Fig 1.
Reward-based learning paradigm.
(A) After the presentation of an Asian symbol, subjects were asked to select one of the two colours by pressing the corresponding button. The decision was followed by outcome presentation (reward or non-reward). (B) In the first learning task, subjects were asked to learn associations between symbols and colours, followed by a reversal of contingencies. (C) In the acquired equivalence task, subjects had to relearn associations after a colour change and were then expected to transfer the newly learned associations to previously presented symbols (modified from [10]).
Table 1.
Characteristics of the healthy control-, risk factor-, and stroke patients: Sociodemographics, risk factors and performance in reward-based learning as well as infarct localization for the stroke patients.
Fig 2.
Performance of healthy control subjects, control patients without stroke with vascular risk factors (‘risk factor patients’) and stroke patients in the reward-based acquisition and reversal, broken down into learning blocks and reward magnitude.
Data are means of correct responses with S.D. values. ANOVA revealed a significant main effect for the factor group in the reversal phase [F(2,30) = 3.47; p = 0.044] reflecting a significantly lower number of correct responses in risk factor patients than healthy controls (p = 0.032). The performance of stroke patients and risk factor patients was very similar (p = 0.999).
Fig 3.
Correlation between the number of vascular risk factors and the number of correct responses in the reward-based acquisition and reversal and equivalence test.
Data were analyzed by Kendall’s tau-b correlations. Note that there was a significant correlation between the number of risk factors and correct responses in the reversal, but no significant correlation in the acquisition phase and equivalence test.