Does sleep flush out the unwanted leftovers of recent cognitive activities?
Lead Research Organisation:
UNIVERSITY OF EXETER
Department Name: Psychology
Abstract
This project examines whether sleep helps flush out unwanted leftovers of recent perceptual and cognitive activities in addition to consolidating new learning.
Traditional views of learning assume that new memories are shaky for a while, but soon consolidate, becoming resistant to amnestic agents and interference from new learning (McGaugh, 2000; Wixted, 2004). Recent theorizing (Stickgold & Walker, 2013), however, insists that memory consolidation is not the uniform and indiscriminate process just described, but is instead highly selective and adaptive, tailored to the goal-directed needs of the organism.
Sleep, with its associated neurophysiological states, is the prime vehicle for a "memory triage" process: only memories that are emotionally salient, or worth remembering for future use, get assimilated into the brain's landscape of ever evolving knowledge. Here we ask what happens to unwanted memories, which also start off in this no man's land of in between memory (i.e., between working memory and long-term memory; henceforth, IBM)? The goal of this project is to determine whether in addition to stabilizing and assimilating useful memories, sleep also cleans the slate of unwanted memories to reset the system, in order to start afresh the next day.
Evidence for offline, sleep-dependent memory consolidation is substantial, showing a variety of transformative results, including increased resilience to amnestic agents, enhanced accessibility, spontaneous recovery, extraction of underlying structures, and integration with existing knowledge. In contrast, the existence of memory clean-up has not yet been substantiated. We suggest this is largely because researchers thought they could just force learners to forget newly learnt information.
Our premise is that unwanted leftovers mostly comprise the lingering activation of long-term memories recently evoked by perceptual, expressive, or imagery-based experience. This activation accumulates records of involvement of a given memory over the course of a day. As such, this could influence rather insidiously how we behave during the next few hours, and perhaps for as long as we remain awake. These persisting activation byproducts are precisely what an active forgetting mechanism would get rid of.
To test this hypothesis, we explore the evolution of memory traces left by language exposure and/or practice and use. Language provides an ideal testbed, as the same linguistic event can provoke both lingering effects that one would not necessarily want to keep and sleep-dependent offline consolidation of unitized new information. We already have linguistic performance measures that index both kinds of effects, and the consolidation of new lexical knowledge through sleep is well documented at this stage.
Work Package 1 examines the fate of memories for novel word forms and their potential for either consolidation or clean-up. Work Package 2 provides multiple tests of whether sleep does clean the slate by removing lingering traces. Our pilot data (Fig. TA6) suggest that it does. Finally, Work Package 3 focuses on at-risk populations, namely older adults and sleep apnoea patients, to evaluate the impact of poor sleep on both memory consolidation and clean-up simultaneously. If older adults show impaired clean-up on top of consolidation problems, reduced clean-up could be one of the factors behind the gradual cognitive decline that characterizes normal aging.
Our experiments focus on language memories to explore whether sleep resets what we have called IBM. Positive findings will provide a proof of concept, with a strong potential for applications in domains as varied as education, work patterns, sports science, aging, extended military missions, and neurocognitive rehabilitation.
Traditional views of learning assume that new memories are shaky for a while, but soon consolidate, becoming resistant to amnestic agents and interference from new learning (McGaugh, 2000; Wixted, 2004). Recent theorizing (Stickgold & Walker, 2013), however, insists that memory consolidation is not the uniform and indiscriminate process just described, but is instead highly selective and adaptive, tailored to the goal-directed needs of the organism.
Sleep, with its associated neurophysiological states, is the prime vehicle for a "memory triage" process: only memories that are emotionally salient, or worth remembering for future use, get assimilated into the brain's landscape of ever evolving knowledge. Here we ask what happens to unwanted memories, which also start off in this no man's land of in between memory (i.e., between working memory and long-term memory; henceforth, IBM)? The goal of this project is to determine whether in addition to stabilizing and assimilating useful memories, sleep also cleans the slate of unwanted memories to reset the system, in order to start afresh the next day.
Evidence for offline, sleep-dependent memory consolidation is substantial, showing a variety of transformative results, including increased resilience to amnestic agents, enhanced accessibility, spontaneous recovery, extraction of underlying structures, and integration with existing knowledge. In contrast, the existence of memory clean-up has not yet been substantiated. We suggest this is largely because researchers thought they could just force learners to forget newly learnt information.
Our premise is that unwanted leftovers mostly comprise the lingering activation of long-term memories recently evoked by perceptual, expressive, or imagery-based experience. This activation accumulates records of involvement of a given memory over the course of a day. As such, this could influence rather insidiously how we behave during the next few hours, and perhaps for as long as we remain awake. These persisting activation byproducts are precisely what an active forgetting mechanism would get rid of.
To test this hypothesis, we explore the evolution of memory traces left by language exposure and/or practice and use. Language provides an ideal testbed, as the same linguistic event can provoke both lingering effects that one would not necessarily want to keep and sleep-dependent offline consolidation of unitized new information. We already have linguistic performance measures that index both kinds of effects, and the consolidation of new lexical knowledge through sleep is well documented at this stage.
Work Package 1 examines the fate of memories for novel word forms and their potential for either consolidation or clean-up. Work Package 2 provides multiple tests of whether sleep does clean the slate by removing lingering traces. Our pilot data (Fig. TA6) suggest that it does. Finally, Work Package 3 focuses on at-risk populations, namely older adults and sleep apnoea patients, to evaluate the impact of poor sleep on both memory consolidation and clean-up simultaneously. If older adults show impaired clean-up on top of consolidation problems, reduced clean-up could be one of the factors behind the gradual cognitive decline that characterizes normal aging.
Our experiments focus on language memories to explore whether sleep resets what we have called IBM. Positive findings will provide a proof of concept, with a strong potential for applications in domains as varied as education, work patterns, sports science, aging, extended military missions, and neurocognitive rehabilitation.
Planned Impact
As this project revolves around the idea that sleep helps flush out unwanted leftovers of recent cognitive activities, it has major implications for understanding the role of sleep on learning and memory. Although we focus on language exposure and practice to explore active forgetting, positive findings will provide a proof of concept, with strong potential applications in domains as varied as education, work patterns, sports science, extended military missions and neurocognitive rehabilitation.
Work Package 3 investigates two populations at risk of weak clean-up of IBM because their sleep is reduced, disturbed, or both: sleep apnoea patients and healthy older adults. As we suggest in the Case for Support, one source of general cognitive decline in aging may be a reduced capacity to actively remove cognitive leftovers of daily activities due to chronic sleep disturbance. Both populations have already shown poor memory consolidation compared to normal or younger controls in some domains of knowledge. Our central claim is that this could be only one edge of a double-edge sword: Sleep may be the key to stabilizing and transforming relevant/salient memories and assimilating them into existing structures, as well as resetting our cognitive apparatus to start afresh the next day. Demonstrating this would be the core contribution of this project.
A search of the Web Of Sciences's core collection returns only 17 hits for papers on sleep AND (unlearning OR "active forgetting"), compared to 1,618 papers on sleep AND "memory consolidation". This demonstrates that very little is known on our topic, and that our project is thus far beyond incremental. Moreover, 6 out of these 17 papers came out in the last three years, with the other 11 papers published between 1993 and 2007. Clearly, as more is understood about how sleep helps to assimilate some memories, there is new interest in the possibility that it could also help us to forget other information. In fact, on Feb. 2 2017, the NY Times had a story on just this topic; this is timely research.
A direct practical implication of our project illustrates its potential impact. Experiment 8 tests whether sleep removes lingering semantic interference in speech production (i.e., naming objects in a given semantic field impairs naming semantically related objects for at least 12 hrs of wake). Although in healthy subjects this effect expresses itself as a mere 30-50 ms increase in speech latencies, in aphasic patients this effect is such that the patient is unable to access the target name and is stuck with the label of a previously named object. If, as suggested by our pilot data, this interference indeed persists and sleep is one way to remove it, then speech remediation protocols should either avoid practice of semantically related items on the same day, or they should include an early afternoon nap to provide a clean break between the items practiced in the morning and those practiced later in the day.
A similar logic underlies the potential impact of our research for extended military missions. Decision making is one of the first higher cognitive functions to degrade because of sleep deprivation (Killgore et al., 2010). This failure is especially likely if the sleep deprivation occurs on top of a chronic lack of sleep, which is the case of most extended sorties. A failure of cognitive control is exactly what one would expect if memory clean-up has not occurred for a period of time. Thus, the optimal micro-nap time needed to allow clean-up should be explored. The efficacy of drugs and dietary complements against sleep deprivation in soldiers should be benchmarked against measures of lingering interference and its natural antidote: sleep-induced clean-up.
These are just two examples of societal implications of our project. If, as our pilot data suggest, sleep actively removes unwanted perceptual and cognitive leftovers, there will be a very wide range of such impacts.
Work Package 3 investigates two populations at risk of weak clean-up of IBM because their sleep is reduced, disturbed, or both: sleep apnoea patients and healthy older adults. As we suggest in the Case for Support, one source of general cognitive decline in aging may be a reduced capacity to actively remove cognitive leftovers of daily activities due to chronic sleep disturbance. Both populations have already shown poor memory consolidation compared to normal or younger controls in some domains of knowledge. Our central claim is that this could be only one edge of a double-edge sword: Sleep may be the key to stabilizing and transforming relevant/salient memories and assimilating them into existing structures, as well as resetting our cognitive apparatus to start afresh the next day. Demonstrating this would be the core contribution of this project.
A search of the Web Of Sciences's core collection returns only 17 hits for papers on sleep AND (unlearning OR "active forgetting"), compared to 1,618 papers on sleep AND "memory consolidation". This demonstrates that very little is known on our topic, and that our project is thus far beyond incremental. Moreover, 6 out of these 17 papers came out in the last three years, with the other 11 papers published between 1993 and 2007. Clearly, as more is understood about how sleep helps to assimilate some memories, there is new interest in the possibility that it could also help us to forget other information. In fact, on Feb. 2 2017, the NY Times had a story on just this topic; this is timely research.
A direct practical implication of our project illustrates its potential impact. Experiment 8 tests whether sleep removes lingering semantic interference in speech production (i.e., naming objects in a given semantic field impairs naming semantically related objects for at least 12 hrs of wake). Although in healthy subjects this effect expresses itself as a mere 30-50 ms increase in speech latencies, in aphasic patients this effect is such that the patient is unable to access the target name and is stuck with the label of a previously named object. If, as suggested by our pilot data, this interference indeed persists and sleep is one way to remove it, then speech remediation protocols should either avoid practice of semantically related items on the same day, or they should include an early afternoon nap to provide a clean break between the items practiced in the morning and those practiced later in the day.
A similar logic underlies the potential impact of our research for extended military missions. Decision making is one of the first higher cognitive functions to degrade because of sleep deprivation (Killgore et al., 2010). This failure is especially likely if the sleep deprivation occurs on top of a chronic lack of sleep, which is the case of most extended sorties. A failure of cognitive control is exactly what one would expect if memory clean-up has not occurred for a period of time. Thus, the optimal micro-nap time needed to allow clean-up should be explored. The efficacy of drugs and dietary complements against sleep deprivation in soldiers should be benchmarked against measures of lingering interference and its natural antidote: sleep-induced clean-up.
These are just two examples of societal implications of our project. If, as our pilot data suggest, sleep actively removes unwanted perceptual and cognitive leftovers, there will be a very wide range of such impacts.
Publications
Baese-Berk MM
(2022)
Just give it time: Differential effects of disruption and delay on perceptual learning.
in Attention, perception & psychophysics
Baese-Berk MM
(2025)
The relationship of speech perception and speech production: It's complicated.
in Psychonomic bulletin & review
Charoy J
(2023)
Bad maps may not always get you lost: Lexically driven perceptual recalibration for substituted phonemes.
in Attention, perception & psychophysics
Charoy J
(2020)
The effect of orthography on the recognition of pronunciation variants.
in Journal of experimental psychology. Learning, memory, and cognition
Dumay N
(2018)
Look more carefully: Even your data show sleep makes memories more accessible. A reply to Schreiner and Rasch (2018).
in Cortex; a journal devoted to the study of the nervous system and behavior
Dumay N
In-Between Memory: How sleep redraws phonemic categories after auditory selective adaptation
in Psychonomic Bulletin and Review (Manuscript Under Review)
Dumay N
Reduced masked orthographic priming after recent exposure to novel word primes is not a marker of lexical learning
in Journal of Experimental Psychology: Learning, Memory and Cognition (Manuscript Under Review)
Harris A
(2021)
All Things Morphology - Its independence and its interfaces
Harris AC
(2024)
Processing and production of clitics in Udi and European Portuguese: Testing a processing account of an extension of the suffixing preference
in Journal of Linguistics
Harris AC
(2024)
Processing and production of affixes in Georgian and English: Testing a processing account of the suffixing preference
in Journal of Linguistics
| Title | The Distance/La Distance |
| Description | This is a 16.38 min sound piece which I wrote based on field recordings collected during the time of the award. The piece captures the memories of my relationship with my son and juxtapose them to create a series of oneiric representations the meaning of which is driven by the interaction of the two juxtaposed memories. While this activity was not planned and did not rely on the award per se, the subject of the piece itself and the approach taken undeniably connect with the theme of sound memories which central to the core research question of the award. |
| Type Of Art | Creative Writing |
| Year Produced | 2024 |
| Impact | The piece was played on a Belgian radio: https://www.radiocampus.be/creation-radiophonique-18-11-2024-14h30-la-distance-nicolas-dumay/ It is also scheduled to be played as part of the Goethe Institute supported Radiophrenia festival, Glasgow, April 7-20th, 2025: https://radiophrenia.scot/news-2/ |
| URL | https://soundcloud.com/nicolasdumay/la-distance?si=a11e778aa261406282a16b808243680f&utm_source=clipb... |
| Description | [Note: This section can be read in a friendlier format and with the addition of figures of results on the OSF website: //osf.io/cgawq/?view_only=d7d5a5606ea441efb4bcf47c2ab95ed3] KEY FINDING 1: SLEEP CLEARS EXISTING KNOWLEDGE FROM WORKING MEMORY Sleep is known to promote the consolidation of new information, through a wide range of transformative processes (for recent reviews, see Berres & Erdfelder, 2021; Squire et al., 2015): for instance, it increases the resilience of new memories to amnestic agents (Abel et al., 2023; Ellenbogen et al., 2009); boosts the recovery of inaccessible information (Drosopoulos et al., 2007; Dumay, 2016, 2018; Fenn et al., 2003); promotes the extraction of statistical patterns in the environment (Gomez et al., 2006; Monaghan et al., 2015); and drives the integration of novel information into long-term, existing semantic networks (Dumay & Gaskell, 2007; for a review, see Schimke et al., 2022). Our Workpackage 2b specifically focused instead on well-established representations brought into working memory for the purpose of solving a given perceptual or cognitive task. The question was whether sleep (as opposed remaining awake) would clear working memory of these lingering representations once their engagement is no longer needed. We have evidence that this is indeed the case. In a series of four experiments (total N = 341), we exposed listeners to either known words (e.g., 'beef') or nonwords (e.g., 'baff'). We then tested them on how well they perceived other nonwords (e.g., 'peef'; 'paff') that were similar to the items heard during the exposure phase. In agreement with earlier results (Sumner & Samuel, 2007), the ease with which participants could determine that the test nonwords were not in their vocabulary depended on whether something similar had been presented during exposure, but also on whether exposure items were themselves words in the language, or not: whereas exposure to a real word made it harder 15-20 minutes later to reject a similar nonword, exposure to a similar nonword made this rejection easier. The key finding was observed in the variations on the protocol that extended the exposure-to-test interval to 12 hr and manipulated the presence of sleep within this interval: in agreement with the notion of consolidation of perceptual knowledge, the sensitization of sublexical representations that facilitated the processing of similar nonwords was found to be intact after 12 hr filled mostly with sleep, but was no longer detectable after 12 hr awake. In contrast, literally the opposite was found when the sensitization in question concerned real words: the sensitization endured after wake, but was no longer detectable after sleep. In sum, while these results not only replicate Sumner and Samuel (2007) and provide additional evidence that sleep promotes the consolidation of new information, first and foremost they tell us that sleep at the same time cleanses working memory of existing representations recently engaged by perception. These findings are reported in a manuscript which we are currently revising for the Elsevier journal Cognition (5-year impact factor: 3.5). They were also presented as talks at two international conferences [Samuel & Dumay, 2023. Abstracts of the 23rd Conference of the European Society for Cognitive Psychology (p. 116), Porto, Portugal; Samuel & Dumay, 2022. Abstracts of the 63rd Annual Meeting of the Psychonomic Society (p. 100), Boston MA]. KEY FINDING 2: SLEEP BELATEDLY UPDATES PHONEMIC CATEGORIES TO REFLECT HOW OFTEN WE HEARD THESE SOUNDS DURING PRIOR WAKEFULNESS Perceptual boundaries between speech sounds (between /ba/ and /wa/, for example) are constantly being adjusted depending on the listener's experience. This perceptual learning occurs, for instance, when an ambiguous token is heard in the context of disambiguating information (e.g., subtitles or lip movements). The token is now unambiguously ascribed to the category in question and the breadth of the latter as a result has expanded into the competing category (Bertelson et al., 2003). In our exploration of the effect of sleep on lingering representations, we focused on a related phenomenon called "auditory selective adaptation" (Eimas & Corbit, 1973). In selective adaptation, repeated exposure to a sound (e.g., /wa/) results in listeners perceiving that sound less often on an immediate post-test compared to a pre-test. For instance, after many exposures to an unambiguous /wa/ (i.e., the "adaptor" sound), listeners hear fewer instances on a test continuum between /ba/ and /wa/, as "wa" (i.e., they report hearing "ba" more often than at pre-test). Within this award, we first examined how long this perceptual shift endured, by tracking the dissipation of adaptation in awake participants: identification shifts were mostly intact after 25 min, much smaller but still present after 90 min, and still measurable after 5 hr and 30 min. These findings were published in a journal article (Samuel & Dumay, 2021, Journal of Experimental Psychology: Human Perception and Performance; 5-year impact factor: 2.6) and presented as a talk at an international conference [Samuel, Yi, & Dumay, 2021. Abstracts of the 62nd Annual Meeting of the Psychonomic Society (p. 58)]. Given the timecourse of this dissipation, we looked at whether sleeping during the interval would consolidate the recently displaced category boundary, resulting in a more fundamental alteration of category structure (Workpackage 2c). There are many demonstrations in the literature that sleep stabilizes, or even sharpens, recently learned and likely slowly degrading, perceptual skills (Atienza et al., 2004; Brawn et al., 2010; Fenn et al., 2003; Karni et al., 1994; Mednick et al., 2002; Takamaki et al., 2020). Two variations of a sleep/wake protocol were designed: In the "6-hr" variation, a Sleep group underwent adaptation at 24:00 and returned to the lab for a post-tested at 06:00 the next morning, after a (short) night's sleep. This was compared to a Wake group undergoing adaptation at 18:00 and post-tested at 24:00. The other variation used a more "classic" PM-AM versus AM-PM protocol, using a 10-hr interval: adaptation and post-test occurred at 22:00 and at 08:00 the next morning for the Sleep group, versus 10:00 and 20:00 the same day for the Wake group. The 10-hr variation tracked the dissipation of adaptation in the awake state beyond 6 hr, and provided the potential for an internal replication of sleep effects observed with the 6-hr interval. The Sleep and Wake groups (total N = 109) showed equivalent identification shifts as the immediate result of repeated exposure to the adaptor (i.e., the /wa/ prototype), and there was no influence of time of day. At the retest, either 6 or 10 hr later, adaptation shifts were gone for the Wake group, but for the Sleep group a striking reversal of the effect, with more "wa" reports than even before adaptation, was uncovered. In sum, sleep does not consolidate possible in-the-moment perceptual adjustments triggered by exposure. Instead, it implements a change in phoneme category frequency to reflect the statistical properties of the input. In broader terms this tells us that sleep belatedly updates the priors of mental categories to reflect their importance in the environment. These findings are reported in a manuscript currently under review at Psychonomic Bulletin and Review (5-year impact factor: 4.8). KEY FINDING 3: THE TESTING EFFECT INTERACTS WITH PRECEDING SLEEP IN WAYS THAT SHOULD BE HARNESSED TO OPTIMIZE LEARNING AND REHABILITATION STRATEGIES Testing one's knowledge is a powerful means of securing learning beyond what can be achieved through repeated exposure (for a review, see Adesope et al., 2017). For instance, taking a recall test at the end of a study phase?as opposed to merely restudying?produces more stable knowledge of the studied material in the long term (i.e., days later; Roediger & Karpicke, 2006). Because the "testing effect" is observed irrespective of whether participants recall a lot or little on the immediate test, the long-term advantage clearly does not reflect a possible re-exposure during retrieval. It comes from practising the test itself ahead of the main assessment. Because the long-term study-and-test advantage is tested after learners have slept and because we know sleep plays a pivotal role in the stabilization and strengthening of new information (Berres & Erdfelder, 2021, for a review), researchers have examined whether sleep plays a role in the emergence of the testing effect. Yet, they have found no difference between participants sleeping vs. remaining awake during the 12 hr that follow learning (Abel et al., 2019; Bäuml et al., 2014). Whether the testing effect interacts with sleep, however, has been examined only in relation to the sleep interval that follows the encoding of target material. Yet, what typically occurs in the classroom is that a teacher would divide a big study load into smaller chunks and then each day would teach one chunk before testing their pupils on all the chunks acquired so far. In this scenario, the test therefore concerns not only information learnt minutes ago, but also information learnt during the preceding day and thus consolidated overnight. Hence, during the test, the consolidated information could appear more relevant and fluid than recently learnt information, which could prioritize the consolidated information for further consolidation during the subsequent night, possibly at the expense of what was just acquired by the pupils. Using a protocol that we developed as part of this award, we focused precisely on this multiple-chunk and multiple-night scenario and tested the ability of participants (i.e., adult skilled readers; total N = 168) to visually discriminate between two highly similar novel words (e.g., 'argenal/arbenal'). In the PM group, half of the pairs (Set 1) were trained at 20:00, whereas the other half (Set 2) were trained the next morning, at 08:00. The AM group, in contrast, learnt Set 1 at 08:00 and Set 2 at 20:00 with no sleep in-between. The perceptual discrimination test was first taken immediately after learning Set 2 and then again after another 24 hr. The first post-sleep test demonstrated that sleep makes newly learnt words more distinct: 12-hr-old (Set 1) items were more easily discriminated than 0-hr-old (Set 2) items, but only in the PM group. The key result, however, was what transpires when both groups were retested after another 24 hr, that is at the end of day 2 for the AM group, but at the start of day 3 for the PM group: in contrast to the AM group which showed a benefit of sleep on both sets, the PM group showed no sleep benefit of Set 2, but a cumulative benefit of sleep over the two nights of the protocol for Set 1. The key here is whether Set 1 has been slept on by the time Set 2 is learnt: in the AM group, the two sets reach sleep together and show consolidation of equal magnitude; in the PM group, in contrast, Set 1 reaches sleep a day before Set 2 does, resulting in the prioritization of Set 1 for further consolidation. In the next step, we asked whether the first post-sleep test (on day 2) was instrumental in this prioritization. We therefore ran another PM group, but this time, only with the final retest, 24 hr after learning Set 2. In contrast to the earlier PM group, this retest-only PM group showed each set to benefit from only the sleep interval subsequent to learning. This tells us that the testing effect interacts with the preceding sleep, and thereby dictates the fate of information learnt immediately before the test. These findings ought to be harnessed to optimize learning and rehabilitation strategies. They are reported in two manuscripts: One is currently being revised for resubmission to APA Journal of Experimental Psychology: Learning, Memory and Cognition (5-year impact factor: 2.9); the other is being written up to be submitted to Psychological Science (5-year impact factor: 7.4). They were also presented as conference talks [Dumay, 2022. Abstracts of the 63rd Annual Meeting of the Psychonomic Society (p. 113), Boston MA; Dumay et al., 2022. Abstracts of the 22nd Conference of the European Society for Cognitive Psychology (p. 42), Lille, France]. |
| Exploitation Route | For all key findings: Research could be carried out to investigate what sleep mechanism(s) are at play behind each of the three key findings of this award. Key finding 1: The demonstration that sleep cleanses working memory from known representations recently engaged in perception or cognition is a strong and further argument to recommend that schoolers of all ages should have a nap early afternoon. This is also a further argument to sensitize the public on the need to have decent sleep, both in terms of duration and quality. Key finding 2: Knowing that sleep belatedly updates the priors of mental categories to reflect their importance in the environment has implications for protocols that train individuals to detect specific types of objects in the environment. Here, we showed the phenomenon in the case of repeated exposure to phonemic prototypes. However, there is no reason to expect that this effect should be specific to speech sounds, but should instead generalize across sensory domains. Therefore, applied research should examine whether this finding can affect performance in sensitive domains, like security and screening by human operators. Key finding 3: The finding that sleep plays an instrumental role in turning new linguistic objects (e.g., words, foreign sounds, etc.) into holistic representations able to support identification of their parts (e.g., letters, gestural features) has implications for reading acquisition and language learning. By extension, this sleep-associated unitization process also has implications for any perceptual learning domain in which objects (e.g., objects, bodies, faces, artwork, melodies, etc.) have to be distinguished from one another. More importantly, the demonstration that the testing effect interacts with preceding sleep has clear potential implications for pedagogy: When splitting a study load into multiple chunks in order to study a chunk each day, it is not a good idea, at least when these chunks are independent from each other (e.g., vocabulary lists vs. the lines in a poem), to each day test one's knowledge of all that was acquired so far including today's chunk. Instead, testing should be done on dedicated days when no chunk would be studied for the first time. This is obviously highly relevant for learning and teaching practice, as well as for remediation protocols. This finding is likely to be the one to have the strongest impact. |
| Sectors | Digital/Communication/Information Technologies (including Software) Education Healthcare |
| URL | http://osf.io/cgawq/ |
| Description | Our key finding 3, that the testing effect interacts with preceding sleep, tells us that when splitting a study load into multiple chunks in order to study a chunk each day, it is not a good idea, at least when these chunks are independent from each other (e.g., vocabulary lists vs. the lines in a poem), to each day test one's knowledge of all that was acquired so far including today's chunk. Instead, testing should be done on dedicated days when no chunk would be studied for the first time. The PI has started to implement these elements within his teaching practice. Through invited talks at other psychology and education departments in the UK and abroad, he also has started to sensitize colleagues to this issue. In fact, the University of Exeter press office is in touch with the BBC to run a story on these findings as soon as they are scheduled to appear in the scientific literature. |
| First Year Of Impact | 2024 |
| Sector | Education |
| Impact Types | Societal |
| Description | Connecting Words: The Role of Co-Activation in Lexical Acquisition (PI: Samuel, A. G.) |
| Amount | € 167,410 (EUR) |
| Funding ID | PID2020-113348GB |
| Organisation | Ministry of Science and Innovation (MICINN) |
| Sector | Public |
| Country | Spain |
| Start | 01/2021 |
| End | 12/2024 |
| Description | Is Testing Your Knowledge Of What You Learnt Yesterday Alongside That Of What You Learnt Today Always A Good Review Strategy? (PI: Nicolas Dumay) |
| Amount | £9,947 (GBP) |
| Funding ID | SRG2425\251683 |
| Organisation | The British Academy |
| Department | BA/Leverhulme Small Research Grants |
| Sector | Public |
| Country | United Kingdom |
| Start | 04/2025 |
| End | 05/2027 |
| Description | Lexical Trajectories: Tracking the Encoding, Establishment, and Development of Words in the Mental Lexicon (PI: Samuel, A.G.) |
| Amount | € 119,000 (EUR) |
| Funding ID | PID2023-146423NB-I00 |
| Organisation | Ministry of Science and Innovation (MICINN) |
| Sector | Public |
| Country | Spain |
| Start | 01/2024 |
| End | 12/2028 |
| Description | Exploring the structure of the reading system via word learning |
| Organisation | Ohio State University |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | I am a full contributor to this project resumed earlier this academic year, in which we (Blair Armstrong and Dennis Miller, from Toronto Psychology Dept, Mark Pitt, from Ohio State Psychology Dept, and myself) study how learning to read aloud proceeds, by means of neural network simulations and experiments on human participants. I contribute intellectually to developing research protocols, analysing results and writing up research findings. In addition, students and research interns inmy lab are running the experiments on human participants under my supervision. After a first strong publication in Journal of Experimental Psychology: General (5-yr Impact Factor: 5.3) in 2017 (Armstrong, B. C., Dumay, N., Kim, W., & Pitt, M. A. (2017). Generalization from newly learned words reveals structural properties of the human reading system. Journal of Experimental Psychology: General, 146(2), 227-249. https://doi.org/10.1037/xge0000257) before this project went dormant for 2 years, we will be presenting our new simulation results at the Annual Conference of the Cognitive Science Society, publishing a 6-p peer reviewed article in their proceedings. This paper is currently under review (see the abstract below). The submitted data will be included in a larger paper to combine human and computer data. Abstract: How do neural network models of quasiregular domains, such as spelling-sound correspondences in English, learn to represent knowledge that varies in its consistency with the domain, and generalize this knowledge appropriately? Recent work proposed that a graded ``warping'' mechanism allows for the implicit representation of how a new word's pronunciation should generalize when it is first learned. We explored the micro-structure of this proposal by training a network to pronounce new made-up words that were consistent with the dominant pronunciation (regulars), were comprised of a completely unfamiliar pronunciation (exceptions), or were consistent with a subordinate pronunciation in English (ambiguous). We also ``diluted'' these pronunciations, such that we either presented one or multiple made-up words that shared the same rhyme, increasing context variability. We observed that dilution promoted generalization of novel pronunciations. These results point to the importance of context variability in modulating warping in quasiregular domains. |
| Collaborator Contribution | Postdoctoral research assistant Dennis Miller is the computer simulation wizzard in this project and works under the supervision of Blair Armstrong in Toronto. The latter is also in charge of organizing several studies on human participants to be carried out at Toronto University. Mark Pitt contributes intellectually to the project, and like all of us is involved at the write-up stage. |
| Impact | - Miller, I. D., Dumay, N., Pitt, M.A., Lam, B., & Armstrong, B.C. (Under revision). Context variability promotes generalization in reading aloud: Insight from a neural network simulation. To appear in Proceedings of the Annual Conference of Cognitive Science Society. |
| Start Year | 2019 |
| Description | Exploring the structure of the reading system via word learning |
| Organisation | University of Toronto |
| Country | Canada |
| Sector | Academic/University |
| PI Contribution | I am a full contributor to this project resumed earlier this academic year, in which we (Blair Armstrong and Dennis Miller, from Toronto Psychology Dept, Mark Pitt, from Ohio State Psychology Dept, and myself) study how learning to read aloud proceeds, by means of neural network simulations and experiments on human participants. I contribute intellectually to developing research protocols, analysing results and writing up research findings. In addition, students and research interns inmy lab are running the experiments on human participants under my supervision. After a first strong publication in Journal of Experimental Psychology: General (5-yr Impact Factor: 5.3) in 2017 (Armstrong, B. C., Dumay, N., Kim, W., & Pitt, M. A. (2017). Generalization from newly learned words reveals structural properties of the human reading system. Journal of Experimental Psychology: General, 146(2), 227-249. https://doi.org/10.1037/xge0000257) before this project went dormant for 2 years, we will be presenting our new simulation results at the Annual Conference of the Cognitive Science Society, publishing a 6-p peer reviewed article in their proceedings. This paper is currently under review (see the abstract below). The submitted data will be included in a larger paper to combine human and computer data. Abstract: How do neural network models of quasiregular domains, such as spelling-sound correspondences in English, learn to represent knowledge that varies in its consistency with the domain, and generalize this knowledge appropriately? Recent work proposed that a graded ``warping'' mechanism allows for the implicit representation of how a new word's pronunciation should generalize when it is first learned. We explored the micro-structure of this proposal by training a network to pronounce new made-up words that were consistent with the dominant pronunciation (regulars), were comprised of a completely unfamiliar pronunciation (exceptions), or were consistent with a subordinate pronunciation in English (ambiguous). We also ``diluted'' these pronunciations, such that we either presented one or multiple made-up words that shared the same rhyme, increasing context variability. We observed that dilution promoted generalization of novel pronunciations. These results point to the importance of context variability in modulating warping in quasiregular domains. |
| Collaborator Contribution | Postdoctoral research assistant Dennis Miller is the computer simulation wizzard in this project and works under the supervision of Blair Armstrong in Toronto. The latter is also in charge of organizing several studies on human participants to be carried out at Toronto University. Mark Pitt contributes intellectually to the project, and like all of us is involved at the write-up stage. |
| Impact | - Miller, I. D., Dumay, N., Pitt, M.A., Lam, B., & Armstrong, B.C. (Under revision). Context variability promotes generalization in reading aloud: Insight from a neural network simulation. To appear in Proceedings of the Annual Conference of Cognitive Science Society. |
| Start Year | 2019 |
| Description | Individual differences in plasticity in speech perception |
| Organisation | Korea Aerospace University |
| Country | Korea, Republic of |
| Sector | Academic/University |
| PI Contribution | I am the main investigator of this project in which we (Donghyun Kim from University of Exeter, Meghan Clayards from McGill University, and Eun Jong Kong from Korea Aerospace University) study how listeners flexibly adapt to unfamiliar speech patterns such as foreign accents. In this project, I have been in charge of conceptualizing research goals, designing experiments, data collection, formal analysis, writing an original draft, and revisions. This paper has been revised and resubmitted to a journal and under review now. Abstract: The present study examines whether listeners flexibly adapt to unfamiliar speech patterns such as those encountered in foreign-accented English vowels, where the relative informativeness of primary (spectral quality) and secondary (duration) cues tends to be reversed (e.g., spectrally similar but exaggerated duration differences between bet and bat). This study further tests whether listeners' adaptive strategies are related to individual differences in phoneme categorization gradiency and cognitive abilities. Native English listeners (N=36) listened to a continuum of vowels from /?/ to /æ/ (as in head and had) varying in spectral and duration values to complete a perceptual adaptation task and a visual analog scaling (VAS) task. Participants also completed cognitive tasks examining executive function capacities. Results showed that listeners mostly used spectral quality to signal vowel category at baseline, but flexibly adapted by up-weighting reliance on duration when spectral quality became no longer diagnostic. In the VAS task, some listeners made more categorical responses while others made more gradient responses in vowel categorization, but these differences were not linked to their adaptive patterns. Results of cognitive tasks revealed that individual differences in inhibitory control correlated, to some degree, with the amount of adaptation. Together, these findings suggest that listeners flexibly adapt to unfamiliar speech categories using distributional information in the input and individual differences in cognitive abilities may influence their adaptability. |
| Collaborator Contribution | Meghan Clayards contributes to development of methodology, discussions of results, and revisions to different versions of the manuscripts. Eun Jong Kong also contributes to discussions and revisions to different versions of the manuscripts. |
| Impact | Kim, D., Clayards, M., & Kong, E. J. (revised and resubmitted). Individual differences in perceptual adaptation to unfamiliar phonetic categories. Journal of Phonetics. |
| Start Year | 2018 |
| Description | Individual differences in plasticity in speech perception |
| Organisation | McGill University |
| Country | Canada |
| Sector | Academic/University |
| PI Contribution | I am the main investigator of this project in which we (Donghyun Kim from University of Exeter, Meghan Clayards from McGill University, and Eun Jong Kong from Korea Aerospace University) study how listeners flexibly adapt to unfamiliar speech patterns such as foreign accents. In this project, I have been in charge of conceptualizing research goals, designing experiments, data collection, formal analysis, writing an original draft, and revisions. This paper has been revised and resubmitted to a journal and under review now. Abstract: The present study examines whether listeners flexibly adapt to unfamiliar speech patterns such as those encountered in foreign-accented English vowels, where the relative informativeness of primary (spectral quality) and secondary (duration) cues tends to be reversed (e.g., spectrally similar but exaggerated duration differences between bet and bat). This study further tests whether listeners' adaptive strategies are related to individual differences in phoneme categorization gradiency and cognitive abilities. Native English listeners (N=36) listened to a continuum of vowels from /?/ to /æ/ (as in head and had) varying in spectral and duration values to complete a perceptual adaptation task and a visual analog scaling (VAS) task. Participants also completed cognitive tasks examining executive function capacities. Results showed that listeners mostly used spectral quality to signal vowel category at baseline, but flexibly adapted by up-weighting reliance on duration when spectral quality became no longer diagnostic. In the VAS task, some listeners made more categorical responses while others made more gradient responses in vowel categorization, but these differences were not linked to their adaptive patterns. Results of cognitive tasks revealed that individual differences in inhibitory control correlated, to some degree, with the amount of adaptation. Together, these findings suggest that listeners flexibly adapt to unfamiliar speech categories using distributional information in the input and individual differences in cognitive abilities may influence their adaptability. |
| Collaborator Contribution | Meghan Clayards contributes to development of methodology, discussions of results, and revisions to different versions of the manuscripts. Eun Jong Kong also contributes to discussions and revisions to different versions of the manuscripts. |
| Impact | Kim, D., Clayards, M., & Kong, E. J. (revised and resubmitted). Individual differences in perceptual adaptation to unfamiliar phonetic categories. Journal of Phonetics. |
| Start Year | 2018 |
| Description | Starting-up Sleep Polysomnography and Cognition Research at Exeter University |
| Organisation | University of Exeter |
| Department | School of Psychology |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Over the last two months PI Nicolas Dumay has been collaborating with newly appointed colleague Dr Lawrence Wong to seek fund in order to acquire and set-up a one-bed sleep research lab in the Exeter Psychology Department. The PI helped frame the application to a Strategic Development Fund (£25k) internal to the College which our department sits under, and to coordinate with the HoD so as to find space for this lab to be created. We recently received the fund and have just secured the space on campus and purchased the equipment. |
| Collaborator Contribution | Partner/colleague Dr Lawrence Wong has dealt with the technical details and will be in charge of heading the lab once built. |
| Impact | NA |
| Start Year | 2022 |
| Description | Starting-up Sleep Polysomnography and Cognition Research at Exeter University |
| Organisation | University of Exeter |
| Department | School of Psychology |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Over the last two months PI Nicolas Dumay has been collaborating with newly appointed colleague Dr Lawrence Wong to seek fund in order to acquire and set-up a one-bed sleep research lab in the Exeter Psychology Department. The PI helped frame the application to a Strategic Development Fund (£25k) internal to the College which our department sits under, and to coordinate with the HoD so as to find space for this lab to be created. We recently received the fund and have just secured the space on campus and purchased the equipment. |
| Collaborator Contribution | Partner/colleague Dr Lawrence Wong has dealt with the technical details and will be in charge of heading the lab once built. |
| Impact | NA |
| Start Year | 2022 |
| Description | Organizing a research symposium at the Bi-annual Conference of the European Society for Cognitive Psychology |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | This symposium proposal, the abstract of which is pasted below has been accepted as part of the program of the next Conference of the European Society for Cognitive Psychology (Porto, September 2023). It includes 5 speakers (3 males/2 females) from the US, Spain, the UK, and Canada. The typical audience at the conference (circa 2,500 individuals) includes researchers and academics, as well as postgraduate students. As several sessions are run in parallel, I except an audience ranging between 100 and 500 people. The symposium has dedicated time for interactions between presenters and the audience. The research that Prof Samuel will be presenting and mine are both directly funded by this award. SLEEP AND THE CONSOLIDATION AND UPDATING OF LINGUISTIC KNOWLEDGE Organizer: Nicolas Dumay, University of Exeter, UK The notion that sleep and memory consolidation play a key role in language learning and processing has been around for at least two decades. This symposium aims to provide an overview of what we know and do not know, identify current directions in the field, and generate new ideas and ways to solve points of contention. D. Titone opens the ball by evaluating memory models in light of the literature on word acquisition in the native and non-native language. She also shows how prior knowledge and word properties together determine post-sleep memory. A.G. Samuel looks at the persistence of activation in lexical and sublexical representations, and whether sleep has an impact on these long-lasting by-products of perception. N. Dumay examines the influence of sleep on subphonemic mismatch effects in the visual-world paradigm and explores the idea that these index both sublexical plasticity and lexical learning. A. Takashima and C. Ekerdt look at the brain structures underpinning systems-consolidation of spoken words, from a developmental perspective. Finally, G. Gaskell reports on semantic priming and sentence memory experiments and argues that sleep plays a role also in supporting the maintenance and updating of linguistic knowledge. Keywords: language plasticity, word learning, sleep, memory consolidation, bilingualism |
| Year(s) Of Engagement Activity | 2023 |
| URL | https://escop2023.org/program/symposia |