4. Variation criteria

4.1 What is a variation?

A variation is a named version of a task that changes what the participant experiences or does such that the event structure in the recorded data would differ. The key test:

If you compared the event logs from the standard version and the variation, would there be structural differences in the types of events, their temporal organization, or the participant’s required responses?

4.2 Examples of genuine variations

• Different response modalities: Verbal naming vs. button press (Picture Naming Task)

• Different stimulus configurations: Simultaneous masking vs. forward masking vs. backward masking (Auditory Masking Task)

• Different cognitive demands: 1-choice vs. 2-choice vs. go/no-go versions of the same paradigm

• Different task structures: Blocked vs. interleaved conditions when this changes what the participant must track (e.g., interleaved pro/anti-saccade trials require task-set switching)

• Additional participant actions: Production version of AGL (participant generates strings, not just judges them)

• Different stimulus-response mappings: Prosaccade vs. antisaccade (same cue, opposite required response)

• Named sub-paradigms: Sally-Anne, Smarties Task, Animated Triangles as distinct False Belief implementations

• With vs. without response feedback: Continuous Performance Task

4.3 What is NOT a variation? (12 active DROP categories + 1 retired)

The following do not count as task variations because they do not change what the participant experiences or does (EMOT was retired; see section 5.1):

Code	Category	Description	Examples
MEAS	Measurement modality	Adding or changing recording equipment	“with fMRI,” “with EEG,” “with eye-tracking,” “with SCR/startle probe,” “with MEG,” “with TMS recording”
ANAL	Analysis method	Post-hoc data analysis technique	Computational modeling, DDM, ROC analysis, Gratton effect analysis, process dissociation, clustering analysis, strategy analysis, locus-of-slack logic, reverse correlation
DESG	Design/parameter choice	Experimenter decisions about trial structure	Blocked vs. event-related design, varying ISI/SOA (as generic sweep), parametric difficulty, variable set size (as parameter sweep), speed-accuracy tradeoff instructions
STIM	Stimulus substitution	Swapping one stimulus set for an equivalent one	IAPS->OASIS/NAPS, race-specific face sets with identical procedures, alternative word lists, translated stimuli
POPL	Population/clinical use	Testing a different population	“in amnesia,” “for children” (unless procedure changes), “clinical screening,” “developmental version,” “in schizophrenia,” cross-cultural comparison
IDIF	Individual differences	Using a task as a correlational measure	“as individual differences measure,” correlational studies
TRAN	Training/intervention	Using repeated task exposure as an intervention	Bias modification training, working memory training, practice/training interventions, memory specificity training
PHAR	Pharmacological challenge	Administering drugs during the task	“under pharmacological challenge,” medication on/off designs
SCOR	Scoring method	How performance is quantified	Partial-credit scoring, B-minus-A derived scores, B/A ratio, trial-level bias scores
ALIA	Alias/redundant	Restates the canonical task or duplicates another variation	“Standard X” that merely restates the canonical definition, near-duplicate entries from dual-source generation
MOTI	Motivation/reward add-on	Adding incentives without changing task structure	“Rewarded X,” reward modulation, mood induction before task
DUAL	Dual-task add-on	Adding a concurrent secondary task	Articulatory suppression, working memory load, concurrent secondary task (unless it creates a recognized named paradigm)
EMOT	Emotional stimulus swap - RETIRED	~~Replacing neutral stimuli with emotional ones~~	This category was retired by user decision. All attested Emotional-X paradigms are now kept as variations under their parent tasks. No emotional variations are dropped on EMOT grounds. See section 5.1 for the resolution.

4.4 Applying the criteria consistently

The DROP categories are applied uniformly across all 103 tasks. If “with fMRI” is dropped for one task, it must be dropped for all tasks. If “in children” is dropped when only stimuli change for age-appropriateness, it must be dropped everywhere that applies.

The one exception is when a modification creates a recognized named paradigm with its own literature. For example, the Emotional Stroop Task is kept as a separate top-level task entry because it has a distinct, established identity in the literature. Note that the EMOT category was retired entirely (see section 5.1) - all attested Emotional-X paradigms are now kept as variations, whether or not they have independent literatures.