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Cerebral Cortex (New York, N.Y. : 1991) Aug 2018Long-term memory (LTM) helps to efficiently direct and deploy the scarce resources of the attentional system; however, the neural substrates that support LTM-guidance of...
Long-term memory (LTM) helps to efficiently direct and deploy the scarce resources of the attentional system; however, the neural substrates that support LTM-guidance of visual attention are not well understood. Here, we present results from fMRI experiments that demonstrate that cortical and subcortical regions of a network defined by resting-state functional connectivity are selectively recruited for LTM-guided attention, relative to a similarly demanding stimulus-guided attention paradigm that lacks memory retrieval and relative to a memory retrieval paradigm that lacks covert deployment of attention. Memory-guided visuospatial attention recruited posterior callosal sulcus, posterior precuneus, and lateral intraparietal sulcus bilaterally. Additionally, 3 subcortical regions defined by intrinsic functional connectivity were recruited: the caudate head, mediodorsal thalamus, and cerebellar lobule VI/Crus I. Although the broad resting-state network to which these nodes belong has been referred to as a cognitive control network, the posterior cortical regions activated in the present study are not typically identified with supporting standard cognitive control tasks. We propose that these regions form a Memory-Attention Network that is recruited for processes that integrate mnemonic and stimulus-based representations to guide attention. These findings may have important implications for understanding the mechanisms by which memory retrieval influences attentional deployment.
Topics: Adult; Attention; Brain; Brain Mapping; Eye Movements; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Memory, Long-Term; Mental Recall; Neural Pathways; Oxygen; Photic Stimulation; Time Factors; Visual Perception; Young Adult
PubMed: 28968648
DOI: 10.1093/cercor/bhx172 -
Neurobiology of Aging Jul 2018Decline in cognitive functions, including hippocampus-dependent spatial memory, is commonly observed at a later stage of aging (e.g., >20 months old in rodents) and...
Decline in cognitive functions, including hippocampus-dependent spatial memory, is commonly observed at a later stage of aging (e.g., >20 months old in rodents) and typically studied after a discrete learning event. How normal aging, particularly at an early stage, affects the modulatory aspect of memory persistence is underinvestigated. Previous studies in young animals show that weak, fading memories can last longer if a modulating event, such as spatial novelty, is introduced around memory encoding. This is known as behavioral tagging and capture (BTC). Here, we investigated how early aging (10-13 months old) affects BTC in an appetitive delayed-matching-to-place task. We trained rats when they were young and middle aged and found that novelty facilitated long-term memory persistence in young but not in middle-aged rats. However, re-exposure to the encoded environment after learning improved memory persistence in middle-aged rats. BTC, combined with memory reactivation, facilitated memory persistence through reconsolidation. Our results point toward a weakened tagging and capture mechanism before reduction of plasticity-related proteins at an early stage of aging.
Topics: Animals; Appetite; Behavior, Animal; Cognitive Aging; Hippocampus; Male; Maze Learning; Memory, Long-Term; Neuronal Plasticity; Rats, Inbred Strains; Spatial Memory
PubMed: 29609080
DOI: 10.1016/j.neurobiolaging.2018.02.023 -
Psychonomic Bulletin & Review Oct 2022When memories share similar features, this can lead to interference, and ultimately forgetting. With experience, however, interference can be resolved. This raises the...
When memories share similar features, this can lead to interference, and ultimately forgetting. With experience, however, interference can be resolved. This raises the important question of how memories change, with experience, to minimize interference. Intuitively, interference might be minimized by increasing the precision and accuracy of memories. However, recent evidence suggests a potentially adaptive role for memory distortions. Namely, similarity can trigger exaggerations of subtle differences between memories (repulsion). Here, we tested whether repulsion specifically occurs on feature dimensions along which memories compete and whether repulsion is predictive of reduced memory interference. To test these ideas, we developed synthetic faces in a two-dimensional face space (affect and gender). This allowed us to precisely manipulate similarity between faces and the feature dimension along which faces differed. In three experiments, participants learned to associate faces with unique cue words. Associative memory tests confirmed that when faces were similar (face pairmates), this produced interference. Using a continuous face reconstruction task, we found two changes in face memory that preferentially occurred along the feature dimension that was "diagnostic" of the difference between face pairmates: (1) there was a bias to remember pairmates with exaggerated differences (repulsion) and (2) there was an increase in the precision of feature memory. Critically, repulsion and precision were each associated with reduced associative memory interference, but these were statistically dissociable contributions. Collectively, our findings reveal that similarity between memories triggers dissociable, experience-dependent changes that serve an adaptive role in reducing interference.
Topics: Humans; Learning; Memory; Memory, Long-Term; Mental Recall
PubMed: 35380409
DOI: 10.3758/s13423-022-02082-4 -
Proceedings of the National Academy of... Feb 2023Reactivation of long-term memories enables experience-dependent strengthening, weakening, or updating of memory traces. Although coupling of hippocampal and cortical...
Reactivation of long-term memories enables experience-dependent strengthening, weakening, or updating of memory traces. Although coupling of hippocampal and cortical activity patterns facilitates initial memory consolidation, whether and how these patterns are involved in postreactivation memory processes are not known. Here, we monitored the hippocampal-cortical network as rats repetitively learned and retrieved spatial and nonspatial memories. We show that interactions between hippocampal sharp wave-ripples (SPW-R), cortical spindles (SPI), and cortical ripples (CXR) are jointly modulated in the absence of memory demand but independently recruited depending on the stage of memory and task type. Reconsolidation of memory after retrieval is associated with an increased and extended window of coupling between hippocampal SPW-Rs and CXRs compared to the initial consolidation. Hippocampal SPW-R and cortical spindle interactions are preferentially engaged during memory consolidation. These findings suggest that specific, time-limited patterns of oscillatory coupling can support the distinct memory processes required to flexibly manage long-term memories in a dynamic environment.
Topics: Rats; Animals; Hippocampus; Memory, Long-Term; Memory; Learning; Memory Consolidation
PubMed: 36749719
DOI: 10.1073/pnas.2207909120 -
Genes To Cells : Devoted To Molecular &... Apr 2022A newly formed memory is initially unstable. However, if it is consolidated into the brain, the consolidated memory is stored as stable long-term memory (LTM). Despite...
A newly formed memory is initially unstable. However, if it is consolidated into the brain, the consolidated memory is stored as stable long-term memory (LTM). Despite the recent progress, the molecular and cellular mechanisms of LTM have not yet been fully elucidated. The fruitfly Drosophila melanogaster, for which various genetic tools are available, has been used to clarify the molecular mechanisms of LTM. Using the Drosophila courtship-conditioning assay as a memory paradigm, we previously identified that the circadian clock gene period (per) plays a vital role in consolidating LTM, suggesting that per-expressing clock neurons are critically involved in LTM. However, it is still incompletely understood which clock neurons are essential for LTM. Here, we show that dorsal-lateral clock neurons (LNds) play a crucial role in LTM. Using an LNd-specific split-GAL4 line, we confirmed that disruption of synaptic transmission in LNds impaired LTM maintenance. On the other hand, induction of per RNAi or the dominant-negative transgene of Per in LNds impaired LTM consolidation. Our results reveal that transmitter release and Per function in LNds are involved in courtship memory processing.
Topics: Animals; Drosophila; Drosophila Proteins; Drosophila melanogaster; Memory, Long-Term; Mushroom Bodies; Neurons
PubMed: 35094465
DOI: 10.1111/gtc.12923 -
Proceedings of the National Academy of... Aug 2022Memory consolidation is promoted by sleep. However, there is also evidence for consolidation into long-term memory during wakefulness via processes that preferentially...
Memory consolidation is promoted by sleep. However, there is also evidence for consolidation into long-term memory during wakefulness via processes that preferentially affect nonhippocampal representations. We compared, in rats, the effects of 2-h postencoding periods of sleep and wakefulness on the formation of long-term memory for objects and their associated environmental contexts. We employed a novel-object recognition (NOR) task, using object exploration and exploratory rearing as behavioral indicators of these memories. Remote recall testing (after 1 wk) confirmed significant long-term NOR memory under both conditions, with NOR memory after sleep predicted by the occurrence of EEG spindle-slow oscillation coupling. Rats in the sleep group decreased their exploratory rearing at recall testing, revealing successful recall of the environmental context. By contrast, rats that stayed awake after encoding showed equally high levels of rearing upon remote testing as during encoding, indicating that context memory was lost. Disruption of hippocampal function during the postencoding interval (by muscimol administration) suppressed long-term NOR memory together with context memory formation when animals slept, but enhanced NOR memory when they were awake during this interval. Testing remote recall in a context different from that during encoding impaired NOR memory in the sleep condition, while exploratory rearing was increased. By contrast, NOR memory in the wake rats was preserved and actually superior to that after sleep. Our findings indicate two distinct modes of long-term memory formation: Sleep consolidation is hippocampus dependent and implicates event-context binding, whereas wake consolidation is impaired by hippocampal activation and strengthens context-independent representations.
Topics: Animals; Memory Consolidation; Memory, Long-Term; Mental Recall; Rats; Sleep; Wakefulness
PubMed: 35969775
DOI: 10.1073/pnas.2203165119 -
Vision Research Nov 2019Although there is empricial support for the old adage that "we never forget a face" (Journal of Experimental Psychology: General 104 (1975) 54-75), the cognitive...
Although there is empricial support for the old adage that "we never forget a face" (Journal of Experimental Psychology: General 104 (1975) 54-75), the cognitive processes responsible for our long-term face memories are not well understood. By manipulating the upright and inverted orientation of faces during encoding and retrieval, we investigated the influence of holistic processing on our ability to recognize faces stored in long-term memory. In Experiment 1, participants were trained to identify 12 novel upright faces (six male, six female) by name (e.g., "Joe," "Sue") to a criterion of 100% accuracy. Following learning, holistic memory for the upright and inverted faces was tested using the parts/wholes face recognition task. Different groups of participants were tested either immediately, one week, or two weeks after learning. A significant holistic effect was found for faces tested in their original upright orientation that was stable over the immediate, one-week, and two-week testing periods. In contrast, recognition of the same faces when shown inverted was poor and showed no evidence of holistic processing. In Experiment 2, faces were learned in their inverted orientations with 100% accuracy and tested in their upright and inverted orientations. At the immediate, one-week, or two-week intervals, recognition of inverted faces was relatively poor and there was no evidence of holistic processing for faces tested either in inverted or upright orientations. Collectively, these results indicate holistic processing provides an efficient means for the encoding and retrieval of faces in long-term memory that are relatively stable with the passage of time.
Topics: Adolescent; Adult; Facial Recognition; Female; Humans; Male; Memory, Long-Term; Orientation; Photic Stimulation; Reaction Time; Recognition, Psychology; Young Adult
PubMed: 31585389
DOI: 10.1016/j.visres.2019.07.007 -
Biochemistry. Biokhimiia Mar 2017Investigation of biochemical mechanisms underlying the long-term storage of information in nervous system is one of main problems of modern neurobiology. As a molecular... (Review)
Review
Investigation of biochemical mechanisms underlying the long-term storage of information in nervous system is one of main problems of modern neurobiology. As a molecular basis of long-term memory, long-term changes in kinase activities, increase in the level and changes in the subunit composition of receptors in synaptic membranes, local activity of prion-like proteins, and epigenetic modifications of chromatin have been proposed. Perhaps a combination of all or of some of these factors underlies the storage of long-term memory in the brain. Many recent studies have shown an exclusively important role of atypical protein kinases (PKCζ, PKMζ, and PKCι/λ) in processes of learning, consolidation and maintenance of memory. The present review is devoted to consideration of mechanisms of transcriptional and translational control of atypical protein kinases and their roles in induction and maintenance of long-term synaptic plasticity and memory in vertebrates and invertebrates.
Topics: Animals; Humans; Learning; Memory, Long-Term; Nerve Tissue Proteins; Neuronal Plasticity; Protein Kinases
PubMed: 28320265
DOI: 10.1134/S0006297917030026 -
Molecular Brain May 2023Dysregulation of HDAC4 expression and/or nucleocytoplasmic shuttling results in impaired neuronal morphogenesis and long-term memory in Drosophila melanogaster. A recent...
Dysregulation of HDAC4 expression and/or nucleocytoplasmic shuttling results in impaired neuronal morphogenesis and long-term memory in Drosophila melanogaster. A recent genetic screen for genes that interact in the same molecular pathway as HDAC4 identified the cytoskeletal adapter Ankyrin2 (Ank2). Here we sought to investigate the role of Ank2 in neuronal morphogenesis, learning and memory. We found that Ank2 is expressed widely throughout the Drosophila brain where it localizes predominantly to axon tracts. Pan-neuronal knockdown of Ank2 in the mushroom body, a region critical for memory formation, resulted in defects in axon morphogenesis. Similarly, reduction of Ank2 in lobular plate tangential neurons of the optic lobe disrupted dendritic branching and arborization. Conditional knockdown of Ank2 in the mushroom body of adult Drosophila significantly impaired long-term memory (LTM) of courtship suppression, and its expression was essential in the γ neurons of the mushroom body for normal LTM. In summary, we provide the first characterization of the expression pattern of Ank2 in the adult Drosophila brain and demonstrate that Ank2 is critical for morphogenesis of the mushroom body and for the molecular processes required in the adult brain for the formation of long-term memories.
Topics: Animals; Ankyrins; Courtship; Drosophila melanogaster; Drosophila Proteins; Memory, Long-Term; Morphogenesis; Mushroom Bodies; Neurons
PubMed: 37194019
DOI: 10.1186/s13041-023-01026-w -
Psychonomic Bulletin & Review Feb 2022Prior learning can hinder subsequent memory, especially when there is conflict between old and new information. The ability to handle this proactive interference is an...
Prior learning can hinder subsequent memory, especially when there is conflict between old and new information. The ability to handle this proactive interference is an important source of differences in memory performance between younger and older adults. In younger participants, Oberauer et al. (2017, Journal of Experimental Psychology: Learning, Memory, and Cognition, 43[1], 1) report evidence of proactive facilitation from previously learned information in a working memory task in the absence of proactive interference between long-term and working memory. In the present work, we examine the generality of these findings to different stimulus materials and to older adults. Participants first learned image-word associations and then completed an image-word working memory task. Some pairs were the same as those initially learned, for which we expected facilitation relative to previously unencountered pairs. Other pairs were made up of previously learned elements in different combinations, for which we might expect interference. Younger and older participants showed similar levels of facilitation from previously learned associations relative to new pairs. In addition, older participants exhibited proactive interference from long-term to working memory, whereas younger participants exhibited facilitation, even for pairings that conflicted with those learned earlier in the experiment. These findings confirm older adults' greater susceptibility to proactive interference and we discuss the theoretical implications of younger adults' apparent immunity to interference.
Topics: Aged; Aging; Humans; Learning; Memory, Long-Term; Memory, Short-Term; Mental Recall; Proactive Inhibition
PubMed: 34322845
DOI: 10.3758/s13423-021-01981-2