scholarly journals EEG and fMRI Evidence for Autobiographical Memory Reactivation in Empathy

2019 ◽  
Author(s):  
Federica Meconi ◽  
Juan Linde-Domingo ◽  
Catarina S. Ferreira ◽  
Sebastian Michelmann ◽  
Bernhard Staresina ◽  
...  
Keyword(s):  
Memory Retrieval ◽  
Posterior Parietal Cortex ◽  
Direct Evidence ◽  
Inferior Parietal Lobule ◽  
Autobiographical Memories ◽  
Retrieval Task ◽  
Electrophysiological Activity ◽  
Posterior Parietal ◽  
The Brain ◽  
Eeg Pattern

AbstractEmpathy relies on the ability to mirror and to explicitly infer others’ inner states. Theoretical accounts suggest that memories play a role in empathy but direct evidence of a reactivation of autobiographical memories (AM) in empathy is yet to be shown. We addressed this question in two experiments. In experiment 1, electrophysiological activity (EEG) was recorded from 28 participants who performed an empathy task in which targets for empathy were depicted in contexts for which participants either did or did not have an AM, followed by a task that explicitly required memory retrieval of the AM and non-AM contexts. The retrieval task was implemented to extract the neural fingerprints of AM and non-AM contexts, which were then used to probe data from the empathy task. An EEG pattern classifier was trained and tested across tasks and showed evidence for AM reactivation when participants were preparing their judgement in the empathy task. Participants self-reported higher empathy for people depicted in situations they had experienced themselves as compared to situations they had not experienced. A second independent fMRI experiment replicated this behavioural finding and showed the predicted activation in the brain networks underlying both AM retrieval and empathy: precuneus, posterior parietal cortex, superior and inferior parietal lobule and superior frontal gyrus. Together, our study reports behavioural, electrophysiological and fMRI evidence that robustly supports the involvement of AM reactivation in empathy.

scholarly journals Comparative metabolic profiling of posterior parietal cortex, amygdala, and hippocampus in conditioned fear memory

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yoonjeong Jeon ◽  
Yun Lim ◽  
Jiwoo Yeom ◽  
Eun-Kyoung Kim
Keyword(s):  
Mental Disorders ◽  
Parietal Cortex ◽  
Metabolic Pathways ◽  
Memory Retrieval ◽  
Posterior Parietal Cortex ◽  
Conditioned Fear ◽  
Fear Memory ◽  
Glutathione Metabolism ◽  
Potential Biomarker ◽  
Posterior Parietal

AbstractFear conditioning and retrieval are suitable models to investigate the biological basis of various mental disorders. Hippocampus and amygdala neurons consolidate conditioned stimulus (CS)-dependent fear memory. Posterior parietal cortex is considered important for the CS-dependent conditioning and retrieval of fear memory. Metabolomic screening among functionally related brain areas provides molecular signatures and biomarkers to improve the treatment of psychopathologies. Herein, we analyzed and compared changes of metabolites in the hippocampus, amygdala, and posterior parietal cortex under the fear retrieval condition. Metabolite profiles of posterior parietal cortex and amygdala were similarly changed after fear memory retrieval. While the retrieval of fear memory perturbed various metabolic pathways, most metabolic pathways that overlapped among the three brain regions had high ranks in the enrichment analysis of posterior parietal cortex. In posterior parietal cortex, the most perturbed pathways were pantothenate and CoA biosynthesis, purine metabolism, glutathione metabolism, and NAD+ dependent signaling. Metabolites of posterior parietal cortex including 4′-phosphopantetheine, xanthine, glutathione, ADP-ribose, ADP-ribose 2′-phosphate, and cyclic ADP-ribose were significantly regulated in these metabolic pathways. These results point to the importance of metabolites of posterior parietal cortex in conditioned fear memory retrieval and may provide potential biomarker candidates for traumatic memory-related mental disorders.

Memory Engrams in the Neocortex

2020 ◽  
pp. 107385842094152
Author(s):  
Svenja Brodt ◽  
Steffen Gais
Keyword(s):  
Posterior Parietal Cortex ◽  
Brain Regions ◽  
Loss Of Function ◽  
Noninvasive Methods ◽  
New Era ◽  
Parallel Memory ◽  
Memory Representations ◽  
Posterior Parietal ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

While in the past much of our knowledge about memory representations in the brain has relied on loss-of-function studies in which whole brain regions were temporarily inactivated or permanently lesioned, the recent development of new methods has ushered in a new era of downright “engram excitement.” Animal research is now able to specifically label, track, and manipulate engram cells in the brain. While early studies have mostly focused on single brain regions like the hippocampus, recently more and more evidence for brain-wide distributed engram networks is emerging. Memory research in humans has also picked up pace, fueled by promising magnetic resonance imaging (MRI)-based methods like diffusion-weighted MRI (DW-MRI) and brain decoding. In this review, we will outline recent advancements in engram research, with a focus on human data and neocortical representations. We will illustrate the available noninvasive methods for the detection of engrams in different neocortical regions like the medial prefrontal cortex and the posterior parietal cortex and discuss evidence for systems consolidation and parallel memory encoding. Finally, we will explore how reactivation and prior knowledge can lead to and enhance engram formation in the neocortex.

scholarly journals From thought to action: The brain–machine interface in posterior parietal cortex

2019 ◽  
Vol 116 (52) ◽  
pp. 26274-26279 ◽  
Author(s):  
Richard A. Andersen ◽  
Tyson Aflalo ◽  
Spencer Kellis
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
The Body ◽  
Assistive Device ◽  
Brain Machine Interface ◽  
Wide Range ◽  
Cord Injury ◽  
Posterior Parietal ◽  
Machine Interface ◽  
The Brain

A dramatic example of translational monkey research is the development of neural prosthetics for assisting paralyzed patients. A neuroprosthesis consists of implanted electrodes that can record the intended movement of a paralyzed part of the body, a computer algorithm that decodes the intended movement, and an assistive device such as a robot limb or computer that is controlled by these intended movement signals. This type of neuroprosthetic system is also referred to as a brain–machine interface (BMI) since it interfaces the brain with an external machine. In this review, we will concentrate on BMIs in which microelectrode recording arrays are implanted in the posterior parietal cortex (PPC), a high-level cortical area in both humans and monkeys that represents intentions to move. This review will first discuss the basic science research performed in healthy monkeys that established PPC as a good source of intention signals. Next, it will describe the first PPC implants in human patients with tetraplegia from spinal cord injury. From these patients the goals of movements could be quickly decoded, and the rich number of action variables found in PPC indicates that it is an appropriate BMI site for a very wide range of neuroprosthetic applications. We will discuss research on learning to use BMIs in monkeys and humans and the advances that are still needed, requiring both monkey and human research to enable BMIs to be readily available in the clinic.

scholarly journals Are Trauma Memories Disjointed from other Autobiographical Memories in Posttraumatic Stress Disorder? An Experimental Investigation

2008 ◽  
Vol 36 (2) ◽  
pp. 221-234 ◽  
Author(s):  
Birgit Kleim ◽  
Franziska Wallott ◽  
Anke Ehlers
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Memory Retrieval ◽  
Stress Disorder ◽  
Negative Life Event ◽  
Trauma Survivors ◽  
Autobiographical Memories ◽  
Retrieval Task ◽  
Traumatic Memories ◽  
Assault Survivors

AbstractThis study tested the hypothesis that trauma memories are disjointed from other autobiographical material in posttraumatic stress disorder (PTSD). Assault survivors with (n = 25) and without PTSD (n = 49) completed an autobiographical memory retrieval task during script-driven imagery of (a) the assault and (b) an unrelated negative event. When listening to a taped imagery script of the worst moment of their assault, survivors with PTSD took longer to retrieve unrelated non-traumatic autobiographical information than those without PTSD, but not when listening to a taped script of the worst moment of another negative life event. The groups also did not differ in general retrieval latencies, neither at baseline nor after the imagery tasks. The findings are in line with suggestions that traumatic memories are less integrated with other autobiographical information in trauma survivors with PTSD than in those without PTSD.

scholarly journals Neurometabolite Changes in Hyperthyroid Patients Before and After Antithyroid Treatment: An in vivo1H MRS Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Mukesh Kumar ◽  
Sadhana Singh ◽  
Poonam Rana ◽  
Pawan Kumar ◽  
Tarun Sekhri ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Brain Regions ◽  
Before And After ◽  
Antithyroid Treatment ◽  
Posterior Parietal ◽  
Positive Correlations ◽  
The Brain ◽  
Hyperthyroid Patients

Purpose: Patients with hyperthyroidism have frequent neuropsychiatric symptoms such as lack of attention, concentration, poor memory, impaired executive functions, depression, and anxiety. These neurocognitive impairments such as memory, attention, and executive functions appear to be associated with dysfunction in brain regions. This study was conducted to investigate the metabolic changes in the brain subcortical regions, i.e., posterior parietal cortex and dorsolateral prefrontal cortex (DLPFC), in patients with hyperthyroidism before and after antithyroid treatment using proton magnetic resonance spectroscopy (1H MRS).Materials and Methods: We collected neuropsychological and 1H MRS data from posterior parietal cortex and DLPFC, in both control (N = 30) and hyperthyroid (N = 30) patients. In addition, follow-up data were available for 19 patients treated with carbimazole for 30 weeks. The relative ratios of the neurometabolites were calculated using the Linear Combination Model (LCModel). Analysis of co-variance using Bonferroni correction was performed between healthy controls and hyperthyroid patients, and a paired t-test was applied in patients at baseline and follow-up. Spearman’s rank-order correlation was used to analyze bivariate associations between thyroid hormone levels and metabolite ratios, and the partial correlation analysis was performed between neuropsychological scores and metabolite ratios, with age and sex as covariates, in the patients before and after treatment.Results: Our results revealed a significant decrease in choline/creatine [glycerophosphocholine (GPC) + phosphocholine (PCh)/creatine (tCr)] in both the posterior parietal cortex and DLPFC in hyperthyroid patients, and these changes were reversible after antithyroid treatment. The posterior parietal cortex also showed significantly reduced glutamate/creatine (Glu/tCr), (glutamate + glutamine)/creatine (Glx/tCr), and increased glutathione/creatine (GSH/tCr) ratios in the hyperthyroid patients over control subjects. In DLPFC, only (N-acetyl aspartate + N-acetyl aspartyl-glutamate)/creatine (NAA + NAAG)/tCr was increased in the hyperthyroid patients. After antithyroid treatment, (GPC + PCh)/tCr increased, and Glx/tCr decreased in both brain regions in the patients at follow-up. Gln/tCr in the posterior parietal cortex was decreased in patients at follow-up. Interestingly, (GPC + PCh)/tCr in DLPFC showed a significantly inverse correlation with free tri-iodothyronine (fT3) in hyperthyroid patients at baseline, whereas NAA/tCr showed positive correlations with fT3 and free thyroxine (fT4) in hyperthyroid patients before and after antithyroid treatment, in the posterior parietal cortex. In DLPFC, only (NAA + NAAG)/tCr showed positive correlations with fT3 and fT4 in the patients before treatment.Conclusion: The overall findings suggest that all the brain metabolite changes were not completely reversed in the hyperthyroid patients after antithyroid treatment, even after achieving euthyroidism.

scholarly journals Distinct encoding of decision confidence in human medial prefrontal cortex

2018 ◽  
Vol 115 (23) ◽  
pp. 6082-6087 ◽  
Author(s):  
Dan Bang ◽  
Stephen M. Fleming
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Posterior Parietal Cortex ◽  
Behavioral Control ◽  
Anterior Cingulate ◽  
Decision Confidence ◽  
Expected Performance ◽  
Posterior Parietal ◽  
Sensory Evidence ◽  
The Brain

Our confidence in a choice and the evidence pertaining to a choice appear to be inseparable. However, an emerging computational consensus holds that the brain should maintain separate estimates of these quantities for adaptive behavioral control. We have devised a psychophysical task to decouple confidence in a perceptual decision from both the reliability of sensory evidence and the relation of such evidence with respect to a choice boundary. Using human fMRI, we found that an area in the medial prefrontal cortex, the perigenual anterior cingulate cortex (pgACC), tracked expected performance, an aggregate signature of decision confidence, whereas neural areas previously proposed to encode decision confidence instead tracked sensory reliability (posterior parietal cortex and ventral striatum) or boundary distance (presupplementary motor area). Supporting that information encoded by pgACC is central to a subjective sense of decision confidence, we show that pgACC activity does not simply covary with expected performance, but is also linked to within-subject and between-subject variation in explicit confidence estimates. Our study is consistent with the proposal that the brain maintains choice-dependent and choice-independent estimates of certainty, and sheds light on why dysfunctional confidence often emerges following prefrontal lesions and/or degeneration.

scholarly journals The posterior parietal cortex and subjectively perceived confidence during memory retrieval

2018 ◽  
Vol 25 (8) ◽  
pp. 382-389 ◽  
Author(s):  
Syanah C. Wynn ◽  
Marc P. H. Hendriks ◽  
Sander M. Daselaar ◽  
Roy P. C. Kessels ◽  
Dennis J. L. G. Schutter
Keyword(s):  
Parietal Cortex ◽  
Memory Retrieval ◽  
Posterior Parietal Cortex ◽  
Posterior Parietal
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