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The Journal of Neuroscience : the... Nov 2023The ability to store information about the past to dynamically predict and prepare for the future is among the most fundamental tasks the brain performs. To date, the...
The ability to store information about the past to dynamically predict and prepare for the future is among the most fundamental tasks the brain performs. To date, the problems of understanding how the brain stores and organizes information about the past (memory) and how the brain represents and processes temporal information for adaptive behavior have generally been studied as distinct cognitive functions. This Symposium explores the inherent link between memory and temporal cognition, as well as the potential shared neural mechanisms between them. We suggest that working memory and implicit timing are interconnected and may share overlapping neural mechanisms. Additionally, we explore how temporal structure is encoded in associative and episodic memory and, conversely, the influences of episodic memory on subsequent temporal anticipation and the perception of time. We suggest that neural sequences provide a general computational motif that contributes to timing and working memory, as well as the spatiotemporal coding and recall of episodes.
Topics: Brain; Mental Recall; Cognition; Memory, Short-Term; Memory, Episodic
PubMed: 37940593
DOI: 10.1523/JNEUROSCI.1430-23.2023 -
JAMA Network Open Oct 2023Perioperative neurocognitive disorder, particularly postoperative cognitive impairment, is common and associated with multiple medical and social adversities, although...
IMPORTANCE
Perioperative neurocognitive disorder, particularly postoperative cognitive impairment, is common and associated with multiple medical and social adversities, although data from China are lacking.
OBJECTIVE
To examine the incidence, trajectory, and risk factors for subjective cognitive and short-term memory impairment after surgery in the Chinese population.
DESIGN, SETTING, AND PARTICIPANTS
This cohort study used data from the China Surgery and Anesthesia Cohort to assess surgical patients aged 40 to 65 years from 2 medical centers between July 15, 2020, and March 31, 2023, with active follow-up within 1 year after the surgery. Of 11 158 patients who were successfully recruited (response rate, 94.4%), 10 149 participants were eligible and available for analysis. From this population, separate cohorts were constructed for analyzing subjective cognitive impairment (8105 noncardiac and 678 cardiac surgery patients) and short-term memory impairment (5246 noncardiac and 454 cardiac surgery patients).
EXPOSURES
Twenty-four potential risk factors regarding comorbidities, preoperative psychological conditions, anesthesia- or surgery-related factors, and postsurgical events were included.
MAIN OUTCOMES AND MEASURES
Outcomes included subjective cognitive function measured by the 8-Item Informant Interview to Differentiate Aging and Dementia (AD8; scores range from 0 to 8, with higher scores indicating more severe cognitive impairment) and short-term memory measured by the 3-Word Recall Test (TRT; scores range from 0 to 3, with lower scores indicating more severe short-term memory impairment) at 1, 3, 6, and 12 months after noncardiac and cardiac surgery. Generalized linear mixed models were used to identify risk factors associated with the presence of AD8 (score ≥2) or TRT (score <3) abnormality as well as the aggressively deteriorative trajectories of those cognitive measurements.
RESULTS
For noncardiac surgery patients, the AD8 analysis included 8105 patients (mean [SD] age, 52.3 [7.1] years; 3378 [41.7%] male), and the TRT analysis included 5246 patients (mean [SD] age, 51.4 [7.0] years; 1969 [37.5%] male). The AD8 abnormality incidence rates after noncardiac surgery increased from 2.2% (175 of 8105) at 7 days to 17.1% (1059 of 6191) at 6 months after surgery, before appearing to decrease. In contrast, the TRT abnormality incidence rates followed a U-shaped pattern, with the most pronounced incidence rates seen at 7 days (38.9% [2040 of 5246]) and 12 months (49.0% [1394 of 2845]). Similar patterns were seen among cardiac surgery patients for the AD8 analysis (678 patients; mean [SD] age, 53.2 [6.3] years; 393 [58.0%] male) and TRT analysis (454 patients; mean [SD] age, 52.4 [6.4] years; 248 [54.6%] male). Among noncardiac surgery patients, the top risk factors for aggressively deteriorative AD8 trajectory and for AD8 abnormality, respectively, after surgery were preoperative sleep disturbances (Pittsburgh Sleep Quality Index ≥16 vs 0-5: odds ratios [ORs], 4.04 [95% CI, 2.20-7.40] and 4.54 [95% CI, 2.40-8.59]), intensive care unit stay of 2 days or longer (ORs, 2.43 [95% CI, 1.26-4.67] and 3.07 [95% CI, 1.67-5.65]), and preoperative depressive symptoms (ORs, 1.76 [95% CI, 1.38-2.24] and 2.23 [95% CI, 1.79-2.77]). Analyses for TRT abnormality and trajectory, as well as the analyses conducted among cardiac surgery patients, found fewer associated factors.
CONCLUSIONS AND RELEVANCE
This cohort study of middle-aged Chinese surgery patients found subjective cognitive and short-term memory impairment within 12 months after both cardiac and noncardiac surgery, with multiple identified risk factors, underscoring the potential of preoperative psychological interventions and optimized perioperative management for postoperative cognitive impairment prevention.
Topics: Female; Humans; Male; Middle Aged; Cognition; Cognitive Dysfunction; Cohort Studies; Delirium; East Asian People; Memory, Short-Term; Adult; Aged; Postoperative Cognitive Complications; Memory Disorders; Surgical Procedures, Operative
PubMed: 37815831
DOI: 10.1001/jamanetworkopen.2023.36985 -
Immediate and short-term effects of single-task and motor-cognitive dual-task on executive function.PloS One 2023Executive function plays an important role in our daily life and can be affected by both single task (acute aerobic exercise or cognitive training) and dual-task (acute... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
Executive function plays an important role in our daily life and can be affected by both single task (acute aerobic exercise or cognitive training) and dual-task (acute motor-cognitive training) interventions. Here we explored the immediate and short-term effect on executive function to texted whether dual-task interventions are more effective at promoting executive function.
METHODS
Forty-six young men were recruited (mean age: 20.65 years) and assigned randomly to aerobic exercise (n = 15), cognitive training (n = 15), or dual-task (n = 16) groups. Executive functions were assessed before, immediately after, and 30 min after intervention using Go/No-go, 2-back, and More-Odd-Shifting tests.
RESULTS
Working memory function improved after all three interventions (significant Time effect, F(2,86) = 7.05, p = 0.001). Performance on the 2-back test was significantly better immediately after dual-task intervention (p = 0.038) and the response time was shorter (p = 0.023). Performance on the More-Odd-Shifting test improved over time (significant Time effect, F(2,86) = 30.698, p = 0.01), both immediately after the dual-task intervention (p = 0.015), and 30 min later (p = 0.001). Shifting-test performance was also better immediately after (p = 0.005) and 30 min after (p < 0.001) aerobic exercise.
CONCLUSION
Executive function was enhanced by single-task (acute aerobic exercise or cognitive training) and dual-task interventions. The effect continued for 30 min after both the single-task aerobic exercise and the dual-task intervention. For short-term intervention, the dual-task was not more effective than either of the single tasks.
Topics: Male; Humans; Young Adult; Adult; Executive Function; Cognition; Exercise; Exercise Therapy; Memory, Short-Term
PubMed: 37585447
DOI: 10.1371/journal.pone.0290171 -
Frontiers in Behavioral Neuroscience 2023Many living organisms of the animal kingdom have the fundamental ability to form and retrieve memories. Most information is initially stored as short-term memory, which...
Many living organisms of the animal kingdom have the fundamental ability to form and retrieve memories. Most information is initially stored as short-term memory, which is then converted to a more stable long-term memory through a process called memory consolidation. At the neuronal level, synaptic plasticity is crucial for memory storage. It includes the formation of new spines, as well as the modification of existing spines, thereby tuning and shaping synaptic efficacy. Cofilin critically contributes to memory processes as upon activation, it regulates the shape of dendritic spines by targeting actin filaments. We previously found that prolonged activation of cofilin in hippocampal neurons attenuated the formation of long-term object-location memories. Because the modification of spine shape and structure is also essential for short-term memory formation, we determined whether overactivation of hippocampal cofilin also influences the formation of short-term memories. To this end, mice were either injected with an adeno-associated virus expressing catalytically active cofilin, or an eGFP control, in the hippocampus. We show for the first time that cofilin overactivation improves short-term memory formation in the object-location memory task, without affecting anxiety-like behavior. Surprisingly, we found no effect of cofilin overactivation on AMPA receptor expression levels. Altogether, while cofilin overactivation might negatively impact the formation of long-lasting memories, it may benefit short-term plasticity.
PubMed: 37638111
DOI: 10.3389/fnbeh.2023.1243524 -
PloS One 2024The networks proposed here show how neurons can be connected to form flip-flops, the basic building blocks in sequential logic systems. The novel neural flip-flops...
The networks proposed here show how neurons can be connected to form flip-flops, the basic building blocks in sequential logic systems. The novel neural flip-flops (NFFs) are explicit, dynamic, and can generate known phenomena of short-term memory. For each network design, all neurons, connections, and types of synapses are shown explicitly. The neurons' operation depends only on explicitly stated, minimal properties of excitement and inhibition. This operation is dynamic in the sense that the level of neuron activity is the only cellular change, making the NFFs' operation consistent with the speed of most brain functions. Memory tests have shown that certain neurons fire continuously at a high frequency while information is held in short-term memory. These neurons exhibit seven characteristics associated with memory formation, retention, retrieval, termination, and errors. One of the neurons in each of the NFFs produces all of the characteristics. This neuron and a second neighboring neuron together predict eight unknown phenomena. These predictions can be tested by the same methods that led to the discovery of the first seven phenomena. NFFs, together with a decoder from a previous paper, suggest a resolution to the longstanding controversy of whether short-term memory depends on neurons firing persistently or in brief, coordinated bursts. Two novel NFFs are composed of two and four neurons. Their designs follow directly from a standard electronic flip-flop design by moving each negation symbol from one end of the connection to the other. This does not affect the logic of the network, but it changes the logic of each component to a logic function that can be implemented by a single neuron. This transformation is reversible and is apparently new to engineering as well as neuroscience.
Topics: Memory, Short-Term; Neurons; Logic; Synapses; Pleasure
PubMed: 38489250
DOI: 10.1371/journal.pone.0300534 -
Pharmacological Reports : PR Dec 2023Psychedelics are compounds acting by serotonin 5-hydroxytryptamine (5-HT) receptor activation and induce several behavioral responses. They are of special interest... (Review)
Review
Psychedelics are compounds acting by serotonin 5-hydroxytryptamine (5-HT) receptor activation and induce several behavioral responses. They are of special interest because of their positive effects on neuropsychiatric disorders (depression and posttraumatic stress disorder). However, several findings revealed that some psychedelic actions are similar to symptoms observed in schizophrenia (psychosis, sensorimotor gating impairments, attention, and working memory deficits) which might limit their clinical applications. Psychedelics activate some neurotransmitters, i.e., serotonergic, and glutamatergic, that are also impaired in schizophrenia. Therefore, the neurobiological background of psychedelics and schizophrenia is partially similar. Another important aspect to discuss is the perspective of using psychedelics in schizophrenia therapy. Postmortem studies showed a loss of synapses in schizophrenia, and the positive effects of psychedelics on neuroplasticity (synaptogenesis, neurogenesis, and neuritogenesis) might be essential in the context of schizophrenia therapy. However, because of psychedelics' psychotic action, the recommended doses of psychedelics in schizophrenia treatment are not established, and subpsychedelic dosing or microdosing are considered. Exploratory studies are needed to determine the tolerability of treatment and appropriate dosing regimen. Another therapeutic option is using non-hallucinogenic psychedelic analogs that also induce neuroplastic outcomes but do not have psychotogenic effects. Further preclinical and clinical studies are needed to recognize the potential effectiveness of 5-HT agonists in schizophrenia therapy.
Topics: Humans; Hallucinogens; Schizophrenia; Serotonin; Psychotic Disorders; Memory, Short-Term
PubMed: 37899392
DOI: 10.1007/s43440-023-00546-5 -
Current Opinion in Neurobiology Dec 2023Theories and models of working memory (WM) were at least since the mid-1990s dominated by the persistent activity hypothesis. The past decade has seen rising concerns... (Review)
Review
Theories and models of working memory (WM) were at least since the mid-1990s dominated by the persistent activity hypothesis. The past decade has seen rising concerns about the shortcomings of sustained activity as the mechanism for short-term maintenance of WM information in the light of accumulating experimental evidence for so-called activity-silent WM and the fundamental difficulty in explaining robust multi-item WM. In consequence, alternative theories are now explored mostly in the direction of fast synaptic plasticity as the underlying mechanism. The question of non-Hebbian vs Hebbian synaptic plasticity emerges naturally in this context. In this review, we focus on fast Hebbian plasticity and trace the origins of WM theories and models building on this form of associative learning.
Topics: Memory, Short-Term; Neuronal Plasticity
PubMed: 37980802
DOI: 10.1016/j.conb.2023.102809 -
Scientific Reports Nov 2023A physical trainer often physically guides a learner's limbs to teach an ideal movement, giving the learner proprioceptive information about the movement to be...
A physical trainer often physically guides a learner's limbs to teach an ideal movement, giving the learner proprioceptive information about the movement to be reproduced later. This instruction requires the learner to perceive kinesthetic information and store the instructed information temporarily. Therefore, (1) proprioceptive acuity to accurately perceive the taught kinesthetics and (2) short-term memory to store the perceived information are two critical functions for reproducing the taught movement. While the importance of proprioceptive acuity and short-term memory has been suggested for active motor learning, little is known about passive motor learning. Twenty-one healthy adults (mean age 25.6 years, range 19-38 years) participated in this study to investigate whether individual learning efficiency in passively guided learning is related to these two functions. Consequently, learning efficiency was significantly associated with short-term memory capacity. In particular, individuals who could recall older sensory stimuli showed better learning efficiency. However, no significant relationship was observed between learning efficiency and proprioceptive acuity. A causal graph model found a direct influence of memory on learning and an indirect effect of proprioceptive acuity on learning via memory. Our findings suggest the importance of a learner's short-term memory for effective passive motor learning.
Topics: Adult; Humans; Young Adult; Memory, Short-Term; Psychomotor Performance; Proprioception; Learning; Kinesthesis
PubMed: 38012253
DOI: 10.1038/s41598-023-48101-9 -
Brain Structure & Function Jul 2023The mammillary body (MB) is a component of the extended hippocampal system and many studies have shown that its functions are vital for mnemonic processes. Together with... (Review)
Review
The mammillary body (MB) is a component of the extended hippocampal system and many studies have shown that its functions are vital for mnemonic processes. Together with other subcortical structures, such as the anterior thalamic nuclei and tegmental nuclei of Gudden, the MB plays a crucial role in the processing of spatial and working memory, as well as navigation in rats. The aim of this paper is to review the distribution of various substances in the MB of the rat, with a description of their possible physiological roles. The following groups of substances are reviewed: (1) classical neurotransmitters (glutamate and other excitatory transmitters, gamma-aminobutyric acid, acetylcholine, serotonin, and dopamine), (2) neuropeptides (enkephalins, substance P, cocaine- and amphetamine-regulated transcript, neurotensin, neuropeptide Y, somatostatin, orexins, and galanin), and (3) other substances (calcium-binding proteins and calcium sensor proteins). This detailed description of the chemical parcellation may facilitate a better understanding of the MB functions and its complex relations with other structures of the extended hippocampal system.
Topics: Rats; Animals; Mammillary Bodies; Neurochemistry; Anterior Thalamic Nuclei; Amino Acids; Memory, Short-Term
PubMed: 37378855
DOI: 10.1007/s00429-023-02673-4 -
Dyslexia (Chichester, England) Nov 2023Many studies have highlighted short-term memory (STM) impairment in dyslexic individuals. Several studies showed deficits for both item and serial order aspects of...
Many studies have highlighted short-term memory (STM) impairment in dyslexic individuals. Several studies showed deficits for both item and serial order aspects of verbal STM in dyslexic individuals. These group-based studies, however, do not inform us about the prevalence of these deficits and, importantly, their potential heterogeneity at the individual level. The present study examined both group-level and individual STM profiles in dyslexic and age-matched non-dyslexic children. While confirming previous group-based results of both item and serial order STM deficits, individual analyses indicated two distinct profiles: one profile was associated with verbal item STM and phonological impairment while another profile showed selective serial STM deficits in both verbal and visual domains. Our results highlight the need for practitioners to consider the heterogeneous nature of STM impairment in dyslexia and to adapt STM and reading treatment strategies accordingly.
Topics: Humans; Child; Memory, Short-Term; Dyslexia; Memory Disorders; Reading; Articulation Disorders; Phonetics
PubMed: 37519030
DOI: 10.1002/dys.1749