scholarly journals Progression from feature-specific brain activity to hippocampal binding during episodic encoding

2019 ◽  
Author(s):  
Rose A. Cooper ◽  
Maureen Ritchey
Keyword(s):  
Cognitive Abilities ◽  
Spatial Information ◽  
Temporal Dynamics ◽  
Human Subjects ◽  
Brain Activity ◽  
Imaging Data ◽  
Left Hippocampus ◽  
Episodic Encoding ◽  
The Rich ◽  
Event Representations

ABSTRACTThe hallmark of episodic memory is recollecting multiple perceptual details tied to a specific spatial-temporal context. To remember an event, it is therefore necessary to integrate such details into a coherent representation during initial encoding. Here we tested how the brain encodes and binds multiple, distinct kinds of features in parallel, and how this process evolves over time during the event itself. We analyzed data from 27 human subjects (16 females, 11 males) who learned a series of objects uniquely associated with a color, a panoramic scene location, and an emotional sound while functional magnetic resonance imaging data were collected. By modeling how brain activity relates to memory for upcoming or just-viewed information, we were able to test how the neural signatures of individual features as well as the integrated event changed over the course of encoding. We observed a striking dissociation between early and late encoding processes: left inferior frontal and visuo-perceptual signals at the onset of an event tracked the amount of detail subsequently recalled and were dissociable based on distinct remembered features. In contrast, memory-related brain activity shifted to the left hippocampus toward the end of an event, which was particularly sensitive to binding item color and sound associations with spatial information. These results provide evidence of early, simultaneous feature-specific neural responses during episodic encoding that predict later remembering and suggest that the hippocampus integrates these features into a coherent experience at an event transition.SIGNIFICANCE STATEMENTUnderstanding and remembering complex experiences is crucial for many socio-cognitive abilities, including being able to navigate our environment, predict the future, and share experiences with others. Probing the neural mechanisms by which features become bound into meaningful episodes is a vital part of understanding how we view and reconstruct the rich detail of our environment. By testing memory for multimodal events, our findings show a functional dissociation between early encoding processes that engage lateral frontal and sensory regions to successfully encode event features, and later encoding processes that recruit hippocampus to bind these features together. These results highlight the importance of considering the temporal dynamics of encoding processes supporting multimodal event representations.

scholarly journals Resting‐State EEG Microstates Parallel Age‐Related Differences in Allocentric Spatial Working Memory Performance

2021 ◽  
Author(s):  
Adeline Jabès ◽  
Giuliana Klencklen ◽  
Paolo Ruggeri ◽  
Christoph M. Michel ◽  
Pamela Banta Lavenex ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Resting State ◽  
Cognitive Aging ◽  
Temporal Dynamics ◽  
Spatial Working Memory ◽  
Brain Activity ◽  
Memory Performance ◽  
Brain Regions ◽  
Age Related

AbstractAlterations of resting-state EEG microstates have been associated with various neurological disorders and behavioral states. Interestingly, age-related differences in EEG microstate organization have also been reported, and it has been suggested that resting-state EEG activity may predict cognitive capacities in healthy individuals across the lifespan. In this exploratory study, we performed a microstate analysis of resting-state brain activity and tested allocentric spatial working memory performance in healthy adult individuals: twenty 25–30-year-olds and twenty-five 64–75-year-olds. We found a lower spatial working memory performance in older adults, as well as age-related differences in the five EEG microstate maps A, B, C, C′ and D, but especially in microstate maps C and C′. These two maps have been linked to neuronal activity in the frontal and parietal brain regions which are associated with working memory and attention, cognitive functions that have been shown to be sensitive to aging. Older adults exhibited lower global explained variance and occurrence of maps C and C′. Moreover, although there was a higher probability to transition from any map towards maps C, C′ and D in young and older adults, this probability was lower in older adults. Finally, although age-related differences in resting-state EEG microstates paralleled differences in allocentric spatial working memory performance, we found no evidence that any individual or combination of resting-state EEG microstate parameter(s) could reliably predict individual spatial working memory performance. Whether the temporal dynamics of EEG microstates may be used to assess healthy cognitive aging from resting-state brain activity requires further investigation.

Managing the Edentulous Mandible using Recent Technological Developments: A Case Study

2013 ◽  
Vol 2 (2) ◽  
pp. 50-54
Author(s):  
Ashok Sethi ◽  
Thomas Kaus ◽  
Naresh Sharma ◽  
Peter Sochor
Keyword(s):  
Computed Tomography ◽  
Spatial Information ◽  
Imaging Techniques ◽  
Accurate Information ◽  
Imaging Data ◽  
Surgical Guide ◽  
Prosthetic Reconstruction ◽  
Anterior Teeth ◽  
Edentulous Mandible ◽  
Cad Cam

Safe clinical practice in implant dentistry requires an accurate investigation of the availability of bone for implant placement and the avoidance of critical anatomical structures. Modern imaging techniques using computed tomography (CT) and cone beam computed tomography (CBCT) provide the clinician with the required information. The imaging thus obtained provides accurate representation of the height, width and length of the available bone.1 In addition, whenever adequate radiation dose is used, accurate information about the bone density in Hounsfield units can be obtained. Important spatial information regarding the orientation of the ridges and the relationship to the proposed prosthetic reconstruction can be obtained with the aid of radiopaque templates during the acquisition of CT scan data. Modern software also provides the facility to decide interactively upon the positioning of the implants and is able to relate this to a stereolithographic model constructed from the imaging data. A surgical guide for the accurate positioning of the implants can be constructed. The construction of screw retained prostheses is fraught with difficulties regarding the accuracy of the construction. Accurate fit of the prosthesis is difficult to obtain due to the inherent errors in impression taking, component discrepancies, investing and casting inaccuracies.2,3 CAD/CAM technology eliminates the inaccuracies involved with the investing and casting of superstructures. Clinical Case This case describes the management of an 84 year old female patient, who had recently lost her remaining mandibular anterior teeth. This resulted in the patient's inability to wear conventional dentures in the mandible.

scholarly journals Adaptive brain activity changes during tongue movement with palatal coverage from fMRI data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuka Inamochi ◽  
Kenji Fueki ◽  
Nobuo Usui ◽  
Masato Taira ◽  
Noriyuki Wakabayashi
Keyword(s):  
Spatial Information ◽  
Brain Activity ◽  
Motor Impairment ◽  
Angular Gyrus ◽  
Tongue Movement ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Oral Environment ◽  
Motor Dexterity ◽  
The Brain

AbstractSuccessful adaptation to wearing dentures with palatal coverage may be associated with cortical activity changes related to tongue motor control. The purpose was to investigate the brain activity changes during tongue movement in response to a new oral environment. Twenty-eight fully dentate subjects (mean age: 28.6-years-old) who had no experience with removable dentures wore experimental palatal plates for 7 days. We measured tongue motor dexterity, difficulty with tongue movement, and brain activity using functional magnetic resonance imaging during tongue movement at pre-insertion (Day 0), as well as immediately (Day 1), 3 days (Day 3), and 7 days (Day 7) post-insertion. Difficulty with tongue movement was significantly higher on Day 1 than on Days 0, 3, and 7. In the subtraction analysis of brain activity across each day, activations in the angular gyrus and right precuneus on Day 1 were significantly higher than on Day 7. Tongue motor impairment induced activation of the angular gyrus, which was associated with monitoring of the tongue’s spatial information, as well as the activation of the precuneus, which was associated with constructing the tongue motor imagery. As the tongue regained the smoothness in its motor functions, the activation of the angular gyrus and precuneus decreased.

Cannabidiol Has a Unique Effect on Global Brain Activity: A Pharmacological, Functional MRI Study in Awake Mice 

2021 ◽  
Author(s):  
Aymen Sadaka ◽  
Ana Ozuna ◽  
Richard Ortiz ◽  
Praveen Kulkarni ◽  
Clare Johnson ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Brain Activity ◽  
Stress Disorders ◽  
Functional Coupling ◽  
Specific Information ◽  
Imaging Data ◽  
Post Traumatic Stress ◽  
Brain Areas ◽  
Dose Dependent ◽  
The Brain

Abstract Background: The phytocannabinoid cannabidiol (CBD) is a potential treatment for post-traumatic stress disorders. How does CBD interact with the brain to alter behavior? We hypothesized that CBD would produce a dose-dependent reduction in brain activity and functional coupling in neural circuitry associated with fear and defense. Methods: During the scanning session awake mice were given vehicle or CBD (3, 10, or 30 mg/kg I.P.) and imaged for 10 min post treatment. Mice were also treated with the 10 mg/kg dose of CBD and imaged one hr later for resting state BOLD functional connectivity (rsFC). Imaging data were registered to a 3D MRI mouse atlas providing site-specific information on 138 different brain areas. Blood samples were collected for CBD measurements.Results: CBD produced a dose-dependent polarization of activation along the rostral-caudal axis of the brain. The olfactory bulb and prefrontal cortex showed an increase in positive BOLD whereas the brainstem and cerebellum showed a decrease in BOLD signal. This negative BOLD affected many areas connected to the ascending reticular activating system (ARAS). The ARAS was decoupled to much of the brain but was hyperconnected to the olfactory system and prefrontal cortex. The pattern of ARAS connectivity closely overlapped with brain areas showing high levels N-acyl-phosphatidylethanolamines-specific phospholipase D (NAPE-PLD) messenger RNA.Conclusion: The CBD-induced decrease in ARAS activity is consistent with an emerging literature suggesting that CBD reduces autonomic arousal under conditions of emotional and physical stress. The putative target and mechanism of action is NAPE-PLD the enzyme responsible for the biosynthesis of lipid signaling molecules like anandamide.

scholarly journals Design and Development of a Low Cost Personal Computer Based ECG Monitor

2013 ◽  
Vol 4 (1) ◽  
pp. 115-125 ◽  
Author(s):  
K Siddique-e Rabbani ◽  
A Raihan Abir ◽  
AKM Bodiuzzaman
Keyword(s):  
Service Providers ◽  
Human Subjects ◽  
Medical Physics ◽  
Low Cost ◽  
Large Population ◽  
Telemedicine System ◽  
The Rich ◽  
Safety Features ◽  
The Third World ◽  
The Cost

ECG equipment is vital for diagnosis of cardiac problems. However, such equipment come from the rich Western countries at a huge cost in both procurement and maintenance, and therefore cannot offer services to a large population in the Third World countries. The only solution is to design and develop such equipment in individual countries by developing local expertise. With three decades of experience, the Dhaka University group has taken a step towards developing prototypes of ECG equipment for dissemination to the healthcare service providers. This paper presents the detailed design of an PC based ECG equipment where optimized choice of components and of the design have been made keeping the cost and maintenance in view, but not sacrificing the quality, and incorporating necessary safety features to protect the patient from known hazards. Both the hardware and the software have been developed locally and are detailed in this paper. Outputs obtained from human subjects are shown which are of reasonable good quality, and have been verified using standard ECG equipment. The PC based ECG system will allow digital post processing of signals for improved diagnosis through software. Besides, this can also become part of a nationwide telemedicine system. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14701 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 115-125

scholarly journals Model-based fMRI reveals dissimilarity processes underlying base rate neglect

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Sean R O'Bryan ◽  
Darrell A Worthy ◽  
Evan J Livesey ◽  
Tyler Davis
Keyword(s):  
Computational Models ◽  
Human Subjects ◽  
Base Rate ◽  
Imaging Data ◽  
Multivoxel Pattern Analysis ◽  
Activation Patterns ◽  
Model Based ◽  
Base Rate Neglect ◽  
Rate Information ◽  
Rare Category

Extensive evidence suggests that people use base rate information inconsistently in decision making. A classic example is the inverse base rate effect (IBRE), whereby participants classify ambiguous stimuli sharing features of both common and rare categories as members of the rare category. Computational models of the IBRE have either posited that it arises from associative similarity-based mechanisms or dissimilarity-based processes that may depend upon higher-level inference. Here we develop a hybrid model, which posits that similarity- and dissimilarity-based evidence both contribute to the IBRE, and test it using functional magnetic resonance imaging data collected from human subjects completing an IBRE task. Consistent with our model, multivoxel pattern analysis reveals that activation patterns on ambiguous test trials contain information consistent with dissimilarity-based processing. Further, trial-by-trial activation in left rostrolateral prefrontal cortex tracks model-based predictions for dissimilarity-based processing, consistent with theories positing a role for higher-level symbolic processing in the IBRE.

scholarly journals Part-of-Speech Classification from Magnetoencephalography Data Using 1-Dimensional Convolutional Neural Network

2020 ◽  
Author(s):  
Alessandro Lopopolo ◽  
Antal van den Bosch
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Mental State ◽  
Human Subjects ◽  
Brain Activity ◽  
Neural Decoding ◽  
Significant Progress ◽  
Part Of Speech ◽  
Syntactic Information ◽  
Speech Classification

Neural decoding of speech and language refers to the extraction of information regarding the stimulus and the mental state of subjects from recordings of their brain activity while performing linguistic tasks. Recent years have seen significant progress in the decoding of speech from cortical activity. This study instead focuses on decoding linguistic information. We present a deep parallel temporal convolutional neural network (1DCNN) trained on part-of-speech (PoS) classification from magnetoencephalography (MEG) data collected during natural language reading. The network is trained on data from 15 human subjects separately, and yields above-chance accuracies on test data for all of them. The level of PoS was targeted because it offers a clean linguistic benchmark level that represents syntactic information and abstracts away from semantic or conceptual representations.

scholarly journals SPARC Data Structure: Rationale and Design of a FAIR Standard for Biomedical Research Data

2021 ◽  
Author(s):  
Anita Bandrowski ◽  
Jeffrey S. Grethe ◽  
Anna Pilko ◽  
Tom Gillespie ◽  
Gabi Pine ◽  
...  
Keyword(s):  
Data Structure ◽  
Biomedical Research ◽  
Large Scale ◽  
Open Data ◽  
Cell Types ◽  
Research Data ◽  
Imaging Data ◽  
Organ Specific ◽  
The Rich ◽  
Automated Tools

AbstractThe NIH Common Fund’s Stimulating Peripheral Activity to Relieve Conditions (SPARC) initiative is a large-scale program that seeks to accelerate the development of therapeutic devices that modulate electrical activity in nerves to improve organ function. Integral to the SPARC program are the rich anatomical and functional datasets produced by investigators across the SPARC consortium that provide key details about organ-specific circuitry, including structural and functional connectivity, mapping of cell types and molecular profiling. These datasets are provided to the research community through an open data platform, the SPARC Portal. To ensure SPARC datasets are Findable, Accessible, Interoperable and Reusable (FAIR), they are all submitted to the SPARC portal following a standard scheme established by the SPARC Curation Team, called the SPARC Data Structure (SDS). Inspired by the Brain Imaging Data Structure (BIDS), the SDS has been designed to capture the large variety of data generated by SPARC investigators who are coming from all fields of biomedical research. Here we present the rationale and design of the SDS, including a description of the SPARC curation process and the automated tools for complying with the SDS, including the SDS validator and Software to Organize Data Automatically (SODA) for SPARC. The objective is to provide detailed guidelines for anyone desiring to comply with the SDS. Since the SDS are suitable for any type of biomedical research data, it can be adopted by any group desiring to follow the FAIR data principles for managing their data, even outside of the SPARC consortium. Finally, this manuscript provides a foundational framework that can be used by any organization desiring to either adapt the SDS to suit the specific needs of their data or simply desiring to design their own FAIR data sharing scheme from scratch.

scholarly journals Developmental changes in story-evoked responses in the neocortex and hippocampus

2021 ◽  
Author(s):  
Samantha Syd Cohen ◽  
Christopher Baldassano
Keyword(s):  
Division Of Labor ◽  
Life Events ◽  
Developmental Changes ◽  
Fmri Data ◽  
Evoked Responses ◽  
Age Related ◽  
Brain Responses ◽  
Episodic Encoding ◽  
Upcoming Event ◽  
Event Representations

How does the representation of naturalistic life events change with age? Here we analyzed fMRI data from 415 children and adolescents (5 - 19 years) as they watched a narrative movie. In addition to changes in the degree of inter-subject correlation (ISC) with age in sensory and medial parietal regions, we used a novel measure (between-groups ISC) to reveal age-related shifts in the responses across the majority of the neocortex. Over the course of development, brain responses became more discretized into stable and coherent events, and shifted earlier in time to anticipate upcoming event transitions. However, hippocampal responses to event boundaries actually decreased with age, suggesting a shifting division of labor between episodic encoding processes and schematic event representations between the ages of 5 and 19.

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