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38
Remembering the past and imagining the future: a neural model of spatial memory and imagery
- Psychological Review
"... The authors model the neural mechanisms underlying spatial cognition, integrating neuronal systems and behavioral data, and address the relationships between long-term memory, short-term memory, and imagery, and between egocentric and allocentric and visual and ideothetic representations. Long-term ..."
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Cited by 78 (7 self)
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The authors model the neural mechanisms underlying spatial cognition, integrating neuronal systems and behavioral data, and address the relationships between long-term memory, short-term memory, and imagery, and between egocentric and allocentric and visual and ideothetic representations. Long-term spatial memory is modeled as attractor dynamics within medial–temporal allocentric representations, and short-term memory is modeled as egocentric parietal representations driven by perception, retrieval, and imagery and modulated by directed attention. Both encoding and retrieval/imagery require translation between egocentric and allocentric representations, which are mediated by posterior parietal and retrosplenial areas and the use of head direction representations in Papez’s circuit. Thus, the hippocampus effectively indexes information by real or imagined location, whereas Papez’s circuit translates to imagery or from perception according to the direction of view. Modulation of this translation by motor efference allows spatial updating of representations, whereas prefrontal simulated motor efference allows mental exploration. The alternating temporal–parietal flows of information are organized by the theta rhythm. Simulations demonstrate the retrieval and updating of familiar spatial scenes, hemispatial neglect in memory, and the effects on hippocampal place cell firing of lesioned head direction representations and of conflicting visual and ideothetic inputs.
A contextbased theory of recency and contiguity in free recall
- Psychological Review
, 2008
"... 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 ..."
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Cited by 43 (19 self)
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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.
The medial temporal lobe and the left inferior prefrontal cortex jointly support interference resolution in verbal working memory
- J. Cogn. Neurosci
, 2009
"... & During working memory retrieval, proactive interference (PI) can be induced by semantic similarity and episodic familiarity. Here, we used fMRI to test hypotheses about the role of the left inferior frontal gyrus (LIFG) and the medial temporal lobe (MTL) regions in successful resolution of PI. ..."
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Cited by 14 (2 self)
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& During working memory retrieval, proactive interference (PI) can be induced by semantic similarity and episodic familiarity. Here, we used fMRI to test hypotheses about the role of the left inferior frontal gyrus (LIFG) and the medial temporal lobe (MTL) regions in successful resolution of PI. Participants studied six-word lists and responded to a recognition probe after a short distracter period. We induced semantic PI by using study lists containing words within the same semantic category (e.g., animals). We also measured PI induced by recent study, which should increase episodic familiarity, by comparing recent negative probes (lures studied in previous trial) to distant negative probes (lures that had not been presented within a block). Resolving both types of PI resulted in enhanced activation in LIFG and MTL regions. We propose that the LIFG and the MTL support successful resolution of interference via controlled retrieval processes that serve to recover detailed episodic (e.g., listspecific or source) information: Specifically, the data suggest that BOLD activation in the LIFG reflects the deployment of controlled retrieval operations, regardless of whether the retrieval attempt succeeds in recovering the target information, whereas MTL activation specifically reflects access to relevant episodic information that serves to successfully resolve PI. &
Bridging the gap: Transitive associations between items presented in similar temporal contexts
, 2007
"... Associations in episodic memory are formed between items presented close together in time. The temporal context model (TCM) hypothesizes that this contiguity effect is a consequence of shared temporal contexts rather than temporal proximity per se. Using double function lists of paired associates, w ..."
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Cited by 12 (2 self)
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Associations in episodic memory are formed between items presented close together in time. The temporal context model (TCM) hypothesizes that this contiguity effect is a consequence of shared temporal contexts rather than temporal proximity per se. Using double function lists of paired associates, which include chains of pairs (e.g. A-B, B-C), we examined associations between items that were not presented close together in time but were presented in similar temporal contexts. For instance A and C do not appear together, but both occur in the context of B. Although within-pair associations (e.g. A-B) were asymmetric, across-pair associations (e.g. A-C) showed no evidence for asymmetry. We attempted to describe these transitive associations using two models. One was a heteroassociative model in which the A-C associations resulted from mediated chaining as a result of “stepping through ” the links in the chain. Although this heteroassociative model and TCM make identical predictions regarding simple contiguity effects, the heteroassociative model had great difficulty accounting for the form of transitive associations between items. TCM provided an excellent fit to the data. These data raise the surprising possiblity that episodic contiguity effects do not reflect direct associations between items but rather a process of binding, encoding and retrieval of a gradually-changing
Temporal associations and prior-list intrusions in free recall
- Journal of Experimental Psychology: Learning, Memory, and Cognition
, 2006
"... When asked to recall the words from a just-presented target list, subjects occasionally recall words that were not on the list. These intrusions either appeared on earlier lists (prior-list intrusions, or PLIs) or had not appeared over the course of the experiment (extra-list intrusions). The author ..."
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Cited by 9 (4 self)
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When asked to recall the words from a just-presented target list, subjects occasionally recall words that were not on the list. These intrusions either appeared on earlier lists (prior-list intrusions, or PLIs) or had not appeared over the course of the experiment (extra-list intrusions). The authors examined the factors that elicit PLIs in free recall. A reanalysis of earlier studies revealed that PLIs tend to come from semantic associates as well as from recently studied lists, with the rate of PLIs decreasing sharply with list recency. The authors report 3 new experiments in which some items in a given list also appeared on earlier lists. Although repetition enhanced recall of list items, subjects were significantly more likely to make PLIs following the recall of repeated items, suggesting that temporal associations formed in earlier lists can induce recall errors. The authors interpret this finding as evidence for the interacting roles of associative and contextual retrieval processes in recall. Although contextual information helps to focus recall on words in the target list, it does not form an impermeable boundary between current- and prior-list experiences.
Semantic structure and episodic memory
"... In remembering a list of words, subjects ’ order of recall can reveal the influence of both semantic and temporal associations among items. In this chapter, we examine how well measures of semantic relatedness (e.g., Landauer & Dumais, 1997; Steyvers, Shiffrin, & Nelson, 2004) predict the o ..."
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Cited by 7 (4 self)
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In remembering a list of words, subjects ’ order of recall can reveal the influence of both semantic and temporal associations among items. In this chapter, we examine how well measures of semantic relatedness (e.g., Landauer & Dumais, 1997; Steyvers, Shiffrin, & Nelson, 2004) predict the order of subject’s recalls. Analysis of recall transitions reveal that subtle variations in semantic relatedness strongly influence memory retrieval. Contrary to the view that temporal and semantic similarity strictly compete as retrieval cues, the data reveal that these two factors are separately modifiable, at least under certain conditions. These findings are not easily reconciled within current models of episodic and semantic memory. A central function of episodic memory is to form and utilize associations between items experienced at nearby times. In addition to these newly–formed episodic associations, subjects enter the laboratory with a great deal of knowledge about verbal stimuli. Studying the relation between episodic and pre–existing, or semantic, associations can help shed
Context, Learning, and Extinction
"... A. Redish et al. (2007) proposed a reinforcement learning model of context-dependent learning and extinction in conditioning experiments, using the idea of “state classification ” to categorize new observations into states. In the current article, the authors propose an interpretation of this idea i ..."
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Cited by 7 (4 self)
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A. Redish et al. (2007) proposed a reinforcement learning model of context-dependent learning and extinction in conditioning experiments, using the idea of “state classification ” to categorize new observations into states. In the current article, the authors propose an interpretation of this idea in terms of normative statistical inference. They focus on renewal and latent inhibition, 2 conditioning paradigms in which contextual manipulations have been studied extensively, and show that online Bayesian inference within a model that assumes an unbounded number of latent causes can characterize a diverse set of behavioral results from such manipulations, some of which pose problems for the model of Redish et al. Moreover, in both paradigms, context dependence is absent in younger animals, or if hippocampal lesions are made prior to training. The authors suggest an explanation in terms of a restricted capacity to infer new causes.
Dissociable networks involved in spatial and temporal order source retrieval
- Neuroimage
, 2011
"... Space and time are important components of our episodic memories. Without this information, we cannot determine the "where and when" of our recent memories, rendering it difficult to disambiguate individual episodes from each other. The neural underpinnings of spatial and temporal order m ..."
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Cited by 3 (0 self)
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Space and time are important components of our episodic memories. Without this information, we cannot determine the "where and when" of our recent memories, rendering it difficult to disambiguate individual episodes from each other. The neural underpinnings of spatial and temporal order memory in humans remain unclear, in part because of difficulties in disentangling the contributions of these two types of source information. To address this issue, we conducted an experiment in which participants first navigated a virtual city, experiencing unique routes in a specific temporal order and learning about the spatial layout of the city. Spatial and temporal order information were dissociated in our task such that learning one type of information did not facilitate the other behaviorally. This allowed us to then address the extent to which the two types of information involved functionally distinct or overlapping brain areas. During functional magnetic resonance imaging (fMRI), participants retrieved information about the relative distance of stores within the city (spatial task) and the temporal order of stores from each other (temporal task). Comparable hippocampal activity was observed during these two tasks, but greater prefrontal activity was seen during temporal order retrieval whereas greater parahippocampal activity was seen during spatial retrieval. We suggest that while the brain possesses dissociable networks for maintaining and representing spatial layout and temporal order components of episodic memory, this information may converge into a common representation for source memory in areas such as the hippocampus.
Cause as an implication
- Studia Logica
, 1987
"... dietary habits of ethnic groups in Europe and ..."
The Influence of Context Boundaries on Memory for the Sequential Order of Events
"... Episodic memory allows people to reexperience the past by recovering the sequences of events that characterize those prior experiences. Although experience is continuous, people are able to selectively retrieve and reexperience more discrete episodes from their past, raising the possibility that som ..."
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Cited by 2 (0 self)
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Episodic memory allows people to reexperience the past by recovering the sequences of events that characterize those prior experiences. Although experience is continuous, people are able to selectively retrieve and reexperience more discrete episodes from their past, raising the possibility that some elements become tightly related to each other in memory, whereas others do not. The current series of experiments was designed to ask how shifts in context during an experience influence how people remember the past. Specifically, we asked how context shifts influence the ability to remember the relative order of past events, a hallmark of episodic memory. We found that memory for the order of events was enhanced within, rather than across, context shifts, or boundaries (Experiment 1). Next, we showed that this relative enhancement in order memory was eliminated when across-item associative processing was disrupted (Experiment 2), suggesting that context shifts have a selective effect on sequential binding. Finally, we provide evidence that the act of making order memory judgments involves the reactivation of representations that bridged the tested items (Experiment 3). Together, these data suggest that boundaries may serve to parse continuous experience into sequences of contextually related events and that this organization facilitates remembering the temporal order of events that share the same context.
