Table 2.
Behavioral Measures Used within an Impulsivity Framework
| Measure | Description | What is Impulsive? | Population | Key Reference(s) |
|---|---|---|---|---|
| 5-Choice Serial Reaction Time Task | Requires the subject to identify which of five locations was signaled to receive a reinforcer. Difficulty is increased by decreasing the duration the location is signaled. Responses also must be withheld during an inter-trial interval. | Typically, more premature responses (responses during the inter-trial interval). Infrequently applied measures include more perseverative responses at the same location (compulsion) or response accuracy (attention) | Both (Mostly Animal) | Robbins (2002) |
| Antisaccade Task | Measurement of eye movements when a participant is instructed to not look at a presented object. | More antisaccade errors (i.e., looking at a presented object) | Human | Currie, Ramsden, McArthur, and Maruff (1991) |
| Balloon Analogue Risk Task (BART) | Participants are asked to click to "pump up" a balloon with each pump adding money to possible earnings. Earnings may be cashed out at any time or participants may continue clicking. Too many clicks result in an overinflated balloon and no earnings are received. The number of clicks to over-inflation is varied between trials. | Higher average number of pumps on unexploded balloons | Human | Lejuez et al. (2002) |
| Circle Tracing Task | Participants are instructed to trace over a circle as slow and accurately as possible. | Faster tracing time | Human | Bachorowski and Newman (1990) |
| Continuous Performance Test (CPT) | Measure of sustained attention in which participants must respond when a target stimulus is presented (e.g., 0) and refrain from responding when a rarer non-target stimulus is presented (e.g., X). | Higher commission errors (responses to nontarget stimuli); Higher omission errors (nonresponses to target stimuli) | Both (Mostly Human) | Conners, Epstein, Angold, and Klaric (2003); Young, Light, Marston, Sharp, & Geyer, 2009 |
| Cued Go/No-Go | Presentation of a go or no-go cues that are typically followed by go or no-go targets, respectively. Critical trials evaluate inhibition of a response when a go cue is followed by a no-go target. | Higher commission errors (responses to no-go targets following go cues) | Both | Eagle et al. (2008); Fillmore (2003) |
| Delay Discounting Tasks | Evaluate choices between a smaller, sooner reinforcer and a larger, later reinforcer using a discrete choice procedure. | Higher discounting; More choices for the smaller, sooner reinforcer | Both | Ainslie (1975); Evenden and Ryan (1996); M. W. Johnson and Bickel (2002); Kirby, Petry, and Bickel (1999) |
| Delay of Gratification | Evaluate choices between a smaller reward available at any time and a larger reward available after a delay. Participants are required to sustain selection for the delayed reward as the opportunity to defect to the smaller reward is available until the delayed reward is delivered. | Choices for the smaller reward (i.e., delayed choice defection) | Human | Mischel et al. (1989) |
| Flanker Task | A target stimulus (e.g., left arrow) is surrounded by stimuli that are congruent (e.g., left arrows), incongruent (e.g., right arrows), or neutral (e.g., boxes). Participants must respond to the target stimulus while ignoring the surrounding information (e.g., in this example respond left to the left arrow). | Higher (longer) reaction time differences between incongruent and congruent trials | Human | Eriksen and Eriksen (1974) |
| Immediate and Delayed Memory Tasks (IMT/DMT) | A form of continuous performance task in which participants must respond to matching numbers presented sequentially. The IMT evaluates responses for immediately preceding matches and the DMT evaluates responses for matching numbers separated by presentation of a filler sequence. Catch stimuli that are similar to the target are also included (e.g., 20315 for the target 20325). | More responses to catch trials | Human | Dougherty, Marsh, and Mathias (2002) |
| Iowa Gambling Task | Participants must choose between four decks of cards that vary in amount won and lost for selecting that card. Variations in amounts won and lost for each set of cards mean some are more or less advantageous. | Greater number of choices for disadvantageous decks | Human | Bechara et al. (1994) |
| Matching Familiar Figures Task | Individuals are instructed to identify stimuli that exactly match a target stimulus within a field of stimuli that are very similar in appearance. | Higher error rates and faster response times | Human | Kagan (1966) |
| Porteus Maze Task | Completion of a series of mazes that vary in complexity. Complexity increases over trials and successful completion requires planning an appropriate route prior to initiation of the maze. | Fewer mazes completed | Human | Gow and Ward (1982); Porteus (1942) |
| Probability Discounting Tasks | Evaluates choices between a smaller, certain reinforcer and a larger, probabilistic reinforcer using a discrete choice procedure. | Both lower and higher discounting (see Precision in Language and Precision in Both Constructs section) | Both | Cardinal and Howes (2005); Green and Myerson (2004); Rachlin et al. (1991) |
| Stop-Signal Task | Participants respond to a stimulus (e.g., press left if left arrow and right if right arrow) and are asked to withhold a response in the presence of a tone. The delay to the tone is titrated to a point of 50% success in inhibition. | Longer (slower) stop signal reaction times indicating a need for a shorter delay to tone for successful inhibition. | Both | Eagle et al. (2008); Logan (1994) |
| Stroop Task | Evaluates responses to stimuli in which the requested response (e.g., color of word ink; red) mismatches the stimulus (e.g., the word purple printed in red ink). | More errors to incongruent response-stimulus pairs (purple printed in red ink). | Human | MacLeod (1991); Stroop (1935) |
| TIME Paradigm | Measures time estimation and time production. Time estimation involves estimation of a specifiedtime interval by starting and stopping a timer after the elapsed interval is estimated to elapsed. Time production involves maintenance of a response (e.g., button press) for the intended interval. | Poorer accuracy in time estimation or production | Human | Dougherty et al. (2005) |
| Tower of London Test | Problem-solving task in which colored blocks must be moved to match a target. A specific move set must be used to match the target in the minimum number of moves. | More moves to completion or more attempts to achieve minimum move number. | Human | Shallice (1982) |
| Trail Making Task | Connection of dots in sequential order (Part A) or based on an alternating order (Part B; e.g., 1, A, 2, B). Participants are instructed to respond as quickly as possible. | Longer times to complete the task | Human | Tombaugh (2004) |
| Wisconsin Card Sorting Task | Stimulus cards are presented to participants in which they are instructed to match cards, but no instructions on the rules for matching (e.g., color, symbols). Rules change throughout the task (e.g., every 10 trials). | More perseverative errors (i.e., responses under prior rule set when rule set changes). | Human | Grant and Berg (1948) |
Note. Tasks described have, at times, been used within the impulsivity literature and related to this umbrella construct. Population column refers to if the task is used in human participants, animal subjects, or both (or in some cases if it is used dominantly by one of those populations). Key references provide historical and contemporary overviews of tasks.