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Neuroscience Letters Jan 2022Accumulating evidence has demonstrated significant clinical post-traumatic stress disorder (PTSD) symptoms after anesthesia or surgery. Fear extinction dysfunction is a...
Accumulating evidence has demonstrated significant clinical post-traumatic stress disorder (PTSD) symptoms after anesthesia or surgery. Fear extinction dysfunction is a notable feature of PTSD. Although anesthetics and surgery profoundly affect memory processes, their designated effects on fear extinction have not been dissertated. Previous studies have suggested that innate immune system activation disrupts fear extinction, and surgery has been shown to increase the inflammatory response. Thus, in the current study, we examined the effects of propofol, sevoflurane, dexmedetomidine and surgery on fear extinction in adolescent mice, and further tested whether dexmedetomidine could reverse the injury effect of surgery on fear extinction through its anti-inflammatory effects. Our results showed that propofol (200 mg/kg) impaired the acquisition and recall of cued fear extinction, and surgery disrupted cued fear extinction acquisition/recall and consolidation. In contrast to cued fear extinction, contextual fear extinction was not affected by propofol or surgery. Moreover, dexmedetomidine prevented surgery-induced impairment of cued extinction acquisition and recall but not consolidation. Finally, TNF-α and IL-6 levels in the ventromedial prefrontal cortex were not necessary for the dexmedetomidine treatment effect of surgery-induced fear extinction dysfunction. The study results showed that propofol and surgery selective impaired the cued fear extinction stage in adolescent mice, and dexmedetomidine may unleash a protective effect in preventing postoperative PTSD.
Topics: Anesthesia; Anesthetics; Animals; Anti-Inflammatory Agents; Dexmedetomidine; Extinction, Psychological; Fear; Mental Recall; Mice; Propofol; Sevoflurane; Stress Disorders, Post-Traumatic; Surgical Procedures, Operative
PubMed: 34808271
DOI: 10.1016/j.neulet.2021.136347 -
American Journal of Pharmaceutical... Aug 2020The ability to follow instructions is an important aspect of everyday life. Depending on the setting and context, following instructions results in outcomes that have... (Review)
Review
The ability to follow instructions is an important aspect of everyday life. Depending on the setting and context, following instructions results in outcomes that have various degrees of impact. In a clinical setting, following instructions may affect life or death. Within the context of the academic setting, following instructions or failure to do so can impede general learning and development of desired proficiencies. Intuitively, one might think that following instructions requires simply reading instructional text or paying close attention to verbal directions and performing the intended action afterward. This commentary provides a brief overview of the cognitive architecture required for following instructions and will explore social behaviors and mode of instruction as factors further impacting this ability.
Topics: Attention; Cognition; Cooperative Behavior; Education, Pharmacy; Humans; Learning; Mental Recall; Reading; Social Behavior
PubMed: 32934383
DOI: 10.5688/ajpe7779 -
Journal of Sleep Research Aug 2022Several studies have tried to identify the neurobiological bases of dream experiences, nevertheless some questions are still at the centre of the debate. Here, we... (Review)
Review
Several studies have tried to identify the neurobiological bases of dream experiences, nevertheless some questions are still at the centre of the debate. Here, we summarise the main open issues concerning the neuroscientific study of dreaming. After overcoming the rapid eye movement (REM) - non-REM (NREM) sleep dichotomy, investigations have focussed on the specific functional or structural brain features predicting dream experience. On the one hand, some results underlined that specific trait-like factors are associated with higher dream recall frequency. On the other hand, the electrophysiological milieu preceding dream report upon awakening is a crucial state-like factor influencing the subsequent recall. Furthermore, dreaming is strictly related to waking experiences. Based on the continuity hypothesis, some findings reveal that dreaming could be modulated through visual, olfactory, or somatosensory stimulations. Also, it should be considered that the indirect access to dreaming remains an intrinsic limitation. Recent findings have revealed a greater concordance between parasomnia-like events and dream contents. This means that parasomnia episodes might be an expression of the ongoing mental sleep activity and could represent a viable direct access to dream experience. Finally, we provide a picture on nightmares and emphasise the possible role of oneiric activity in psychotherapy. Overall, further efforts in dream science are needed (a) to develop a uniform protocol to study dream experience, (b) to introduce and integrate advanced techniques to better understand whether dreaming can be manipulated, (c) to clarify the relationship between parasomnia events and dreaming, and (d) to determine the clinical valence of dreams.
Topics: Dreams; Humans; Mental Recall; Parasomnias; Sleep; Sleep, REM
PubMed: 35417930
DOI: 10.1111/jsr.13609 -
Neuron Sep 2020The hippocampus and its extended network contribute to encoding and recall of episodic experiences. Drawing from recent anatomical, physiological, and behavioral... (Review)
Review
The hippocampus and its extended network contribute to encoding and recall of episodic experiences. Drawing from recent anatomical, physiological, and behavioral studies, we propose that hippocampal engrams function as indices to mediate memory recall. We broaden this idea to discuss potential relationships between engrams and hippocampal place cells, as well as the molecular, cellular, physiological, and circuit determinants of engrams that permit flexible routing of information to intra- and extrahippocampal circuits for reinstatement, a feature critical to memory indexing. Incorporating indexing into frameworks of memory function opens new avenues of study and even therapies for hippocampal dysfunction.
Topics: Animals; Hippocampus; Humans; Mental Recall; Place Cells
PubMed: 32763146
DOI: 10.1016/j.neuron.2020.07.011 -
Proceedings of the National Academy of... Mar 2022
Topics: Cues; Mental Recall
PubMed: 35290116
DOI: 10.1073/pnas.2201332119 -
Memory (Hove, England) Sep 2023Autobiographical memory (AM) is an important psychological phenomenon that has significance for self-development and mental health. The psychological mechanisms of...
Autobiographical memory (AM) is an important psychological phenomenon that has significance for self-development and mental health. The psychological mechanisms of emotional AM retrieval and their association with individual emotional symptoms remain largely unclear in the literature. For this purpose, the current study provided cue words to elicit emotional AMs. Event-related potentials (ERPs) associated with the retrieval process of AMs were recorded and analyzed. We found that the ERP component N400 was sensitive to both emotional valence and retrieval state, such that its amplitude was larger for negative compared to positive AMs, and larger responses for unrecalled compared to recalled AMs. Further, the N400 amplitude in the positive recalled condition was correlated with individual difference in depression (measured by the Beck Depression Inventory). Another ERP component, the late positive potential (LPP), was also sensitive to emotional valence, such that its amplitude was larger (i.e., more positive-going) for positive compared to negative cues. No significant effect was observed on the early ERP components P1, N1, or P2. The current findings bring new understanding on the difference between positive and negative AMs retrieval in the time domain. Also, the importance of this difference to the individual level of depression is worth noting.
Topics: Humans; Male; Female; Electroencephalography; Memory, Episodic; Evoked Potentials; Emotions; Mental Recall
PubMed: 37428138
DOI: 10.1080/09658211.2023.2220160 -
Psychological Research Sep 2022This review reanalyses the data from four experiments originally designed to test the fragmentation hypothesis. Participants were asked to recall triple or quadruple... (Review)
Review
This review reanalyses the data from four experiments originally designed to test the fragmentation hypothesis. Participants were asked to recall triple or quadruple associates, cued by each of their components in turn, and to guess if they could not remember. There were many errors in recall and many of those errors were repetitions of previous errors. This reanalysis focuses, not on the fragmentation hypothesis, but on the repetition of errors. It works backwards through sequences of test trials to discover the best prior match to the responses on each trial. It reports frequencies of different categories of repetition, conditional probabilities of repetition, correct recalls, and the probability of repetition in relation to the lag between trial and match in the test sequence. These results may be summarised as (1) every event (a stimulus or a response or just a retrieval) to which the participant attends is separately recorded in memory, creating an ordered record of those events that have engaged the participant's attention; (2) the compilation of the record is automatic; while attention to a stimulus is at the participant's disposal, the consequent entry into memory is not, and (3) the retrieval of a potential response from memory is spontaneous; that retrieval becomes an overt response if it is compatible with the cue. This makes sense of a number of historic anomalies in the study of recall and informs some contemporary problems in the study of short-term memory.
Topics: Cues; Humans; Memory, Short-Term; Mental Recall
PubMed: 35288792
DOI: 10.1007/s00426-021-01598-z -
Memory & Cognition Apr 2022The distinction between a semantic memory system, encompassing conceptual knowledge, and an episodic memory system, characterized by specific episodes, is one of the... (Review)
Review
The distinction between a semantic memory system, encompassing conceptual knowledge, and an episodic memory system, characterized by specific episodes, is one of the most important theoretical proposals in cognitive science. However, the distinction between systems has rarely been discussed in relation to spontaneous thought that comes to mind with reduced cognitive effort and intentionality. In this review, we propose that the growing research on spontaneous thought can contribute to current discussions on the interaction between the episodic and semantic systems. Firstly, we review research that shows that, as in deliberate retrieval, spontaneous thoughts are influenced by both episodic and semantic memory, as reflected by the mix of semantic and episodic elements in descriptions of spontaneous thoughts, as well as semantic priming effects in spontaneous thoughts. We integrate the current evidence based on the interplay between cues and semantic activation. Namely, we suggest that cues are key to access episodic memory and modulate the frequency of spontaneous thought, while semantic activation modulates the content of spontaneous thought. Secondly, we propose that spontaneous retrieval is a privileged area to explore the question of functional independence between systems, because it provides direct access to the episodic system. We review the evidence for spontaneous thought in semantic dementia, which suggests that episodic and semantic systems are functionally independent. We acknowledge the scarcity of evidence and suggest that future studies examine the contents of spontaneous thought descriptions and their neural correlates to test the functional relationship and inform the interaction between episodic and semantic systems.
Topics: Cues; Humans; Knowledge; Memory, Episodic; Mental Recall; Semantics
PubMed: 34374025
DOI: 10.3758/s13421-021-01211-z -
Progress in Neurobiology Dec 2022Although memory has long been recognized as a generative process, neural research of memory in recent decades has been predominantly influenced by Tulving's "mental time... (Review)
Review
Although memory has long been recognized as a generative process, neural research of memory in recent decades has been predominantly influenced by Tulving's "mental time traveling" perspective and focused on the reactivation and consolidation of encoded memory representations. With the development of multiple powerful analytical approaches to characterize the contents and formats of neural representations, recent studies are able to provide detailed examinations of the representations at various processing stages and have provided exciting new insights into the transformative nature of episodic memory. These studies have revealed the rapid, substantial, and continuous transformation of memory representation during the encoding, maintenance, consolidation, and retrieval of both single and multiple events, as well as event sequences. These transformations are characterized by the abstraction, integration, differentiation, and reorganization of memory representations, enabling the long-term retention and generalization of memory. These studies mark a significant shift in perspective from remembering to reconstruction, which might better reveal the nature of memory and its roles in supporting more effective learning, adaptive decision-making, and creative problem solving.
Topics: Humans; Memory, Episodic; Mental Recall; Learning
PubMed: 36089107
DOI: 10.1016/j.pneurobio.2022.102351 -
Psychonomic Bulletin & Review Apr 2021The literature suggests that semantic similarity has a weak or null effect for immediate serial reconstruction and a facilitative effect for immediate serial recall.... (Meta-Analysis)
Meta-Analysis Review
The literature suggests that semantic similarity has a weak or null effect for immediate serial reconstruction and a facilitative effect for immediate serial recall. These observed semantic similarity effects are inconsistent with the assumptions of short-term memory (STM) models on the detrimental effect of similarity (e.g., confusion) and with observations of a robust detrimental effect of phonological similarity. Our review indicates that the experimental results are likely dependent on the manipulation strength for semantic similarity and that manipulations used in previous studies might have affected semantic assvociation as well as semantic similarity. To address these possible issues, two indices are proposed: (a) strength of manipulation on semantic similarity, gained by quantifying semantic similarity based on Osgood and associates' dimensional view of semantics, and (b) inter-item associative strength, a possible confounding factor. Our review and the results of a meta-regression analysis using these two indices suggest that semantic similarity has a detrimental effect on both serial reconstruction and serial recall, while semantic association, which is correlated with semantic similarity, contributes to an apparent facilitative effect. An effect that is not attributable to similarity or association was also implied. Review on item and order memory further suggests the facilitative effect of semantic association on item memory and the detrimental effect of the semantic similarity on order memory. Based on our findings, we propose a unified explanation of observations of semantic similarity effects for both serial reconstruction and serial recall that is in good accord with STM models.
Topics: Humans; Memory, Short-Term; Mental Recall; Regression Analysis; Semantics; Serial Learning
PubMed: 33006122
DOI: 10.3758/s13423-020-01815-7