Table 2.

Svartdal (2008) experimental versus simulations-based set-up

	Svartdal (2008)	Simulation
Subjects	56 students (male and female)	50 simulations with different initial random seeds
Apparatus	(1) A vertical metal console (33 $\times$ 33 cm), (2) two transluminated ’stimulus’ keys on a table in front of the console, (3) two push button ‘response’ keys on table, (4) sound attenuated room	MATLAB program adapting Cosivina NeuralGdynamic software framework (http://roboticsschool.ini.rub.de/software.php)
External stimuli	Stim. 1 $=$ red light, Stim. 2 $=$ green light	Binary valued Stimulus 1 and Stimulus 2
Pre-training	No	No
Acquisition learning trials	180 trials	180 trials
Extinction trials	40 trials	40 trials
Inter-trial interval (ITI)	3 s	No ITI, neural activation reset at the end of trial
Inter-stimulus interval (ISI)	0.7 s	22 processing steps (stimulus outcome)
Response requirement	To choose opposite sequence from that presented by the computer on lamps on the vertical console. 4 possible response contingencies: LL, LR, RL, RR (wrt push button positions). So 1/4 correct chance over blocks of 5 trials	A single response selection.
Response reward	Rewards $=$ score of 1 at probability: High dens $=$ 0.8 Low dens $=$ 0.4	Rewards $=$ score of 1 at probability: High dens $=$ 0.8 Low dens $=$ 0.4
Between-subjects design	LOW: S1 & S2$\to$Low dens $=$ 0.4; HIGH: S1 & S2$\to$High dens $=$ 0.8.	LOW: S1 & S2: Low dens $=$ 0.4; HIGH: S1 & S2: High dens $=$ 0.8
Trial ordering	Random presentation of S1 or S2	(1) Trial transition probability pseudo-random; (2) No more than 3 successive trials of the same type could occur (for CRF and PRF types)