Parameters of the 2CE1 model.

Fitted parameters for the preferred 2CE1 model are listed for each participant group based on learning performance. To characterize the dimensions of distinct behavioral profiles for each participant, the signs of individual fits are categorized as “discriminative” (-1 ≤ gA < 0) or “none” (gA = 0) for action generalization; “discriminative” (-1 ≤ gS < 0), “none” (gS = 0), or “associative” (0 < gS ≤ 1) for state generalization; “leftward” or (βR < 0) “rightward” (βR > 0) for constant bias; and “alternation” (β1 < 0) or “repetition” (β1 > 0) for hysteretic bias. Also listed are metrics for absolute constant bias |βR|, absolute hysteretic bias |β1|, and overall bias |βR|+|β1|, which is inversely related to the probability of a correct response (p < 0.05). The residual deviance Ddf (with degrees of freedom in the subscript) corresponds to the 2CE1 model’s improvement in fit relative to either the XC model with only constant bias or the complete nonlearning model XCE1 adding exponential hysteresis. Standard deviations are listed in parentheses below corresponding means.