Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 06, 2018
Last Modified: January 31, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the Number Bisection Task based on:
Nuerk, H., Geppert, B., van Herten, M., & Willmes, K. (2002). On the impact of different number representations in the number bisection task. Cortex, 1, 691–715.
45 minutes
Participants view a series of triplets of numbers (e.g. 5-7-9), each presented for max.3s, and have to decide whether the center number is the arithmetic mean of the flanking numbers.
1. Practice: 32 trials
• 16 bisectional triplets (range: 2-18); 16 non-bisectional triplets (range: 2-18)
• triplets presented randomly
• performance feedback provided for 1000s
Trial Sequence:
• presentation of triplets: max. 3000ms (terminates with response)
• feedback for 1000ms
• interstimulus interval of 1.5s in between triplets (presents a fixation cross)
( the SOA during practice is variable due to the feedback presentation)
2. Test:
• 5 Blocks of 72 trials each = 360 trials total
• each blocks runs 9 trials of each of the 8 possible trials
(trial.bisectional_multi_small...trial.nonbisectional_impossible_far)
• order of trials is selected randomly (as is the selection of the triplets)
• no feedback
Trial Sequence:
• A new triplet appears with a stimulus onset asynchrony (SOA) of 4.5s
• each triplet is presented for max. 3s (= response window)
• interstimulus interval of min. 1.5s in between triplets (presents a fixation cross)
Test Triplets: This script uses the 360 triplets provided by Nuerk et al (2002)
the size can be fine-tuned under section Editable Parameters
Practice Triplets: the practice triplets are novel triplets generated by Millisecond (none of the practice
triplets are used during the test)
- half of the practice triplets (16) are bisectional triplets (range: 2, 4, 6, 8, 10, 12, 18; two of each)
- half of the practice triplets (16) are non-bisectional triplets (range: 2, 4, 6, 8, 10, 12, 18; two of each)
all triplets can be edited under section Editable Stimuli
provided by Millisecond - can be edited under section Editable Instructions
File Name: numberbisectiontask_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| 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 |
| propCorrectPractice | Proportion correct during practice |
| meanRTPractice | Mean response time of correct responses during practice |
| propCorrectBisectionalMultiSmall | Proportion correct responses for bisectional, 'multiplication-triplets' problems with a small task range |
| meanRTBisectionalMultiSmall | Mean response time (in ms) of correct responses for bisectional, 'multiplication-triplets' problems with a small task range |
| propCorrectBisectionalMultiWide | Proportion correct responses for bisectional, 'multiplication-triplets' problems with a wide task range |
| meanRTBisectionalMultiWide | Mean response time (in ms) of correct responses for bisectional, 'multiplication-triplets' problems with a wide task range |
| propCorrectBisectionalNonmultiSmall | Proportion correct responses for bisectional, 'non-multiplication-triplets' problems with a small task range |
| meanRTBisectionalNonmultiSmall | Mean response time (in ms) of correct responses for bisectional, 'non-multiplication-triplets' problems with a small task range |
| propCorrectBisectionalNonmultiWide | Proportion correct responses for bisectional, 'nonmultiplication-triplets' problems with a wide task range |
| meanRTBisectionalNonmultiWide | Mean response time (in ms) of correct responses for bisectional, 'non-multiplication-triplets' problems with a wide task range |
| propCorrectNonbisectionalPossibleNear | Proportion correct responses for nonbisectional, 'possible mean' problems with a near distance of suggested mean to actual mean |
| meanRTNonbisectionalPossibleNear | Mean response time (in ms) of correct responses for nonbisectional, 'possible mean' problems with a near distance of suggested mean to actual mean |
| propCorrectNonbisectionalPossibleFar | Proportion correct responses for nonbisectional, 'possible mean' problems with a far distance of suggested mean to actual mean |
| meanRTNonbisectionalPossibleFar | Mean response time (in ms) of correct responses for nonbisectional, 'possible mean' problems with a far distance of suggested mean to actual mean |
| propCorrectNonbisectionalImpossibleNear | Proportion correct responses for nonbisectional, 'impossible mean' problems with a near distance of suggested mean to actual mean |
| meanRTNonbisectionalImpossibleNear | Mean response time (in ms) of correct responses for nonbisectional, 'impossible mean' problems with a near distance of suggested mean to actual mean |
| propCorrectNonbisectionalImpossibleFar | Proportion correct responses for nonbisectional, 'impossible mean' problems with a far distance of suggested mean to actual mean |
| meanRTNonbisectionalImpossibleFar | Mean response time (in ms) of correct responses for nonbisectional, 'impossible mean' problems with a far distance of suggested mean to actual mean |
File Name: numberbisectiontask_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockCode | Name of the current block |
| blockNum | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| blockCount | Block count (for test blocks only) |
| trialCount | Number of test trials run in the current block |
| bisectionality | 1 = bisectional; 2 = non-bisectional |
| multiplicativity | For bisectional problems only 1 = multiplication triplets from a number sequence (e.g. 2-4-6, 14-21-28) 2 = otherwise (e.g. 3-8-13) |
| bisectionTaskRange | For bisectional problems only 1 = difference btw. the target numbers ('outer numbers') is btw. 2-8 (e.g. 4-7-10 => 10-4 = 6) 2 = difference btw. the target numbers ('outer' numbers) is btw. 12-18 (e.g. 4-12-20 => 20-4 = 16) |
| bisectionPossibility | For non-bisectional problems only 1 = the actual arithmetic mean of the target numbers (=mean of first and third number) is an integer (e.g. 4-8-10; (4+10)/2 = 7) 2 = otherwise (e.g. 4-7-9 => (4+9)/2 = 6.5) |
| distance | For non-bisectional problems only 1 = the absolute difference btw. the actual mean of the target numbers (=mean of first and third number) and the provided arithmetic mean (= the second number) is 0.5-1.5 (e.g. 3-6-7; (3+7)/2=5; 6-5 = 1) 2 = the absolute difference btw. the actual mean of the target numbers (=mean of first and third number) |
| and the provided arithmetic mean (= the second number) is 2-8 | (e.g. 12-18-20; (12+20)/2=16; 18-16 = 2) |
| stimulusItem | The presented number triplet |
| response | Scancode of response button (0 = no response) 18 = E => yes 23 = I => no |
| resp | "yes" vs. "no" vs " " (empty = no response) |
| correct | Accuracy of response: 1 = correct response; 0 = otherwise |
| latency | The response latency (in ms); measured from: measured from: onset of number triplets |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| numberOfPracticeTrials | The number of practice trials to run Notes (1) the number should be divisible by 2 (2) for numbers > 32, triplets will be repeated (3) for numbers < 32, the randomly selected ranges of the triplets (range = difference btw. outer numbers) might not be balanced across bisectionable and non-bisectionable triplets To get a balanced number of ranges, consider reducing the appropriate item lists under section Editable Stimuli (item.practice_bisect; item.practice_nonbisect) | 32 |
| numberOfTestBlocks | The number of test blocks to run ; each testblocks runs 72 trials Notes (1) for numbers > 5, triplets will be repeated (2) for numbers < 5, randomly chosen triplets will not be the same across participants. To get the same triplets for all participants, consider reducing the appropriate item lists under section Editable Stimuli. | 5 |
| stimPresentationTime | Maximum stimulus presentation time in ms => response window | 3000ms |
| isi | Minimum interstimulus interval in ms a new triplet appears every 4.5s (SOA= 3000ms + 1500ms) | 1500ms |
| minLatency | The minimum response time that is considered a valid response time | 200ms |
| stimSize | The proportional size of the triplets (relative to canvas) | 7% |
| fixationSize | The proportional size of the fixation cross (relative to canvas) responseKeys: see Tools -> Keyboard Scancodes | 7% |
| responseKeyYes | The 'yes' response button (here: "E"); left response key | |
| responseKeyNo | The 'no' response button (here: "I"); right response key for this script to operate correctly on touchscreen devices, the 'yes' response key should be located left to the 'no' key. |