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Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Estudios de Filosofía is the property of Universidad de Antioquia, Instituto de Filosofia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The recent development of specialized research fields in philosophy of memory and philosophy of perception invites a dialogue about the relationship between these mental capacities. Following a brief review of some of the key issues that can be raised at the interface of memory and perception, this introduction provides an overview of the contributions to the special issue, and outlines possible directions for further research. [ABSTRACT FROM AUTHOR]

The author offers insights on the biomedical aspects of sleep. Topics discussed include the significant impact of sleep on human physiology and psychiatry, the contribution of sleep to memory health, learning, and general nerve functions, and the highlights of various neurophysiological studies concerning rapid eye movement (REM) sleep, slow-wave sleep, and dreaming.

In this article, we have studied a memory dependent prey–predator model with logistic type prey growth subject to the Allee effect and Holling type‐III functional response. To include the memory effect, we have used here a fractional order system. The model contains at most four equilibrium points among which one is trivial, two are axial, and the last one is interior. Here we have studied behavior of these four equilibrium points using eigen analysis method. Our investigation shows that the trivial equilibrium point is stable for strong Allee effect, and unstable for weak Allee effect. Between the two axial equilibrium points, one is stable under certain condition but the other is always unstable. This unstable equilibrium point exists only for strong Allee case. The interior equilibrium point arises when the axial equilibrium point is unstable. Stability condition of this interior equilibrium point depends on the parametric relationship. The schematic diagram divides the a‐p plane into five sub‐regions in both the cases of memory dependent and memory less system. The number and nature of the equilibrium points in different sub‐regions are different. Finally, we have drawn the bifurcation diagrams considering all the equilibrium points in different sub‐regions and the results are concluded at the end. [ABSTRACT FROM AUTHOR]

Copyright of Dialogue: Canadian Philosophical Review is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • Exposure to low levels of Fluoride (F) during pregnancy and lactation were studied. • Low F concentrations produced dysfunction in the central nervous system. • Female adult offspring exposed to low F concentrations showed memory impairment. • Exposure to F reduced expression of α7 nAChR subunit mRNA in hippocampus. • Low F concentrations induced oxidative stress in hippocampus. Abstract Daily exposure to fluoride (F) depends mainly on the intake of this element with drinking water. When administered during gestation and lactation, F has been associated with cognitive deficits in the offspring. However, the mechanisms underlying the neurotoxicity of F remain obscure. In the current study, we investigated the effects of oral exposure to low levels of F during the gestational and lactation periods, on the memory of adult female rat offspring. We also considered a possible underlying neurotoxic mechanism. Our results showed that this exposure reduced step-down latency in the inhibitory avoidance task, and decreased both mRNA expression of the α7 nicotinic receptor (nAChR) and catalase activity in hippocampus. Our data indicates that low F concentrations administrated during gestation and lactation decrease the memory of 90-day-old female offspring. This suggests that the mechanism might be connected with an α7 nAChR deficit in the hippocampus, induced by oxidative stress. [ABSTRACT FROM AUTHOR]

Over the 40 years that TINS has been in existence, there has been substantial progress in understanding the types, organisation, and neural mechanisms of memory. The selectivity of memory maintenance and retention remains a puzzle, and we here summarise two contributions of our own research to this enigma: the striking impact of the novelty and surprise often of other events happening around the time that a new memory is encoded and how activated prior knowledge guides the updating process that characterises aspects of memory consolidation. Highlights Over the past 40 years, there has been substantial progress in understanding the types, organisation, and neural mechanisms of memory. We here summarise two contributions of our own research on the mechanistic underpinnings explaining why some events are remembered and others are doomed to be forgotten. Fine-grained molecular understanding is emerging on how novelty and surprise around the time of encoding help stabilise new memories. We describe initial insights into how activated prior knowledge guides the updating process that characterises aspects of memory consolidation. [ABSTRACT FROM AUTHOR]

Recent indications are suggesting that high fat and sugar-enriched foods do not only evoke harmful physiological conditions, but they also endure evident structural alterations in cerebral regions controlling cognitive and feeding behaviors. Food consumption plus neuronal energy regulatory mechanisms seem to constitute a complex system assuring that food calories do not exceed body requirements. At the same time obesogenic-related properties of limbic feeding stations like the hypothalamus (HTH), hippocampus (HIP) and amygdala (AMY) tend to control eating habits through the interaction of distinct neuropeptides. For this purpose, it was our intention to correlate expression differences of a key anti-obesogenic neuropeptide receptor i.e. neurotensin1 (NTR1) on mnemonic performances in the hibernating hamster ( Mesocricetus auratus ) exposed to a high fat diet (HFD). Interestingly, these hamsters exhibited a notable enhanced (p < 0.01) body weight from the fifth on to the twelfth week of treatment, which was accompanied by elevated blood lipid cholesterolo and triglycerides and glucose levels. At the same time these hamsters provided diminished locomotor activities such as exploratory bouts, rearing and grooming behaviors. Of greater relevance was their very extreme (p < 0.001) inability of identifying new objects during novel object recognition (NOR) tests along with not having correctly chosen the chamber of the conditioned place preference (CPP) apparatus, which contained the gratifying reward. Surprisingly the altered behavioral plus mnemonic tasks of HFD hamsters were tightly related to elevated NTR1 expression changes in the above limbic sites thus proposing this neuronal system as a highly probable alternative for treating obesity-dependent mnemonic dysfunctions. [ABSTRACT FROM AUTHOR]

Aging is marked by memory decline that is exacerbated with attentional loading. Portraying older adults' neural functions when encoding information in conditions of high and low attentional load is a necessary step toward understanding this phenomenon. Furthermore, the information gained may be used to devise strategies aimed to prevent age-related decline in memory. To address this issue, a group of older adults underwent fMRI scanning while encoding short movies under two levels of attentional loading. High attentional load was associated with increased inter-subject correlation (inter-SC) in only a subset of prefrontal regions that were previously identified in younger adults. It was also associated with lower inter-SC in task-relevant visual regions, suggesting that as load increased, visual processing became less synchronized across participants. Critically, while we have shown that inter-SC in the dorsal posterior cingulate cortex (dPCC) was increased for younger adults at high load, older adults did not generally show this effect. However, those older adults who did display this pattern also displayed a 'younger-like' memory profile. These results point to a pivotal role of the dPCC in the interplay between attention and memory across the lifespan. [ABSTRACT FROM AUTHOR]

Background Gastrin Releasing Peptide (GRP) may play a role in fear learning. The GRP Receptor is expressed in the basolateral amygdala and hippocampus, and central administration of GRP mediates fear learning. The effects of GRP on reconsolidation, however, have been minimally explored. Reconsolidation, the process by which formed memories are rendered labile following recall, provides a window of opportunity for pharmacological intervention. Although evidence suggests the window of opportunity to alter reactivated consolidation memory can be as long as 6 h, shorter intervals have not been extensively investigated. Method Male Sprague-Dawley rats received six 1.0 mA continuous footshocks. 24 h later, were re-exposed to the context (shock chamber). Immediately following memory retrieval rats received i.p. injection of GRP (10 nmol/kg), Flumazenil (1 mg/kg), GRP + Flumazenil (10 nmol/kg GRP with 1 mg/kg Flumazenil), or Vehicle. Other groups received GRP or Vehicle at 0, 10, 30, or 60 min post-reactivation. 24 h and 5 days later rats were assessed for fear expression upon re-exposure to the fearful stimulus. Results GRP significantly attenuated the reconsolidation of learned fear when administered immediately (but not 10 min or longer) following recall. Some of the variability in the impact of treatments aimed at disrupting fear memories may be governed, in part, by the time-frame of the reconsolidation window. Our results indicate that the effect of immediate administration persisted for at least 5 days. Co-administration of benzodiazepine-receptor antagonist Flumazenil blocked this effect, suggesting the effect is mediated via a GABAergic mechanism. [ABSTRACT FROM AUTHOR]

The present study addresses the issue of whether spatial information impacts immediate verbatim recall of verbal navigation instructions. Subjects heard messages instructing them to move within a two-dimensional depiction of a three-dimensional space consisting of four stacked grids displayed on a computer screen. They repeated the instructions orally and then followed them manually by clicking with a mouse on the grids. Two groups with identical instructions were compared; they differed only in whether the starting position was indicated before or after the instructions were given and repeated, with no differences in the manual movements to be made. Accuracy on both the oral repetition and manual movement responses was significantly higher when the starting position was indicated before the instructions. The results are consistent with the proposal that there is only a single amodal mental representation, rather than distinct verbal and nonverbal representations, of navigation instructions. The advantage for the before condition was found even for the oral repetition responses, implying that the creation of the amodal representation occurred immediately, while the instructions were being held in working memory. In practical terms, the findings imply that being able to form a mental representation of the movement path while being given verbal navigation instructions should substantially facilitate memory for the instructions and execution of them. [ABSTRACT FROM AUTHOR]

How do we rapidly process incoming streams of information in working memory, a cognitive mechanism central to human behavior? Dominant views of working memory focus on the prefrontal cortex (PFC), but human hippocampal recordings provide a neurophysiological signature distinct from the PFC. Are these regions independent, or do they interact in the service of working memory? We addressed this core issue in behavior by recording directly from frontotemporal sites in humans performing a visuospatial working memory task that operationalizes the types of identity and spatiotemporal information we encounter every day. Theta band oscillations drove bidirectional interactions between the PFC and medial temporal lobe (MTL; including the hippocampus). MTL theta oscillations directed the PFC preferentially during the processing of spatiotemporal information, while PFC theta oscillations directed the MTL for all types of information being processed in working memory. These findings reveal an MTL theta mechanism for processing space and time and a domain-general PFC theta mechanism, providing evidence that rapid, dynamic MTL–PFC interactions underlie working memory for everyday experiences. [ABSTRACT FROM AUTHOR]

Research from multiple areas in neuroscience suggests a link between self-locomotion and memory. In two free recall experiments with adults, we looked for a link between (a) memory, and (b) the coherence of movement and optic flow. In both experiments, participants heard lists of words while on a treadmill and wearing a virtual reality (VR) headset. In the first experiment, the VR scene and treadmill were stationary during encoding. During retrieval, all participants walked forward, but the VR scene was stationary, moved forward, or moved backwards. In the second experiment, during encoding all participants walked forward and viewed a forward-moving VR scene. During retrieval, all participants continued to walk forward but the VR scene was stationary, forward-moving, or backward-moving. In neither experiment was there a significant difference in the amount recalled, or output order strategies, attributable to differences in movement conditions. Thus, any effects of movement on memory are more limited than theories of hippocampal function and theories in cognitive psychology anticipate. [ABSTRACT FROM AUTHOR]

When [Simon Fraser University] opened in 1965, there was a department that was created that was the Centre for Studies in Communications and the Arts. Nobody knew what that was except that they were going to hire a couple of artists and Communication people and we were to discover our own identity, what we would be doing together. [ABSTRACT FROM AUTHOR]

Many genetic studies for Alzheimer's disease (AD) have been focused on the identification of common genetic variants associated with AD risk and not on other aspects of the disease, such as age at onset or rate of dementia progression. There are multiple approaches to untangling the genetic architecture of these phenotypes. We hypothesized that the genetic architecture of rate of progression is different than the risk for developing AD dementia. To test this hypothesis, we used longitudinal clinical data from ADNI and the Knight-ADRC at Washington University, and we calculated PRS (polygenic risk score) based on the IGAP study to compare the genetic architecture of AD risk and dementia progression. Dementia progression was measured by the change of Clinical Dementia Rating Sum of Boxes (CDR)-SB per year. Out of the 21 loci for AD risk, no association with the rate of dementia progression was found. The PRS rate was significantly associated with the rate of dementia progression (β= 0.146, p = 0.03). In the case of rare variants, TREM2 (β= 0.309, p = 0.02) was also associated with the rate of dementia progression. TREM2 variant carriers showed a 23% faster rate of dementia compared with non-variant carriers. In conclusion, our results indicate that the recently identified common and rare variants for AD susceptibility have a limited impact on the rate of dementia progression in AD patients. [ABSTRACT FROM AUTHOR]

Detrimental effects of volatile anaesthetics, including sevoflurane, on the structure and function of the developing brain have been reported. The internalization of N-methyl-D-aspartate receptors (NMDARs) contributes to anaesthetic neurotoxicity. Both nicotinic acetylcholine receptors (nAChRs) and NMDAR play a critical role in the development of the nervous system. Moreover, nAChR can interact with NMDAR, and previous studies have demonstrated modulation of NMDAR by nAChR. In our study, we used an α7 nicotinic acetylcholine receptor (α7nAChR) agonist and α7nAChR antagonist to explore the role of α7nAChR and NMDAR in sevoflurane-induced long-term effects on memory and dendritic spine both in vivo and in vitro. The results revealed that the activation of α7nAChR attenuated the development of sevoflurane-induced memory deficit and dendritic spine changes, which might be by regulating NR2B-containing NMDAR trafficking from the intracellular pool to the cell surface pool in the hippocampus. Moreover, we demonstrated that α7nAChR could regulate NR2B-containing NMDAR via Src-family tyrosine kinase (SFK). Thus, our current study indicates that the trafficking of NR2B-containing NMDAR is regulated by α7nAChR via SFK in neonatal rat hippocampus, which may be secondary to sevoflurane-induced cognitive deficits in the developing hippocampus. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a neurodegenerative disorder related, in part, to the accumulation of amyloid-β peptide (Aβ) and especially the Aβ peptide 1-42 (Aβ 1-42 ). The aim of this study was to design nanocarriers able to: (i) interact with the Aβ 1-42 in the blood and promote its elimination through the “ sink effect ” and (ii) correct the memory defect observed in AD-like transgenic mice. To do so, biodegradable, PEGylated nanoparticles were surface-functionalized with an antibody directed against Aβ 1-42 . Treatment of AD-like transgenic mice with anti-Aβ 1-42 -functionalized nanoparticles led to: (i) complete correction of the memory defect; (ii) significant reduction of the Aβ soluble peptide and its oligomer level in the brain and (iii) significant increase of the Aβ levels in plasma. This study represents the first example of Aβ 1-42 monoclonal antibody-decorated nanoparticle-based therapy against AD leading to complete correction of the memory defect in an experimental model of AD. [ABSTRACT FROM AUTHOR]

Throughout life animals learn to recognize cues that signal danger and instantaneously initiate an adequate threat response. Memories of such associations may last a lifetime and far outlast the intracellular molecules currently found to be important for memory processing. The memory engram may be supported by other more stable molecular components, such as the extracellular matrix structure of perineuronal nets (PNNs). Here, we show that recall of remote, but not recent, visual fear memories in rats depend on intact PNNs in the secondary visual cortex (V2L). Supporting our behavioral findings, increased synchronized theta oscillations between V2L and basolateral amygdala, a physiological correlate of successful recall, was absent in rats with degraded PNNs in V2L. Together, our findings suggest a role for PNNs in remote memory processing by stabilizing the neural network of the engram. [ABSTRACT FROM AUTHOR]

Millions of North Americans sustain a concussion or a mild traumatic brain injury annually, and are at risk of cognitive, emotional, and physical sequelae. Although functional MRI (fMRI) studies have provided an initial framework for examining functional deficits induced by concussion, particularly working memory and attention, the temporal dynamics underlying these deficits are not well understood. We used magnetoencephalography (MEG), a modality with millisecond temporal resolution, in conjunction with a 1-back visual working memory (VWM) paradigm using scenes from everyday life to characterize spatiotemporal functional differences at specific VWM stages, in adults had had or had not had a recent concussion. MEG source-level differences between groups were determined by whole-brain analyses during encoding and recognition phases. Despite comparable behavioral performance, abnormal hypo- and hyperactivation patterns were found in brain areas involving frontoparietal, ventral occipitotemporal, temporal, and subcortical areas in concussed patients. These patterns and their timing varied as a function of VWM stagewise processing, linked to early attentional control, visuoperceptual scene processing, and VWM maintenance and retrieval processes. Parietal hypoactivation, starting at 60 ms during encoding, was correlated with symptom severity, possibly linked to impaired top-down attentional processing. Hyperactivation in the scene-selective occipitotemporal areas, the medial temporal complex, specifically the right hippocampus and orbitofrontal areas during encoding and/or recognition, lead us to posit inefficient but compensatory visuoperceptual, relational, and retrieval processing. Although injuries sustained after the concussion were considered 'mild,' these data suggest that they can have prolonged effects on early attentional and VWM processes. [ABSTRACT FROM AUTHOR]

Two datasets of 110 young adults were examined to investigate the relationship between individual differences in working memory capacity (WMC) and dynamic cognitive control. The results delve into the specific differences between high- and low-WMC individuals' ability to enact and maintain cognitive control using the AX version of the continuous performance test (AX-CPT). Compared to high-WMC individuals, low-WMC individuals: (a) made more errors, specifically to AX targets; (b) exhibited a partial shift to proactive control with more time-on-task; (c) had more exaggerated slower AX target responses in the tail of the response time distribution; and (d) were equally likely to adjust control after conflict. These results fit with the dual mechanisms of cognitive control theory and goal-maintenance account, and further clarify how individual differences in WMC manifests as intra-individual variability in cognitive control. [ABSTRACT FROM AUTHOR]

Previous studies have shown action potentiation during conceptual processing of manipulable objects. In four experiments, we investigated whether these motor actions also play a role in long-term memory. Participants categorized objects that afforded either a power grasp or a precision grasp as natural or artifact by grasping cylinders with either a power grasp or a precision grasp. In all experiments, responses were faster when the affordance of the object was compatible with the type of grasp response. However, subsequent free recall and recognition memory tasks revealed no better memory for object pictures and object names for which the grasp affordance was compatible with the grasp response. The present results therefore do not support the hypothesis that motor actions play a role in long-term memory. [ABSTRACT FROM AUTHOR]

Recent findings suggest that acute stress can improve the execution of delayed intentions (prospective memory, PM). However, it is unclear whether this improvement can be explained by altered executive control processes or by altered associative memory functioning. To investigate this issue, we used physical-psychosocial stressors to induce acute stress in laboratory settings. Then participants completed event- and time-based PM tasks requiring the different contribution of control processes and a control task (letter fluency) frequently used to measure executive functions. According to our results, acute stress had no impact on ongoing task performance, time-based PM, and verbal fluency, whereas it enhanced event-based PM as measured by response speed for the prospective cues. Our findings indicate that, here, acute stress did not affect executive control processes. We suggest that stress affected event-based PM via associative memory processes. [ABSTRACT FROM AUTHOR]

Models of preclinical Alzheimer's disease (AD) propose that cerebral amyloidosis leads to neurodegeneration and subsequent cognitive decline. This study investigated whether APOE genotype is related to β-amyloid (Aβ) burden in brain regions preferentially affected by AD and whether Aβ burden is associated with gray-matter (GM) fraction (as a marker of neurodegeneration) and episodic memory performance in cognitively normal middle-aged individuals at varying genetic risk for AD. Three groups of cognitively normal participants aged 50–65 years with a first-degree family history of AD ( APOE genotype ε4ε4 [n = 15], ε3ε4 [n = 15], and ε3ε3 [n = 15]) underwent [ 11 C]PiB positron emission tomography scans to quantify cortical Aβ, brain magnetic resonance imaging, and neuropsychological testing. APOE ε4ε4 participants demonstrated significantly higher cortical Aβ burden than APOE ε3ε3 ( p < 0.001). Furthermore, cortical Aβ burden was inversely associated with cortical GM fraction ( p = 0.017) but not episodic memory performance. In cognitively normal, middle-aged individuals, Aβ burden is significantly associated with GM fraction but not episodic memory performance. These findings are consistent with models of preclinical AD in which neurodegeneration occurs before manifest cognitive decline. [ABSTRACT FROM AUTHOR]

The idea that synchronous neural activity underlies cognition has driven an extensive body of research in human and animal neuroscience. Yet, insufficient data on intracranial electrical connectivity has precluded a direct test of this hypothesis in a whole-brain setting. Through the lens of memory encoding and retrieval processes, we construct whole-brain connectivity maps of fast gamma (30-100 Hz) and slow theta (3-8 Hz) spectral neural activity, based on data from 294 neurosurgical patients fitted with indwelling electrodes. Here we report that gamma networks desynchronize and theta networks synchronize during encoding and retrieval. Furthermore, for nearly all brain regions we studied, gamma power rises as that region desynchronizes with gamma activity elsewhere in the brain, establishing gamma as a largely asynchronous phenomenon. The abundant phenomenon of theta synchrony is positively correlated with a brain region's gamma power, suggesting a predominant low-frequency mechanism for inter-regional communication. [ABSTRACT FROM AUTHOR]

Background: Effect of neurofeedback training (NFT) on enhancement of cognitive function or amelioration of clinical symptoms is inconclusive. The trainability of brain rhythm using a neurofeedback system is uncertainty because various experimental designs are used in previous studies. The current study aimed to develop a portable wireless NFT system for alpha rhythm and to validate effect of the NFT system on memory with a sham-controlled group.Methods: The proposed system contained an EEG signal analysis device and a smartphone with wireless Bluetooth low-energy technology. Instantaneous 1-s EEG power and contiguous 5-min EEG power throughout the training were developed as feedback information. The training performance and its progression were kept to boost usability of our device. Participants were blinded and randomly assigned into either the control group receiving random 4-Hz power or Alpha group receiving 8-12-Hz power. Working memory and episodic memory were assessed by the backward digital span task and word-pair task, respectively.Results: The portable neurofeedback system had advantages of a tiny size and long-term recording and demonstrated trainability of alpha rhythm in terms of significant increase of power and duration of 8-12 Hz. Moreover, accuracies of the backward digital span task and word-pair task showed significant enhancement in the Alpha group after training compared to the control group.Conclusions: Our tiny portable device demonstrated success trainability of alpha rhythm and enhanced two kinds of memories. The present study suggest that the portable neurofeedback system provides an alternative intervention for memory enhancement. [ABSTRACT FROM AUTHOR]

Learning and memory are among the executive functions attributed to intelligent forms of life. Unfortunately, there is a lack of clear understanding regarding the underlying mechanisms governing these functions. Most of the modern day scientists attribute these functions solely to brain. However, in the latter half of last century, a number of reports suggested existence of extra-cranial memory and potential of its transfer between animals. Some have linked this phenomenon to RNA while others believed that peptides were responsible. The terms like "educated RNA" and "scotophobin" were coined. This atypical work involving flatworms, yeast RNA and scotophobin was received with deep skepticism and ultimately disregarded. However, the recent reproduction of some of this earlier work by scientists at Tufts University has reignited the debate on the mechanisms of learning and memory. Keeping this in view, we believe it is high time to summarize this historical work and discuss the possibilities to delineate these atypical claims. The objective is to incite the present day researchers to explore this opportunity under the perspective of newer advancements in science. [ABSTRACT FROM AUTHOR]

Recognition memory is based on the ability to assess the familiarity of a previously encountered stimulus. It can be approached using tests for different sensorial modalities. Excitotoxic lesions of the perirhinal cortex (Prh) were performed in order to assess the relevance of its integrity for object and flavor recognition memory. Object recognition memory was impaired with a 24 h retention interval. Flavor neophobia attenuation was prevented on a second encounter with the tastant. These results support a role of the perirhinal cortex in mediating the transition from novel to familiar, both in object and flavor recognition memory. [ABSTRACT FROM AUTHOR]

Recent findings on alpha band oscillations suggest their important role in memory consolidation and suppression of external distractors such as environmental noise. However, less attention was given to the phenomenon of internal distracting information being solely inherent to the stimuli content. Human memory may be prone to internal distractions caused by semantic relatedness between the meaning of words (e.g., atom, neutron, nucleus, etc.) to be encoded, i.e., semantic interference. Our study investigates the brain oscillatory dynamics behind the semantic interference phenomenon, whose possible outcome is known as false memories. In this direction, Deese-Roediger-McDermott word lists were appropriated for a modified Sternberg paradigm in auditory modality. Participants received semantically related and unrelated word lists via headphones while EEG data were acquired. Semantic interference triggered the false memory rates to be higher than those of other types of memory errors. Analysis demonstrated that the upper part of alpha band (∼10–12 Hz) power decreases on parieto-occipital channels in the retention interval, prior to the probe item for semantically related condition. Our study elucidates the oscillatory mechanisms behind semantic interference by relying on alpha functional inhibition theory. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of caffeine, caffeic acid, and their combination on critical enzymes of brain function. Wistar male rats weighing an average of 205 g were divided into four groups ( n = 5) and treated with these compounds for seven successive days. The results of the study revealed that the levels of nitric oxide, total thiol, nonprotein thiol, and acetylcholinesterase activities were increased while the levels of lipid peroxidation, arginase, and adenosine deaminase activities were decreased in animals treated with caffeine when compared to the control. These findings indicate that moderate short-term consumption of caffeine may be beneficial for brain function. Practical applications The results suggest that moderate short-term consumption of a combination of caffeine and caffeic acid can effectively improve brain function via improvements in the antioxidant status, decreased lipid peroxidation, and inhibition of acetylcholinesterase, adenosine deaminase, and arginase activities in the brain and cerebral cortex. [ABSTRACT FROM AUTHOR]

The influence of encoding focus on source memory was investigated using event-related potentials (ERPs). Encoding was focused on the self (self-focus) or on the speaker (other-focus) while hearing words spoken in a male or female voice. Examination of the behavioral and ERP evidence suggests that encoding focus alters the amount of diagnostic recollection. Self-focus encoding produced more positive encoding ERPs, led to greater old/new recognition, and elicited a greater Late Positive Component (LPC; the putative neural correlate of recollection) during the source test. Other-focus encoding led to greater source memory and a smaller LPC amplitude. Collectively, the results suggest that encoding focus alters the information bound in the memory trace that leads to varying levels of source-diagnostic features. Drawing attention to the speaker facilitates binding of source-diagnostic features (i.e., voice), whereas self-focus encoding facilitates binding a host of non-diagnostic features. The results have important implications for situations that depend on encoding processes, such as false memory or classroom learning, and they provide evidence that the LPC tracks recollected details but not necessarily diagnostic recollection. [ABSTRACT FROM AUTHOR]

This article analyzes the association between knowledge of the Truth and Reconciliation Commission (TRC), evaluation of TRC's achievements, experience of victimization, attitudes toward remembering and forgetting past political violence, perceptions of socioemotional climate (SEC), belief in forgiveness and attitudes toward violence in Peru based on a study conducted in three Peruvian cities with different rates of victimization due to political violence during 1980-2000 (n = 1200). Results showed that a positive attitude toward remembering the past of political violence was predominant and related to a positive evaluation of TRC's achievements. Attitude toward remembering also has an ambivalent collective effect increasing both positive and negative SECs, and it is less accepted by victims of political violence. On the other hand, attitude toward forgetting is less accepted by participants, and it also has an ambivalent effect by increasing positive and negative SECs. Attitude toward forgetting has more societal costs, since it is related to attitudes toward violence and decreased knowledge and a positive evaluation of TRC. In general, findings suggest that remembering traumatic events has an emotional cost, but also it is shown that remembering seems to be more beneficial for society in the long-term than forgetting. [ABSTRACT FROM AUTHOR]

Cav1.3 has been suggested to mediate hippocampal neurogenesis of adult mice and contribute to hippocampal-dependent learning and memory processes. However, the mechanism of Cav1.3 contribution in these processes is unclear. Here, roles of Cav1.3 of mouse dorsal hippocampus during newborn cell development were examined. We find that knock-out (KO) of Cav1.3 resulted in the reduction of survival of newborn neurons at 28 days old after mitosis. The retroviral eGFP expression showed that both dendritic complexity and the number and length of mossy fiber bouton (MFB) filopodia of newborn neurons at ≥ 14 days old were significantly reduced in KO mice. Both contextual fear conditioning (CFC) and object-location recognition tasks were impaired in recent (1 day) memory test while passive avoidance task was impaired only in remote (≥ 20 days) memory in KO mice. Results using adeno-associated virus (AAV)-mediated Cav1.3 knock-down (KD) or retrovirus-mediated KD in dorsal hippocampal DG area showed that the recent memory of CFC was impaired in both KD mice but the remote memory was impaired only in AAV KD mice, suggesting that Cav1.3 of mature neurons play important roles in both recent and remote CFC memory while Cav1.3 in newborn neurons is selectively involved in the recent CFC memory process. Meanwhile, AAV KD of Cav1.3 in ventral hippocampal area has no effect on the recent CFC memory. In conclusion, the results suggest that Cav1.3 in newborn neurons of dorsal hippocampus is involved in the survival of newborn neurons while mediating developments of dendritic and axonal processes of newborn cells and plays a role in the memory process differentially depending on the stage of maturation and the type of learning task. [ABSTRACT FROM AUTHOR]

The predominant focus in the neurobiological study of memory has been on remembering (persistence). However, recent studies have considered the neurobiology of forgetting (transience). Here we draw parallels between neurobiological and computational mechanisms underlying transience. We propose that it is the interaction between persistence and transience that allows for intelligent decision-making in dynamic, noisy environments. Specifically, we argue that transience (1) enhances flexibility, by reducing the influence of outdated information on memory-guided decision-making, and (2) prevents overfitting to specific past events, thereby promoting generalization. According to this view, the goal of memory is not the transmission of information through time, per se. Rather, the goal of memory is to optimize decision-making. As such, transience is as important as persistence in mnemonic systems. [ABSTRACT FROM AUTHOR]

The resting connectivity of the brain's salience network, particularly the ventral subsystem of the salience network, has been previously associated with variousmeasures of affective reactivity. Numerous studies have demonstrated that increased affective arousal leads to enhanced consolidation ofmemory. This suggests that individuals with greater ventral salience network connectivity will exhibit greater responses to affective experience, leading to a greater enhancement ofmemory by affect. To test this hypothesis, resting ventral salience connectivity wasmeasured in 41 young adults, who were then exposed to neutral and negative affect inductions during a paired associatememory test.Memory performance formaterial learned under both negative and neutral induction was tested for correlation with resting connectivity betweenmajor ventral salience nodes. The results showed a significant interaction betweenmood induction (negative vs neutral) and connectivity between ventral anterior insula and pregenual anterior cingulate cortex, indicating that salience node connectivity predictedmemory formaterial encoded under negative, but not neutral induction. These findings suggest that the network state of the perceiver, measured prior to affective experience,meaningfully influences the extent to which affectmodulatesmemory. Implications of these findings for individuals with affective disorder, who show alterations in both connectivity andmemory, are considered. [ABSTRACT FROM AUTHOR]

We sleep almost one-third of our lives and sleep plays an important role in critical brain functions like memory formation and consolidation. The role of sleep in cerebellar processing, however, constitutes an enigma in the field of neuroscience; we know little about cerebellar sleep-physiology, cerebro–cerebellar interactions during sleep, or the contributions of sleep to cerebellum-dependent memory consolidation. Likewise, we do not understand why cerebellar malfunction can lead to changes in the sleep–wake cycle and sleep disorders. In this review, we evaluate how sleep and cerebellar processing may influence one another and highlight which scientific routes and technical approaches could be taken to uncover the mechanisms underlying these interactions. [ABSTRACT FROM AUTHOR]

Normally, we do not act within a single effector system only, but rather coordinate actions across several output modules (cross-modal action). Such cross-modal action demands can vary substantially with respect to their complexity in terms of the number of taskrelevant response combinations and to-be-retrieved stimulus--response (S-R) mapping rules. In the present study, we study the impact of these two types of cross-modal action complexity on dual-response costs (i.e., performance differences between single- and dual-action demands). In Experiment 1, we combined a manual and an oculomotor task, each involving four response alternatives. Crucially, one (unconstrained) condition involved all 16 possible combinations of response alternatives, whereas a constrained condition involved only a subset of possible response combinations. The results revealed that preparing for a larger number of response combinations yielded a significant, but moderate increase in dual-response costs. In Experiment 2, we utilized one common lateralized auditory (e.g., left) stimulus to trigger incompatible response compounds (e.g., left saccade and right key press or vice versa). While one condition only involved one set of task-relevant S-R rules, another condition involved two sets of task-relevant rules (coded by stimulus type: noise/tone), while the number of task-relevant response combinations was the same in both conditions. Here, an increase in the number of to-be-retrieved S-R rules was associated with a substantial increase in dual-response costs that were also modulated on a trial-by-trial basis when switching between rules. Taken together, the results shed further light on the dependency of cross-modal action control on both action- and rule-related memory retrieval processes. [ABSTRACT FROM AUTHOR]

Summary Although it is now well established that the hippocampus supports memory encoding [ 1, 2 ], little is known about hippocampal activity during spontaneous memory retrieval. Recent intracranial electroencephalographic (iEEG) work has shown that hippocampal activity during encoding predicts subsequent temporal organization of memories [ 3 ], supporting a role in contextual binding. It is an open question, however, whether the hippocampus similarly supports contextually mediated processes during retrieval. Here, we analyzed iEEG recordings obtained from 215 epilepsy patients as they performed a free recall task. To identify neural activity specifically associated with contextual retrieval, we compared correct recalls, intrusions (incorrect recall of either items from prior lists or items not previously studied), and deliberations (matched periods during recall when no items came to mind). Neural signals that differentiate correct recalls from both other retrieval classes reflect contextual retrieval, as correct recalls alone arise from the correct context. We found that in the hippocampus, high-frequency activity (HFA, 44–100 Hz), a proxy for neural activation [ 4 ], was greater prior to correct recalls relative to the other retrieval classes, with no differentiation between intrusions and deliberations. This pattern was not observed in other memory-related cortical regions, including DLPFC, thus supporting a specific hippocampal contribution to contextually mediated memory retrieval. [ABSTRACT FROM AUTHOR]