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								Road Sign Reaction Time Task
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 9-14-2017
last updated: 10-09-2017 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Script Copyright © 10-09-2017 Millisecond Software


BACKGROUND INFO 

											*Purpose*
This script implements a computerized Road Sign Reaction Time Task similarly to the one described in:

Edwards J., Ross , L.A., Wadley, V.G., Clay, O.J., Crowe, M., Roenker, D.L., Ball, K.K. (2006).
The useful field of view test: Normative data for older adults.
Archives of Clinical Neuropsychology, 21, 275–286.


											  *Task*
Participants see sets of three or six traffic signs (sets are sampled from four different signs:
left arrow, right arrow, bicycle, pedestrian) that are all crossed out by a red cross.
After a random delay (1000-6000ms, steps of 1000ms), the cross is removed from one of the signs, 
and participant has to choose amongst 4 different responses:
- left arrow => move the mouse to the left
- right arrow => move the mouse to the right
- bicycle => press left mouse button
- pedestrian => press right mouse button

Note: by default, the test is run in a blocked design (N=3 vs. N=6, with N=3 always preceding N=6 block).
To run N=3 and N=6 trials in a randomized mixed design, change parameters.runBlockedDesign under section Editable Parameters.


DATA FILE INFORMATION: 
The default data stored in the data files are:

(1) Raw data file: 'roadsigntest_raw*.iqdat' (a separate file for each participant)*

build:							Inquisit build
computer.platform:				the platform the script was run on
date, time, subject, group:		date and time script was run with the current subject/groupnumber 
blockcode, blocknum:			the name and number of the current block
trialcode, trialnum: 			the name and number of the currently recorded trial
									(Note: not all trials that are run might record data; by 
									default data is collected unless /recorddata = false is set for a particular trial/block) 
/runBlockedDesign:				true (1): the test is split into 2 blocks: first block runs N=3; second block runs N=6 (default)
								false (0): N=3 and N=6 trials are run in a mixed design									
/N:								stores the current set size tested
/delay:							stores the currently randomly sampled target delay in ms (1000-6000ms)
/target:						stores the current target image
/distractor1-
/distractor5:					store the current distractor images

response:						the participant's response (recorded mouse response)
values.response:				description of response: 
									"left turn", 
									"right turn", 
									"LM-bicycle" (left mouse button), 
									"RM-pedestrian" (right mouse button)
			
correct:						accuracy of response: 1 = correct response made after removal of cross; 0 = otherwise
/propCorrect_practice1:			proportion initially correct responses during practice 1
/validrt:						valid response time (in ms); measured from onset of unslashed target
									-> "early response": response was made too early (during practice session 2)
latency: 						the response latency (in ms) of the last measured response; measured from: onset of stims
/PrematureResponse:				number of times participant responded before cross was removed during the current trial


(2) Summary data file: 'roadsigntest_summary*.iqdat' (a separate file for each participant)*

script.startdate:				date script was run
script.starttime:				time script was started
script.subjectid:				subject id number
script.groupid:					group id number
script.elapsedtime:				time it took to run script (in ms)
computer.platform:				the platform the script was run on
/completed:						0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run)
/runBlockedDesign:				true (1): the test is split into 2 blocks: first block runs N=3; second block runs N=6 (default)
								false (0): N=3 and N=6 trials are run in a mixed design
								
/propCorrect_practice1:			the final proportion initially correct responses during practice 1	
/aborted:						1 = script was aborted after practice 1; 0 = script was not aborted after practice 1
								
Note: the following summary variables are based on correct responses made after onset of target
The script considers all correct responses made after onset of target including those trials where a premature response was also registered

/propCorrect_overall:			proportion correct across all test trials 
/meanRT_overall:				mean latency (in ms) of correct responses across all test trials

/propCorrect_3stims:			proportion correct across all test trials with N = 3
/meanRT_3stims:					mean latency (in ms) of correct responses across all test test trials with N = 3

/propCorrect_6stims:			proportion correct across all test trials with N = 6
/meanRT_6stims:					mean latency (in ms) of correct responses across all test test trials with N = 6


/sumPrematureResponses:			the sum of all premature responses (responses before the cross was removed)
/sumPrematureResponses_3signs:  the sum of all premature responses (responses before the cross was removed) in the 3 sign condition
/sumPrematureResponses_6signs:  the sum of all premature responses (responses before the cross was removed) in the 6 sign condition

* separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section
"DATA" and follow further instructions


EXPERIMENTAL SET-UP

Note: by default, the test is run in a blocked design (N=3 vs. N=6).
To run N=3 and N=6 trials in a randomized mixed design, change parameters.runBlockedDesign under section Editable Parameters.

1. Block.mouseCheck:
This script requires an external mouse. 
If no external mouse is attached, participants are asked to quit and come back later.

2. Response Practice:
- 20 trials that present only 1 sign (5 trials per sign); only correct responses terminate trial
- order of signs is randomized
- after the first 20 practice trials, the script checks performance:
	if performance is below a cut-off value (default: 90%, see editable parameters.practice1MinACC),the block is repeated
	if performance is still below cut-off after the second block (default; see editable parameters.maxPractice1Blocks),
	the script aborts.

3. Task Practice:
- 12 trials that run the test set-up but with only 2 signs and with feedback
- each of the four signs is presented as a target 3 times and 3 times as a distractor
- order of targets is randomized
- signs are randomly assigned to two of 12 possible screen locations
- delays (of cross removal) are randomly selected from 1000-6000ms (see list.delays)

4. Test: with N = 3
- 12 trials with sets of 3 signs (no feedback) 
- each of the four signs is presented 3 times as a target 3 and 6 times as distractors
- each non-target sign is presented as a distractor twice with each target and never in the same combination:
Example: target left turn
presented with:
1: right turn, bicycle
2: right turn, pedestrian
3: pedestrian, bicycle
- order of trials is randomized
- signs are randomly assigned to three of 12 possible screen locations
- delays (of cross removal) are randomly selected from 1000-6000ms (see list.delays)

5. Test: with N = 6
- 12 trials with sets of 6 signs (no feedback)
- each target is presented 3 times
- !!!Distractor Selection (2 signs in each display have to be repeats):
 - distractor 1-3: sample from the non-target options (without replacement)
 - distractor 4-5 (repeated signs): sample from all options (without replacement)
 => it's randomly determined whether the target sign is one of the 'double' signs.
 => the frequency of each sign is not controlled for the N=6 trials
- order of trials is randomized
- signs are randomly assigned to six of 12 possible screen locations
- delays (of cross removal) are randomly selected from 1000-6000ms (see list.delays)

6. mixed design block (only run if parameters.runBlockedDesign is turned to false)
- 24 trials: 12 with N=3 and 12 with N = 6, randomized order

Trial Sequence:
fixation cross (until clicked with mouse)-> pretrialpause (default: 1000ms)
-> 3 (6) signs appear, all crossed out -> random delay: 1000-6000ms
-> one cross is removed: target -> waits for response
(Note: responses are collected from onset of stimuli, a valid response terminates the set-up
even if the target has been revealed yet. These trials are noted as "premature responses")


Screen Location of Signs:
- screen locations are randomly sampled from 12 possible screen locations (arranged in a 3 rows x 4 columns matrix) 


STIMULI
provided by Millisecond Software - can be edited under section Editable Stimuli
The signs are 4 traffic signs commonly used in the United States but can easily be exchanged.

INSTRUCTIONS
provided by Millisecond Software as html files.
To edit instructions, edit the html files directly.

EDITABLE CODE:
check below for (relatively) easily editable parameters, stimuli, instructions etc. 
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code to further customize your experiment.

The parameters you can change are:

/runBlockedDesign:							true (1): the test is split into 2 blocks: first block runs N=3; second block runs N=6 (default)
											false (0): N=3 and N=6 trials are run in a mixed design

/minHorizontalChange_px:					any horizontal mouse movements (in pixels) smaller than this value is ignored 
											and not processed as a response (default: 100 pixels).

/picSize:									the proportional size of the images (default: 20%)
											Note: if picSize is increased list.xcoordinates/list.ycoordinates need to be updated accordingly

/maxPractice1Blocks:						the maximum number of response practice blocks run if performance is too low (default: 2)
/practice1MinACC:							the minimum proportion correct that terminates practice 1 (response practice)

/pretrialpause:								the pause (in ms) after pressing the fixation cross and presentation of signs (default: 1000ms)
/responseReminder:							during practice (response learning) a response reminder is presented after this duration (in ms) (default: 5000ms))

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