scholarly journals Changes in patterns of neural activity underlie a time-dependent transformation of memory in rats and humans

2018 ◽  
Author(s):  
Melanie J. Sekeres ◽  
Gordon Winocur ◽  
Morris Moscovitch ◽  
John A.E. Anderson ◽  
Sara Pishdadian ◽  
...  
Keyword(s):  
Memory Trace ◽  
Brain Regions ◽  
Time Dependent ◽  
Memory Representation ◽  
Systems Consolidation ◽  
Different Types ◽  
Episodic Memories ◽  
Context Specific ◽  
Perceptual Detail ◽  
Over Time

AbstractThe dynamic process of memory consolidation involves a reorganization of brain regions that support a memory trace over time, but exactly how the network reorganizes as the memory changes remains unclear. We present novel converging evidence from studies of animals (rats) and humans for the time-dependent reorganization and transformation of different types of memory as measured both by behavior and brain activation. We find that context-specific memories in rats, and naturalistic episodic memories in humans, lose precision over time and activity in the hippocampus decreases. If, however, the retrieved memories retain contextual or perceptual detail, the hippocampus is engaged similarly at recent and remote timepoints. As the interval between the timepoint increases, the medial prefrontal cortex is engaged increasingly during memory retrieval, regardless of the context or the amount of retrieved detail. Moreover, these hippocampal-frontal shifts are accompanied by corresponding changes in a network of cortical structures mediating perceptually-detailed as well as less precise, schematic memories. These findings provide cross-species evidence for the crucial interplay between hippocampus and neocortex that reflects changes in memory representation over time and underlies systems consolidation.

scholarly journals Noradrenergic arousal after encoding reverses the course of systems consolidation in humans

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Valentina Krenz ◽  
Tobias Sommer ◽  
Arjen Alink ◽  
Benno Roozendaal ◽  
Lars Schwabe
Keyword(s):  
Time Dependent ◽  
Consolidation Process ◽  
Memory Decline ◽  
Adrenoceptor Antagonist ◽  
Systems Consolidation ◽  
Hippocampal Activity ◽  
Pattern Similarity ◽  
Recognition Testing ◽  
Episodic Memories ◽  
Over Time

AbstractIt is commonly assumed that episodic memories undergo a time-dependent systems consolidation process, during which hippocampus-dependent memories eventually become reliant on neocortical areas. Here we show that systems consolidation dynamics can be experimentally manipulated and even reversed. We combined a single pharmacological elevation of post-encoding noradrenergic activity through the α2-adrenoceptor antagonist yohimbine with fMRI scanning both during encoding and recognition testing either 1 or 28 days later. We show that yohimbine administration, in contrast to placebo, leads to a time-dependent increase in hippocampal activity and multivariate encoding-retrieval pattern similarity, an indicator of episodic reinstatement, between 1 and 28 days. This is accompanied by a time-dependent decrease in neocortical activity. Behaviorally, these neural changes are linked to a reduced memory decline over time after yohimbine intake. These findings indicate that noradrenergic activity shortly after encoding may alter and even reverse systems consolidation in humans, thus maintaining vividness of memories over time.

scholarly journals Imaging and optogenetically manipulating recent and very remote memories reveals that CA1 is required for retrieving gist memories over time and CA3 for memory precision

2020 ◽  
Author(s):  
Erika Atucha ◽  
Shih-pi Ku ◽  
Michael Friis Lippert ◽  
Frank Walter Ohl ◽  
Magdalena Sauvage
Keyword(s):  
Memory Retrieval ◽  
Contextual Fear Conditioning ◽  
Remote Memory ◽  
Memory Representation ◽  
Contextual Fear ◽  
Cortical Areas ◽  
Causal Approach ◽  
Episodic Memories ◽  
Memory Precision ◽  
Over Time

Episodic memories are hippocampus dependent. Over time such memories undergo consolidation and are thought to transition from precise to gist memories and additionally engage neocortical areas. Whether remote memories still depend on the hippocampus remains a controversy that might stem from the difficulties to distinguish activity from CA1 and CA3 subregions in the hippocampus. CA3 is thought to perform computations that are more time sensitive than CA1 such as pattern completion (completion of a full memory representation based on details). Since details fade over time, we predicted that CA3 would no longer contribute to memory retrieval for very remote memory traces. Further, the contribution of parahippocampal cortical areas which tightly interact with the hippocampus is not well understood. We recently published that indeed CA3 plays a time-limited role in the retrieval of memory while CA1 remains engaged for up to 1-year (equivalent to 40-years-old memory in humans) and that parahippocampal cortical areas were increasingly engaged over time. Here we study the contribution of CA1 and CA3 to the nature (gist/precise) of memory retrieval for recent and up to 1-year-old remote memories using a causal approach. We combined optogenetic cell firing inhibition in CA1 and CA3 with a contextual fear conditioning task to investigate memory precision and measured the neuroanatomical correlates using Arc imaging. While CA3 is required for memory precision at recent time points CA1 contributed to retrieving gist memories independently of the age of the memory trace with the support of the parahippocampal areas for the most remote memories.

Inefficient Encoding as an Explanation for Age-Related Deficits in Recollection-Based Processing

2014 ◽  
Vol 28 (3) ◽  
pp. 148-161 ◽  
Author(s):  
David Friedman ◽  
Ray Johnson
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Cognitive Processes ◽  
Brain Activity ◽  
Memory Performance ◽  
Brain Regions ◽  
Semantic Retrieval ◽  
Age Related ◽  
The Face ◽  
Episodic Memories

A cardinal feature of aging is a decline in episodic memory (EM). Nevertheless, there is evidence that some older adults may be able to “compensate” for failures in recollection-based processing by recruiting brain regions and cognitive processes not normally recruited by the young. We review the evidence suggesting that age-related declines in EM performance and recollection-related brain activity (left-parietal EM effect; LPEM) are due to altered processing at encoding. We describe results from our laboratory on differences in encoding- and retrieval-related activity between young and older adults. We then show that, relative to the young, in older adults brain activity at encoding is reduced over a brain region believed to be crucial for successful semantic elaboration in a 400–1,400-ms interval (left inferior prefrontal cortex, LIPFC; Johnson, Nessler, & Friedman, 2013 ; Nessler, Friedman, Johnson, & Bersick, 2007 ; Nessler, Johnson, Bersick, & Friedman, 2006 ). This reduced brain activity is associated with diminished subsequent recognition-memory performance and the LPEM at retrieval. We provide evidence for this premise by demonstrating that disrupting encoding-related processes during this 400–1,400-ms interval in young adults affords causal support for the hypothesis that the reduction over LIPFC during encoding produces the hallmarks of an age-related EM deficit: normal semantic retrieval at encoding, reduced subsequent episodic recognition accuracy, free recall, and the LPEM. Finally, we show that the reduced LPEM in young adults is associated with “additional” brain activity over similar brain areas as those activated when older adults show deficient retrieval. Hence, rather than supporting the compensation hypothesis, these data are more consistent with the scaffolding hypothesis, in which the recruitment of additional cognitive processes is an adaptive response across the life span in the face of momentary increases in task demand due to poorly-encoded episodic memories.

A Comparison of General and Context-Specific Personality Traits Over Time

2011 ◽  
Author(s):  
Kevin J. Eschleman ◽  
Nathan A. Bowling ◽  
Gary N. Burns
Keyword(s):  
Personality Traits ◽  
Context Specific ◽  
Over Time

Measuring Agency Change Across the Domain of Hypnosis

2019 ◽  
Author(s):  
Vince Polito ◽  
Amanda Barnier ◽  
Erik Woody
Keyword(s):  
Rating Scale ◽  
Sense Of Agency ◽  
Pass Rates ◽  
Current Experiment ◽  
Multidimensional Construct ◽  
Time Points ◽  
Hypnotic Induction ◽  
Different Types ◽  
Over Time ◽  
Postexperimental Inquiry

Building on Hilgard’s (1965) classic work, the domain of hypnosis has been conceptualised by Barnier, Dienes, and Mitchell (2008) as comprising three levels: (1) classic hypnotic items, (2) responding between and within items, and (3) state and trait. The current experiment investigates sense of agency across each of these three levels. Forty-six high hypnotisable participants completed an ideomotor (arm levitation), a challenge (arm rigidity) and a cognitive (anosmia) item either following a hypnotic induction (hypnosis condition) or without a hypnotic induction (wake condition). In a postexperimental inquiry, participants rated their feelings of control at three time points for each item: during the suggestion, test and cancellation phases. They also completed the Sense of Agency Rating Scale (Polito, Barnier, & Woody, 2013) for each item. Pass rates, control ratings, and agency scores fluctuated across the different types of items and for the three phases of each item; also, control ratings and agency scores often differed across participants who passed versus failed each item. Interestingly, whereas a hypnotic induction influenced the likelihood of passing items, it had no direct effect on agentive experiences. These results suggest that altered sense of agency is not a unidimensional or static quality “switched on” by hypnotic induction, but a dynamic multidimensional construct that varies across items, over time and according to whether individuals pass or fail suggestions.

Imagery in the Book of Revelation

2020 ◽  
pp. 52-67
Author(s):  
Konrad Huber
Keyword(s):  
Reception History ◽  
Book Of Revelation ◽  
Imperial Cult ◽  
Emotional Effect ◽  
Greco Roman ◽  
Different Types ◽  
Figurative Speech ◽  
Theological Message ◽  
Over Time ◽  
The Way

The chapter first surveys different types of figurative speech in Revelation, including simile, metaphor, symbol, and narrative image. Second, it considers the way images are interrelated in the narrative world of the book. Third, it notes how the images draw associations from various backgrounds, including biblical and later Jewish sources, Greco-Roman myths, and the imperial cult, and how this enriches the understanding of the text. Fourth, the chapter looks at the rhetorical impact of the imagery on readers and stresses in particular its evocative, persuasive, and parenetic function together with its emotional effect. And fifth, it looks briefly at the way reception history shows how the imagery has engaged readers over time. Thus, illustrated by numerous examples, it becomes clear how essentially the imagery of the book of Revelation constitutes and determines its theological message.

scholarly journals Detection of Acetaminophen and Its Glucuronide in Fingerprint by SALDI Mass Spectrometry Using Zeolite and Study of Time-Dependent Changes in Detected Ion Amount

Analytica ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 66-75
Author(s):  
Toshiki Horikoshi ◽  
Chihiro Kitaoka ◽  
Yosuke Fujii ◽  
Takashi Asano ◽  
Jiawei Xu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Glucuronic Acid ◽  
Laser Desorption ◽  
The Body ◽  
Time Dependent ◽  
Laser Desorption Ionization ◽  
Fingerprint Analysis ◽  
Desorption Ionization ◽  
Acid Conjugate ◽  
Over Time

The ingredients of an antipyretic (acetaminophen, AAP) and their metabolites excreted into fingerprint were detected by surface-assisted laser desorption ionization (SALDI) mass spectrometry using zeolite. In the fingerprint taken 4 h after AAP ingestion, not only AAP but also the glucuronic acid conjugate of AAP (GAAP), caffeine (Caf), ethenzamide (Eth), salicylamide (Sala; a metabolite of Eth), and urea were detected. Fingerprints were collected over time to determine how the amounts of AAP and its metabolite changed with time, and the time dependence of the peak intensities of protonated AAP and GAAP was measured. It was found that the increase of [GAAP+H]+ peak started later than that of [AAP+H]+ peak, reflecting the metabolism of AAP. Both AAP and GAAP reached maximum concentrations approximately 3 h after ingestion, and were excreted from the body with a half-life of approximately 3.3 h. In addition, fingerprint preservation was confirmed by optical microscopy, and fingerprint shape was retained even after laser irradiation of the fingerprint. Our method may be used in fingerprint analysis.

scholarly journals Effect of scent on comfort of aircraft passengers

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S273-S280
Author(s):  
Xinhe Yao ◽  
Yu Song ◽  
Peter Vink
Keyword(s):  
Completion Time ◽  
Aircraft Cabin ◽  
Different Types ◽  
The Relationship ◽  
Over Time

BACKGROUND: Scents may influence the perceived comfort of an environment. There are only a few studies conducted on the relationship between scent and comfort in aircraft cabin. OBJECTIVES: The goal of this research is to explore whether relationships between scents and perceived comfort can be found for passengers in an aircraft cabin. METHODS: 276 participants joined an experiment in a Boeing 737 fuselage. The participants were divided into nine groups and each joined a session for 60 minutes with the exposure to different scents. The effect of the odor was measured by a set of questionnaires at the beginning and at the end of the session. Results of questionnaires were analyzed regarding the effects on the completion time, of the type of scents, of the intensity of the scent and on gender. RESULTS: Significant differences were found at the beginning and at the end of the experiment regarding comfort and emotion, but sometimes no relations could be established. The influence of different scents on comfort/discomfort varied and changed over time. However, in all scenarios, participant’ scores on emotion decreased. Additionally, the added scents influenced the linearity between the changes in comfort and discomfort. CONCLUSIONS: Smell could influence the perceived comfort/discomfort of aircraft passengers over time, and different types of smells have different effects on passengers. The preferences on scents are diverse, which highlights the need for personalization in aircraft cabin design.

scholarly journals Temporal changes in DNA methylation and RNA expression in a small song bird: within- and between-tissue comparisons

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Melanie Lindner ◽  
Irene Verhagen ◽  
Heidi M. Viitaniemi ◽  
Veronika N. Laine ◽  
Marcel E. Visser ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Environmental Conditions ◽  
Brain Regions ◽  
Temporal Changes ◽  
Egg Laying ◽  
Gene Body ◽  
Cpg Site ◽  
Repeated Sampling ◽  
Over Time

Abstract Background DNA methylation is likely a key mechanism regulating changes in gene transcription in traits that show temporal fluctuations in response to environmental conditions. To understand the transcriptional role of DNA methylation we need simultaneous within-individual assessment of methylation changes and gene expression changes over time. Within-individual repeated sampling of tissues, which are essential for trait expression is, however, unfeasible (e.g. specific brain regions, liver and ovary for reproductive timing). Here, we explore to what extend between-individual changes in DNA methylation in a tissue accessible for repeated sampling (red blood cells (RBCs)) reflect such patterns in a tissue unavailable for repeated sampling (liver) and how these DNA methylation patterns are associated with gene expression in such inaccessible tissues (hypothalamus, ovary and liver). For this, 18 great tit (Parus major) females were sacrificed at three time points (n = 6 per time point) throughout the pre-laying and egg-laying period and their blood, hypothalamus, ovary and liver were sampled. Results We simultaneously assessed DNA methylation changes (via reduced representation bisulfite sequencing) and changes in gene expression (via RNA-seq and qPCR) over time. In general, we found a positive correlation between changes in CpG site methylation in RBCs and liver across timepoints. For CpG sites in close proximity to the transcription start site, an increase in RBC methylation over time was associated with a decrease in the expression of the associated gene in the ovary. In contrast, no such association with gene expression was found for CpG site methylation within the gene body or the 10 kb up- and downstream regions adjacent to the gene body. Conclusion Temporal changes in DNA methylation are largely tissue-general, indicating that changes in RBC methylation can reflect changes in DNA methylation in other, often less accessible, tissues such as the liver in our case. However, associations between temporal changes in DNA methylation with changes in gene expression are mostly tissue- and genomic location-dependent. The observation that temporal changes in DNA methylation within RBCs can relate to changes in gene expression in less accessible tissues is important for a better understanding of how environmental conditions shape traits that temporally change in expression in wild populations.

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