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Tower of London Task (TOL) -- Krikorian et al. (1994) Version
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Script Author: David Nitz (dave@millisecond.com) for Millisecond Software, LLC
last updated: 07-22-2021 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 07-22-2021 Millisecond Software
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BACKGROUND INFO
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This script implements the 'Tower of London' task, an assessment of executive functioning
with a focus on planning abilities.
References:
Shallice, T. (1982). Specifc impairments of planning. Philosophical Transactions of the Royal
Society of London, Biology, 298, 199-209.
Procedural details were adapted from:
Krikorian, R., Bartok, J., & Gay, N. (1994). Tower of London procedure: A standard method
and developmental data. Journal of Clinical and Experimental Neuropsychology, 16, 840-850.
Task instructions were adapted from:
Anderson, P., Anderson, V., & Lajoie, G. (1996). The Tower of London test: Validation and
standardization for pediatric populations. The Clinical Neuropsychologist, 10, 54-65.
Further references:
Berg, W. K. & Byrd, D. L. (2002). The Tower of London spatial problem-solving task:
Enhancing clinical and research implementation. Journal of Clinical and Experimental
Neuropsychology, 24(5), 586-604.
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TASK DESCRIPTION
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Participants are asked to arrange three colorful discs on 3 provided pegs
in a specific solution pattern in as few moves as possible.
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DURATION
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the default set-up of the script takes appr. 10 minutes to complete
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DATA FILE INFORMATION
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The default data stored in the data files are:
(1) Raw data file: 'toweroflondon_raw*.iqdat' (a separate file for each participant)
build: The specific Inquisit version used (the 'build') that was run
computer.platform: the platform the script was run on (win/mac/ios/android)
date, time, date and time script was run
subject, group, with the current subject/groupnumber
script.sessionid: with the current session id
blockcode, blocknum: the name and number of the current block (built-in Inquisit variable)
trialcode, trialnum: the name and number of the currently recorded trial (built-in Inquisit variable)
Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those
that do not store data to the data file such as feedback trials. Thus, trialnum
may not reflect the number of main trials run per block.
response: response made (contains the last peg a disc was moved to or 0 for noresponse)
latency: the latency of the response in ms (or if no response: trialduration)
trial.choice.lastdroplatency: time (in ms) between intialization of the last move and its completion; move execution time
trial.choice.lastdropsource: the last moved disc (R, B, G)
trial.choice.lastdroptarget: the last peg that a disc was moved to (apeg, bpeg, cpeg)
values.problemnumber Current problem number. By default the task consists of 1 practice
problem and 12 test problems presented sequentially. 0 indicates
a practice problem.
values.subjectattempts Number of current attempts to solve the given problem.
values.targetmoves Number of prescribed moves for the current problem.
values.subjectmoves Number of subject-performed moves for the current problem.
expressions.excessmoves Returns the difference between number of moves performed by the subject and the
number of target moves for a given problem.
values.movestring Text string containing a record of performed moves. E.g. "B2R3"
indicates that the blue ball (B) was moved to peg 2 (center) and
the red ball (R) was moved to peg 3 (right).
expressions.targetachieved Returns true as soon as the subject has successfully reached a given
problem's target / goal state. Otherwise false.
values.problemscore Score awarded for solving the current problem. See Krikorian et
al. (1994) for details.
values.totalscore Score achieved across the whole set of test problems. Computed
as the sum of individual problem scores. Maximum is 36 in the
standard version.
expressions.firstmovetime Returns the time (in ms) elapsed between initial presentation of
the target configuration and the initialization of the subject's first
move. Sometimes also referred to as "planning time" or simply
"latency". Note: Measure is computed separately for each attempt.
expressions.executiontime Computed as solutiontime - firstmovetime. Note: Measure is
computed separately for each attempt.
expressions.solutiontime Returns the time (in ms) elapsed between initial presentation of
the target configuration and a subject's successful solution.
Note: Measure is computed separately for each attempt.
values.t_choicestart Absolute start time for trial.choice in ms. May be used to derive
additional measures during data analysis (e.g. mean move time).
values.t_choiceend Absolute end time for trial.choice in ms. May be used to derive
additional measures during data analysis (e.g. mean move time).
values.t_firstmove Absolute script timestamp in ms for valid first move
(2) Summary data file: 'toweroflondon_summary*.iqdat' (a separate file for each participant)
computer.platform: the platform the script was run on (win/mac/ios/android)
script.startdate: date script was run
script.starttime: time script was started
script.subjectid: assigned subject id number
script.groupid: assigned group id number
script.sessionid: assigned session id number
script.elapsedtime: time it took to run script (in ms); measured from onset to offset of script
script.completed: 0 = script was not completed (prematurely aborted);
1 = script was completed (all conditions run)
values.totalscore: Score achieved across the whole set of test problems.
Computed as the sum of individual problem scores. Maximum is 36 in the standard version.
Note: the following variables are calculated independent of accuracy of solution:
expressions.mean_solutionTime: the mean solution time (in ms) of all solutions with solutiontime > 0
expressions.SD_solutionTime: the standard deviation (in ms) of solution times of solutions with solutiontime > 0
expressions.mean_executionTime: the mean execution time (in ms) of all solutions with solutiontime > 0
expressions.SD_executionTime: the standard deviation (in ms) of all execution times of all completed solutions with solutiontime > 0
Note: the following variables are calculated for solutions with values.problemscore > 0:
/mean_solutionTime_correctSolutions: the mean solution time (in ms) of all solutions with values.problemscore > 0
/SD_solutionTime_correctSolutions: the standard deviation (in ms) of solution times of solutions values.problemscore > 0
/mean_executionTime_correctSolutions: the mean execution time (in ms) of all solutions with values.problemscore > 0
/SD_executionTime_correctSolutions: the standard deviation (in ms) of all execution times of all completed solutions with values.problemscore > 0
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EXPERIMENTAL SET-UP
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1 Practice trial (problem with 2 moves)
12 Test trials (2 problems with 2 moves, 2 problems with 3 moves, 4 problems with 4 moves, 4 problems with 5 moves:
tested sequentially in fixed order)
Per Problem:
* no time limit
* reset button provided
* 3 attempts per problem to solve it given the max. number of moves. After failure to solve a problem in 3 attempts,
participants are moved to the next problem in the sequence (participants can also move ahead to the next problem
by clicking a 'next' button)
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STIMULI
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see section Editable Stimuli
(to re-create new target states, try EmptyPegs.pptx - provided by Millisecond Software)
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INSTRUCTIONS
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see section Editable Instructions. Instructions are provided in the form of *.html pages. Edits can be made
to the html-files directly.
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EDITABLE CODE
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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:
maxattempts Allowed number of attempts to solve any given problem with
minimum amount of moves. Default is 3.
npracticeproblems Number of practice problems. By default, the task contains 1
practice problem and 12 test problems. Default is 1.
n_a_slots Capacity of peg 1 (left). Default is 3.
n_b_slots Capacity of peg 2 (center). Default is 2.
n_c_slots Capacity of peg 3 (right). Default is 1.
intertrialinterval The intertrial interval (time between problems) in ms. Default is 1000.
feedbackduration Duration of performance feedback in ms. Default is 2000.
h1 -> h3 Horizontal coordinates of pegs 1, 2 and 3 in screen percentages.
Defaults are 20%, 50% and 80%.
v1 -> v3 Available vertical coordinates for the three balls in screen
percentages. Defaults are 80%, 65%, 50%.
r_startX, r_startY Determines the red ball's start position (horizontal, vertical).
g_startX, g_startY Determines the green ball's start position (horizontal, vertical).
b_startX, b_startY Determines the blue ball's start position (horizontal, vertical).