Name: group synchronization during collaborative drawing using functional near-infrared spectroscopy
Uploaded: 2022-08-05T14:00:00
Description: Watch this Scientific Journal Video about Group Synchronization During Collaborative Drawing Using Functional Near-Infrared Spectroscopy at JoVE.com

The authors thank Instituto do C&#233;rebro (InCe-IIEP) and Hospital Israelita Albert Einstein (HIAE) for this study support.&#160;Special thanks to Jos&#233; Bel&#233;m de Oliveira Neto for the English proofreading of this article.

The methodology was approved by the Hospital Israelita Albert Einstein (HIAE) Ethics Committee and is based on a procedure for collecting neural data (fNIRS), as well as gaze behavior data, with young adults during a collaborative drawing experience. All collected data were managed on the Redcap platform (see Table of Materials). The project was audited by the Scientific Integrity Committee of the Hospital Israelita Albert Einstein (HIAE). Young adults, 18-30 years old, were selected as subjects for the ...

This study aimed to create a protocol using hyperscanning on four brains concurrently under naturalistic conditions. The experimental paradigm used different drawing tasks and the correlation of multiple outcome measures, drawing metrics, behaviors, and brain signals. The critical steps within this protocol are the consideration of the challenges arising from its high complexity and the maintenance of its ecological and naturalistic conditions.
Video observation was key to this study. It&#160;...

Interpersonal interaction behavior is an important component of the process of connecting and creating empathic bonds. Previous research indicates that this behavior can be expressed in the occurrence of synchronicity, when biological and behavioral signals align during social contact. Evidence shows that synchronicity can occur between people interacting for the first time1,2,3. Most studies on social interactions and their underlying neural mechanisms use a single person or second person approach2,4, and little is known about transposing this knowledge to group social dynamics. Evaluating interpersonal responses in groups of three or more individuals is still a challenge for scientific research. This leads to the necessity of bringing to the laboratory the complex environment of social interactions in everyday human beings under naturalistic conditions5.
In this context, the functional near-infrared spectroscopy (fNIRS) technique is a promising tool for assessing the relationships between interpersonal interaction in naturalistic contexts and its brain correlates. It presents fewer restrictions on participant mobility compared to functional magnetic resonance imaging (fMRI) and is resilient to motion artifacts6,7. The fNIRS technique works by assessing hemodynamic effects in response to brain activation (changes in blood concentration of oxygenated and deoxygenated hemoglobin). These variations can be measured by the amount of diffusion of infrared light through scalp tissue. Previous studies have demonstrated the flexibility and robustness of the technique in ecological hyperscanning experiments and the potential to expand knowledge in applied neuroscience6,8.
The choice of an experimental task for the naturalistic assessment of the neural correlates of social interaction processes in groups is a crucial step in approaching applied neuroscience studies9.&#160;Some examples already reported in the literature with the use of fNIRS in group paradigms include music performance10,11,12, classroom interaction8, and communication13,14,15,16,17.
One of the aspects not yet explored by previous studies is the use of drawing games that have as the main feature the manipulation of empathic components to assess social interaction. In this context, one of the games frequently used to induce social interaction in dynamics among strangers is the collaborative drawing game18,19. In this game, sheets of paper are divided into equal parts, and the group participants are challenged to draw shared self-portraits of all members. In the end, each member has their portrait drawn in a collaborative way by several hands.
The objective is to promote quick integration among strangers, provoked by directing visual attention to the faces of the group partners. It can be considered an &#34;ice-breaking&#34; activity due to its ability to support curiosity and consequent empathic processes among the members19.
One of the advantages of using drawing tasks is their simplicity and ease of reproduction20. They also do not require any specific technical training or skills, as seen in the studies using musical performance paradigms21,22,23,24. This simplicity also enables the choice of a more naturalistic stimulus within a social context4,9,25.
Besides being an instrument for inducing social behavior in groups, drawing is also considered a tool for psychological evaluation26. Some graphic-projective psychological tests, such as House-Tree-Person (HTP)27,28,29, Human Figure Drawing - Sisto Scale27, and Kinetic Family Drawing30&#160;are used in a complementary way for qualitative and quantitative diagnoses. Their results usually express unconscious processes, giving clues about the individual&#39;s symbolic system and, therefore, their interpretations of the world, experiences, affections, etc.
The practice of drawing makes one think and helps create meaning for experiences and things, adding sensations, feelings, thoughts, and actions31. It gives clues about how to perceive and process these life experiences26. Drawing uses visual codes to allow one to understand and communicate thoughts or feelings, making them accessible to manipulation and, thus, creating the possibility for new ideas and readings31.
In art therapy, drawing is a tool to work on attention, memory, and organization of thoughts and feelings32, and it can be used as means to produce social interaction33.
This study aimed to develop a naturalistic experimental protocol to assess vascular and behavioral brain responses during interpersonal interaction in quartets using a collaborative drawing dynamic. In this protocol, the evaluation of the brain responses of the quartet (individually and the synchronicity between partners) and the possible outcome measures, such as behavioral measures (drawing and gaze behavior)&#160;are proposed. The aim is to provide more information on social neuroscience.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2 NIRSport&#160;</td>
			<td>NIRx Medizintechnik GmbH, Germany</td>
			<td>Nirsport 88</td>
			<td>The equipment belong to InCe ( Instituto do C&#233;rebro - Hospital Israelita Albert Einstein). two continuous-wave systems (NIRSport8x8, NIRx Medical Technologies, Glen Head, NY, USA) with eight LED illumination sources emitting two wavelengths of near-infrared light (760 and 850 nm) and eight optical detectors each. 7.91 Hz. Data were acquired with the NIRStar software version 15.2&#160; (NIRx Medical Technologies, Glen Head, New York) at a sampling rate of 3.472222.</td>
		</tr>
		<tr>
			<td>4 fNIRS caps</td>
			<td>NIRx Medizintechnik GmbH, Germany</td>
			<td></td>
			<td>The blackcaps used in the recordings had a configuration based on the international 10-20</td>
		</tr>
		<tr>
			<td>C&#226;mera 360&#176; - Kodak Pix Pro SP360</td>
			<td>Kodak</td>
			<td></td>
			<td>Kodak PixPro:&#160;https://kodakpixpro.com/cameras/360-vr/sp360</td>
		</tr>
		<tr>
			<td>Cameras de suporte - Iphone 8</td>
			<td>Apple</td>
			<td>Iphone 8</td>
			<td>Supporting Camera</td>
		</tr>
		<tr>
			<td>fOLD toolbox (fNIRS Optodes&#8217; Location Decider)</td>
			<td>Zimeo Morais, G.A., Balardin, J.B. &#38; Sato, J.R. fNIRS Optodes&#8217; Location Decider (fOLD): a toolbox for probe arrangement guided by brain regions-of-interest.&#160;Scientific Reports.&#160;8,&#160;3341 (2018). https://doi.org/10.1038/s41598-018-21716-z</td>
			<td>Version 2.2 (https://github.com/nirx/fOLD-public)</td>
			<td>Optodes placement was guided by the fOLD toolbox (fNIRS Optodes&#8217; Location Decider, which allows placement of sources and detectors in the international 10&#8211;10 system to maximally cover anatomical regions of interest according to several parcellation atlases. The ICBM 152 head model&#160; parcellation was used to generate the montage, which was designed to provide coverage of the most anterior portion of the bilateral prefrontal cortex</td>
		</tr>
		<tr>
			<td>Notebook Microsoft Surface</td>
			<td>Microsoft</td>
			<td></td>
			<td>Notebook receiver of the fNIRS signals</td>
		</tr>
		<tr>
			<td>R platform for statistical computing&#160;</td>
			<td>https://www.r-project.org&#160;</td>
			<td>R version 4.2.0</td>
			<td>R is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS</td>
		</tr>
		<tr>
			<td>REDCap</td>
			<td>REDCap is supported in part by the National Institutes of Health (NIH/NCATS UL1 TR000445)</td>
			<td></td>
			<td>REDCap is a secure web application for building and managing online surveys and databases.</td>
		</tr>
		<tr>
			<td>software Mangold Interact</td>
			<td>Mangold International GmbH, Ed.&#160;</td>
			<td>interact 5.0</td>
			<td>Mangold:&#160;https://www.mangold-international.com/en/products/software/behavior-research-with-mangold-interact.html. Allows analysis of videos for behavioral outcomes and of autonomic monitoring for emotionally driven physiological changes (may require additional software, such as DataView). Allow the use of different camera types simultaneously and hundreds of variations of coding methods.</td>
		</tr>
		<tr>
			<td>software NIRSite</td>
			<td>NIRx Medizintechnik GmbH, Germany</td>
			<td>NIRSite 2.0</td>
			<td>For creating the montage and help optode placement and location in the blackcaps.</td>
		</tr>
		<tr>
			<td>software nirsLAB-2014</td>
			<td>NIRx Medizintechnik GmbH, Germany</td>
			<td>nirsLAB 2014</td>
			<td>fNIRS Data Processing</td>
		</tr>
		<tr>
			<td>software NIRStar</td>
			<td>NIRx Medizintechnik GmbH, Germany</td>
			<td>version 15.2</td>
			<td>&#160;for fNIRS data aquisition: NIRStar software version 15.2&#160; at a sampling rate of 3.472222</td>
		</tr>
		<tr>
			<td>software NIRStim</td>
			<td>NIRx Medizintechnik GmbH, Germany</td>
			<td></td>
			<td>&#160;For creation and organization of paradigm blocks</td>
		</tr>
	</tbody>
</table>

group synchronization during collaborative drawing using functional near-infrared spectroscopy

Functional near-infrared spectroscopy (fNIRS) is a noninvasive method particularly suitable for measuring cerebral cortex activation in multiple subjects, which is relevant for studying group interpersonal interactions in ecological settings. Although many fNIRS systems technically offer the possibility to monitor more than two individuals simultaneously, establishing easy-to-implement setup procedures and reliable paradigms to track hemodynamic and behavioral responses in group interaction is still required. The present protocol combines fNIRS and video-based observation to measure interpersonal synchronization in quartets during a cooperative task.This protocol provides practical recommendations for data acquisition and paradigm design, as well as guiding principles for an illustrative data analysis example. The procedure is designed to assess differences in brain and behavior interpersonal responses between social and non-social conditions inspired by a well-known ice-breaker activity, the Collaborative Face Drawing Task. The described procedures can guide future studies to adapt group naturalistic social interaction activities to the fNIRS environment.

The protocol was applied to a quartet composed of young women (24-27 years old), all of them students on postgraduate programs (Hospital Israelita Albert Einstein, S&#227;o Paulo, Brasil), with master&#39;s or doctorate level education. All participants were right-handed, and only one reported having previous drawing experience. No participants had a reported history of neurological disorders.
For the scales and psychological test results, two participants (2 and 4) showed high scores for anxi...

Watch this Scientific Journal Video about Group Synchronization During Collaborative Drawing Using Functional Near-Infrared Spectroscopy at JoVE.com

Group Synchronization During Collaborative Drawing Using Functional Near-Infrared Spectroscopy

The present protocol combines functional near-infrared spectroscopy (fNIRS) and video-based observationto measure interpersonal synchronization in quartets during a collaborative drawing task.

Functional near-infrared spectroscopy (fNIRS) is a noninvasive method particularly suitable for measuring cerebral cortex activation in multiple subjects, ...

This innovative protocol is relevant for the study of group interpersonal interactions in ecological settings. It is designed to access differences in brain and behavior interpersonal responses in quartets during different drawing tasks. This protocol offers easy to implement procedures and a reliable paradigm using fNIRS to simultaneously measure the hemodynamic responses of a group of four individuals interacting.To prepare for the study, remove all potential eye distractors from the scene. Turn off all electrical devices such as air conditioning during the experimental condition. Ensure that the room has sufficient lighting for people to observe and draw.Upon setting up, position all fNIRS wires such that they remain stable during the experimental task. Position the quartet on the table two by two so that each individual can observe the other three individuals. To perform the drawing paradigm, which is the social condition, have participants draw the forehead and eye area on the top strip of all the paper sheets.Have each paper represent a fully drawn portrait of a participant. Also have the face of each participant depicted in a collaborative way by their partners. For the connect the dots game, which is the non-social condition, ask the participants to connect the numbers in an ascendant way.Select a commercially available 360 degree scene camera and position it on the table so that the eye and head movements of all the participants can be perceived simultaneously. Check for possible interferences on fNIRS reception. Before fNIRS calibration, start the equipment, check the interface, and set the recording mode.For data analysis, select a synchronized view or analysis platform that allows the transcription and coding of several video contents simultaneously such as the INTERACT software. To refine observational data, set parameters that enable the search for patterns or sequences such as individual gaze behavior metrics, head and eye movement, hand movement, facial expressions, and talking behavior. After analysis, start by downloading the video from all cameras in MP4 format and load them into INTERACT.Segment the video data for coding and further analysis. For data extraction, mark the video sections manually and provide them with codes. Click on Define Codes to create the first tier by dividing the block sections into social and non-social conditions and resting periods.Then create a second tier by dividing the behavioral data from the participants along with social conditions. Observe details and determine drawing metrics by counting the details drawn during the experiment. Use the NIRSite tool to locate the optodes over the PFC regions.Configure the distribution of optodes on the caps such that the channels are positioned above the regions of interest on the head of the participant. Divide the optodes among four participants for the simultaneous acquisition of signals. Before setting the fNIRS apparatus, measure the brain perimeters of the four participants like the distances between the nasion and the inion around the head to determine the cap size of each participant.Then fit the sources and detectors to the cap according to the predetermined settings. Put the caps on the head of the participant and position the cap so that the central midline is at the top of the head. Further ensure that the cap is positioned correctly by measuring the distance between the left and right ear above the top of the head and positioning the central midline at the middle of the measure.Then connect the wires of the optodes to the amplifiers and connect both NIRSport 1 and 2 to the computer. After setting up the equipment, enabled the software to acquire the fNIRS data. Click on Configure Hardware on the menu bar.Select the option Tandem Mode on the hardware specification tab to perform the hyper scanning. On the configure hardware tab, select a montage and check the settings in channel masking, topo layout, and channel setup. Perform an automatic calibration by clicking Calibrate on the display panel.When ready to start the procedure, click on Preview to have a preview of how the signals are being received. Then start recording the signals by clicking on Record. Open the blocks programming software NIRStim and start the presentation of the programmed blocks by clicking on Run.NIRStim will close at the end of the experiment. Stop recording in NIRStar. Close the software and verify the file is saved correctly.This method was applied to a quartet composed of women postgraduate students aged 24 to 27 years. The fNIRS preliminary results showed typical brain activation for participants one, two, and three in both the social and non-social drawing conditions. This was observed in both channels located in the left and right hemispheres, although the activation patterns were distinct.On the other hand, participant four showed atypical brain activation. The oxyhemoglobin signal was significantly synchronized between subjects only during the last part of the task both in the connecting the dots condition and in the collaborative drawing condition. This method can provide insights into neuroscience, art, art therapy, and social interaction research areas in general.

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Neuroscience

Using MazeSuite and Functional Near Infrared Spectroscopy to Study Learning in Spatial Navigation

MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments1. MazeSuite can be used to design and edit adapted virtual 3D environments, track a participants' behavioral performance within the virtual environment and synchronize with external devices for physiological and neuroimaging measures, including electroencephalogram and eye tracking.
Functional near-infrared spectroscopy (fNIR) is an optical brain imaging technique that enables continuous, noninvasive, and portable monitoring of changes in cerebral blood oxygenation related to human brain functions2-7. Over the last decade fNIR is used to effectively monitor cognitive tasks such as attention, working memory and problem solving7-11. fNIR can be implemented in the form of a wearable and minimally intrusive device; it has the capacity to monitor brain activity in ecologically valid environments. 
Cognitive functions assessed through task performance involve patterns of brain activation of the prefrontal cortex (PFC) that vary from the initial novel task performance, after practice and during retention12. Using positron emission tomography (PET), Van Horn and colleagues found that regional cerebral blood flow was activated in the right frontal lobe during the encoding (i.e., initial na&iuml;ve performance) of spatial navigation of virtual mazes while there was little to no activation of the frontal regions after practice and during retention tests. Furthermore, the effects of contextual interference, a learning phenomenon related to organization of practice, are evident when individuals acquire multiple tasks under different practice schedules13,14. High contextual interference (random practice schedule) is created when the tasks to be learned are presented in a non-sequential, unpredictable order. Low contextual interference (blocked practice schedule) is created when the tasks to be learned are presented in a predictable order.
Our goal here is twofold: first to illustrate the experimental protocol design process and the use of MazeSuite, and second, to demonstrate the setup and deployment of the fNIR brain activity monitoring system using Cognitive Optical Brain Imaging (COBI) Studio software15. To illustrate our goals, a subsample from a study is reported to show the use of both MazeSuite and COBI Studio in a single experiment. The study involves the assessment of cognitive activity of the PFC during the acquisition and learning of computer maze tasks for blocked and random orders. Two right-handed adults (one male, one female) performed 315 acquisition, 30 retention and 20 transfer trials across four days. Design, implementation, data acquisition and analysis phases of the study were explained with the intention to provide a guideline for future studies.

MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments. Functional near-infrared spectroscopy (fNIR) is an optical brain imaging technique that enables noninvasive and portable monitoring of cerebral blood oxygenation changes. This paper summarizes collective use of MazeSuite and fNIR within a cognitive processing learning paradigm.

MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments1. MazeSuite can be used to design and edit adapted ...

Neuroimaging Field Methods Using Functional Near Infrared Spectroscopy (NIRS) Neuroimaging to Study Global Child Development: Rural Sub-Saharan Africa

Portable neuroimaging approaches provide new advances to the study of brain function and brain development with previously inaccessible populations and in remote locations. This paper shows the development of field functional Near Infrared Spectroscopy (fNIRS) imaging to the study of child language, reading, and cognitive development in a rural village setting of C&#244;te d&#39;Ivoire. Innovation in methods and the development of culturally appropriate neuroimaging protocols allow&#160;a first-time look into the brain&#39;s development and children&#39;s learning outcomes in understudied environments. This paper demonstrates protocols for transporting and setting up a mobile laboratory, discusses considerations for field versus laboratory neuroimaging, and presents a guide for developing neuroimaging consent procedures and building meaningful long-term collaborations with local government and science partners. Portable neuroimaging methods can be used to study complex child development contexts, including the impact of significant poverty and adversity on brain development. The protocol presented here has been developed for use in C&#244;te d&#39;Ivoire, the world&#39;s primary source of cocoa, and where reports of child labor in the cocoa sector are common. Yet, little is known about the impact of child labor on brain development and learning. Field neuroimaging methods have the potential to yield new insights into such urgent issues, and the development of children globally.

Neuroimaging Field Methods Using Functional Near Infrared Spectroscopy NIRS Neuroimaging to Study Global Child Development: Rural Sub-Saharan Africa

Portable neuroimaging approaches (functional Near Infrared Spectroscopy) provide advances to the study of the brain in previously inaccessible regions; here, rural C&#244;te d&#39;Ivoire. Innovation in methods and development of culturally-appropriate neuroimaging protocols permits novel study of the brain&#39;s development and children&#39;s learning outcomes in environments with significant poverty and adversity.

Portable neuroimaging approaches provide new advances to the study of brain function and brain development with previously inaccessible populations and in ...

Conducting Hyperscanning Experiments with Functional Near-Infrared Spectroscopy

Concurrent brain recordings of two or more interacting persons, an approach termed hyperscanning, are gaining increasing importance for our understanding of the neurobiological underpinnings of social interactions, and possibly interpersonal relationships. Functional near-infrared spectroscopy (fNIRS) is well suited for conducting hyperscanning experiments because it measures local hemodynamic effects with a high sampling rate and, importantly, it can be applied in natural settings, not requiring strict motion restrictions. In this article, we present a protocol for conducting fNIRS hyperscanning experiments with parent-child dyads and for analyzing brain-to-brain synchrony. Furthermore, we discuss critical issues and future directions, regarding the experimental design, spatial registration of the fNIRS channels, physiological influences and data analysis methods. The described protocol is not specific to parent-child dyads, but can be applied to a variety of different dyadic constellations, such as adult strangers, romantic partners or siblings. To conclude, fNIRS hyperscanning has the potential to yield new insights into the dynamics of the ongoing social interaction, which possibly go beyond what can be studied by examining the activities of individual brains.

The present protocol describes how to conduct fNIRS hyperscanning experiments and analyze brain-to-brain synchrony. Further, we discuss challenges and possible solutions.

Concurrent brain recordings of two or more interacting persons, an approach termed hyperscanning, are gaining increasing importance for our understanding ...

Functional Magnetic Resonance Spectroscopy at 7 T in the Rat Barrel Cortex During Whisker Activation

Nuclear magnetic resonance (NMR) spectroscopy offers the opportunity to measure cerebral metabolite contents in vivo and noninvasively. Thanks to technological developments over the last decade and the increase in magnetic field strength, it is now possible to obtain good resolution spectra in vivo in the rat brain. Neuroenergetics (i.e., the study of brain metabolism) and, especially, metabolic interactions between the different cell types have attracted more and more interest in recent years. Among these metabolic interactions, the existence of a lactate shuttle between neurons and astrocytes is still debated. It is, thus, of great interest to perform functional proton magnetic resonance spectroscopy (1H-MRS) in a rat model of brain activation and monitor lactate. However, the methyl lactate peak overlaps lipid resonance peaks and is difficult to quantify. The protocol described below allows metabolic and lactate fluctuations to be monitored in an activated brain area. Cerebral activation is obtained by whisker stimulation and 1H-MRS is performed in the corresponding activated barrel cortex, whose area is detected using blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI). All steps are fully described: the choice of anesthetics, coils, and sequences, achieving efficient whisker stimulation directly in the magnet, and data processing.

After checking by blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI) that the corresponding somatosensory barrel field cortex area (called S1BF) is correctly activated, the main goal of this study is to quantify lactate content fluctuations in the activated rat brains by localized proton magnetic resonance spectroscopy (1H-MRS) at 7 T.

Nuclear magnetic resonance (NMR) spectroscopy offers the opportunity to measure cerebral metabolite contents in vivo and noninvasively. Thanks to ...

Using Near-infrared Fluorescence and High-resolution Scanning to Measure Protein Expression in the Rodent Brain

Neuroscience is the study of how cells in the brain mediate various functions. Measuring protein expression in neurons and glia is critical for the study of neuroscience as cellular function is determined by the composition and activity of cellular proteins. In this article, we describe how immunocytochemistry can be combined with near-infrared high-resolution scanning to provide a semi-quantitative measure of protein expression in distinct brain regions. This technique can be used for single or double protein expression in the same brain region. Measuring proteins in this fashion can be used to obtain a relative change in protein expression with an experimental manipulation, molecular signature of learning and memory, activity in molecular pathways, and neural activity in multiple brain regions. Using the correct proteins and statistical analysis, functional connectivity among brain regions can be determined as well. Given the ease of implementing immunocytochemistry in a laboratory, using immunocytochemistry with near-infrared high-resolution scanning can expand the ability of the neuroscientist to examine neurobiological processes at a systems level.

Here, we present a protocol that uses near-infrared dyes in conjunction with immunohistochemistry and high-resolution scanning to assay proteins in brain regions.

Neuroscience is the study of how cells in the brain mediate various functions. Measuring protein expression in neurons and glia is critical for the study ...

Presynapse Formation Assay Using Presynapse Organizer Beads and &ldquo;Neuron Ball&rdquo; Culture

During neuronal development, synapse formation is an important step to establish neural circuits. To form synapses, synaptic proteins must be supplied in appropriate order by transport from cell bodies and/or local translation in immature synapses. However, it is not fully understood how synaptic proteins accumulate in synapses in proper order. Here, we present a novel method to analyze presynaptic formation by using the combination of neuron ball culture with beads to induce presynapse formation. Neuron balls that is neuronal cell aggregates provide axonal sheets far from cell bodies and dendrites, so that weak fluorescent signals of presynapses can be detected by avoiding overwhelming signals of cell bodies. As beads to trigger presynapse formation, we use beads conjugated with leucine-rich repeat transmembrane neuronal 2 (LRRTM2), an excitatory presynaptic organizer. Using this method, we demonstrated that vesicular glutamate transporter 1 (vGlut1), a synaptic vesicle protein, accumulated in presynapses faster than Munc18-1, an active zone protein. Munc18-1 accumulated translation-dependently in presynapse even after removing cell bodies. This finding indicates the Munc18-1 accumulation by local translation in axons, not transport from cell bodies. In conclusion, this method is suitable to analyze accumulation of synaptic proteins in presynapses and source of synaptic proteins. As neuron ball culture is simple and it is not necessary to use special apparatus, this method could be applicable to other experimental platforms.

Presynapse Formation Assay Using Presynapse Organizer Beads and &amp;ldquo;Neuron Ball&amp;rdquo; Culture

Presynapse formation is a dynamic process including accumulation of synaptic proteins in proper order. In this method, presynapse formation is triggered by beads conjugated with a presynapse organizer protein on axonal sheets of &#8220;neuron ball&#8221; culture, so that accumulation of synaptic proteins is easy to be analyzed during presynapse formation.

During neuronal development, synapse formation is an important step to establish neural circuits. To form synapses, synaptic proteins must be supplied in ...

Stimulation Location Determination using a 3D Digitizer with High-Definition Transcranial Direct Current Stimulation

The abundance of neuroimaging data and rapid development of machine learning has made it possible to investigate brain activation patterns. However, causal evidence of brain area activation leading to a behavior is often left missing. Transcranial direct current stimulation (tDCS), which can temporarily alter brain cortical excitability and activity, is a noninvasive neurophysiological tool used to study causal relationships in the human brain. High-definition transcranial direct current stimulation (HD-tDCS) is a noninvasive brain stimulation (NIBS) technique that produces a more focal current compared to conventional tDCS. Traditionally, the stimulation location has been roughly determined through the 10-20 EEG system, because determining precise stimulation points can be difficult. This protocol uses a 3D digitizer with HD-tDCS to increase accuracy in determination of stimulation points. The method is demonstrated using a 3D digitizer for more accurate localization of stimulation points in the right temporo-parietal junction (rTPJ).

Presented here is a protocol to achieve higher accuracy in determination of stimulation location combining a 3D digitizer with high-definition transcranial direct current stimulation.

The abundance of neuroimaging data and rapid development of machine learning has made it possible to investigate brain activation patterns. However, ...

Conducting Concurrent Electroencephalography and Functional Near-Infrared Spectroscopy Recordings with a Flanker Task

Concurrent EEG and fNIRS recordings offer an excellent opportunity to gain a full understanding of the neural mechanism of cognitive processing by inspecting the relationship between the neural and hemodynamic signals. EEG is an electrophysiological technology that can measure the rapid neuronal activity of the cortex, whereas fNIRS relies on the hemodynamic responses to infer brain activation. The combination of EEG and fNIRS neuroimaging techniques can identify more features and reveal more information associated with the functioning of the brain. In this protocol, fused EEG-fNIRS measurements were performed for concurrent recordings of evoked-electrical potentials and hemodynamic responses during a Flanker task. In addition, the critical steps for setting up the hardware and software system as well as the procedures for data acquisition and analysis were provided and discussed in detail. It is expected that the present protocol can pave a new avenue for improving the understanding of the neural mechanisms underlying various cognitive processes by using the EEG and fNIRS signals.

The present protocol describes how to perform concurrent EEG and fNIRS recordings and how to inspect the relationship between the EEG and fNIRS data.&#160;

Concurrent EEG and fNIRS recordings offer an excellent opportunity to gain a full understanding of the neural mechanism of cognitive processing by ...

Morphological and Functional Evaluation of Axons and their Synapses during Axon Death in Drosophila melanogaster

Axon degeneration is a shared feature in neurodegenerative disease and when nervous systems are challenged by mechanical or chemical forces. However, our understanding of the molecular mechanisms underlying axon degeneration remains limited. Injury-induced axon degeneration serves as a simple model to study how severed axons execute their own disassembly (axon death). Over recent years, an evolutionarily conserved axon death signaling cascade has been identified from flies to mammals, which is required for the separated axon to degenerate after injury. Conversely, attenuated axon death signaling results in morphological and functional preservation of severed axons and their synapses. Here, we present three simple and recently developed protocols that allow for the observation of axonal morphology, or axonal and synaptic function of severed axons that have been cut-off from the neuronal cell body, in the fruit fly Drosophila. Morphology can be observed in the wing, where a partial injury results in axon death side-by-side of uninjured control axons within the same nerve bundle. Alternatively, axonal morphology can also be observed in the brain, where the whole nerve bundle undergoes axon death triggered by antennal ablation. Functional preservation of severed axons and their synapses can be assessed by a simple optogenetic approach coupled with a post-synaptic grooming behavior. We present examples using a highwire loss-of-function mutation and by over-expressing dnmnat, both capable of delaying axon death for weeks to months. Importantly, these protocols can be used beyond injury; they facilitate the characterization of neuronal maintenance factors, axonal transport, and axonal mitochondria.

Morphological and Functional Evaluation of Axons and their Synapses during Axon Death in Drosophila melanogaster

Here, we provide protocols to perform three simple injury-induced axon degeneration (axon death) assays in Drosophila melanogaster to evaluate the morphological and functional preservation of severed axons and their synapses.

Axon degeneration is a shared feature in neurodegenerative disease and when nervous systems are challenged by mechanical or chemical forces. However, our ...

Qualitative and Comparative Cortical Activity Data Analyses from a Functional Near-Infrared Spectroscopy Experiment Applying Block Design

Neuroimaging studies play a pivotal role in the evaluation of pre- vs. post-interventional neurological conditions such as in rehabilitation and surgical treatment. Among the many neuroimaging technologies used to measure brain activity, functional near-infrared spectroscopy (fNIRS) enables the evaluation of dynamic cortical activities by measuring the local hemoglobin levels similar to functional magnetic resonance imaging (fMRI). Also, due to lesser physical restriction in fNIRS, multiple variants of sensorimotor tasks can be evaluated. Many laboratories have developed several methods for fNIRS data analysis; however, despite the fact that the general principles are the same, there is no universally standardized method. Here, we present the qualitative and comparative analytic methods of data obtained from a multi-channel fNIRS experiment using a block design. For qualitative analysis, we used a software for NIRS as a mass-univariate approach based on the generalized linear model. The NIRS-SPM analysis shows qualitative results for each session by visualizing the activated area during the task. In addition, the non-invasive three-dimensional digitizer can be used to estimate the fNIRS channel locations relative to the brain. To corroborate the NIRS-SPM findings, the amplitude of the changes in hemoglobin levels induced by the sensorimotor task can be statistically analyzed by comparing the data obtained from two different sessions (before and after intervention) of the same study subject using a multi-channel hierarchical mixed model. Our methods can be used to measure the pre- vs. post-intervention analysis in a variety of neurological disorders such as movement disorders, cerebrovascular diseases, and neuropsychiatric disorders.

We describe the analysis of continuous-wave functional near-infrared spectroscopy experiment using a block design with a sensorimotor task. To increase the reliability of the data analysis, we used the qualitative general linear model-based statistical parametric mapping and the comparative hierarchical mixed models for multi-channels.

Neuroimaging studies play a pivotal role in the evaluation of pre- vs. post-interventional neurological conditions such as in rehabilitation and surgical ...