“…Usually, a larger P3b is observed for unexpected than expected action outcomes (von Borries et al, ). In addition to unexpectedness, it is typically found that negative feedback gives rise to a larger P3b than positive feedback (de Bruijn, Mars, & Hulstijn, ; Fischer & Ullsperger, ; Walentowska, Moors, Paul, & Pourtois, ; but see Hajcak et al, ; Severo, Walentowska, Moors, & Pourtois, , , for a reversed pattern, as well as Yeung & Sanfey, , for the lack of a valence effect), suggesting that action value updating likely depends on both expectedness and valence as well as on the context within which this updating takes place. The second goal of our study was to assess action value updating at the P3b level when different combinations of reward probability and expectancy were created and compared.…”