Name: recording horizontal saccade performances accurately in neurological patients using electro-oculogram
Uploaded: 2018-03-13T12:30:00
Description: Watch this Scientific Journal Video about Recording Horizontal Saccade Performances Accurately in Neurological Patients Using Electro-oculogram at JoVE.com

Dr. Terao was supported by a Research Project Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan [16K09709,16H01497]. YU was supported by a Research Project Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan [No.25293206, No. 22390181, 15H05881, 16H05322]; by grants from the Research Committee on the Best rTMS Treatment of Parkinson's Disease From the Ministry of Health and Welfare of Japan; and by the Research Committee on Dystonia of the Ministry of Health and Welfare of Japan.

All experimental procedures in this study were approved and conducted according to the guidelines of the institution&#39;s human research ethics committee after obtaining informed consent.
1. Prepare the Subject and the Room for Recoding
<ol>
	<li>Perform recording in a room with low ambient illumination, to allow sufficient light adaptation.</li>
	<li>Have subjects sit in front of a black, concave dome-shaped screen measuring 90-cm in diameter that contains light-emitting diodes (LEDs) embe...

<ol>
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N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scleral+search+coils+influence+saccade+dynamics.">Scleral search coils influence saccade dynamics.</a> J Neurophysiol. 88 (2), 692-698 (2002).</li><li>Lappe-Osthege, M., Talamo, S., Helmchen, C., Sprenger, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Overestimation+of+saccadic+peak+velocity+recorded+by+electro-oculography+compared+to+video-oculography+and+scleral+search+coil.">Overestimation of saccadic peak velocity recorded by electro-oculography compared to video-oculography and scleral search coil.</a> Clin Neurophysiol. 121 (10), 1786-1787 (2010).</li><li>Bhidayasiri, R., Riley, D. E., Somers, J. T., Lerner, A. J., B&#252;ttner-Ennever, J. A., Leigh, R. 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-A saccade study on pathophysiology.</a> Clin Neurophysiol. 127 (2), 1491-1502 (2016).</li><li>Terao, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinguishing+spinocerebellar+ataxia+with+pure+cerebellar+manifestation+from+multiple+system+atrophy+(MSA-C)+through+saccade+profiles.">Distinguishing spinocerebellar ataxia with pure cerebellar manifestation from multiple system atrophy (MSA-C) through saccade profiles.</a> Clin Neurophysiol. 128 (1), 31-43 (2016).</li><li>Kato, M., Hikosaka, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Saccade+related+responses+of+external+pallidal+neurons+in+monkey.">Saccade related responses of external pallidal neurons in monkey.</a> Neurosci Res. , 218 (1992).</li><li>Hikosaka, O., Fukuda, H., Kato, M., Uetake, K., Nomura, Y., Segawa, M., Segawa, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deficits+in+saccadic+eye+movements+in+hereditary+progressive+dystonia+with+marked+diurnal+fluctuation.">Deficits in saccadic eye movements in hereditary progressive dystonia with marked diurnal fluctuation.</a> Hereditary Progressive Dystonia With Marked Diurnal Fluctuation. , 159-177 (1993).</li><li>Fukuda, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+saccade+recording+system+in+humans:+simultaneous+measurment+of+electro-oculography+and+video-oculography.">Development of saccade recording system in humans: simultaneous measurment of electro-oculography and video-oculography.</a> 38th Annual Meeting of Japanese Society of Clinical Neurophysiology. , (2008).</li><li>Constable, P. A., Bach, M., Frishman, L. J., Jeffrey, B. G., Robson, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=International+Society+for+Clinical+Electrophysiology+of+Vision.+ISCEV+Standard+for+clinical+electro-oculography+(2017+update).">International Society for Clinical Electrophysiology of Vision. ISCEV Standard for clinical electro-oculography (2017 update).</a> Doc Ophthalmol. 134 (1), 134 (2017).</li><li>Behrens, F., Weiss, L. 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Although nowadays, the prevailing method for recording saccades has become the VOG, the present study showed that EOG can achieve an accuracy almost comparable to that of VOG if properly implemented (Figure 2). The present EOG method has been shown to achieve a good correlation with VOG when recording horizontal saccades and has been successfully used in many previous studies by the same group12,13,14</su...

There are three major ways to record eye movements, the conventional EOG, the VOG recorded by the video-based eye tracking system, and the scleral search coil (SSC) method. Among them, EOG has been frequently used for recording eye movements in patients since the 1970s because of its simplicity. Widely applicable to the clinical population, this method has been extensively utilized for the diagnosis of neurological patients and has provided useful information about the pathophysiology underlying the disorders1,2,3,4,5. In addition, it is still the only technique that can be feasibly used for recording eye movements during sleep (rapid eye movement during REM sleep and other forms of eye movements).
Since the eyeball is positively charged in its anterior aspect including the cornea relative to its posterior aspect, there is a voltage difference between the anterior and posterior aspects of the eyes termed the corneo-retinal potential. Due to the presence of this potential, the right electrode will become more positive than the left when the subjects turns their gaze toward the right, and become negative when they turn their gaze to the left. Since the voltage difference between the left and right electrodes correlates significantly with the rotation angle of the eyeballs for horizontal saccades, it can be used to measure horizontal eye movements. However, this correlation does not hold for the vertical direction, although vertical EOG still can be used to measure eye movements6. On the other hand, some studies mainly use vertical EOG for monitoring blinks.
Recently, however, VOG has largely taken the place of EOG due to its higher spatial accuracy reaching up to 0.25 - 0.5 degrees, and has now become the standard method for saccade recording in the clinical setting. Meanwhile, EOG has come to be considered rather outdated, since its spatial accuracy, at most 0.5 degrees, is inferior to that of VOG.
However, VOG also has its own drawbacks if used in the clinical setting. There are cases in which VOG is not feasible; for example, eye tracking becomes inaccurate in subjects with a narrow eye cleft such as when the greater area of the cornea is occluded by the eyelids. In patients with cataract lenses, aberrant reflection of the infrared light hampers reliable recording of the gaze direction. Furthermore, EOG can offer advantages for some people for whom their movement disorder makes VOG recording difficult. In addition, the VOG system is more expensive compared to the setup of EOG, which often makes the former unavailable in ordinary medical facilities.
On the other hand, the SSC method is regarded as the gold standard for measuring eye movements. Compared with VOG and EOG, this method provides the highest spatial accuracy, down to 0.1 degrees, and is especially useful when the recording involves high-frequency head motion6. However, this method is potentially invasive, i.e., painful and very irritating to the eyes, and allows recording for only a brief period, approximately under 30 min or shorter7,8,9,10. This short duration makes it a method unsuitable for extensive clinical application, although it has been used successfully in some specialized facilities11.
Based on previous studies recording more than 250 neurological patients and 480 normal subjects by the same group12,13,14,15,16,17,18,19, the present study shows that EOG can be accurate enough to serve as a standard technique of eye movement recording, and widely applicable to the clinical population, while circumventing various drawbacks of VOG and SSC. The present article describes a stable EOG recording method, using an electrode with a wide fringe to allow wide and stable contact with the skin, similar to that of an EEG electrode attached securely on the scalp by collodion for recording a long time period. The impedance of the electrode goes down and the recording becomes stable with time, thereby effectively reducing the artifacts from facial muscles and electroencephalography. This method is compared with simultaneously recorded VOG. When properly prepared and implemented, EOG is as good as VOG in terms of accuracy for recording saccades in neurological patients, and EOG may even be more amenable to saccade recording in normal subjects.

<table border="0" cellpadding="0" cellspacing="0" style="width:927px;" width="926">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:297px;">Electrode</td>
			<td style="width:276px;">Nihon-Kohden (Tokyo, Japan)</td>
			<td style="width:119px;">NS111-115</td>
			<td style="width:235px;">cup electrode</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:297px;">Electrode paste</td>
			<td style="width:276px;">Nihon-Kohden (Tokyo, Japan)</td>
			<td style="width:119px;">Gelaid Z-101BA</td>
			<td>gel electrode paste to fill in the cup electrode</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:297px;">Adhesive tape&#160;</td>
			<td style="width:276px;">Nihon-Kohden (Tokyo, Japan)</td>
			<td style="width:119px;">H261</td>
			<td>double-stick tape for fixating the electrode</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:297px;">DC-amplifier</td>
			<td style="width:276px;">Nihon-Kohden (Tokyo, Japan)</td>
			<td style="width:119px;">AN-601G</td>
			<td>amplifier for EOG</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">video-based eye tracking system</td>
			<td style="width:276px;">SR research (Mississauga, Ontario, Canada)</td>
			<td style="width:119px;">Eyelink II</td>
			<td>eye tracking system for recording VOG</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:297px;">Filter</td>
			<td style="width:276px;">NF corporation</td>
			<td style="width:119px;">MS-521</td>
			<td>filter for the EOG signal</td>
		</tr>
	</tbody>
</table>

recording horizontal saccade performances accurately in neurological patients using electro-oculogram

Electro-oculogram (EOG) has been widely used for clinical eye movement recording, especially horizontal saccades, although the video-oculography (VOG) has largely taken the place of it nowadays due to its higher spatial accuracy. However, there are situations in which EOG has clear advantages over VOG, e.g., subjects with narrow eye clefts or having cataract lenses, and patients with movement disorders. The present article shows that if properly implemented, EOG can achieve an accuracy almost as good as VOG with substantial stability for recording, while circumventing problems associated with VOG recording. The present paper describes a practical method for recording horizontal saccades using oculomotor paradigms with high accuracy and stability by EOG in neurological patients. The necessary measures are to use an Ag-AgCl electrode with a wide plastic fringe capable of reducing noise, and to wait for sufficient light adaptation to occur. This waiting period also helps to lower the impedance between the electrodes and the skin, thereby ensuring stable signal recorded as time goes by. Furthermore, re-calibration is performed as needed during the task performance. Using this method, the experimenter can avoid drifts of signals, as well as contamination of artifacts or noise from the electromyogram and electroencephalogram, and can collect sufficient data for clinical evaluation of saccades. Thus when implemented, EOG can still be a method of high practicability that can be widely applied to neurological patients, but may be effective also for studies in normal subjects.

Figure 2&#160;shows representative simultaneous records of EOG and VOG in a normal subject. 8 trials of VGS are superimposed for EOG (gray curves) and VOG (red curves; Figure 2A). Calibrated by the present method, EOG and VOG data are known to be linear over a range of 5-30 degrees, and the spatial accuracy of the data is 0.5 degrees.
The records obtain...

Watch this Scientific Journal Video about Recording Horizontal Saccade Performances Accurately in Neurological Patients Using Electro-oculogram at JoVE.com

Recording Horizontal Saccade Performances Accurately in Neurological Patients Using Electro-oculogram

The article describes a practical method for recording horizontal eye movements with high accuracy by electro-oculogram in neurological patients, using a cup Ag-AgCl electrode with a wide plastic fringe. Stable measurement requires proper selection and fixation of electrodes, taking sufficient time for light adaptation to occur, and re-calibration as needed.

Electro-oculogram (EOG) has been widely used for clinical eye movement recording, especially horizontal saccades, although the video-oculography (VOG) has ...

The overall goal of the present oculogram is to observe the abnormality of saccade performance in patients especially in those with neurological disorders and to look at the pathophysiology underlying the disorder providing useful information about the diagnosis. This method can help answer key questions in the field such as diagnosis of patients with neurological disorders and to elucidate the pathophysiology underlying the disease. The main advantage of this technique is that it allows stable recording of eye movements noninvasively in a relatively short time and is widely applicable to neurological patients.Demonstrating the procedure will be Dr.Hideki Fukuda, an oculomotor researcher at Segawa Neurologic Clinic for Children and Dr.Yuseke Sugiyama, a graduate student from the Department of Neurology, the University of Tokyo. Begin by escorting the subject into a room with low ambient illumination. Have the subject sit in front of a black concave dome-shaped screen measuring 90 centimeters in diameter that contains Light-Emitting Diodes, LEDs, embedded in pinholes which serve as the fixation points and saccade targets used for the oculomotor paradigms.Then provide the subject with a micro switch button connected to a microcomputer which allows them to initiate and terminate the test trial by pressing and releasing the button. Stabilize the subject's head position by chin and forehead rests as well as by a headband. Next, acquire a silver/sulfur chloride cup electrode for recording the Electrooculogram or EOG.Wipe the skin with an alcohol swab. Then fill the cup with electrode paste. Stably fixate the electrode on the skin by placing double stick adhesive tape beneath the plastic and attach the fringe to the skin.For recording horizontal saccades by EOG, place the electrodes at the bilateral canthi of the eyes. Whereas for recording vertical saccades, place the electrodes above and below one eye. Finally, wait 10 to 20 minutes after placing the EOG electrode on the skin until sufficient light adaptation takes place.Begin by using a Direct Current, DC, amplifier for recording the EOG with the signal digitized at 500 hertz. Record Video Oculography, VOG, simultaneously using the video-based eye tracking system which records ocular fixation position data at a sampling rate of 500 to 1, 000 hertz. Then feed the analog output of the horizontal and vertical eye positions and set the filter of the data acquisition system with the signal low-pass filter at 20 hertz.Perform eye movement calibration before each test session by having the subject look at five pre-specified locations such that they view visual targets in the center and those that appear 20 degrees to the left, right, upwards and downwards of the fixation point both for EOG and VOG. Then adjust the gain of EOG as the subject fixates on these spots so that using the custom-built data acquisition system for monitoring the current eye position displayed on the computer screen matches the target position displayed on the screen. Next, instruct the subject about the oculomotor paradigms.Then have the subject press the button and begin the trials. During the session, adjust the gain of EOG during the task performance so that the current eye position displayed on the monitor is always aligned with the target positions simultaneously displayed on the same screen. After the experiment is complete, analyze the filtered and digitized EOG signals from the DC amplifier and VOG by a custom-built computer program and show the EOG and VOG signals together in the same trace in order to compare the performances of the two methodologies.The records obtained by the two methods largely overlap with each other except that the EOG traces are slightly displaced towards the right compared to the VOG traces. These results show a comparison of EOG and VOG traces in the visually-guided saccade task. There is again substantial overlap between the traces for EOG and VOG, but the latency is slightly longer for EOG and the velocity curve of EOG shows a slightly lower peak velocity than that of VOG.Once mastered, this technique can be done in 30 minutes including preparation if it is performed properly. While attempting this procedure, it is important to remember to select proper electrodes and stably attach them as well as to take sufficient time for light adaptation to occur. Following this procedure, other methods like eye movement recording while the eyes are closed can be performed in order to answer additional questions like how the eyes move during sleep.After its development, this technique paved the way for researchers in the field of neurology and psychiatry to explore the pathophysiology of neurological disorders in the clinical setting. After watching this video, you should have a good understanding of how to implement stable recording of electrooculography which can be reliably used in the clinical setting.

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Research

JoVE Journal

Behavior

How to Detect Amygdala Activity with Magnetoencephalography using Source Imaging

In trace fear conditioning a conditional stimulus (CS) predicts the occurrence of the unconditional stimulus (UCS), which is presented after a brief stimulus free period (trace interval)1. Because the CS and UCS do not co-occur temporally, the subject must maintain a representation of that CS during the trace interval. In humans, this type of learning requires awareness of the stimulus contingencies in order to bridge the trace interval2-4. However when a face is used as a CS, subjects can implicitly learn to fear the face even in the absence of explicit awareness*. This suggests that there may be additional neural mechanisms capable of maintaining certain types of "biologically-relevant" stimuli during a brief trace interval. Given that the amygdala is involved in trace conditioning, and is sensitive to faces, it is possible that this structure can maintain a representation of a face CS during a brief trace interval.
It is challenging to understand how the brain can associate an unperceived face with an aversive outcome, even though the two stimuli are separated in time. Furthermore investigations of this phenomenon are made difficult by two specific challenges. First, it is difficult to manipulate the subject's awareness of the visual stimuli. One common way to manipulate visual awareness is to use backward masking. In backward masking, a target stimulus is briefly presented (&lt; 30 msec) and immediately followed by a presentation of an overlapping masking stimulus5. The presentation of the mask renders the target invisible6-8. Second, masking requires very rapid and precise timing making it difficult to investigate neural responses evoked by masked stimuli using many common approaches. Blood-oxygenation level dependent (BOLD) responses resolve at a timescale too slow for this type of methodology, and real time recording techniques like electroencephalography (EEG) and magnetoencephalography (MEG) have difficulties recovering signal from deep sources.
However, there have been recent advances in the methods used to localize the neural sources of the MEG signal9-11. By collecting high-resolution MRI images of the subject's brain, it is possible to create a source model based on individual neural anatomy. Using this model to "image" the sources of the MEG signal, it is possible to recover signal from deep subcortical structures, like the amygdala and the hippocampus*.

This article describes how to record amygdala activity with magnetoencephalography (MEG). In addition this article will describe how to conduct trace fear conditioning without awareness, a task that activates the amygdala. It will cover 3 topics: 1) Designing a trace conditioning paradigm using backward masking to manipulate awareness. 2) Recording brain activity during the task using magnetoencephalography. 3) Using source imaging to recover signal from subcortical structures.

In trace fear conditioning a conditional  stimulus (CS) predicts the occurrence of the unconditional stimulus (UCS),  which is presented after a brief ...

Automated Visual Cognitive Tasks for Recording Neural Activity Using a Floor Projection Maze

Neuropsychological tasks used in primates to investigate mechanisms of learning and memory are typically visually guided cognitive tasks. We have developed visual cognitive tasks for rats using the Floor Projection Maze1,2&#160;that are optimized for visual abilities of rats permitting stronger comparisons of experimental findings with other species.
In order to investigate neural correlates of learning and memory, we have integrated electrophysiological recordings into fully automated cognitive tasks on the Floor Projection Maze1,2. Behavioral software interfaced with an animal tracking system allows monitoring of the animal's behavior with precise control of image presentation and reward contingencies for better trained animals. Integration with an in vivo electrophysiological recording system enables examination of behavioral correlates of neural activity at selected epochs of a given cognitive task.
We describe protocols for a model system that combines automated visual presentation of information to rodents and intracranial reward with electrophysiological approaches. Our model system offers a sophisticated set of tools as a framework for other cognitive tasks to better isolate and identify specific mechanisms contributing to particular cognitive processes.

We describe protocols for training rats for chronic electrophysiological recordings in fully automated cognitive tasks on a Floor Projection Maze.

Neuropsychological tasks used in primates to investigate mechanisms of learning and memory are typically visually guided cognitive tasks. We have ...

Implantation and Recording of Wireless Electroretinogram and Visual Evoked Potential in Conscious Rats

The full-field electroretinogram (ERG) and visual evoked potential (VEP) are useful tools to assess retinal and visual pathway integrity in both laboratory and clinical settings. Currently, preclinical ERG and VEP measurements are performed with anesthesia to ensure stable electrode placements. However, the very presence of anesthesia has been shown to contaminate normal physiological responses. To overcome these anesthesia confounds, we develop a novel platform to assay ERG and VEP in conscious rats. Electrodes are surgically implanted sub-conjunctivally on the eye to assay the ERG and epidurally over the visual cortex to measure the VEP. A range of amplitude and sensitivity/timing parameters are assayed for both the ERG and VEP at increasing luminous energies. The ERG and VEP signals are shown to be stable and repeatable for at least 4 weeks post surgical implantation. This ability to record ERG and VEP signals without anesthesia confounds in the preclinical setting should provide superior translation to clinical data.

We show surgical implantation and Recording procedures to measure visual electrophysiological signals from the eye (electroretinogram) and brain (visual evoked potential) in conscious rats, which is more analogous to the human condition where recordings are conducted without anesthesia confounds.

The full-field electroretinogram (ERG) and visual evoked potential (VEP) are useful tools to assess retinal and visual pathway integrity in both ...

Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to progressive loss of motor and speech abilities. In addition, cognitive functions are impaired in a subset of patients. To evaluate these potential deficits in severely physically impaired ALS patients, eye-tracking is a promising means to conduct cognitive tests. The present article focuses on how eye movements, an indirect means of communication for physically disabled patients, can be utilized to allow for detailed neuropsychological assessment. The requirements, in terms of oculomotor parameters that have to be met for sufficient eye-tracking in ALS patients are presented. The properties of stimuli, including type of neuropsychological tests and style of presentation, best suited to successfully assess cognitive functioning, are also described. Furthermore, recommendations regarding procedural requirements are provided. Overall, this methodology provides a reliable, easy to administer and fast approach for assessing cognitive deficits in patients who are unable to speak or write such as patients with severe ALS. The only confounding factor might be deficits in voluntary eye movement control in a subset of ALS patients.

Cognitive deficits are common in about one third of patients with amyotrophic lateral sclerosis, a neurological condition leading to progressive impairments in speech and movement abilities. To conduct cognitive tests in patients unable to speak or write a reliable and easy to administer eye-tracking paradigm was developed.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to ...

A Wireless, Bidirectional Interface for In Vivo Recording and Stimulation of Neural Activity in Freely Behaving Rats

In vivo electrophysiology is a powerful technique to investigate the relationship between brain activity and behavior at a millisecond and micrometer scale. However, current methods mostly rely on tethered cable recordings or only use unidirectional systems, allowing either recording or stimulation of neural activity, but not at the same time or same target. Here, a new wireless, bidirectional device for simultaneous multichannel recording and stimulation of neural activity in freely behaving rats is described. The system operates through a single portable head stage that both transmits recorded activity and can be targeted in real-time for brain stimulation using a telemetry-based multichannel software. The head stage is equipped with a preamplifier and a rechargeable battery, allowing stable long-term recordings or stimulation for up to 1 h. Importantly, the head stage is compact, weighs 12 g (including battery) and thus has minimal impact on the animal&#180;s behavioral repertoire, making the method applicable to a broad set of behavioral tasks. Moreover, the method has the major advantage that the effect of brain stimulation on neural activity and behavior can be measured simultaneously, providing a tool to assess the causal relationships between specific brain activation patterns and behavior. This feature makes the method particularly valuable for the field of deep brain stimulation, allowing precise assessment, monitoring, and adjustment of stimulation parameters during long-term behavioral experiments. The applicability of the system has been validated using the inferior colliculus as a model structure.

A Wireless, Bidirectional Interface for In Vivo Recording and Stimulation of Neural Activity in Freely Behaving Rats

A wireless, bidirectional system for multi-channel neural recordings and stimulation in freely behaving rats is introduced. The system is light and compact, thus having minimal impact on the animal&#180;s behavioral repertoire. Moreover, this bidirectional system provides a sophisticated tool to assess causal relationships between brain activation patterns and behavior.

In vivo electrophysiology is a powerful technique to investigate the relationship between brain activity and behavior at a millisecond and micrometer ...

Using Electroencephalography Measurements and High-quality Video Recording for Analyzing Visual Perception of Media Content

This article explores a method to detect differences in visual perception in humans. The method used is based on the psychological (or "cognitive") function of eyeblinks. Participants' eyeblinks are detected and acquired while watching videos specifically created for the investigation. The detection and acquisition of eyeblinks are carried out with the help of a 20-channel electroencephalographic (EEG) wireless device. The international 10-20 system for electrode placement is followed. A high-definition (HD) video camera is used to record participants' facial expressions, for contrast purposes. Instead of using pre-existing media content, purpose-made video content has been created following specific criteria of interest for this investigation, with stimuli enabling researchers to manage the precise parameters of interest. Otherwise, results could be contaminated with uncontrolled variables. The synchronization of the presentation of video stimuli with EEG recordings needs to be done in milliseconds. Analysis of collected data is performed with robust software for working with big matrices. Statistically significant differences in eyeblink rate related to media professionalization and editing style are found with the reported experimental procedures.

We present detection, acquisition, and analysis of eyeblink rates while watching media content.

This article explores a method to detect differences in visual perception in humans. The method used is based on the psychological (or "cognitive") ...

Simultaneous Eye Tracking and Single-Neuron Recordings in Human Epilepsy Patients

Intracranial recordings from patients with intractable epilepsy provide a unique opportunity to study the activity of individual human neurons during active behavior. An important tool for quantifying behavior is eye tracking, which is an indispensable tool for studying visual attention. However, eye tracking is challenging to use concurrently with invasive electrophysiology and this approach has consequently been little used. Here, we present a proven experimental protocol to conduct single-neuron recordings with simultaneous eye tracking in humans. We describe how the systems are connected and the optimal settings to record neurons and eye movements. To illustrate the utility of this method, we summarize results that were made possible by this setup. This data shows how using eye tracking in a memory-guided visual search task allowed us to describe a new class of neurons called target neurons, whose response was reflective of top-down attention to the current search target. Lastly, we discuss the significance and solutions to potential problems of this setup. Together, our protocol and results suggest that single-neuron recordings with simultaneous eye tracking in humans are an effective method to study human brain function. It provides a key missing link between animal neurophysiology and human cognitive neuroscience.

We describe a method to conduct single-neuron recordings with simultaneous eye tracking in humans. We demonstrate the utility of this method and illustrate how we used this approach to obtain neurons in the human medial temporal lobe that encode targets of a visual search.

Intracranial recordings from patients with intractable epilepsy provide a unique opportunity to study the activity of individual human neurons during ...

Home-Based Prescribed Pulmonary Exercise in Patients with Stable Chronic Obstructive Pulmonary Disease

As a systemic disease, chronic obstructive pulmonary disease (COPD) affects the respiratory system, inducing restless and exercise dyspnea. It also impacts exercise capacity and forms a vicious circle in which it further aggravates the condition of patients and accelerates disease progression. As a functional holistic exercise, traditional Chinese exercises (TCE) play an important role in the rehabilitation of COPD on the basis of adjusting the breath and performing coordinated movements. This study investigates the effects of prescribed pulmonary exercises (which are modified from TCE) on exercise capacity of upper and lower limbs, endurance exercise capacity, and quality of life in stable COPD patients. The goal is to determine the accessibility of these prescribed exercises in COPD rehabilitation. Participants are randomly divided into a non-exercise control group (CG) or prescribed pulmonary exercise group (PG) at a ratio of 1: 1. The PG receives intervention for 60 min twice per day, 7 days a week, for a total of 3 months. The intensity is measured using the Borg category-ratio 10 scale and with a heart-rate monitor. Then, an exercise capacity test and quality of life questionnaire are scheduled at 1 week before and after the formal intervention. After 3 months of intervention, the 30 s arm curl test, 30 s sit-to-stand test, 6 min walking test, and quality of life show significant improvement in COPD patients (p &#60; 0.05). These findings indicate that prescribed pulmonary exercises can be applied as alternative, convenient, and effective home- and community-based exercises for stable COPD patients.

Presented here is a protocol to investigate the effects of home-based prescribed pulmonary exercise in stable chronic obstructive pulmonary disease (COPD) patients, which is modified based on traditional Chinese exercises according to dyspnea and limited exercise capacity observed in COPD patients.

As a systemic disease, chronic obstructive pulmonary disease (COPD) affects the respiratory system, inducing restless and exercise dyspnea. It also ...

Using Unidirectional Rotations to Improve Vestibular System Asymmetry in Patients with Vestibular Dysfunction

The vestibular system provides information about head movement and mediates reflexes that contribute to balance control and gaze stabilization during daily activities. Vestibular sensors are located in the inner ear on both sides of the head and project to the vestibular nuclei in the brainstem. Vestibular dysfunction is often due to an asymmetry between input from the two sides. This results in asymmetrical neural inputs from the two ears, which can produce an illusion of rotation, manifested as vertigo. The vestibular system has an impressive capacity for compensation, which serves to rebalance how asymmetrical information from the sensory end organs on both sides is processed at the central level. To promote compensation, various rehabilitation programs are used in the clinic; however, they primarily use exercises that improve multisensory integration. Recently, visual-vestibular training has also been used to improve the vestibulo-ocular reflex (VOR) in animals with compensated unilateral lesions. Here, a new method is introduced for rebalancing the vestibular activity on both sides in human subjects. This method consists of five unidirectional rotations in the dark (peak velocity of 320&#176;/s) toward the weaker side. The efficacy of this method was shown in a sequential, double-blinded clinical trial in 16 patients with VOR asymmetry (measured by the directional preponderance in response to sinusoidal rotations). In most cases, VOR asymmetry decreased after a single session, reached normal values within the first two sessions in one week, and the effects lasted up to 6 weeks. The rebalancing effect is due to both an increase in VOR response from the weaker side and a decrease in response from the stronger side. The findings suggest that unidirectional rotation can be used as a supervised rehabilitation method to reduce VOR asymmetry in patients with longstanding vestibular dysfunction.

A new rehabilitation method is presented for rebalancing the vestibular system in patients with asymmetric responses, which consists of unidirectional rotations toward the weaker side. By directly modifying the vestibular pathway rather than enhancing the multisensory aspects of compensation, asymmetry can be normalized within 1-2 sessions and show lasting effects.

The vestibular system provides information about head movement and mediates reflexes that contribute to balance control and gaze stabilization during ...

A Chronic Sleep Fragmentation Model using Vibrating Orbital Rotor to Induce Cognitive Deficit and Anxiety-Like Behavior in Young Wild-Type Mice

Sleep disturbance is generally common in populations as a chronic disease or a complained event. Chronic sleep disturbance is proposed to be closely linked to the pathogenesis of diseases, especially neurodegenerative diseases. We recently found that 2 months of sleep fragmentation initiated Alzheimer&#8217;s disease (AD)-like behavioral and pathological changes in young wild-type mice. Herein, we present a standardized protocol to achieve chronic sleep fragmentation (CSF). Briefly, CSF was induced by an orbital rotor vibrating at 110 rpm and operating with a repetitive cycle of 10 s-on, 110 s-off, during light-ON phase (8:00 AM&#8211;8:00 PM) continuously for up to 2 months. Impairments of spatial learning and memory, anxiety-like but not depression-like behavior in mice as consequences of CSF modeling, were evaluated with Morris water maze (MWM), Novel object recognition (NOR), Open field test (OFT) and Forced swimming test (FST). In comparison with other sleep manipulations, this protocol minimizes the handling labors and maximizes the modeling efficiency. It produces stable phenotypes in young wild-type mice and can be potentially generated for a variety of research purposes.

Presented here is a protocol for chronic sleep fragmentation (CSF) model achieved by an electrically controlled orbital rotor, which could induce confirmed cognitive deficit and anxiety-like behavior in young wild-type mice. This model can be applied to explore the pathogenesis of chronic sleep disturbance and related disorders.

Sleep disturbance is generally common in populations as a chronic disease or a complained event. Chronic sleep disturbance is proposed to be closely ...