task is over after 300s, whichever comes first. At the default speed the disk is completely covered by the wall by 6s, covers the wall hole by 8s and drops off the canvas at 10s. Once the disk is completely covered by the wall, the script waits for a response from the participant (early responses are counted but ignored otherwise). If participant presses the Spacebar within 30s after the disk is completely covered by the wall, the response is counted as valid and the wall hole is filled with the color of the falling disk (=visual feedback of a valid response).
A new estimation task is started after 500ms. If participant does not press the Spacebar within 30s, a beep is played (auditory feedback of invalid response) and a new task starts after 1s.
What it Measures
The Time Wall Estimation Task (TWET) is a measure of time perception and motion estimation
Psychological domains
- Temporal Judgment (Time Perception): Ability to estimate the passage of time without external cues.
- Motion Perception (Visuospatial Processing): Ability to process moving stimuli and predict their trajectory once they are no longer visible.
Main Performance Metrics
- Inaccuracy Score: The percentage difference between the mean estimation Time and the actual calculated Time
- Coefficient of Variation: Response Consistency across trials
Psychiatric Conditions
The following patient groups show impaired performance on the Time Wall Estimation Task:
- Dementia
- Mild Cognitive Impairment (MCI)
- Parkinson’s Disease (PD)
- Attention Deficit/Hyperactivity Disorder (ADHD)
- Schizophrenia
A time estimation task in which participants estimate when an occluded, moving object reaches a target point as described in Englund et al (1987)
References
Search Google Scholar for peer-reviewed, published research using the Inquisit Time Wall Estimation Task.
Englund, C.E., Reeves. D.L., Shingledecker, C.A., Thorne, D.R., Wilson, K.P., & Hegge. F.W. (1987). Unified Tri-Service Cognitive Performance Assessment Battery (UTC-PAB) I. Design and Specification of the Battery. Report No. 87-10, Naval Health Research Center, P 0 BOX 85122, San Diego, CA 92138 Naval Medical Research and Development Command, Bethesday, MD (task description: p.26)