Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 21, 2013
Last Modified: January 18, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the Attention Network Test (ANT), a behavioral measure of alerting, orienting and executive attention. The implemented procedure is based on Fan et al (2002).
The original ANT for adults and the child ANT as well as all stimuli used are generously shared by the original authors/Sackler Institute at: https://www.sacklerinstitute.org/cornell/assays_and_tools/
Fan, J., McCandliss, B. D., Sommer, T., Raz, A., & Posner, M. I. (2002). Testing the efficiency and independence of attentional networks. Journal of Cognitive Neuroscience, 14, 340–347.
20 minutes
Participants are presented arrows either directly above or below a fixation cross. Arrows may be flanked by other stimuli (3 flanker conditions). Participants have to decide whether the arrows point right or left. Several cue conditions (4) (may) alert the participants that the targets are about to come on screen and potentially where on the screen (above or below the fixation cross).
Differences in mean reaction times in the different cue/flanker conditions are used to calculate the following three Attentional Network Effects: • Alert Effect: Effect of achieving and maintaining alertness • Orienting Effect: Effect of orienting attention towards a specific location of information • Conflict Effect: Effect of resolving conflict between several possible responses
4 cue conditions (no cue, center cue, double cue, spatial cue) x 3 flanker conditions (neutral, congruent, incongruent)
within-subjects design
A) 1 Block of 24 Practice trial sequences with full feedback, including summary feedback of speed and accuracy
B) 3 Blocks of 96 trial sequences each - no feedback
EXPERIMENTAL BLOCKS:
96 trial sequences: 2 (repetitions) x 4 (cue conditions) x 3 (flanker conditions) x 2 (target positions) x 2 (target directions)
TRIAL SEQUENCE - randomly selected cue condition
fixation (randomly chosen presentation time) -> cue (100ms) -> fixation (400ms) -> target (1700ms)-> intertrialinterval
(depends: complete trialduration = 4s)
Size of Stimuli:
Fan et al (2002) give specific dimensions of the size and distance of targets/flankers (p.345/346)
=> distance participant/screen: 65 cm
=> single line arrow : 0.55 degree visual angle
=> distance flankers/target: 0.06 degree visual angle (area covered by all: 3.08 degree visual angle)
=> distance target/fixation cross: 1.06 degree visual angle
This script does NOT attempt to replicate these dimensions as different monitors require different fontsizes etc.
Fine-tune fontsize of stimuli, distance of flanker to target, and position of target above and below
fixation cross under section EDITABLE PARAMETERS
Instructions are modelled after the instructions generously made available on:
https://www.sacklerinstitute.org/cornell/assays_and_tools/
Instructions can be edited in script 'ant_instructions_inc.iqjs'
File Name: ant_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| overallPropCorrect | Overall proportion correct across all testblock trials |
| meanRTCorrect | Overall mean RT (of correct responses) for test trials |
| propCorrectNoCue | Proportion correct responses in NoCue condition |
| meanRTNoCue | Mean response time (in ms) of correct responses in NoCue condition |
| propCorrectCenterCue | Proportion correct responses in CenterCue condition |
| meanRTCenterCue | Mean response time (in ms) of correct responses in CenterCue condition |
| propCorrectDoubleCue | Proportion correct responses in DoubleCue condition |
| meanRTDoubleCue | Mean response time (in ms) of correct responses in DoubleCue condition |
| propCorrectSpatialCue | Proportion correct responses in SpatialCue condition |
| meanRTSpatialCue | Mean response time (in ms) of correct responses in SpatialCue condition |
| propCorrectCongruent | Proportion correct responses in trials with target-congruent flankers (flankers that point in the same direction as target) |
| meanRTCongruent | Mean response time (in ms) of correct responses in trials with target-congruent flankers (flankers that point in the same direction as target) |
| propCorrectIncongruent | Proportion correct responses in trials with target-incongruent flankers (flankers that point in the opposite direction as target) |
| meanRTIncongruent | Mean response time (in ms) of correct responses in trials with target-incongruent flankers (flankers that point in the opposite direction as target) |
| propCorrectNeutral | Proportion correct responses in trials with target-incongruent without flankers |
| meanRTNeutral | Mean response time (in ms) of correct responses in trials without flankers |
| propCorrectCongruentNC | Proportion correct responses in trials with target-congruent flankers in No Cue Condition |
| meanRTCorrectCongruentNC | Mean response time (in ms) of correct responses in trials with target-congruent flankers in No Cue Condition |
| propCorrectIncongruentNC | Proportion correct responses in trials with target-incongruent flankers in No Cue Condition |
| meanRTCorrectIncongruentNC | Mean response time (in ms) of correct responses in trials with target-incongruent flankers in No Cue Condition |
| propCorrectNeutralNC | Proportion correct responses in neutral trials in No Cue Condition |
| meanRTCorrectNeutralNC | Mean response time (in ms) of correct responses in in neutral trials in No Cue Condition (same for CC= center condition; DC = double cue condition; SC = spatial condition) |
| alertingEffectAcc | PropCorrectNoCue - propCorrectDoubleCue => Effect of achieving and maintaining alertness (Fan et al, 2002, p.342/343) |
| orientingEffectAcc | PropCorrectCenterCue - propCorrectSpatialCue => Effect of orienting attention towards a specific location of information |
| conflictEffectAcc | PropCorrectIncongruent -propRTCorrectCongruent => Effect of resolving conflict between several possible responses (executive function) |
| alertingEffectRT | MeanRTCorrectNoCue - meanRTCorrectDoubleCue => Effect of achieving and maintaining alertness (Fan et al, 2002, p.342/343) |
| orientingEffectRT | MeanRTCorrectCenterCue - meanRTCorrectSpatialCue => Effect of orienting attention towards a specific location of information |
| conflictEffectRT | MeanRTCorrectincongruent - meanRTCorrectcongruent => Effect of resolving conflict between several possible responses (executive function) |
File Name: ant_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockcode | The name the current block (built-in Inquisit variable) |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialcode | The name of the currently recorded trial (built-in Inquisit variable) |
| trialnum | The number of the currently recorded trial (built-in Inquisit variable) trialnum is a built-in Inquisit variable; it counts all trials run even those that do not store data to the data file. |
| blockCount | Counts the number of test blocks run (custom counter) |
| trialCount | Counts the number of trials run in each block (resets after practice) (custom counter) |
| cueCondition | The current cue condition (NoCue; CenterCue; DoubleCue; SpatialCue) |
| flankerCondition | The current flanker condition (1 = neutral; 2 = congruent; 3 = incongruent) |
| targetPosition | Position of target relative to fixation (2 = above fixation; 1 = below fixation) |
| targetDirection | The direction of the target (0 = right; 1 = left) |
| picture.flanker1.currentItem | The current picture presented as the left flanker |
| picture.flanker2.currentItem | The current picture presented as the center-left flanker |
| picture.target.currentItem | The current picture presented as the center target |
| picture.flanker3.currentItem | The current picture presented as the center-right flanker |
| picture.flanker4.currentItem | The current picture presented as the right flanker |
| targetY | The vertical percentage coordinate of the target (Top = 0% - Bottom = 100%) |
| flanker1Y | The vertical percentage coordinate of the flankers |
| cue1Y | The vertical percentage coordinate of the cues |
| response | The response of participant (scancode of response button: 18 = left E; 23 = right I; 57 = spacebar) |
| correct | Correctness of response (1 = correct, 0 = error) |
| latency | Response latency (in ms); measured from onset of target until response is made or trial times out |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Stimuli Dimension/Placement |
||
| fontSizeFixation | Regulates the size of the fixation cross, in canvas height percentage | 5% |
| cueSize | Regulates the size of the cues, in canvas height percentage | 5% |
| arrowSize | Regulates the size of the target/flanker, in canvas height percentage | 6% |
| flankerDistance | The relative screen distance between stimuli, in canvas width percentage | 7% |
| topY | The y-coordinate of the target above the fixation cross | 45% |
| bottomY | The y-coordinate of the target below the fixation cross | 55% |
Duration Parameters |
||
| readyDuration | Sets the duration (in ms) of the get-ready trial | 2000 |
| completeTrialDuration | Sets the complete duration of one trial sequence | 4000 |
| cueDuration | Sets the duration of the cue presentation | 100 |
| fixation2Duration | Sets the duration of the fixation cross after cue presentation | 400 |
| targetDuration | Sets the maximal duration of the target/flanker presentation | 1700 |
| practiceFeedbackDuration | Sets the duration of the feedback trial during practice | 750 |
Response Keys |
||
| responseKeyLeft | Left response key | "E" |
| responseKeyRight | Right response key | "I" |