The RANOVA of the error rates revealed a significant main effect of task on probe trials [3% difference between discrimination and detection, F (1,13) = 16.68, p < 0.01, η 2 p = 0.56], and a marginally significant main effect of dimension sequence, with dimension repetitions yielding 1.1% more accurate performance than dimension changes, F (1,13) = 4.35, p = 0.06; the interaction between the two was far from significance ( F < 1).
The RANOVA of the PCN amplitudes yielded a significant main effect of task, F (1,13) = 6.61, p < 0.05, η 2 p = 0.43; the main effect of task sequence non-significant ( F < 1); the task × task sequence interaction approached significance, F (1,13) = 3.70, p = 0.08, η 2 p = 0.22), owing to the fact that switching task tended to increase the PCN amplitude for the detection task (−2.12 μV and −2.22 μV for detection → detection and discrimination → detection sequences, respectively), while tending to decrease the amplitude for the discrimination task (−2.52 and −2.29 μV for discrimination → discrimination and detection → discrimination sequences, respectively).