Oliver Kliegl

Bio: Oliver Kliegl is an academic researcher from University of Regensburg. The author has contributed to research in topics: Forgetting & Recall. The author has an hindex of 8, co-authored 16 publications receiving 236 citations. Previous affiliations of Oliver Kliegl include University of California, Los Angeles.

The critical role of retrieval processes in release from proactive interference

Abstract: Proactive interference (PI) refers to the finding that memory for recently studied (target) information can be vastly impaired by the previous study of other (nontarget) information. PI can be reduced in a number of ways, for instance, by directed forgetting of the prior nontarget information, the testing of the prior nontarget information, or an internal context change before study of the target information. Here we report the results of four experiments, in which we demonstrate that all three forms of release from PI are accompanied by a decrease in participants’ response latencies. Because response latency is a sensitive index of the size of participants’ mental search set, the results suggest that release from PI can reflect more focused memory search, with the previously studied nontarget items being largely eliminated from the search process. Our results thus provide direct evidence for a critical role of retrieval processes in PI release.

List-method directed forgetting: The forget cue improves both encoding and retrieval of postcue information

Abstract: In list-method directed forgetting, people are cued to forget a previously studied item list and to learn a new list instead Such cuing typically leads to forgetting of the first list and to memory enhancement of the second, referred to as list 1 forgetting and list 2 enhancement In the present study, two experiments are reported that examined influences of items’ serial learning position in a list and the two lists’ output order on list-method directed forgetting The results show that list output order influences list 2 enhancement but not list 1 forgetting The enhancement was higher when list 2 was recalled first than when list 1 was recalled first and, in both cases, was higher for early list 2 items than for middle and late list 2 items In contrast, the forgetting was equally present for all list 1 items and did not depend on the two lists’ output order The findings suggest that two separate factors can contribute to list 2 enhancement: one (encoding) factor that is restricted to early list 2 items and does not depend on list output order, and another (retrieval) factor that pertains to all list 2 items and varies with the two lists’ output order A new two-mechanism account of directed forgetting is suggested that reconciles previous (encoding or retrieval) views on list 2 enhancement

The contribution of encoding and retrieval processes to proactive interference.

Abstract: Proactive interference (PI) refers to the finding that memory for recently studied (target) material can be impaired by the prior study of other (nontarget) material. Previous accounts of PI differed in whether they attributed PI to impaired retrieval or impaired encoding. Here, we suggest an integrated encoding-retrieval account, which assigns a role for each of the two types of processes in buildup of PI. Employing a typical PI task, we examined (i) the role of encoding processes in PI by recording scalp EEG during study of nontarget and target lists, and (ii) the role of retrieval processes in PI by measuring recall totals and response latencies in target list recall. In addition, we measured subjects' working memory capacity (WMC). Behaviorally, the PI effect arose in both recall totals and response latencies, indicating PI at the sampling and the recovery stage of recall. Neurally, we found an increase in electrophysiological activities in the theta frequency band (5-8 Hz) from nontarget to target list encoding, indicating an increase in memory load during target list encoding. The results demonstrate that impaired retrieval and impaired encoding can contribute to PI. They also show that WMC affects PI. For both encoding and retrieval processes, PI was reduced in high-WMC subjects, suggesting that these subjects are able to separate target from nontarget information and create stronger focus on the target material.

Retrieval-induced remembering and forgetting

Abstract: Selectively retrieving a subset of previously studied information enhances memory of the retrieved information but can cause forgetting of nonretrieved information. This chapter reviews the literature on such retrieval-induced forgetting (RIF), asking whether the forgetting depends on testing format, is retrieval specific and interference dependent, is modulated by retention interval after selective retrieval, and varies between individuals. The most prominent theoretical accounts of RIF are introduced and evaluated against the empirical findings. Also some more recent studies are reviewed, which indicate that, under certain conditions, selective retrieval can also improve memory of the nonretrieved information.

List-method directed forgetting can be selective: evidence from the 3-list and the 2-list tasks.

Abstract: When people are cued to forget previously studied irrelevant information and study new information instead, such cuing typically leads to forgetting of the precue information. But what do people forget if, before the forget cue is provided, both irrelevant and relevant information have been encoded? Using relatively short item lists, we examined in a series of three experiments whether participants are able to selectively forget the irrelevant precue information, when relevant and irrelevant precue items were presented subsequently in two separate lists (3-list task) and when the two types of items were presented alternatingly within a single list (2-list task). Selective forgetting of the irrelevant precue items arose in the 3-list task, independent of modality of item presentation and level of discriminability of the precue lists, and it arose in the 2-list task. The findings suggest that, at least with relatively short precue lists, participants may well be able to selectively forget irrelevant precue information when cued to do so. Implications of the results for theoretical accounts of list-method directed forgetting are discussed.

Neural mechanisms of motivated forgetting

Abstract: Not all memories are equally welcome in awareness. People limit the time they spend thinking about unpleasant experiences, a process that begins during encoding, but that continues when cues later remind someone of the memory. Here, we review the emerging behavioural and neuroimaging evidence that suppressing awareness of an unwelcome memory, at encoding or retrieval, is achieved by inhibitory control processes mediated by the lateral prefrontal cortex. These mechanisms interact with neural structures that represent experiences in memory, disrupting traces that support retention. Thus, mechanisms engaged to regulate momentary awareness introduce lasting biases in which experiences remain accessible. We argue that theories of forgetting that neglect the motivated control of awareness omit a powerful force shaping the retention of our past.

Interpolated memory tests reduce mind wandering and improve learning of online lectures

Abstract: The recent emergence and popularity of online educational resources brings with it challenges for educators to optimize the dissemination of online content. Here we provide evidence that points toward a solution for the difficulty that students frequently report in sustaining attention to online lectures over extended periods. In two experiments, we demonstrate that the simple act of interpolating online lectures with memory tests can help students sustain attention to lecture content in a manner that discourages task-irrelevant mind wandering activities, encourages task-relevant note-taking activities, and improves learning. Importantly, frequent testing was associated with reduced anxiety toward a final cumulative test and also with reductions in subjective estimates of cognitive demand. Our findings suggest a potentially key role for interpolated testing in the development and dissemination of online educational content.

Retrieval-Based Learning: An Episodic Context Account

Abstract: Retrieval is the key process for understanding learning and for promoting learning, yet retrieval is not often granted the central role it deserves. Learning is typically identified with the encoding or construction of knowledge, and retrieval is considered merely the assessment of learning that occurred in a prior experience. The retrieval-based learning perspective outlined here is grounded in the fact that all expressions of knowledge involve retrieval and depend on the retrieval cues available in a given context. Further, every time a person retrieves knowledge, that knowledge is changed, because retrieving knowledge improves one’s ability to retrieve it again in the future. Practicing retrieval does not merely produce rote, transient learning; it produces meaningful, long-term learning. Yet retrieval practice is a tool many students lack metacognitive awareness of and do not use as often as they should. Active retrieval is an effective but undervalued strategy for promoting meaningful learning.

A Context-Based Theory of Recency and Contiguity in Free Recall. Commentary. Authors' reply

Abstract: The authors present a new model of free recall on the basis of M. W. Howard and M. J. Kahana's (2002a) temporal context model and M. Usher and J. L. McClelland's (2001) leaky-accumulator decision model. In this model, contextual drift gives rise to both short-term and long-term recency effects, and contextual retrieval gives rise to short-term and long-term contiguity effects. Recall decisions are controlled by a race between competitive leaky accumulators. The model captures the dynamics of immediate, delayed, and continual distractor free recall, demonstrating that dissociations between short- and long-term recency can naturally arise from a model in which an internal contextual state is used as the sole cue for retrieval across time scales.

Retrieval-Based Learning: Active Retrieval Promotes Meaningful Learning

Abstract: Retrieval is the key process for understanding learning and for promoting learning, yet retrieval is not often granted the central role it deserves. Learning is typically identified with the encoding or construction of knowledge, and retrieval is considered merely the assessment of learning that occurred in a prior experience. The retrieval-based learning perspective outlined here is grounded in the fact that all expressions of knowledge involve retrieval and depend on the retrieval cues available in a given context. Further, every time a person retrieves knowledge, that knowledge is changed, because retrieving knowledge improves one’s ability to retrieve it again in the future. Practicing retrieval does not merely produce rote, transient learning; it produces meaningful, long-term learning. Yet retrieval practice is a tool many students lack metacognitive awareness of and do not use as often as they should. Active retrieval is an effective but undervalued strategy for promoting meaningful learning.