scholarly journals Evidence for the Default Network's Role in Spontaneous Cognition

2010 ◽  
Vol 104 (1) ◽  
pp. 322-335 ◽  
Author(s):  
Jessica R. Andrews-Hanna ◽  
Jay S. Reidler ◽  
Christine Huang ◽  
Randy L. Buckner
Keyword(s):  
Cognitive Processes ◽  
Medial Temporal Lobe ◽  
External World ◽  
Brain Regions ◽  
Self Report ◽  
Default Network ◽  
Considerable Variability ◽  
Major Focus ◽  
The Past ◽  
Cortical Regions

A set of brain regions known as the default network increases its activity when focus on the external world is relaxed. During such moments, participants change their focus of external attention and engage in spontaneous cognitive processes including remembering the past and imagining the future. However, the functional contributions of the default network to shifts in external attention versus internal mentation have been difficult to disentangle because the two processes are correlated under typical circumstances. To address this issue, the present study manipulated factors that promote spontaneous cognition separately from those that change the scope of external attention. Results revealed that the default network increased its activity when spontaneous cognition was maximized but not when participants increased their attention to unpredictable foveal or peripheral stimuli. To examine the nature of participants' spontaneous thoughts, a second experiment used self-report questionnaires to quantify spontaneous thoughts during extended fixation epochs. Thoughts about one's personal past and future comprised a major focus of spontaneous cognition with considerable variability. Activity correlations between the medial temporal lobe and distributed cortical regions within the default network predicted a small, but significant, portion of the observed variability. Collectively, these results suggest that during passive states, activity within the default network reflects spontaneous, internally directed cognitive processes.

scholarly journals Imaging recent to very remote object-in-place memories in the medial temporal lobe and prefrontal cortex

2020 ◽  
Author(s):  
Erika Atucha ◽  
Celia Fuerst ◽  
Magdalena Sauvage
Keyword(s):  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Brain Regions ◽  
Remote Memory ◽  
General Mechanism ◽  
Cortical Areas ◽  
Prefrontal Cortical ◽  
Place Task ◽  
Cortical Regions ◽  
Over Time

Studies on patient H.M inspired many experiments on the role of the hippocampus and the neocortex in retrieving recent and remote memories. Cortical regions become increasingly engaged for memory retrieval over time, while conflicting results emerge regarding the engagement of the hippocampus, suggested to be ongoing by some or restricted to the retrieval of recent memories by others. In the study of Lux et al, 2016 we tested that this discrepancy might stem from failing to dissociate CA1 from CA3s contribution to memory retrieval over time as CA3 is known to support computations more sensitive to time than CA1. We also reported that parahippocampal cortical areas with tied anatomical connections with the hippocampus were increasingly engaged over time (Lux et al., elife , 2016). This study used a fear conditioning paradigm as emotionally arousing experiences are better remembered than memories devoid of fear content. Here we address whether the differential contribution of brain regions is a general mechanism also subserving memory retrieval devoid of fear content. We succeeded in developing an object-in-place task to investigate remote memory retrieval up to 6 months and the contribution of CA1, CA3, parahippocampal and prefrontal cortical areas to the retrieval of recent versus very remote memories using a high resolution molecular imaging technique based on the detection of the IEG RNA Arc. Preliminary results show that the disengagement of CA3 and persistent engagement of CA1 seem to be a general mechanism in supporting retrieval of remote memory for events.

scholarly journals Self-Regulation of Implicit Social Cognition

2019 ◽  
Author(s):  
Andrew M Rivers
Keyword(s):  
Social Psychology ◽  
Social Cognition ◽  
Cognitive Processes ◽  
Implicit Association Test ◽  
Self Regulation ◽  
Self Report ◽  
Implicit Measures ◽  
Brand Evaluations ◽  
The Past ◽  
Broad Array

Implicit measures of social cognition have grown increasingly popular over the past two decades. Not only have they become ubiquitous within social psychology, but they are also now commonly applied in a broad array of domains beyond social psychology, ranging from brand evaluations to phobias to addiction. Their widespread use is largely due to the assumption that implicit measures provide a more clear view into hidden cognitive processes than do explicit (i.e., self-report) measures. However, there is debate about which cognitive processes implicit measures primarily reflect. Tasks such as the Implicit Association Test (IAT) were initially designed to measure behavioral impulses induced by mental association between concepts (e.g., the outgroup) and attributes (e.g., negative). Although measures like the IAT do reflect behavioral impulses, self-regulation also plays an important role in inhibiting undesirable impulses.

scholarly journals Inferences about mental states

2009 ◽  
Vol 364 (1521) ◽  
pp. 1309-1316 ◽  
Author(s):  
Jason P. Mitchell
Keyword(s):  
Cognitive Processes ◽  
Mental States ◽  
Brain Regions ◽  
Use Of Self ◽  
The Past ◽  
Neuroscience Research ◽  
Spatial Layouts ◽  
Underlying Mechanisms ◽  
Current Experience ◽  
Cognitive Challenges

Human social cognition relies on an ability to predict what others will think, feel or do in novel situations. Research in social neuroscience has consistently observed several brain regions that contribute ubiquitously to these abilities, including medial prefrontal cortex and aspects of lateral and medial parietal cortex. Interestingly, parallel work has suggested that this same network of regions subserves several seemingly distinct phenomena—notably, the abilities to remember the past, imagine the future and visualize spatial layouts—suggesting the existence of a common set of cognitive processes devoted to projecting oneself into worlds that differ mentally, temporally or physically from one's current experience. This use of self-projection to understand others' minds requires perceivers to solve three distinct cognitive challenges: (i) generating a simulated facsimile of one's own hypothetical mental states in a given situation, (ii) suppressing one's own current mental states, and (iii) deciding on the appropriateness of simulated states for understanding a particular other person. The present paper reviews recent psychology and neuroscience research aimed at understanding the underlying mechanisms that allow humans to solve each of these cognitive challenges to use self-projection to predict and understand the mental states of others.

Fluorescent potentiometric dyes for membrane-potential imaging

1994 ◽  
Vol 52 ◽  
pp. 166-167
Author(s):  
Leslie M. Loew
Keyword(s):  
Membrane Potential ◽  
Single Cells ◽  
Quantitative Imaging ◽  
Optical Recording ◽  
Biological Processes ◽  
Major Focus ◽  
The Past ◽  
Excitable Systems ◽  
Major Application ◽  
The Impact

A major application of potentiometric dyes has been the multisite optical recording of electrical activity in excitable systems. After being championed by L.B. Cohen and his colleagues for the past 20 years, the impact of this technology is rapidly being felt and is spreading to an increasing number of neuroscience laboratories. A second class of experiments involves using dyes to image membrane potential distributions in single cells by digital imaging microscopy - a major focus of this lab. These studies usually do not require the temporal resolution of multisite optical recording, being primarily focussed on slow cell biological processes, and therefore can achieve much higher spatial resolution. We have developed 2 methods for quantitative imaging of membrane potential. One method uses dual wavelength imaging of membrane-staining dyes and the other uses quantitative 3D imaging of a fluorescent lipophilic cation; the dyes used in each case were synthesized for this purpose in this laboratory.

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.

Methods in Year 50: Preserving the Past and Preparing for the Future

2011 ◽  
Vol 50 (01) ◽  
pp. 1-6 ◽  
Author(s):  
D. Aronsky ◽  
T. Y. Leong ◽  
A. T. McCray ◽  
R. Haux
Keyword(s):  
Medical Informatics ◽  
Strategic Decisions ◽  
Major Focus ◽  
Editorial Policies ◽  
The Past ◽  
Processing Data ◽  
Online Access ◽  
Aims And Scope ◽  
Online Methods ◽  
Sixth Decade

Summary Background: Founded in 1962 and, therefore, the oldest international journal in medical informatics, Methods of Information in Medicine will publish its 50th volume in 2011. At the start of the journal’s sixth decade, a discussion on the journal’s profile seems appropriate. Objectives: To report on the new opportunities for online access to Methods publications as well as on the recent strategic decisions regarding the journal‘s aims and editorial policies. Methods: Describing and analyzing the journal’s aims and scope. Reflecting on recent publications and on the journal’s development during the last decade. Results: From 2011 forward all articles of Methods from 1962 until the present can be accessed online. Methods of Information in Medicine stresses the basic methodology and scientific fundamentals of processing data, information and knowledge in medicine and health care. Although the journal‘s major focus is on publications in medical informatics, it has never been restricted to publications only in this discipline. For example, articles in medical biometry, in or close to biomedical engineering, and, later, articles in bioinformatics continue to be a part of this journal. Conclusions: There is a continuous and, as it seems, ever growing overlap in the research methodology and application areas of the mentioned disciplines. As there is a continuing and even growing need for such a publication forum, Methods of Information in Medicine will keep its broad scope. As an organizational consequence, the journal’s number of associate editors has increased accordingly.

Neuro-Clinical Signatures of Language Impairments: A Theoretical Framework for Function-to-structure Mapping in Clinics

2020 ◽  
Vol 20 (9) ◽  
pp. 800-811 ◽  
Author(s):  
Ferath Kherif ◽  
Sandrine Muller
Keyword(s):  
Brain Mapping ◽  
Theoretical Framework ◽  
Brain Regions ◽  
Language Impairments ◽  
Structure Mapping ◽  
Language Functions ◽  
The Past ◽  
Language Recovery ◽  
The Brain ◽  
Bow Tie

In the past decades, neuroscientists and clinicians have collected a considerable amount of data and drastically increased our knowledge about the mapping of language in the brain. The emerging picture from the accumulated knowledge is that there are complex and combinatorial relationships between language functions and anatomical brain regions. Understanding the underlying principles of this complex mapping is of paramount importance for the identification of the brain signature of language and Neuro-Clinical signatures that explain language impairments and predict language recovery after stroke. We review recent attempts to addresses this question of language-brain mapping. We introduce the different concepts of mapping (from diffeomorphic one-to-one mapping to many-to-many mapping). We build those different forms of mapping to derive a theoretical framework where the current principles of brain architectures including redundancy, degeneracy, pluri-potentiality and bow-tie network are described.

scholarly journals Characterizing Bilingual Effects on Cognition: The Search for Meaningful Individual Differences

2021 ◽  
Vol 11 (1) ◽  
pp. 81
Author(s):  
Kristina C. Backer ◽  
Heather Bortfeld
Keyword(s):  
Individual Differences ◽  
Cognitive Processes ◽  
Language Background ◽  
Bilingual Advantage ◽  
The Past ◽  
General Movement ◽  
And Performance ◽  
Task Irrelevant ◽  
Analytical Approaches ◽  
The Relationship

A debate over the past decade has focused on the so-called bilingual advantage—the idea that bilingual and multilingual individuals have enhanced domain-general executive functions, relative to monolinguals, due to competition-induced monitoring of both processing and representation from the task-irrelevant language(s). In this commentary, we consider a recent study by Pot, Keijzer, and de Bot (2018), which focused on the relationship between individual differences in language usage and performance on an executive function task among multilingual older adults. We discuss their approach and findings in light of a more general movement towards embracing complexity in this domain of research, including individuals’ sociocultural context and position in the lifespan. The field increasingly considers interactions between bilingualism/multilingualism and cognition, employing measures of language use well beyond the early dichotomous perspectives on language background. Moreover, new measures of bilingualism and analytical approaches are helping researchers interrogate the complexities of specific processing issues. Indeed, our review of the bilingualism/multilingualism literature confirms the increased appreciation researchers have for the range of factors—beyond whether someone speaks one, two, or more languages—that impact specific cognitive processes. Here, we highlight some of the most salient of these, and incorporate suggestions for a way forward that likewise encompasses neural perspectives on the topic.

scholarly journals 106 Self-Reported Sleep and Resilience

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A43-A44
Author(s):  
Michelle Persich ◽  
Sara Cloonan ◽  
Michael Grandner ◽  
William Killgore
Keyword(s):  
Sleep Quality ◽  
Sleep Time ◽  
Self Report ◽  
Subjective Perception ◽  
Psychological Resilience ◽  
Cross Sectional ◽  
Sleep Quantity ◽  
The Past ◽  
Resilience Scale ◽  
Longitudinal Effects

Abstract Introduction Psychological resilience is the ability to withstand setbacks, adapt positively to challenges, and bounce back from the adversities of life. While the construct of resilience is broadly understood, the specific individual factors that contribute to the ability to be resilient and persevere in the face of difficulties remain poorly understood. We recently showed that psychological resilience during the COVID-19 pandemic was associated with a number of factors, including fewer complaints of insomnia, and others have suggested that sleep is an important contributor. We therefore tested the hypothesis that sleep quality and acute sleep quantity would combine to predict measures of psychological resilience and perseverance (i.e. “grit”). Methods We asked 447 adults (18–40 yrs; 72% female) to report the number of hours of sleep obtained the night before their assessment session (SLEEP), and complete several questionnaires, including the Pittsburgh Sleep Quality Index (PSQI), the Connor-Davidson Resilience Scale (CD-RISC), Bartone Dispositional Resilience Scale (Hardiness), and the Grit Scale. Sleep metrics were used to predict resilience, hardiness, and grit using multiple linear regression. Results For resilience, PSQI (β=-.201, p<.00003) and SLEEP (β=.155, p<.001) each contributed uniquely to prediction of CD-RISC (R2=.08, p<.00001). Hardiness was also predicted (R2=.08, p<.00001) by a combination of PSQI (β=-.218, p<.00001) and SLEEP (β=.128, p=.007). Interestingly, worse sleep quality over the past month on the PSQI (β=.13, p=.008) in combination with more SLEEP the night before the assessment (β=.137, p=.005) each contributed uniquely to higher Grit (i.e., perseverance; R2=.03, p=.003). Conclusion Self-reported sleep quality and quantity were both independently associated with greater self-reported resilience, hardiness, and grit. While better sleep quality and more sleep the night before testing each uniquely predicted greater resilience and hardiness, a different pattern emerged for Grit. The combination of lower quality sleep over the past month followed by greater recent sleep duration was associated with increased perseverance. Whereas sleep quality appears to be more important for general resilience/hardiness, recent sleep time appears more important for the subjective perception of perseverance. Because these data are purely self-report and cross sectional, future work will need to determine the longitudinal effects on behavior. Support (if any):

scholarly journals In vivo synaptic density relates to glucose metabolism at rest in healthy subjects, but is strongly modulated by regional differences

2021 ◽  
pp. 0271678X2098150
Author(s):  
June van Aalst ◽  
Jenny Ceccarini ◽  
Stefan Sunaert ◽  
Patrick Dupont ◽  
Michel Koole ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Medial Temporal Lobe ◽  
Regional Differences ◽  
Specific Binding ◽  
Aerobic Glycolysis ◽  
Glucose Consumption ◽  
Brain Regions ◽  
Synaptic Density ◽  
Energy Demands

Preclinical and postmortem studies have suggested that regional synaptic density and glucose consumption (CMRGlc) are strongly related. However, the relation between synaptic density and cerebral glucose metabolism in the human brain has not directly been assessed in vivo. Using [11C]UCB-J binding to synaptic vesicle glycoprotein 2 A (SV2A) as indicator for synaptic density and [18F]FDG for measuring cerebral glucose consumption, we studied twenty healthy female subjects (age 29.6 ± 9.9 yrs) who underwent a single-day dual-tracer protocol (GE Signa PET-MR). Global measures of absolute and relative CMRGlc and specific binding of [11C]UCB-J were indeed highly significantly correlated ( r > 0.47, p < 0.001). However, regional differences in relative [18F]FDG and [11C]UCB-J uptake were observed, with up to 19% higher [11C]UCB-J uptake in the medial temporal lobe (MTL) and up to 17% higher glucose metabolism in frontal and motor-related areas and thalamus. This pattern has a considerable overlap with the brain regions showing different levels of aerobic glycolysis. Regionally varying energy demands of inhibitory and excitatory synapses at rest may also contribute to this difference. Being unaffected by astroglial and/or microglial energy demands, changes in synaptic density in the MTL may therefore be more sensitive to early detection of pathological conditions compared to changes in glucose metabolism.

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