scholarly journals Monkey V1 epidural field potentials provide significant information about stimulus location, size, shape, and color

2020 ◽  
Author(s):  
Benjamin Fischer ◽  
Detlef Wegener
Keyword(s):  
Functional Organization ◽  
Basic Research ◽  
Specific Information ◽  
Signal Source ◽  
Field Potentials ◽  
Significant Information ◽  
Invasive Approach ◽  
High Stimulus ◽  
Stimulus Features ◽  
Stimulus Classification

AbstractBrain signal recordings with epidural microarrays constitute a low-invasive approach for recording distributed neuronal signals. Epidural field potentials (EFPs) may serve as a safe and highly beneficial signal source for a variety of research questions arising from both basic and applied neuroscience. A wider use of these signals, however, is constrained by a lack of data on their specific information content. Here, we make use of the high spatial resolution and the columnar organization of macaque primary visual cortex (V1) to investigate whether and to what extent EFP signals preserve information about various visual stimulus features. Two monkeys were presented with different feature combinations of location, size, shape, and color, yielding a total of 375 stimulus conditions. Visual features were chosen to access different spatial levels of functional organization. We found that, besides being highly specific for locational information, EFPs were significantly modulated by small differences in size, shape, and color, allowing for high stimulus classification rates even at the single-trial level. The results support the notion that EFPs constitute a low-invasive, highly beneficial signal source for longer-term recordings for medical and basic research by showing that they convey significant and reliable information about constituent features of activating stimuli.

scholarly journals Monkey V1 epidural field potentials provide detailed information about stimulus location, size, shape, and color

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Benjamin Fischer ◽  
Detlef Wegener
Keyword(s):  
Functional Organization ◽  
Basic Research ◽  
Specific Information ◽  
Signal Source ◽  
Field Potentials ◽  
Invasive Approach ◽  
Columnar Organization ◽  
High Stimulus ◽  
Stimulus Features ◽  
Stimulus Classification

AbstractBrain signal recordings with epidural microarrays constitute a low-invasive approach for recording distributed neuronal signals. Epidural field potentials (EFPs) may serve as a safe and highly beneficial signal source for a variety of research questions arising from both basic and applied neuroscience. A wider use of these signals, however, is constrained by a lack of data on their specific information content. Here, we make use of the high spatial resolution and the columnar organization of macaque primary visual cortex (V1) to investigate whether and to what extent EFP signals preserve information about various visual stimulus features. Two monkeys were presented with different feature combinations of location, size, shape, and color, yielding a total of 375 stimulus conditions. Visual features were chosen to access different spatial levels of functional organization. We found that, besides being highly specific for locational information, EFPs were significantly modulated by small differences in size, shape, and color, allowing for high stimulus classification rates even at the single-trial level. The results support the notion that EFPs constitute a low-invasive, highly beneficial signal source for longer-term recordings for medical and basic research by showing that they convey detailed and reliable information about constituent features of activating stimuli.

scholarly journals Delivery of the UN Convention on the Rights of the Child in an acute paediatric setting: an audit of information available and service gap analysis

2019 ◽  
Vol 3 (1) ◽  
pp. e000445
Author(s):  
Marianna A Przybylska ◽  
Niall Burke ◽  
Clare Harris ◽  
Marcel Kazmierczyk ◽  
Ellie Kenton ◽  
...  
Keyword(s):  
Gap Analysis ◽  
Information Provision ◽  
Well Being ◽  
Information Resources ◽  
Depth Information ◽  
Specific Information ◽  
Children And Families ◽  
Significant Information ◽  
Rights Of The Child ◽  
Qualitative Feedback

BackgroundThe United Nations Convention on Children’s Rights stresses the importance of providing children with information relating to their health and well-being, yet reports suggest children are offered insufficient support in healthcare environments. We audited the information provided to children and families requiring planned surgical admission in comparison to those admitted acutely to medical paediatrics. Additionally, we identified examples of child-specific information resources in national and international hospitals.MethodsThree approaches were taken to gain insight into practice locally, nationally and internationally.(1) Information resources provided to paediatric inpatients admitted to the acute receiving unit were audited in comparison to information given to children with planned admissions via process observations.(2) Qualitative feedback was gained from play specialists (n=2), families (n=30) and children (n=9; aged 3–15 years) via interviews.(3) A review, including UK, Australian and US hospitals, was conducted to assess child-specific information resources (n=36 hospitals) and to systematically compare the information available on websites (n=9 hospitals).ResultsAt the study site, no child-specific information resources were available for acute admissions, whereas planned admissions were offered significant information face-to-face with supplemental resources. Child, parent and play specialist interviews highlighted gaps in information provision regarding hospital practicalities and processes. Twelve external child-specific resources were identified, for 4–14 year olds, explaining key care information: medical procedures, equipment and staff. These resources could positively respond to the topics cited as lacking by the interviewed patients and families at the study site. International hospital websites provided considerably more in-depth information compared with UK hospitals.ConclusionsThe hospital experience of children and families can be improved by ensuring they are provided with adequate information relating to their hospital stay. It is essential that suitable high-quality resources are consistently available and that feedback from children informs the process of resource development.

scholarly journals Local field potentials allow accurate decoding of muscle activity

2012 ◽  
Vol 108 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Robert D. Flint ◽  
Christian Ethier ◽  
Emily R. Oby ◽  
Lee E. Miller ◽  
Marc W. Slutzky
Keyword(s):  
Upper Limb ◽  
Local Field ◽  
Muscle Activity ◽  
Primary Motor Cortex ◽  
Target Location ◽  
Local Field Potentials ◽  
Field Potentials ◽  
Reach To Grasp ◽  
Significant Information ◽  
Complex Movement

Local field potentials (LFPs) in primary motor cortex include significant information about reach target location and upper limb movement kinematics. Some evidence suggests that they may be a more robust, longer-lasting signal than action potentials (spikes). Here we assess whether LFPs can also be used to decode upper limb muscle activity, a complex movement-related signal. We record electromyograms from both proximal and distal upper limb muscles from monkeys performing a variety of reach-to-grasp and isometric wrist force tasks. We show that LFPs can be used to decode activity from both proximal and distal muscles with performance rivaling that of spikes. Thus, motor cortical LFPs include information about more aspects of movement than has been previously demonstrated. This provides further evidence suggesting that LFPs could provide a highly informative, long-lasting signal source for neural prostheses.

scholarly journals Visual epidural field potentials possess high functional specificity in single trials

2019 ◽  
Vol 122 (4) ◽  
pp. 1634-1648 ◽  
Author(s):  
Benjamin Fischer ◽  
Andreas Schander ◽  
Andreas K. Kreiter ◽  
Walter Lang ◽  
Detlef Wegener
Keyword(s):  
Visual Cortex ◽  
Minimally Invasive ◽  
Primary Visual Cortex ◽  
Neuronal Activity ◽  
Large Scale ◽  
Field Potentials ◽  
Operating Characteristics ◽  
Invasive Approach ◽  
Spatial Selectivity ◽  
Minimal Invasiveness

Recordings of epidural field potentials (EFPs) allow neuronal activity to be acquired over a large region of cortical tissue with minimal invasiveness. Because electrodes are placed on top of the dura and do not enter the neuronal tissue, EFPs offer intriguing options for both clinical and basic science research. On the other hand, EFPs represent the integrated activity of larger neuronal populations and possess a higher trial-by-trial variability and a reduced signal-to-noise ratio due the additional barrier of the dura. It is thus unclear whether and to what extent EFPs have sufficient spatial selectivity to allow for conclusions about the underlying functional cortical architecture, and whether single EFP trials provide enough information on the short timescales relevant for many clinical and basic neuroscience purposes. We used the high spatial resolution of primary visual cortex to address these issues and investigated the extent to which very short EFP traces allow reliable decoding of spatial information. We briefly presented different visual objects at one of nine closely adjacent locations and recorded neuronal activity with a high-density epidural multielectrode array in three macaque monkeys. With the use of receiver operating characteristics (ROC) to identify the most informative data, machine-learning algorithms provided close-to-perfect classification rates for all 27 stimulus conditions. A binary classifier applying a simple max function on ROC-selected data further showed that single trials might be classified with 100% performance even without advanced offline classifiers. Thus, although highly variable, EFPs constitute an extremely valuable source of information and offer new perspectives for minimally invasive recording of large-scale networks. NEW & NOTEWORTHY Epidural field potential (EFP) recordings provide a minimally invasive approach to investigate large-scale neural networks, but little is known about whether they possess the required specificity for basic and clinical neuroscience. By making use of the spatial selectivity of primary visual cortex, we show that single-trial information can be decoded with close-to-perfect performance, even without using advanced classifiers and based on very few data. This labels EFPs as a highly attractive and widely usable signal.

scholarly journals Parietal representations of stimulus features are amplified during memory retrieval and flexibly aligned with top-down goals

2018 ◽  
Author(s):  
Serra E. Favila ◽  
Rosalie Samide ◽  
Sarah C. Sweigart ◽  
Brice A. Kuhl
Keyword(s):  
Parietal Cortex ◽  
Memory Retrieval ◽  
Human Subjects ◽  
Stimulus Level ◽  
Specific Information ◽  
Top Down ◽  
Control Functions ◽  
Feature Information ◽  
Stimulus Features ◽  
High Level

AbstractIn studies of human episodic memory, the phenomenon of reactivation has traditionally been observed in regions of occipitotemporal cortex (OTC) involved in sensory experience. However, reactivation also occurs in lateral parietal cortex (LPC), and recent evidence indicates that reactivation of stimulus-specific information may be stronger in LPC than in OTC. These observations raise a number of questions about the nature of memory representations in LPC and their relation to representations in OTC. Here, we report two fMRI experiments that quantify stimulus feature information (color and object category) within LPC and OTC, separately during perception and memory retrieval, in male and female human subjects. Across both experiments, we show a clear dissociation between OTC and LPC: while feature information in OTC is relatively stronger during perception than memory, feature information in LPC is relatively stronger during memory than perception. Thus, while OTC and LPC represent common stimulus features, they preferentially represent this information during different stages. We show that this transformation of feature information across regions co-occurs with stimulus-level reinstatement within LPC and high-level OTC. In Experiment 2, we consider whether feature information in LPC during memory retrieval is flexibly and dynamically shaped by top-down goals. Indeed, we find that dorsal LPC preferentially represents retrieved feature information that addresses current goals. In contrast, ventral LPC represents retrieved features independent of current goals. Collectively, these findings provide insight into the nature and significance of mnemonic representations in LPC and constitute an important bridge between putative mnemonic and control functions of parietal cortex.

Parallel distributed network characteristics of the DSCT

1992 ◽  
Vol 68 (4) ◽  
pp. 1100-1112 ◽  
Author(s):  
C. E. Osborn ◽  
R. E. Poppele
Keyword(s):  
Time Course ◽  
Functional Organization ◽  
Activity Patterns ◽  
Three Dimensional ◽  
Principal Component ◽  
Specific Information ◽  
Distributed Network ◽  
Network Characteristics ◽  
Large Populations ◽  
Excitatory Responses

1. We examined the functional organization of the dorsal spinocerebellar tract (DSCT) and found that it is similar to that of a parallel distributed network having widespread connectivity among parallel elements. The prevailing view is that the DSCT provides receptor-specific information to the cerebellum regarding muscle and cutaneous inputs from the hindlimbs, but that view does not consider the convergent inputs to DSCT neurons from multimodal polysynaptic pathways. 2. Spontaneously active DSCT neurons respond to peripheral stimulation with changes in their firing probability. We characterized the temporal patterns of poststimulus excitability changes for a large number of neurons using principal component analysis. The response of each neuron was represented by a response vector in three-dimensional principal component space, in which similar vectors represent responses having a similar waveform for their poststimulus activity patterns. 3. We compared the responses of large populations of DSCT units to two types of stimuli: small (3-8 deg) passive rotations of the foot at the ankle of an intact limb (234 cells) and stretch or contraction of an isolated muscle group (gastrocnemius-soleus, 168 cells). Most of the cells tested had significant responses (P < 0.05) to both types of stimuli (40-78% responded to muscle stimulation and 88% to foot rotation), and they exhibited similar patterns of poststimulus activity. Long-lasting inhibitory responses and excitatory responses with a range of peak times (< 10- > 60 ms) were prevalent in all cases. The population response to each stimulus was characterized by the relative incidence of response types among the units in a representative sample of the population. 4. The time course of excitability changes induced in DSCT cells by the stimuli could have been determined primarily by the presynaptic circuitry or by postsynaptic factors intrinsic to the DSCT cells. The evidence presented suggests that the selection of response waveforms and their distribution among the DSCT cells was determined presynaptically. We found that individual cells were capable of diverse responses to different stimuli. 5. Sample groups of 7-30 cells were selected at random and also on the basis of the similarity of their responses to one type of stimulus. The distributions of response types among the cells of the sample groups were compared to the distributions for the entire population recorded for each stimulus.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Local field potentials in the parietal reach region reveal mechanisms of bimanual coordination

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eric Mooshagian ◽  
Charles D. Holmes ◽  
Lawrence H. Snyder
Keyword(s):  
Local Field ◽  
Bimanual Coordination ◽  
Local Field Potentials ◽  
Specific Information ◽  
Field Potentials ◽  
Beta Band ◽  
Common Input ◽  
Bimanual Movements ◽  
Shared Information ◽  
Average Unit

AbstractPrimates use their arms in complex ways that frequently require coordination between the two arms. Yet the planning of bimanual movements has not been well-studied. We recorded spikes and local field potentials (LFP) from the parietal reach region (PRR) in both hemispheres simultaneously while monkeys planned and executed unimanual and bimanual reaches. From analyses of interhemispheric LFP-LFP and spike-LFP coherence, we found that task-specific information is shared across hemispheres in a frequency-specific manner. This shared information could arise from common input or from direct communication. The population average unit activity in PRR, representing PRR output, encodes only planned contralateral arm movements while beta-band LFP power, a putative PRR input, reflects the pattern of planned bimanual movement. A parsimonious interpretation of these data is that PRR integrates information about the movement of the left and right limbs, perhaps in service of bimanual coordination.

scholarly journals Cell-type and subcellular compartment-specific APEX2 proximity labeling reveals activity-dependent nuclear proteome dynamics in the striatum

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
V. Dumrongprechachan ◽  
R. B. Salisbury ◽  
G. Soto ◽  
M. Kumar ◽  
M. L. MacDonald ◽  
...  
Keyword(s):  
Mouse Brain ◽  
Functional Organization ◽  
Projection Neurons ◽  
Specific Information ◽  
Striatal Neurons ◽  
Cell Type ◽  
Indirect Pathway ◽  
Subcellular Compartment ◽  
Cell Type Specific ◽  
And Function

AbstractThe vertebrate brain consists of diverse neuronal types, classified by distinct anatomy and function, along with divergent transcriptomes and proteomes. Defining the cell-type specific neuroproteomes is important for understanding the development and functional organization of neural circuits. This task remains challenging in complex tissue, due to suboptimal protein isolation techniques that often result in loss of cell-type specific information and incomplete capture of subcellular compartments. Here, we develop a genetically targeted proximity labeling approach to identify cell-type specific subcellular proteomes in the mouse brain, confirmed by imaging, electron microscopy, and mass spectrometry. We virally express subcellular-localized APEX2 to map the proteome of direct and indirect pathway spiny projection neurons in the striatum. The workflow provides sufficient depth to uncover changes in the proteome of striatal neurons following chemogenetic activation of Gαq-coupled signaling cascades. This method enables flexible, cell-type specific quantitative profiling of subcellular proteome snapshots in the mouse brain.

scholarly journals A systematic review of neuroimaging approaches to single-subject localization of language in the brain

2019 ◽  
Author(s):  
Aahana Bajracharya ◽  
Jonathan E. Peelle
Keyword(s):  
Systematic Review ◽  
Functional Organization ◽  
Center Of Mass ◽  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Basic Research ◽  
Single Subject ◽  
Language Mapping ◽  
Clinical Prognosis ◽  
The Brain

Background. Task-based functional MRI has become the method of choice for researchers studying functional localization in the human brain. However, for a deeper understanding of brain function beyond group level generalizations, it is crucial to account for the reliability of brain activations in a single subject. Individual differences can influence group results in a multitude of ways and consequently lead to the mischaracterization of functional organization. Such errors can be detrimental to the accuracy of both basic research and clinical prognosis. Methodology. We performed a systematic review with the goal of understanding the state of the literature pertaining to mapping language regions using fMRI in individual participants. A thorough database search was carried out on published literature through April 2020. Results. Out of 977 papers identified through our literature search, 121 met our inclusion criteria for reporting single-subject fMRI results. Of these, 20 papers reported using single-subject level test-retest as a reliability measure. Among these papers, overlap measures such as Dice coefficient, Intraclass Correlation Coefficient, Euclidean Distance between peak activation or center of mass, or Receiver Operating Characteristic were used to further quantify the variability in their results. Among other categories, papers focused on comparing performance between language tasks, multimodal validation of fMRI results, technical development of protocols and clinical case studies on specific disease conditions. Conclusion. Incorporating reliability and validity measures in language mapping paradigms increases the likelihood that task-based activations in the brain are reproducible. However, very few papers reported measures of test-retest reliability. In the absence of quantified reproducibility, results from paradigms used for single-subject language mapping may need to be treated with caution. Future attempts to optimize the localization of language networks in individuals will benefit from the broader adoption of reliability metrics for different tasks and acquisition parameters.

scholarly journals CA1 20-40 Hz oscillatory dynamics reflect trial-specific information processing supporting nonspatial sequence memory

2020 ◽  
Author(s):  
Sandra Gattas ◽  
Gabriel A. Elias ◽  
Michael A. Yassa ◽  
Norbert J. Fortin
Keyword(s):  
Functional Organization ◽  
Critical Role ◽  
Memory Task ◽  
Field Potential ◽  
Specific Information ◽  
Oscillatory Dynamics ◽  
Processing Information ◽  
Potential Activity ◽  
Sequence Memory ◽  
40 Hz

AbstractThe hippocampus is known to play a critical role in processing information about temporal context. However, it remains unclear how hippocampal oscillations are involved, and how their functional organization is influenced by connectivity gradients. We examined local field potential activity in CA1 as rats performed a complex odor sequence memory task. We find that odor sequence processing epochs were characterized by increased power in the 4-8 Hz and 20-40 Hz range, with 20-40 Hz oscillations showing a power gradient increasing toward proximal CA1. Running epochs were characterized by increased power in the 8-12 Hz range and across higher frequency ranges (>24 Hz), with power gradients increasing toward proximal and distal CA1, respectively. Importantly, 20-40 Hz power increased with knowledge of the sequence and carried trial-type-specific information. These results suggest that 20-40 Hz oscillations are associated with trial-specific processing of nonspatial information critical for order memory judgments.

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