The Mechanisms Underlying Interference and Inhibition: A Review of Current Behavioral and Neuroimaging Research

The memory literature has identified interference and inhibition as two major sources of forgetting. While interference is generally considered to be a passive cause of forgetting arising from exposure to additional information that impedes subsequent recall of target information, inhibition concerns a more active and goal-directed cause of forgetting that can be achieved intentionally. Over the past 25 years, our knowledge of the neural mechanisms underlying both interference-induced and inhibition-induced forgetting has expanded substantially. The present paper gives a critical overview of this research, pointing out empirical gaps in the current work and providing suggestions for future studies

A (Preliminary) Recipe for Obtaining a Testing Effect in Preschool Children: Two Critical Ingredients

The testing effect refers to the finding that retrieval of previously learned information improves retention of that information more than restudy practice does. While there is some evidence that the testing effect can already arise in preschool children when a particular experimental task is employed, it remains unclear whether, for this age group, the effect exists across a wider range of tasks. To examine the issue, the present experiments sought to determine the potential roles of retrieval-practice and final-test formats, and of immediate feedback during retrieval practice for the testing effect in preschoolers. Experiments 1 and 2 showed no testing effect in preschoolers when a free-recall task was applied during the final test, regardless of whether free recall (Experiment 1) or cued recall (Experiment 2) were conducted during retrieval practice. In contrast, if cued-recall tasks were used during both retrieval practice and the final test (Experiment 3), a reliable testing effect arose. Furthermore, the magnitude of the effect was dramatically enhanced when, in addition, immediate feedback was provided during retrieval practice (Experiment 4). The present findings suggest that cued-recall practice and test formats, as well as immediate feedback during practice, are crucial ingredients for obtaining the testing effect in preschoolers

Feedback at Test Can Reverse the Retrieval-Effort Effect

The testing effect refers to the finding that retrieving previously encoded material typically improves subsequent recall performance more on a later test than does restudying that material. Storm et al. (2014) demonstrated, however, that when feedback is provided on such a later test the testing advantage then turns to a restudying advantage on subsequent tests. The goal of the present research was to examine whether there is a similar consequence of feedback when the difficulty of initial retrieval practice is modulated. Replicating prior research, we found that on an initial delayed test, recall of to-be-learned items was better following difficult than easy practice. Critically, however, providing immediate feedback on an initial delayed test reversed this pattern. Our findings are consistent with a distribution-based interpretation of how feedback at test modifies recall performance

On the cognitive processes mediating intentional memory updating

In list-method directed forgetting (LMDF), cuing people to forget previously studied information and to encode new material instead facilitates recall of the new material (postcue enhancement) but reduces recall of the previously studied information (precue forgetting). The first part of this thesis investigated the nature of postcue enhancement, with Experiments 1A-1C finding that postcue enhancement is accompanied with decreased response latencies. Because response latency is a sensitive index of participants' mental search set, this finding suggests that postcue enhancement arises due to a more focused memory search. In addition, response latency analysis suggested that such retrieval processes are not only crucial regarding postcue enhancement, but also improve memory of new material when previously studied material is tested prior to encoding of the new material (Experiment 2) or when a context change takes place prior to encoding of the new material (Experiment 3). The second part of this thesis examined the mechanisms underlying precue forgetting by testing whether people can selectively forget only part of the previously studied information while keeping in mind the remaining information. To this end, selectivity in LMDF was examined for two different study formats in Experiment 4: relevant and irrelevant precue items were either presented alternatingly or blocked. Selectivity arose for both study formats, which is consistent with an inhibitory account of precue forgetting. I finally argue that the present data affirm and substantiate a recent LMDF account that attributes precue forgetting to such an inhibitory mechanism and postcue enhancement to a combination of encoding and retrieval processes

Buildup and release from proactive interference – Cognitive and neural mechanisms

Interference from related memories is generally considered one of the major causes of forgetting in human memory. The most prevalent form of interference may be proactive interference (PI), which refers to the finding that memory of more recently studied information can be impaired by the previous study of other information. PI is a fairly persistent effect, but numerous studies have shown that there can also be release from PI. PI buildup and release have primarily been studied using paired-associate learning, the Brown-Peterson task, or multiple-list learning. The review first introduces the three experimental tasks and, for each task, summarizes critical findings on PI buildup and release, from both behavioral and imaging work. Then, an overview is provided of suggested cognitive mechanisms operating on the encoding and retrieval stages as well as of neural correlates of these mechanisms. The results indicate that, in general, both encoding and retrieval processes contribute to PI buildup and release. Finally, empirical gaps in the current work are emphasized and suggestions for future studies are provided

When retrieval practice promotes new learning – The critical role of study material

The forward testing effect (FTE) refers to the finding that retrieval practice of previously studied information can facilitate learning and memory of newly studied information. The goal of the present set of six experiments was to examine whether the FTE is influenced by study material. We replicated prior work by showing that the FTE can arise with both unrelated and categorized item lists. Going beyond the prior work, we found that parallel FTEs for the two types of lists arose only for short retention interval and when the lag between study of the previous lists and study of the final critical list was also short. When there was a prolonged retention interval or a prolonged lag, the FTE was observed with categorized lists but disappeared with unrelated lists. Moreover, semantic generation of extra-list items interspersed between study of the single lists produced an FTE with unrelated lists but not with categorized lists. These findings on the critical role of study material for the FTE are consistent with a two-factor explanation of the FTE, which assumes contributions of both strategy change and context change for the FTE. The account suggests that the FTE is mainly driven by strategy change with categorized material and is mainly driven by context change with unrelated material

Retrieval practice can insulate items against intralist interference: Evidence from the list-length effect, output interference, and retrieval-induced forgetting

This study sought to determine whether nonselective retrieval practice after study can reduce memories' susceptibility to intralist interference, as it is observed in the list-length effect, output interference, and retrieval-induced forgetting. Across 3 experiments, we compared the effects of nonselective retrieval practice and restudy on previously studied material with regard to these 3 forms of episodic forgetting. When study of an item list was followed by a restudy cycle, recall from a longer list was worse than recall from a shorter list (list-length effect), preceding recall of studied nontarget items impaired recall of the list's target items (output interference), and repeated selective retrieval of some list items attenuated recall of other nonretrieved items at test (retrieval-induced forgetting). In contrast, none of these effects arose when study of the list was followed by a nonselective retrieval cycle. The findings are consistent with a combination of contextual variability theory and a variant of study-phase retrieval theory that assumes that retrieval can create more distinct context features for retrieved items than restudy does for restudied items, thus reducing items' susceptibility to interference relative to restudy cycles. The findings add to the view that nonselective retrieval practice can stabilize and consolidate memories