diff --git a/+cltasks/startIEDmorphobes.m b/+cltasks/startIEDmorphobes.m
index d39b730..b8e03c2 100644
--- a/+cltasks/startIEDmorphobes.m
+++ b/+cltasks/startIEDmorphobes.m
@@ -47,14 +47,22 @@ function startIEDmorphobes(in)
 	if ~exist('in','var'); in = struct('task','ied','taskType','sd cd sr cr ids idr eds edr'); end
 	in = clutil.checkInput(in);
 
-	% Parse taskType into a row string array of stage codes
+	% Parse taskType into a row string array of stage codes.
+	% Accepts 'sd cd cr ...' or the GUI array-literal format
+	% '[ "sd" "sr" "cd" "cr" "ids" "idr" "eds" "edr" ]' (brackets, quotes
+	% and commas are stripped).
 	stages = string(in.taskType);
 	if isscalar(stages)
+		stages = replace(stages, {'[', ']', '"', '''', ',', ';'}, ' ');
 		stages = split(strip(stages));
 	end
-	stages = lower(stages(:)'); 
+	stages = lower(strip(stages));
+	stages = stages(~ismissing(stages) & stages ~= "");
+	stages = stages(:)';
 	in.stages = stages;
-	in.taskType = char(stages(1));
+	if ~isempty(stages)
+		in.taskType = char(stages(1));
+	end
 
 	% IED progression defaults
 	if ~isfield(in, 'criterion') || isempty(in.criterion); in.criterion = 6; end
@@ -67,16 +75,17 @@ function startIEDmorphobes(in)
 	end
 	numTargets = in.numTargets;
 
-	% Dimension assignment
+	% Dimension assignment — normalised with clutil.normaliseDimension so
+	% plurals ('appendages') and case variants ('Appendage') are accepted.
 	if ~isfield(in, 'idDimension') || isempty(in.idDimension)
-		in.idDimension = 'shape';
+		in.idDimension = 'colour';
 	end
 	if ~isfield(in, 'edDimension') || isempty(in.edDimension)
-		in.edDimension = 'colour';
+		in.edDimension = 'shape';
 	end
+	in.idDimension = clutil.normaliseDimension(in.idDimension);
+	in.edDimension = clutil.normaliseDimension(in.edDimension);
 	validDims = {'shape','colour','appendage','texture'};
-	in.idDimension = lower(char(in.idDimension));
-	in.edDimension = lower(char(in.edDimension));
 	if ~ismember(in.idDimension, validDims)
 		warning('idDimension ''%s'' invalid. Defaulting to colour.', in.idDimension);
 		in.idDimension = 'colour';
@@ -134,6 +143,15 @@ function startIEDmorphobes(in)
 		dimLevels = config.dimLevels;
 		setExemplars = config.setExemplars;
 
+		% Warn if the ED dimension is constant in the final set (EDS/EDR):
+		% the 2D config only varies shape+colour, so appendage/texture ED
+		% shifts are only meaningful with numTargets=4.
+		if numel(unique(dimLevels.(in.edDimension)(3, :))) < 2
+			warning('startIEDmorphobes:ConstantEDDimension', ...
+				'edDimension ''%s'' has constant levels in set 3 (EDS/EDR). For a meaningful ED shift use numTargets=4 (4D config varies all dimensions).', ...
+				in.edDimension);
+		end
+
 		%% ============================create targets in grid
 		targetL = imageStimulus('size', in.objectSize, 'randomiseSelection', false);
 		targets = metaStimulus('stimuli', repmat({targetL}, 1, numTargets));
diff --git a/+cltasks/startIEDmorphobes4D.m b/+cltasks/startIEDmorphobes4D.m
deleted file mode 100644
index 51e63f4..0000000
--- a/+cltasks/startIEDmorphobes4D.m
+++ /dev/null
@@ -1,421 +0,0 @@
-function startIEDmorphobes4D(in)
-	% startIEDmorphobes4D(in)
-	% Start a four-target, four-dimension Intra-Dimensional / Extra-Dimensional
-	% Set Shifting Task derived from CANTAB IED, using morphobes parametric
-	% microorganism stimuli.
-	%
-	% Four dimensions: shape (12), colour (8), appendage (7), texture (5).
-	% One dimension is the intradimensional (ID) dimension — relevant for
-	% SD through IDR. Another is the extradimensional (ED) shift target
-	% at EDS. The two remaining dimensions are irrelevant distractors
-	% throughout. The ID/ED assignment is configurable per session.
-	%
-	% Four targets are presented in a 2x2 grid. At each stage, one target
-	% is correct (determined by the relevant dimension's value). Criterion
-	% controls stage advancement; maxIncorrect triggers task termination.
-	%
-	% in comes from CageLab GUI or can be a struct with the following fields:
-	% Example:
-	%   in = struct();
-	%   in.taskType = 'sd cd cr ids idr eds edr'; % stages run in sequence
-	%   in.idDimension = 'colour'; % 'shape','colour','appendage','texture' — ID dim
-	%   in.edDimension = 'shape';  % 'shape','colour','appendage','texture' — ED dim
-	%   in.criterion = 6;         % consecutive correct to advance
-	%   in.maxIncorrect = 50;     % incorrect trials on stage before task terminates
-	%   in.objectSize = 8;        % size of objects in degrees
-	%   in.objectSep = 12;        % separation of objects in degrees
-	%   in.sampleY = 0;           % vertical centre of the 2x2 grid in degrees
-	%   in.trialTime = 5.0;       % max trial time in seconds
-	%   in.targetHoldTime = 0.2;  % target hold time in seconds
-	%   in.morphobesFolder = '';  % morphobes dataset folder (defaults to resources/morphobes_ied4d)
-	%
-
-	if ~exist('in','var'); in = struct('taskType','sd cd cr ids idr eds edr'); end
-	in = clutil.checkInput(in);
-
-	% Parse taskType into a row string array of stage codes
-	stages = string(in.taskType);
-	if isscalar(stages)
-		stages = split(strip(stages));
-	end
-	stages = lower(stages(:)');
-	in.stages = stages;
-	in.taskType = char(stages(1));
-
-	% IED progression defaults
-	if ~isfield(in, 'criterion') || isempty(in.criterion); in.criterion = 6; end
-	if ~isfield(in, 'maxIncorrect') || isempty(in.maxIncorrect); in.maxIncorrect = 50; end
-	in.totalTrials = 1e6;
-
-	% Dimension assignment
-	if ~isfield(in, 'idDimension') || isempty(in.idDimension)
-		in.idDimension = 'colour';
-	end
-	if ~isfield(in, 'edDimension') || isempty(in.edDimension)
-		in.edDimension = 'shape';
-	end
-	validDims = {'shape','colour','appendage','texture'};
-	in.idDimension = lower(char(in.idDimension));
-	in.edDimension = lower(char(in.edDimension));
-	if ~ismember(in.idDimension, validDims)
-		warning('idDimension ''%s'' invalid. Defaulting to colour.', in.idDimension);
-		in.idDimension = 'colour';
-	end
-	if ~ismember(in.edDimension, validDims)
-		warning('edDimension ''%s'' invalid. Defaulting to shape.', in.edDimension);
-		in.edDimension = 'shape';
-	end
-	if strcmp(in.idDimension, in.edDimension)
-		warning('idDimension and edDimension are the same. Using shape as edDimension.');
-		in.edDimension = setdiff(validDims, in.idDimension);
-		in.edDimension = in.edDimension{1};
-	end
-
-	% Morphobes dataset folder
-	if ~isfield(in, 'morphobesFolder') || isempty(in.morphobesFolder)
-		in.morphobesFolder = [in.folder filesep 'morphobes_ied4d'];
-	end
-
-	bgName = 'redmarbleA.jpg';
-	prefix = 'IEDmorphobes4D';
-
-	try
-		%% ============================shared initialisation
-		[sM, aM, rM, tM, r, dt, in] = clutil.initialise(in, bgName, prefix);
-
-		%% ============================load morphobes metadata
-		metaTable = readtable(fullfile(in.morphobesFolder, 'metadata.csv'), ...
-			'VariableNamingRule', 'preserve', 'TextType', 'string');
-
-		% 5-parameter lookup: (shape, colour, appendage, texture, exemplar)
-		lookupPNG = @(shapeLv, colourLv, appendageLv, textureLv, exemplar) ...
-			char(fullfile(in.morphobesFolder, metaTable.png_path(...
-				metaTable.shape_level == shapeLv & ...
-				metaTable.colour_level == colourLv & ...
-				metaTable.appendage_level == appendageLv & ...
-				metaTable.texture_level == textureLv & ...
-				metaTable.exemplar == exemplar)));
-
-		%% ============================dimension level configuration
-		% Each dimension: 3 sets of 4 levels (rows = sets, cols = targets 1-4).
-		% Set 1: SD, SR, CD, CR.  Set 2: IDS, IDR.  Set 3: EDS, EDR.
-		% Dimensions with fewer than 12 levels reuse levels across sets,
-		% using different exemplars to create novel-looking stimuli.
-		dimLevels = struct();
-		dimLevels.shape     = [0 1 2 3; 4 5 6 7; 0 1 2 3];   % 8 unique
-		dimLevels.colour    = [0 1 2 3; 4 5 6 7; 0 1 2 3];   % 8 unique
-		dimLevels.appendage = [0 1 2 3; 0 1 2 3; 0 1 2 3];   % 4 levels, all reuse
-		dimLevels.texture   = [0 1 2 3; 0 1 2 3; 0 1 2 3];   % 4 levels, all reuse
-
-		% Exemplar per set — all dimensions within a set use the same exemplar
-		% (exemplar affects shape, appendage, texture simultaneously; colour is unaffected)
-		setExemplars = [0 1 2];
-
-		%% ============================create 4 targets in 2x2 grid
-		targetL = imageStimulus('size', in.objectSize, 'randomiseSelection', false);
-		targets = metaStimulus('stimuli', {targetL, clone(targetL), clone(targetL), clone(targetL)});
-
-		% 2x2 grid positions: top-left, top-right, bottom-left, bottom-right
-		posX = [-in.objectSep/2, in.objectSep/2, -in.objectSep/2, in.objectSep/2];
-		posY = [in.objectSep/2, in.objectSep/2, -in.objectSep/2, -in.objectSep/2];
-		for i = 1:4
-			targets{i}.xPosition = posX(i);
-			targets{i}.yPosition = posY(i) + in.sampleY;
-		end
-		targets.stimulusSets{1} = 1:4;
-		targets.fixationChoice = 1;
-
-		%% ============================setup
-		setup(r.fix, sM);
-		setup(targets, sM);
-		hide(targets);
-		targets.edit(1:4, 'colourOut', [1 1 1]);
-
-		in.doNegation = true;
-
-		%% ============================validate all stages
-		validTaskTypes = {'sd','sr','cd','cr','ids','idr','eds','edr'};
-		for i = 1:length(stages)
-			if ~ismember(stages(i), validTaskTypes)
-				warning('Unknown task type %s. Defaulting to SD.', stages(i));
-				stages(i) = 'sd';
-			end
-		end
-		in.stages = stages;
-
-		%% ============================IED stage progression state
-		r.stageIdx = 1;
-		r.consecutiveCorrect = 0;
-		r.stageIncorrect = 0;
-		r.stageTrialN = 0;
-		r.stagesTotal = length(stages);
-		r.stagesCompleted = 0;
-		r.taskFailed = false;
-
-		%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-		while r.keepRunning
-
-			%% ==============================initialise trial
-			r = clutil.initTrialVariables(r);
-			txt = '';
-			fail = false; hld = false;
-
-			%% ==============================determine stage parameters
-			r.stage = stages(r.stageIdx);
-
-			% Set number
-			if ismember(r.stage, {'sd','sr','cd','cr'})
-				setNum = 1;
-			elseif ismember(r.stage, {'ids','idr'})
-				setNum = 2;
-			else
-				setNum = 3;
-			end
-
-			% Relevant dimension: ID for sets 1-2, ED for set 3
-			if setNum <= 2
-				relDim = in.idDimension;
-			else
-				relDim = in.edDimension;
-			end
-
-			% Correct value index: 1 for non-reversal, 2 for reversal
-			if ismember(r.stage, {'sr','cr','idr','edr'})
-				correctIdx = 2;
-			else
-				correctIdx = 1;
-			end
-
-			% Distractor behavior: constant (SD/SR) or randomised (CD+)
-			distractorsConstant = ismember(r.stage, {'sd','sr'});
-
-			% Exemplar for this set
-			exemplar = setExemplars(setNum);
-
-			% Distractor dimensions
-			allDims = {'shape','colour','appendage','texture'};
-			distDims = allDims(~strcmp(allDims, relDim));
-
-			% Log trial parameters
-			r.store.stage = r.stage;
-			r.store.stageIdx = r.stageIdx;
-			r.store.stagesTotal = r.stagesTotal;
-			r.store.consecutiveCorrect = r.consecutiveCorrect;
-			r.store.stageIncorrect = r.stageIncorrect;
-			r.store.stageTrialN = r.stageTrialN;
-			r.store.stagesCompleted = r.stagesCompleted;
-			r.store.taskFailed = r.taskFailed;
-			r.store.criterion = in.criterion;
-			r.store.maxIncorrect = in.maxIncorrect;
-			r.store.relDim = string(relDim);
-			r.store.idDim = string(in.idDimension);
-			r.store.edDim = string(in.edDimension);
-			r.store.setNum = setNum;
-			r.store.exemplar = exemplar;
-			r.store.distractorsConstant = distractorsConstant;
-
-			%% ==============================select stimuli for 4 targets
-			% Relevant dimension: 4 unique values from current set
-			relLevels = dimLevels.(relDim)(setNum, :);
-
-			% Stimulus values for 4 targets (column = target)
-			stimVals = struct('shape', zeros(1,4), 'colour', zeros(1,4), ...
-				'appendage', zeros(1,4), 'texture', zeros(1,4));
-			stimVals.(relDim) = relLevels;
-
-			% Set distractor values
-			if distractorsConstant
-				for d = 1:length(distDims)
-					stimVals.(distDims{d})(:) = 0;
-				end
-			else
-				for d = 1:length(distDims)
-					availLv = dimLevels.(distDims{d})(setNum, :);
-					stimVals.(distDims{d}) = availLv(randperm(4));
-				end
-			end
-
-			% Randomise positions
-			idx = randperm(4);
-
-			% Look up PNGs and assign to targets
-			pngs = strings(1, 4);
-			for t = 1:4
-				pngs(t) = lookupPNG(stimVals.shape(t), stimVals.colour(t), ...
-					stimVals.appendage(t), stimVals.texture(t), exemplar);
-				targets{idx(t)}.filePath = pngs(t);
-			end
-
-			% Set correct target
-			targets.fixationChoice = idx(correctIdx);
-
-			% Log stimulus config
-			r.store.idx = idx;
-			r.store.correctIdx = correctIdx;
-			r.store.stimVals = stimVals;
-			r.store.shapeVals = stimVals.shape;
-			r.store.colourVals = stimVals.colour;
-			r.store.appendageVals = stimVals.appendage;
-			r.store.textureVals = stimVals.texture;
-
-			% Trial info
-			r.sampleNames = pngs;
-			r.summary = sprintf(...
-				"4D | Stage: %s(%d/%d) | RelDim: %s | Excplr: %d | Correct: %d | SHA:%s CLA:%s APA:%s TXA:%s", ...
-				upper(r.stage), r.stageIdx, r.stagesTotal, ...
-				relDim, exemplar, idx(correctIdx), ...
-				strjoin(string(stimVals.shape),","), strjoin(string(stimVals.colour),","), ...
-				strjoin(string(stimVals.appendage),","), strjoin(string(stimVals.texture),","));
-
-			showSet(targets, 1);
-			update(targets);
-
-			%% ==============================Wait for release + initiate
-			r = clutil.ensureTouchRelease(r, tM, sM, false);
-			[r, dt, r.vblInitT] = clutil.initTouchTrial(r, in, tM, sM, dt);
-
-			%% ==============================stimulus presentation
-			if matches(string(r.touchInit), "yes")
-
-				r.trialN = r.trialN + 1;
-				r.touchResponse = '';
-
-				[x, y] = targets.getFixationPositions;
-				tM.updateWindow(x, y, repmat(in.objectSize/1.9, 1, length(x)),...
-				repmat(in.doNegation, 1, length(x)), ones(1, length(x)), true(1, length(x)),...
-				repmat(in.trialTime, 1, length(x)), ...
-				repmat(in.targetHoldTime, 1, length(x)), ones(1, length(x)));
-
-				if ~isempty(r.sbg); draw(r.sbg); end
-				vbl = flip(sM);
-				r.stimOnsetTime = vbl;
-				r.vblInit = vbl + r.sv.ifi;
-				syncTime(tM, r.vblInit);
-
-				while isempty(r.touchResponse) && vbl <= (r.vblInit + in.trialTime)
-					if ~isempty(r.sbg); draw(r.sbg); end
-					draw(targets);
-					if in.debug && ~isempty(tM.x) && ~isempty(tM.y)
-						drawText(sM, txt);
-						xy = sM.toPixels([tM.x tM.y]);
-						Screen('glPoint', sM.win, [1 0 0], xy(1), xy(2), 10);
-					end
-					vbl = flip(sM);
-					% [out, held, heldtime, release, releasing, searching, failed, touch, negation] = testHold
-					[r.touchResponse, hld, r.hldtime, rel, ~, ~, fail, tch, negation] = testHold(tM, 'yes', 'no');
-					if tch || negation
-						r.reactionTime = vbl - r.vblInit;
-						r.anyTouch = true;
-					end
-					if in.debug; txt = sprintf('Response=%i x=%.2f y=%.2f h:%i ht:%i r:%i tch:%i fail:%i neg:%i',...
-						r.touchResponse, tM.x, tM.y, hld, r.hldtime, rel, ...
-						tch, fail, negation);
-					end
-					[~,~,c] = KbCheck();
-					if c(r.quitKey); r.keepRunning = false; break; end
-					if c(r.shotKey); sM.captureScreen; end
-				end
-			end
-
-			r.vblFinal = GetSecs;
-			r.value = hld;
-
-			%% ==============================check result logic
-			if matches(r.touchInit, 'no')
-				r.result = -5;
-			elseif fail || hld == -100 || matches(r.touchResponse, 'no')
-				r.result = 0;
-			elseif matches(r.touchResponse, 'yes')
-				r.result = 1;
-			else
-				r.result = -1;
-			end
-
-			% Determine chosen target from touchManager's windowTouched
-			if tch && tM.windowTouched > 0 && tM.windowTouched <= 4
-				chosenTarget = tM.windowTouched;
-			else
-				chosenTarget = 0;
-			end
-
-			%% ==============================store trial outcome
-			r.store.result = r.result;
-			r.store.anyTouch = r.anyTouch;
-			r.store.chosenTarget = chosenTarget;
-			r.store.fixationChoice = targets.fixationChoice;
-			r.store.correctDim = string(relDim);
-
-			%% ==============================Wait for release + update
-			r = clutil.ensureTouchRelease(r, tM, sM, true);
-			[dt, r] = clutil.updateTrialResult(in, dt, r, sM, tM, rM, aM);
-
-			%% ==============================IED stage progression
-			if r.keepRunning && (r.result == 1 || r.result == 0)
-				r.stageTrialN = r.stageTrialN + 1;
-				if r.result == 1
-					r.consecutiveCorrect = r.consecutiveCorrect + 1;
-				else
-					r.consecutiveCorrect = 0;
-					r.stageIncorrect = r.stageIncorrect + 1;
-				end
-
-				if r.consecutiveCorrect >= in.criterion
-					r.stagesCompleted = r.stagesCompleted + 1;
-					t = sprintf('===> Stage %d/%d [%s] CRITERION MET (%d correct, %d trials, dim=%s)', ...
-						r.stageIdx, r.stagesTotal, upper(r.stage), r.consecutiveCorrect, r.stageTrialN, relDim);
-					addMessage(r.tL, r.loopN, GetSecs, [], t, "getsecs", "Experimental-note");
-					disp(t);
-
-					if r.stageIdx < r.stagesTotal
-						r.stageIdx = r.stageIdx + 1;
-						r.consecutiveCorrect = 0;
-						r.stageIncorrect = 0;
-						r.stageTrialN = 0;
-						t = sprintf('===> Advancing to stage %d/%d: %s', ...
-							r.stageIdx, r.stagesTotal, upper(stages(r.stageIdx)));
-						addMessage(r.tL, r.loopN, GetSecs, [], t, "getsecs", "Experimental-note");
-						disp(t);
-					else
-						t = sprintf('===> All %d stages complete. IED 4D task finished.', r.stagesTotal);
-						addMessage(r.tL, r.loopN, GetSecs, [], t, "getsecs", "Experimental-note");
-						disp(t);
-						r.keepRunning = false;
-					end
-
-				elseif r.stageIncorrect >= in.maxIncorrect
-					r.taskFailed = true;
-					t = sprintf('===> Stage %d/%d [%s] FAILED (%d incorrect, %d trials). Task terminated.', ...
-						r.stageIdx, r.stagesTotal, upper(r.stage), r.stageIncorrect, r.stageTrialN);
-					addMessage(r.tL, r.loopN, GetSecs, [], t, "getsecs", "Experimental-note");
-					disp(t);
-					r.keepRunning = false;
-				end
-			end
-
-		end % while keepRunning
-
-		%% ================================shutdown
-		clutil.endTask(dt, in, r, sM, tM, rM, aM);
-
-	catch ME
-		getReport(ME)
-		try writelines(sprintf("Error IEDmorphobes4D: " + ME.Message), "~/cagelab-start.txt", WriteMode="append"); end
-		try if in.remote; r.status.updateStatusToStopped();end;end
-		try clutil.broadcastTrial(in, r, dt, false); end
-		try if IsLinux && in.remote; system('xset s 600 dpms 600 0 0'); end; end
-		try reset(targets); end %#ok<*TRYNC>
-		try reset(r.fix); end
-		try reset(r.rtarget); end
-		try reset(r.sbg); end
-		try close(sM); end
-		try close(tM); end
-		try close(rM); end
-		try close(aM); end
-		try Priority(0); end
-		try ListenChar(0); end
-		try RestrictKeysForKbCheck([]); end
-		try ShowCursor; end
-		rethrow(ME)
-	end
-
-end
diff --git a/+clutil/checkInput.m b/+clutil/checkInput.m
index f594c93..fdc60bd 100644
--- a/+clutil/checkInput.m
+++ b/+clutil/checkInput.m
@@ -103,6 +103,12 @@
 	defaults.easyMode = true;
 	defaults.ITI = 1;
 
+	% Capture which fields the caller actually supplied BEFORE the generic
+	% defaults fill below, so user overrides (e.g. numTargets=4 or
+	% edDimension='appendage') are never silently overwritten, while
+	% missing fields still receive the task-specific defaults.
+	userFields = fieldnames(in);
+
 	fields = fieldnames(defaults);
 	for i = 1:numel(fields)
 		f = fields{i};
@@ -115,42 +121,53 @@
 		case {'dmts' 'dnts' 'mts' 'nmts'}
 
 		case 'ied'
-			in.taskType = 'sd cd cr ids idr eds edr'; % stages run in sequence
-			in.numTargets = 2;        % 2D variant: two targets (left/right)
-			in.idDimension = 'colour'; % 'shape','colour','appendage','texture' — ID dim
-			in.edDimension = 'shape';  % 'shape','colour','appendage','texture' — ED dim
-			in.criterion = 6;         % consecutive correct to advance
-			in.maxIncorrect = 50;     % incorrect trials on stage before task terminates
-			in.objectSize = 10;       % size of objects in degrees
-			in.objectSep = 15;        % separation of objects in degrees
-			in.sampleY = 0;           % vertical position in degrees
-			in.trialTime = 5.0;				% max trial time in seconds
-			in.targetHoldTime = 0.2;	% target hold time in seconds
-			in.morphobesFolder = '';	% morphobes dataset folder (defaults to resources/morphobes_ied)
-			in.fixSize = 2;				% fixation size in degrees
-			in.fixWindow = 4;			% fixation window size in degrees
+			% Classic 'ied' defaults to 2D, but if the caller explicitly
+			% sets numTargets=4 then 4D sizing follows.
+			n = 2;
+			if isfield(in, 'numTargets') && ~isempty(in.numTargets)
+				n = in.numTargets;
+			end
+			if n == 4
+				in = applyIedDefaults(in, userFields, 4, 8, 12);
+			else
+				in = applyIedDefaults(in, userFields, 2, 10, 15);
+			end
 		case {'ied-2' 'ied-4'}
-			in.taskType = 'sd cd cr ids idr eds edr'; % stages run in sequence
-			in.idDimension = 'colour'; % 'shape','colour','appendage','texture' — ID dim
-			in.edDimension = 'shape';  % 'shape','colour','appendage','texture' — ED dim
-			in.criterion = 6;         % consecutive correct to advance
-			in.maxIncorrect = 50;     % incorrect trials on stage before task terminates
-			in.objectSize = 8;        % size of objects in degrees
-			in.objectSep = 12;        % separation of objects in degrees
-			in.sampleY = 0;           % vertical centre of the 2x2 grid in degrees
-			in.trialTime = 5.0;				% max trial time in seconds
-			in.targetHoldTime = 0.2;	% target hold time in seconds
-			in.morphobesFolder = '';	% morphobes dataset folder (defaults to resources/morphobes)
-			in.fixSize = 2;				% fixation size in degrees
-			in.fixWindow = 4;			% fixation window size in degrees
 			if strcmp(in.task, 'ied-2')
-				in.numTargets = 2;    % 2D variant: two targets (left/right)
+				n = 2;
 			else
-				in.numTargets = 4;    % 4D variant: four targets in 2x2 grid
+				n = 4;
 			end
+			in = applyIedDefaults(in, userFields, n, 8, 12);
 		otherwise
 
 	end
+end
 
-
+% ===================================================================
+%> @brief Apply IED task defaults, but never overwrite a field the caller
+%> explicitly supplied (tracked in userFields).
+% ===================================================================
+function in = applyIedDefaults(in, userFields, numTargets, objectSize, objectSep)
+	iedDefaults = struct( ...
+		'taskType', 'sd cd cr ids idr eds edr', ...
+		'numTargets', numTargets, ...
+		'idDimension', 'colour', ...
+		'edDimension', 'shape', ...
+		'criterion', 6, ...
+		'maxIncorrect', 50, ...
+		'objectSize', objectSize, ...
+		'objectSep', objectSep, ...
+		'sampleY', 0, ...
+		'trialTime', 5.0, ...
+		'targetHoldTime', 0.2, ...
+		'morphobesFolder', '', ...
+		'fixSize', 2, ...
+		'fixWindow', 4);
+	f = fieldnames(iedDefaults);
+	for i = 1:numel(f)
+		if ~ismember(f{i}, userFields) || isempty(in.(f{i}))
+			in.(f{i}) = iedDefaults.(f{i});
+		end
+	end
 end
diff --git a/+clutil/normaliseDimension.m b/+clutil/normaliseDimension.m
new file mode 100644
index 0000000..9b8fb6c
--- /dev/null
+++ b/+clutil/normaliseDimension.m
@@ -0,0 +1,32 @@
+function dim = normaliseDimension(dim)
+	% NORMALISEDIMENSION Normalise a morphobes dimension name to its
+	% canonical singular form.
+	%   dim = normaliseDimension(dim)
+	%
+	% Accepts case-insensitive, plural and whitespace-tolerant variants:
+	%   'shape' / 'shapes'         -> 'shape'
+	%   'colour' / 'colours'       -> 'colour'
+	%   'appendage' / 'appendages' -> 'appendage'
+	%   'texture' / 'textures'     -> 'texture'
+	% Anything else returns '' so the caller can warn and apply a default.
+	%
+	% @param dim char|string dimension name to normalise
+	% @return dim char canonical dimension name or ''
+	arguments (Input)
+		dim {mustBeTextScalar}
+	end
+	arguments (Output)
+		dim char
+	end
+	dim = strip(lower(char(dim)));
+	% strip a trailing 's' to accept plurals, e.g. appendages -> appendage
+	if endsWith(dim, 's') && numel(dim) > 1
+		cand = dim(1:end-1);
+		if ismember(cand, {'shape', 'colour', 'appendage', 'texture'})
+			dim = cand;
+		end
+	end
+	if ~ismember(dim, {'shape', 'colour', 'appendage', 'texture'})
+		dim = '';
+	end
+end
diff --git a/tests/ClutilTest.m b/tests/ClutilTest.m
index 5a793c3..d12dca7 100644
--- a/tests/ClutilTest.m
+++ b/tests/ClutilTest.m
@@ -47,7 +47,8 @@ function testCheckInputDefaults(testCase)
 			verifyEqual(testCase, in.port, 9012);
 			verifyTrue(testCase, in.debug);
 			verifyTrue(testCase, in.dummy);
-			verifyEqual(testCase, in.task, 'generic');
+			verifyEqual(testCase, in.task, 'train', ...
+				'default task is train (touch training)');
 			verifyEqual(testCase, in.session.subjectName, 'TestSubject');
 			repoRoot = fileparts(fileparts(which('clutil.checkInput')));
 			verifyEqual(testCase, in.folder, ...
diff --git a/tests/StartIEDMorphobesTest.m b/tests/StartIEDMorphobesTest.m
index c752b3d..1231d59 100644
--- a/tests/StartIEDMorphobesTest.m
+++ b/tests/StartIEDMorphobesTest.m
@@ -123,6 +123,102 @@ function testCheckInputIed4Defaults(testCase)
 				"sd cd cr ids idr eds edr");
 		end
 
+		% ===================================================================
+		%> @brief User-supplied numTargets must NOT be overwritten by the
+		%> task defaults (regression: task='ied' + numTargets=4 previously
+		%> collapsed to two targets).
+		% ===================================================================
+		function testCheckInputIedRespectsUserNumTargets(testCase)
+			in = clutil.checkInput(struct('task', 'ied', 'numTargets', 4));
+			verifyEqual(testCase, in.numTargets, 4, ...
+				'numTargets=4 with task=ied must be preserved');
+			verifyEqual(testCase, in.objectSize, 8, ...
+				'4D sizing applies when numTargets=4');
+
+			in2 = clutil.checkInput(struct('task', 'ied', 'numTargets', 2));
+			verifyEqual(testCase, in2.numTargets, 2);
+			verifyEqual(testCase, in2.objectSize, 10, ...
+				'2D sizing applies when numTargets=2');
+		end
+
+		% ===================================================================
+		%> @brief User-supplied id/ed dimensions must NOT be overwritten by
+		%> the task defaults (regression: edDimension='appendage' previously
+		%> collapsed to shape).
+		% ===================================================================
+		function testCheckInputIedRespectsUserDimensions(testCase)
+			in = clutil.checkInput(struct('task', 'ied', ...
+				'edDimension', 'appendage', 'idDimension', 'texture'));
+			verifyEqual(testCase, in.edDimension, 'appendage', ...
+				'edDimension=appendage must be preserved');
+			verifyEqual(testCase, in.idDimension, 'texture', ...
+				'idDimension=texture must be preserved');
+		end
+
+		% ===================================================================
+		%> @brief User-supplied criterion/maxIncorrect must be preserved.
+		% ===================================================================
+		function testCheckInputIedRespectsUserCriteria(testCase)
+			in = clutil.checkInput(struct('task', 'ied', ...
+				'criterion', 2, 'maxIncorrect', 3));
+			verifyEqual(testCase, in.criterion, 2);
+			verifyEqual(testCase, in.maxIncorrect, 3);
+		end
+
+		% ===================================================================
+		%> @brief clutil.normaliseDimension handles plurals, case and
+		%> whitespace variants of the four morphobes dimensions.
+		% ===================================================================
+		function testNormaliseDimension(testCase)
+			verifyEqual(testCase, clutil.normaliseDimension('appendage'), 'appendage');
+			verifyEqual(testCase, clutil.normaliseDimension('appendages'), 'appendage');
+			verifyEqual(testCase, clutil.normaliseDimension('Appendage'), 'appendage');
+			verifyEqual(testCase, clutil.normaliseDimension('APPENDAGES'), 'appendage');
+			verifyEqual(testCase, clutil.normaliseDimension('shape'), 'shape');
+			verifyEqual(testCase, clutil.normaliseDimension('shapes'), 'shape');
+			verifyEqual(testCase, clutil.normaliseDimension('colour'), 'colour');
+			verifyEqual(testCase, clutil.normaliseDimension('colours'), 'colour');
+			verifyEqual(testCase, clutil.normaliseDimension('texture'), 'texture');
+			verifyEqual(testCase, clutil.normaliseDimension('textures'), 'texture');
+			verifyEqual(testCase, clutil.normaliseDimension('  shape  '), 'shape');
+			verifyEqual(testCase, clutil.normaliseDimension('sound'), '', ...
+				'invalid dimension returns empty');
+			verifyEqual(testCase, clutil.normaliseDimension(''), '', ...
+				'empty returns empty');
+		end
+
+		% ===================================================================
+		%> @brief The task source uses the normaliseDimension helper and
+		%> the EDS/EDR stage switches to the configured ED dimension.
+		% ===================================================================
+		function testSourceUsesEDDimensionForShift(testCase)
+			source = fileread(which('cltasks.startIEDmorphobes'));
+			verifyTrue(testCase, contains(source, 'clutil.normaliseDimension'));
+			verifyTrue(testCase, contains(source, 'relDim = in.edDimension'));
+			verifyTrue(testCase, contains(source, 'relDim = in.idDimension'));
+		end
+
+		% ===================================================================
+		%> @brief The task stage parser accepts the GUI's bracket/quoted
+		%> taskType format: '[ "sd" "sr" ... ]'.
+		% ===================================================================
+		function testSourceParsesGuiTaskType(testCase)
+			source = fileread(which('cltasks.startIEDmorphobes'));
+			verifyTrue(testCase, contains(source, '''['''), ...
+				'source strips brackets from taskType');
+			verifyTrue(testCase, contains(source, 'replace(stages'));
+		end
+
+		% ===================================================================
+		%> @brief EDS/EDR with appendage ED is only meaningful in 4D; the
+		%> source must warn when the ED dimension has constant levels.
+		% ===================================================================
+		function testSourceWarnsConstantEDDimension(testCase)
+			source = fileread(which('cltasks.startIEDmorphobes'));
+			verifyTrue(testCase, contains(source, 'ConstantEDDimension'));
+			verifyTrue(testCase, contains(source, 'numTargets=4'));
+		end
+
 		% ===================================================================
 		%> @brief All eight CANTAB IED stages remain in the task source.
 		% ===================================================================