SAMPL: The Spreading Activation and Memory PLasticity Model

Sievers, Beau; Momennejad, Ida

doi:10.1101/778563

Cited by 5 publications

(9 citation statements)

References 56 publications

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“…The Evening group exhibited reliably negative generalization in this experiment, meaning they tended to rate novel bridge- inconsistent satellites as more functional and more familiar than novel bridge-consistent satellites. This result may be consistent with non-monotonic accounts of memory plasticity [ 77 , 78 ]: Moderate instead of strong activation of related satellites during the study of the bridge items, possibly due to higher inhibition in the evening than morning, could result in repulsion instead of integration of the bridged categories.…”

Section: Resultssupporting

confidence: 87%

Examining the effects of time of day and sleep on generalization

et al. 2021

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Extracting shared structure across our experiences allows us to generalize our knowledge to novel contexts. How do different brain states influence this ability to generalize? Using a novel category learning paradigm, we assess the effect of both sleep and time of day on generalization that depends on the flexible integration of recent information. Counter to our expectations, we found no evidence that this form of generalization is better after a night of sleep relative to a day awake. Instead, we observed an effect of time of day, with better generalization in the morning than the evening. This effect also manifested as increased false memory for generalized information. In a nap experiment, we found that generalization did not benefit from having slept recently, suggesting a role for time of day apart from sleep. In follow-up experiments, we were unable to replicate the time of day effect for reasons that may relate to changes in category structure and task engagement. Despite this lack of consistency, we found a morning benefit for generalization when analyzing all the data from experiments with matched protocols (n = 136). We suggest that a state of lowered inhibition in the morning may facilitate spreading activation between otherwise separate memories, promoting this form of generalization.

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Section: Resultssupporting

confidence: 87%

Examining the effects of time of day and sleep on generalization

et al. 2021

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“…The Evening group exhibited reliably negative generalization in this experiment, meaning they tended to rate novel bridge-inconsistent satellites as more functional and more familiar than novel bridgeconsistent satellites. This result may be consistent with non-monotonic accounts of memory plasticity (Ritvo et al, 2019;Sievers & Momennejad, 2019): Moderate instead of strong activation of related satellites during the study of the bridge items, due to higher inhibition in the evening than morning, could result in repulsion instead of integration of the bridged categories.…”

Section: Methodssupporting

confidence: 84%

“…In addition, we found some evidence that the Evening group exhibited a sort of antigeneralization: They were more likely to falsely recognize and to endorse as functional novel bridgeinconsistent exemplars. Under non-monotonic plasticity accounts (Ritvo et al, 2019;Sievers & Momennejad, 2019), this "repulsion" between concepts can occur when related memories are only moderately activated, as might occur in the evening in a state of higher inhibition. Notably, Retrieval-Induced Forgetting, a memory phenomenon that taps into these non-monotonic plasticity and repulsion processes (Hulbert & Norman, 2015;Norman et al, 2007), is stronger at optimal times of day and this has been attributed to higher inhibition (Pica et al, 2014).…”

Section: Discussionmentioning

confidence: 99%

Influences of time of day on generalization

Tandoc

Bayda

Poskanzer

et al. 2020

Preprint

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Extracting shared structure across our experiences allows us to generalize our knowledge to novel contexts. How do different brain states influence this ability to generalize? Using a novel category learning paradigm, we assess the effect of both sleep and time of day on generalization that depends on the flexible integration of recent information. Counter to our expectations, we found no evidence that this form of generalization is better after a night of sleep relative to a day awake. Instead, we observed an effect of time of day, with better generalization in the morning than the evening. This effect also manifested as increased false memory for generalized information. In a nap experiment, we found that generalization did not benefit from having slept recently, suggesting a role for circadian rhythms apart from sleep. We found, however, that this time of day effect appears to be sensitive to category structure and to task engagement more generally. We propose that a state of lowered inhibition in the morning may facilitate spreading activation between otherwise separate memories, promoting this form of generalization.

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“…Theoretically, we have proposed that a given state has higher representational similarity to its frequently visited successors along the planned path (Ezzyat & Davachi, 2014;Garvert et al, 2017;Momennejad et al, 2017;Stachenfeld et al, 2017). Our interpretation can also be discussed in terms of increased association, integration, abstraction, and clustering (Ritvo, Turk-Browne, & Norman, 2019), or the spread of activation across memory networks (Sievers & Momennejad, 2019). One may also ask whether the similarity to successor states reported here could be due to the replay of previous trajectories or paths (Ambrose, Pfeiffer, & Foster, 2016;Wu & Foster, 2014).…”

Section: Prefrontal Hierarchymentioning

confidence: 77%

“…Our interpretation can also be discussed in terms of increased association, integration, abstraction, and clustering (Ritvo, Turk-Browne, & Norman, 2019). This similarity could also be due to the spread of activation across memory networks (Sievers & Momennejad, 2019) . While there are clever analytic designs to hint one way or another, a clear-cut dissociation of these hypotheses requires higher spatio-temporal resolutions such as electrophysiology, MEG, and other methods across species.…”

Section: Discussionmentioning

confidence: 99%

Predictive Representations in Hippocampal and Prefrontal Hierarchies

Brunec

Momennejad

2019

Preprint

Self Cite

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As we navigate the world we learn about associations among events, extract relational structures, and store them in memory. This relational knowledge, in turn, enables generalization, inference, and hierarchical planning. Here we investigated relational knowledge during spatial navigation as multiscale predictive representations in the brain. We hypothesized that these representations are organized at multiple scales along posterior-anterior hierarchies in prefrontal and hippocampal regions. To test this, we conducted model-based representational similarity analyses of neuroimaging data measured during virtual reality navigation of familiar and unfamiliar paths with realistically long distances. We tested the pattern similarity of each point-along each navigational path-to a weighted sum of its successor points within different temporal horizons. Predictive similarity was significantly higher for familiar paths. Overall, anterior PFC showed predictive horizons at the largest scales (~875m) and posterior hippocampus at the lowest (~25m), while the anterior hippocampus (~175m), pre-polar PFC, and orbitofrontal regions (~350m) were in between. These findings support the idea that predictive representations are maintained at higher scales of abstraction in the anterior PFC, and unfolded at lower scales by pre-polar PFC and hippocampal regions. This representational hierarchy can support generalization, hierarchical planning, and subgoals at multiple scales.

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SAMPL: The Spreading Activation and Memory PLasticity Model

Cited by 5 publications

References 56 publications

Examining the effects of time of day and sleep on generalization

Examining the effects of time of day and sleep on generalization

Influences of time of day on generalization

Predictive Representations in Hippocampal and Prefrontal Hierarchies

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