Functional underpinnings of feedback-enhanced test-potentiated encoding.

The testing effect describes the finding that retrieval practice enhances memory performance compared to restudy practice. Prior evidence demonstrates that this effect can be boosted by providing feedback after retrieval attempts (i.e. test-potentiated encoding [TPE]). The present fMRI study investigated the neural processes during successful memory retrieval underlying this beneficial effect of correct answer feedback compared with restudy and whether additional performance feedback leads to further benefits. Twenty-seven participants learned cue-target pairs by (i) restudying, (ii) standard TPE including a restudy opportunity, or (iii) TPE including a restudy opportunity immediately after a positive or negative performance feedback. One day later, a cued retrieval recognition test was performed inside the MRI scanner. Behavioral results confirmed the testing effect and that adding explicit performance feedback-enhanced memory relative to restudy and standard TPE. Stronger functional engagement while retrieving items previously restudied was found in lateral prefrontal cortex and superior parietal lobe. By contrast, lateral temporo-parietal areas were more strongly recruited while retrieving items previously tested. Performance feedback increased the hippocampal activation and resulted in stronger functional coupling between hippocampus, supramarginal gyrus, and ventral striatum with lateral temporo-parietal cortex. Our results unveil the main functional dynamics and connectivity nodes underlying memory benefits from additional performance feedback.

Performance feedback enhances test-potentiated encoding.

Introduction: Long-term memory retention is enhanced after testing compared to restudying (testing effect). Notably, memory retrieval further improves when correct-answer feedback is provided after the retrieval attempt (test-potentiated encoding-TPE). Methods: To evaluate whether explicit positive or negative feedback further enhances memory performance beyond the effect of TPE, in two experiments additional explicit positive or negative performance-contingent feedback was presented before providing correct-answer feedback. After an initial exposure to the full material, 40 participants learned 210 weakly associated cue-target word pairs by either restudying or testing (Experiment 1). Depending on the accuracy of the retrieval attempt, the tested word pairs were followed by positive or negative performance feedback (50%) or no feedback (50%). Irrespective of the type of repetition, trials were followed by a restudy opportunity. Participants returned to perform a final cued-recall test (Day 2). Results: Final test results replicated the testing effect (better memory performance for tested compared to restudied items). Explicit performance feedback in addition to correct-answer feedback increased retrieval performance, but only on Day 2. This pattern of results was replicated in Experiment 2 in an independent sample of 25 participants. To assess the specific effects of learning history, we also examined retrieval accuracy and reaction times during repetition cycles: Explicit feedback improved retrieval for material successfully encoded in the initial study phase (consistent positive feedback) as well as for material learned during the repetition phase (mixed positive and negative feedback). Discussion: Performance feedback improves learning beyond the effects of retrieval practice and correct-answer feedback, suggesting that it strengthens memory representations and promotes re-encoding of the material.

Neural correlates of feedback processing during a sensory uncertain speech - nonspeech discrimination task.

Performance feedback during a speech-nonspeech discrimination task was used to investigate (neuro-)cognitive processes underlying feedback processing under uncertainty. Sensory uncertainty was manipulated by creating stimuli that were stepwise morphs of the German vowels /a/ and /a:/ (speech) and their spectrally rotated counterparts (non-speech). The anterior N1 associated with early attentional modulation was largest following negative feedback. Both negative and uninformative feedback showed larger FRN amplitudes, suggesting a classification as worse than expected. Sensory uncertainty affected only the feedback-P3, in terms of larger amplitudes for (1) stimuli with high uncertainty and (2) positive feedback. Confidence ratings revealed that sensory uncertainty reduced the accuracy of stimulus categorization, but did not modulate participants' response confidence. Results suggest that feedback processing follows three distinct and successive stages, starting with initial screening for behavioral relevance (anterior N1, enhanced for unexpected negative feedback), followed by a binary valence distinction (FRN), and a more detailed analysis (P3).