Table 1.

Materials, stimuli and targeted participant tasks by experiment phase.

	Materials and Stimuli Available	Participant Task
Pretraining: Sample Coding Training	Handheld arrow card available. Verbal cue, “Where does it go?” Sample S shown on computer screen, visual cues on screen used to indicate arrow card placement. Cues then faded.	Coded sample stimuli by placing arrow card in specific position relative to axis of symmetry (symmetrical shapes only) of shape.
Pre-training: Comparison Coding Training	Handheld arrow card available. Comparison stimuli shown on computer screen. Single comparison shown at first. Additional distracter comparisons added after mastery with each number of comparisons. Verbal cue, “Where is it?”	Ss taught to code the stimulus that corresponded to the arrow card when the arrow card was given in a particular orientation.
Pre-training: Orientation Rotation Training	Handheld arrow card available. Verbal cue, “How do you turn it?” Rotation cues shown on computer screen at 90, 180, 270 and 360 degree position plus rotation cues on arrow cards.	Trained Ss to rotate arrow card 90 degrees clockwise from position at beginning of trial.
Pre-training: Final Training	All verbal cues faded systematically. Comparisons first displayed after sample was coded, then comparisons and samples displayed at same time. Handheld arrow card available.	Ss trained to code sample in the presence of sample plus comparisons, rotate arrow card then select corresponding comparison. 12 trials.
Probe: Training Set Baseline	Training set shapes shown on computer screen. Each screen included sample in the middle plus comparisons in each corner. Handheld arrow card available.	Ss Tested for coding sample in the presence of sample plus comparisons, rotating arrow card, then selecting corresponding comparison. Twelve trials.
Probe: Transfer Set 1	Computer screens with training set shapes, including samples plus comparisons; interspersed with similar screens containing new shapes. Handheld arrow card available.	The task was the same as in Training Set Baseline, above, except consisted of 24 trials instead of 12.
Probe: Coding Response Prevention	Same arrangement as Transfer Set 1 except handheld arrow card NOT available.	The task was similar to that in Training Set Baseline, above, except that the arrow card was NOT available.
Probe: Transfer Set 2	Computer screens with training set shapes, interspersed with similar screens containing second set of new shapes. Handheld arrow card available.	The task was the same as in Training Set Baseline, above.