Name: method for simultaneous fmri/eeg data collection during a focused attention suggestion for differential thermal sensation
Uploaded: 2014-01-05T14:00:00
Duration: 6 min 33 s
Description: Watch this Scientific Journal Video about Method for Simultaneous fMRI/EEG Data Collection during a Focused Attention Suggestion for Differential Thermal Sensation at JoVE.com

This work was supported by funds from the Korean Basic Science Institute (KBSI) grant, Neuroimaging Studies of Hypnotically Induced Deception.

The following experimental protocol was reviewed and approved by the UCLA Institutional Review Board. Prior to commencing the experiment, subjects underwent a phone prescreening that excluded subject that were potentially pregnant, under the age of eighteen, or who had worked in a machine show or otherwise had metallic implants. Left-handed subjects, or those with a history of mental illness were also excluded from the subject pool. Included participants were then instructed to abstain from caffeine, drugs, and alcohol on the day of the experiment. Written informed consent and comprehension of consent was obtained from each participant on the day of the experiment.
1. EEG Sensor Net Application
The EEG data are recorded using a 256-channel MRI compatible Geodesic Sensor Net. Impedance levels in electrodes should be monitored (step 1.5) at approximately 20 min intervals throughout the experiment to make sure that electrodes have not dried out and that impedances remain below threshold.
<ol>
	<li>Determine proper net size by measuring the head circumference from the glabella brow ridge to approximately 2.5 cm above the inion.</li>
	<li>HydroCel Saline potassium chloride electrolyte solution was made according to EGI instructions. EEG Electrogeodesic 256 sensor net was then soaked in electrolyte solution for 10 min.</li>
	<li>The vertex, or Cz, point on the head was determined by measuring the midpoint between nasion and inion and aligning this with the midpoint that dissects the preauricular points. The EEG net was then placed such that the Cz reference electrode aligns with the vertex point.</li>
	<li>We collected photographic images of the head and electrodes using the EGI Geodesic Photogrammetry System (GPS) in order to calibrate the sensor space to be used in EEG source analysis.</li>
	<li>Electrode impedances were then measured. Contact with the scalp was checked for those electrodes with impedance levels above threshold. The electrodes placements are adjusted, and additional electrolyte solution was added to electrodes as necessary to reduce the impedance.</li>
</ol>
2. Concurrent EEG/fMRI and Temperature Recording Protocol Prior to Hypnosis
After the EEG net is applied appropriately, the subject proceeds to the MR scanner room. All metal objects are removed. Structural MRI and functional MRI scans are collected on a Siemens Allegra 3T scanner. Simultaneous EEG/fMRI data is collected prior to hypnotic induction in order to establish a functional baseline for each subject.
<ol>
	<li>MPRAGE Structural Scan</li>
	<li>T2 Matched Bandwidth - a specialized scanning sequence designed to provide good contrast for image registration, while sharing the same metric distortions as the functional scans that follow.</li>
	<li>Functional Scan - T2*-weighted echo-planar pulse sequence with a TR=2.5 sec, TE=40 msec, Field of View=200 mm x 200 mm, Flip Angle=90&#176;, collecting whole brain images with a resolution=64 x 64 x 28, voxel size=3 mm3. Data are collected for a total of five minutes.</li>
	<li>EEG data are concurrently recorded using an MR-Compatible Electrical Geodesics (EGI) 256-channel system during the five-minute functional MRI recordings to establish a baseline EEG prior to the hypnotic induction. Our lab has pioneered methods for simultaneous fMRI/EEG collection using software and hardware that removes MR artifact and balistocardiogram noise, in real-time (see reference25 for additional details).</li>
	<li>After the resting state scan, subjects listen to a tape that instructs them to visualize that their left hand is immersed in a bucket of cold ice water. Temperature differences between each hand are quantified using our differential thermometry device described below.</li>
</ol>
3. Hypnotic Induction
Subjects were then seated comfortably in a dimly lit, quiet room. EEG data were recorded throughout the duration of the hypnotic induction and progressive relaxation deepening technique.
<ol>
	<li>Hypnotic induction began with a brief interview by the hypnotherapist to determine subject specific spatial cues that cause relaxation. Subjects were then asked a number of questions to determine if they were capable of visualizing.</li>
	<li>The hypnotherapist then began the induction using an ideomoter suggestion known as the arm raising technique. During this time, the hypnotherapist continually gave the subject the suggestion that their arm felt as though it was getting lighter, and at some point their arm would rise in the air automatically without volitional effort. After the subject&#39;s arm elevated, they were then instructed to bend their arm and touch their forehead with their fingertips. As soon as the subject complied, the hypnotherapist asked the subject to close his or her eyes and relax as if in a deep sleep.</li>
	<li>Level of hypnotic susceptibility was then assessed via the 12-point Stanford Scale of hypnotic susceptibility, form C test.</li>
	<li>A deepening technique, in the form of a progressive relaxation, was then used to bring the subject into a greater level of hypnotic depth.</li>
	<li>EEG data are recorded throughout the hypnotic induction in a dimly lit copper shielded room during the hypnotic induction.</li>
</ol>
4. EEG/fMRI Data Collection and Differential Thermometry Post Hypnotic Induction
<ol>
	<li>Following hypnotic induction and progressive relaxation, the subject, again enters the MRI scanning room with the MR compatible EEG sensor net in continually in place. At this time, temperature sensors were taped onto the medial portion of both wrists. Wristbands were then placed over the taped temperature sensors to help stabilize placement.</li>
	<li>Temperature sensors should be configured according to the schematic in Figure 2. Calibration was performed prior to the experiment, and was accomplished by immersing sensor tips in two solutions of varying temperatures (37 &#176;C&#177; 5). Sensor output was checked against thermometer readings.</li>
	<li>The subject then listens to a prerecorded progressive relaxation tape made by the hypnotherapist via MR compatible headphones. During this time, fMRI data are collected according to pulse sequences described in step 1.1, with concurrent EEG recording.</li>
	<li>Collection of resting state EEG/fMRI data following hypnotic induction proceeds according to steps 2.2-2.4.</li>
	<li>The hypnotherapist then administers the &#39;cold glove&#39; suggestion for the subsequent EEG/fMRI data collection, which again proceeds according to steps 2.2-2.5. During the suggestion, the hypnotherapist repeatedly asks the subject to visualize their hand is immersed in a cold water bath, and to imagine that their left hand was growing progressively colder from fingertips to wrist. Differential thermometry measurements are recorded throughout this block.</li>
</ol>

<ol>
	<li>Kirsch, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnosis+and+Placebos:+Response+Expectancy+as+a+Mediator+of+Suggestion+Effects.">Hypnosis and Placebos: Response Expectancy as a Mediator of Suggestion Effects.</a> Anales de Psicolog&#237;a. 15, 99-110 (1999).</li><li>McGeown, W. J., Mazzoni, G., Venneri, A., Kirsch, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnotic+induction+decreases+anterior+default+mode+activity.">Hypnotic induction decreases anterior default mode activity.</a> Conscious. Cogn. 18, 848-855 (2009).</li><li>Karlin, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnotizability+and+attention.">Hypnotizability and attention.</a> J. Abnorm Psychol. 88, 92-95 (1979).</li><li>Terhune, D. B., Carde&#241;a, E., Lindgren, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+frontal-parietal+phase+synchrony+during+hypnosis+as+a+function+of+hypnotic+suggestibility.">Differential frontal-parietal phase synchrony during hypnosis as a function of hypnotic suggestibility.</a> Psychophysiology. , (2011).</li><li>Tellegen, A., Atkinson, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Openness+to+absorbing+and+self-altering+experiences+(&amp;#34;absorption&amp;#34;),+a+trait+related+to+hypnotic+susceptibility.">Openness to absorbing and self-altering experiences (&amp;#34;absorption&amp;#34;), a trait related to hypnotic susceptibility.</a> J. Abnorm. Psychol. 83, 268-277 (1974).</li><li>Oakley, D. A., Halligan, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnotic+suggestion+and+cognitive+neuroscience.">Hypnotic suggestion and cognitive neuroscience.</a> Trends Cogn. Sci. 13, 264-270 (2009).</li><li>Kihlstrom, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnosis.">Hypnosis.</a> Annu Rev Psychol. 36, 385-418 (1985).</li><li>Piccione, C., Hilgard, E. R., Zimbardo, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+degree+of+stability+of+measured+hypnotizability+over+a+25-year+period.">On the degree of stability of measured hypnotizability over a 25-year period.</a> J. Pers. Soc. Psychol. 56, 289-295 (1989).</li><li>Weitzenhoffer, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimation+of+hypnotic+susceptibility+in+a+group+situation.">Estimation of hypnotic susceptibility in a group situation.</a> Am. J. Clin. Hypn. 5, 115-126 (1962).</li><li>Weitzenhoffer, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+significance+of+hypnotic+depth+in+therapy.">The significance of hypnotic depth in therapy.</a> Int. J. Clin. Exp. Hypn. 10, 75-78 (1962).</li><li>Hilgard, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Stanford+Hypnotic+Susceptibility+Scales+as+related+to+other+measures+of+hypnotic+responsiveness.">The Stanford Hypnotic Susceptibility Scales as related to other measures of hypnotic responsiveness.</a> Am. J. Clin. Hypn. 21, 68-83 (1978).</li><li>Weitzenhoffer, A. M., Sjoberg, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suggestibility+with+and+without+&amp;#34;induction+of+hypnosis&amp;#34.">Suggestibility with and without &amp;#34;induction of hypnosis&amp;#34.</a> J. Nerv. Ment. Dis. 13 (2), 204-220 (1961).</li><li>Jamieson, G. A., Sheehan, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+empirical+test+of+Woody+and+Bowers's+dissociated-control+theory+of+hypnosis.">An empirical test of Woody and Bowers's dissociated-control theory of hypnosis.</a> Int. J. Clin. Exp. Hypn. 52, 232-249 (2004).</li><li>Egner, T., Jamieson, G., Gruzelier, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnosis+decouples+cognitive+control+from+conflict+monitoring+processes+of+the+frontal+lobe.">Hypnosis decouples cognitive control from conflict monitoring processes of the frontal lobe.</a> Neuroimage. 27, 969-978 (2005).</li><li>Derbyshire, S. W. G., Whalley, M. G., Stenger, V. A., Oakley, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+activation+during+hypnotically+induced+and+imagined+pain.">Cerebral activation during hypnotically induced and imagined pain.</a> Neuroimage. 23, 392-401 (2004).</li><li>Derbyshire, S. W. G., Whalley, M. G., Oakley, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fibromyalgia+pain+and+its+modulation+by+hypnotic+and+non-hypnotic+suggestion:+an+fMRI+analysis.">Fibromyalgia pain and its modulation by hypnotic and non-hypnotic suggestion: an fMRI analysis.</a> Eur. J. Pain. 13, 542-550 (2009).</li><li>Casiglia, E., 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=Neurophysiological+correlates+of+post-hypnotic+alexia:+a+controlled+study+with+Stroop+test.">Neurophysiological correlates of post-hypnotic alexia: a controlled study with Stroop test.</a> Am. J. Clin. Hypn. 52, 219-233 (2010).</li><li>Raz, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Attention+and+hypnosis:+neural+substrates+and+genetic+associations+of+two+converging+processes.">Attention and hypnosis: neural substrates and genetic associations of two converging processes.</a> Int. J. Clin. Exp. Hypn. 53, 237-258 (2005).</li><li>Mendelsohn, A., Chalamish, Y., Solomonovich, A., Dudai, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesmerizing+memories:+brain+substrates+of+episodic+memory+suppression+in+posthypnotic+amnesia.">Mesmerizing memories: brain substrates of episodic memory suppression in posthypnotic amnesia.</a> Neuron. 57, 159-170 (2008).</li><li>Raij, T. T., Numminen, J., N&#228;rv&#228;nen, S., Hiltunen, J., Hari, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain+correlates+of+subjective+reality+of+physically+and+psychologically+induced+pain.">Brain correlates of subjective reality of physically and psychologically induced pain.</a> Proc. Natl. Acad. Sci. U.S.A. 102, 2147-2151 (2005).</li><li>Raij, T. T., Numminen, J., N&#228;rv&#228;nen, S., Hiltunen, J., Hari, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strength+of+prefrontal+activation+predicts+intensity+of+suggestion-induced+pain.">Strength of prefrontal activation predicts intensity of suggestion-induced pain.</a> Hum. Brain Mapp. 30, 2890-2897 (2009).</li><li>R&#246;der, C. H., Michal, M., Overbeck, G., Gvan de Ven, V., Linden, D. E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pain+response+in+depersonalization:+a+functional+imaging+study+using+hypnosis+in+healthy+subjects.">Pain response in depersonalization: a functional imaging study using hypnosis in healthy subjects.</a> Psychother. Psychosom. 76, 115-121 (2007).</li><li>Schulz-St&#252;bner, S., 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=Clinical+hypnosis+modulates+functional+magnetic+resonance+imaging+signal+intensities+and+pain+perception+in+a+thermal+stimulation+paradigm.">Clinical hypnosis modulates functional magnetic resonance imaging signal intensities and pain perception in a thermal stimulation paradigm.</a> Reg. Anesth. Pain Med. 29, 549-556 (2004).</li><li>Holroyd, J. C., Nuechterlein, K. H., Shapiro, D., Ward, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Individual+differences+in+hypnotizability+and+effectiveness+of+hypnosis+or+biofeedback.">Individual differences in hypnotizability and effectiveness of hypnosis or biofeedback.</a> Int. J. Clin. Exp. Hypn. 30, 45-65 (1982).</li><li>Mart&#237;nez-Montes, E., Vald&#233;s-Sosa, P. A., Miwakeichi, F., Goldman, R. I., Cohen, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Concurrent+EEG/fMRI+analysis+by+multiway+Partial+Least+Squares.">Concurrent EEG/fMRI analysis by multiway Partial Least Squares.</a> Neuroimage. 22, 1023-1034 (2004).</li><li>Frischholz, E. J., Tryon, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnotizability+in+relation+to+the+ability+to+learn+thermal+biofeedback.">Hypnotizability in relation to the ability to learn thermal biofeedback.</a> Am. J. Clin. Hypn. 23, 53-56 (1980).</li><li>Engstrom, D. R., London, P., Hart, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypnotic+susceptibility+increased+by+EEG+alpha+training.">Hypnotic susceptibility increased by EEG alpha training.</a> Nature. 227, 1261-1262 (1970).</li></ol>

Following its acceptance and publication, Electrical Geodesics, Inc. has underwritten the open access fee for this article

There appears to be wide variability in suggestion methods used to induce subjects into a state of hypnosis1. We demonstrate here that a suggestion for nonvolitional motor movement followed by the SHSS, form C, can be used to alter EEG power spectrum. We note that although the subject used in this study had been hypnotized in the past, there was no attempt made via Harvard Group Suggestibility Scale or other mechanism to find a highly susceptible subject. We hypothesize that the magnitude of changes in EEG frequency subbands likely varies according to subject level of susceptibility, as has been reported4.
We also demonstrated a setup to measure hand temperature fluctuations that may occur during a concurrent EEG/fMRI session. Although subjects can eventually learn to accomplish hand temperature changes without hypnosis using biofeedback cues, this typically takes many training sessions26. Frischholz and&#160;Tryon26 were unable to replicate the association between changes in hand temperature and hypnotic depth using the cold glove suggestion paradigm, contrary to that reported by others27. Additional work is required to resolve this controversy. Nonetheless, the method for measuring hand temperature changes during a functional neuroimaging session may prove useful in assessing the neural correlates of the hypnotic 'cold glove' suggestion following hypnotic induction.

Since its inception, there has been considerable controversy as to what hypnosis is, and how exactly measurable physiologic changes in susceptible individuals are produced. Studies aimed at understanding the neural correlates of hypnosis and responses to hypnotic suggestion have generally produced varied results1, which may be due, at least in part, to differences in hypnotic induction and suggestion techniques2, thus providing motivation for a detailed methodology and protocol description.
Although hypnosis has conventionally been defined as a state of inner concentration and focused attention1,3, a more complete operational definition also includes: diminished awareness of exogenous stimuli4, increased absorption5, or effortless attention to words of the experimenter and diminished spontaneous thought6. A hypnotic induction is generally defined as a set of verbal instructions that facilitate hypnosis and absorption6. Hypnotizability varies greatly between individuals, but is generally stable within individuals over time7,8; suggestibility is typically measured in terms of behavioral response to suggestion with the most commonly applied metric being the Stanford Hypnotic Susceptibility Scale, (SHSS) form C9-12.
Studies that examine the neural correlates of hypnosis generally fall into two categories. Either they examine networks of activity intrinsically activated during &#39;resting state&#39; hypnosis, or they study changes in neural activity that occur in response to hypnotic suggestion6. In a recent EEG study, highly suggestible individuals were found to display higher event related desynchrony of the frontal-parietal network in the alpha-2 band during hypnosis compared to low suggestible subjects4. Recently, functional magnetic resonance imaging (fMRI) has also revealed changes in anterior default mode networks during &#39;resting state&#39; hypnosis without a corresponding increase in activity in other brain areas2. Converging evidence suggests that hypnosis is associated with dissociated anterior attentional control13.
Changes in fMRI blood oxygenation level dependent (BOLD) signals in response to a variety of hypnotic suggestions have also recently been reported14-23. The majority of suggestion-response studies correlate brain signal changes with subjective ratings of altered perception. However, hypnotic suggestion has also been used to alter physiologic parameters such as blood pressure,&#160;heart rate, and subject hand temperature in response24.
Here, we extend these earlier findings by developing an experimental paradigm, referred to here as the &#39;cold glove&#39; paradigm, whereby subjects are directed to perceive that one of their hands is colder in temperature than the other, in absence of any external physical manipulation of temperature. These verbal instructions are delivered via MR compatible headphones during data recording.
In the present work, we first demonstrate our method for simultaneous EEG/fMRI data recording. We then demonstrate the cold glove paradigm, which includes collection of EEG/fMRI data along with hand temperature measurements both before and after hypnotic induction. Our method for hypnotic induction includes an ideomotor suggestion described by1, followed by a depth assessment using the SSHS, form C. We detect reliable changes in the EEG power spectrum that occur following hypnotic induction. We also demonstrate that our MRI compatible differential thermometry device is capable of measuring hand temperature changes during simultaneous EEG/fMRI data collection session. This procedure may provide important quantitative EEG/fMRI measurements in assessing brain signal changes that occur during intrinsic &#39;resting state&#39; hypnosis as well as measuring signal changes in response to hypnotic suggestion for altered thermal perception.

<table border="1">
	<tbody>
		<tr>
			<td>Equipment Name</td>
			<td>Company</td>
			<td>Catalogue Number</td>
			<td>Comment</td>
		</tr>
		<tr>
			<td>Precision Monolithic Temperature Sensor</td>
			<td>National Semiconductor Corporation</td>
			<td>LM34/LM35</td>
			<td>100 mV/&#176;C; accurate to within &#177;0.4&#160;&#176;C at room temperature</td>
		</tr>
		<tr>
			<td>Precision Instrumentation Amplifier</td>
			<td>National Semiconductor Corporation</td>
			<td>INA114</td>
			<td>Part of Magnet Room I/O interface</td>
		</tr>
		<tr>
			<td>HydroCel Saline</td>
			<td>Electrical Geodescis Inc.</td>
			<td>N-PRT-KCL-1000-000</td>
			<td></td>
		</tr>
		<tr>
			<td>HydroCel Geodesic Sensor Net with a 256-channel High Density Electrode Array</td>
			<td>Electrical Geodescis Inc.</td>
			<td>256-channel HCGSN</td>
			<td></td>
		</tr>
		<tr>
			<td>Geodesics Photogrammetry System</td>
			<td>Electrical Geodescis Inc.</td>
			<td>EGI GPS</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipettes</td>
			<td>Electrical Geodescis Inc.</td>
			<td>N-ACC-PIP-1000-000</td>
			<td></td>
		</tr>
	</tbody>
</table>

method for simultaneous fmri/eeg data collection during a focused attention suggestion for differential thermal sensation

In the present work, we demonstrate a method for concurrent collection of EEG/fMRI data. In our setup, EEG data are collected using a high-density 256-channel sensor net. The EEG amplifier itself is contained in a field isolation containment system (FICS), and MRI clock signals are synchronized with EEG data collection for subsequent MR artifact characterization and removal. We demonstrate this method first for resting state data collection. Thereafter, we demonstrate a protocol for EEG/fMRI data recording, while subjects listen to a tape asking them to visualize that their left hand is immersed in a cold-water bath and referred to, here, as the cold glove paradigm. Thermal differentials between each hand are measured throughout EEG/fMRI data collection using an MR compatible temperature sensor that we developed for this purpose. We collect cold glove EEG/fMRI data along with simultaneous differential hand temperature measurements both before and after hypnotic induction. Between pre and post sessions, single modality EEG data are collected during the hypnotic induction and depth assessment process. Our representative results demonstrate that significant changes in the EEG power spectrum can be measured during hypnotic induction, and that hand temperature changes during the cold glove paradigm can be detected rapidly using our MR compatible differential thermometry device.

Figure 1 shows the EEG power spectrum in a representative channel (Figure 1a) averaged over 1,000 msec in a single subject during the alert wakeful period that preceded hypnotic induction (Figure 1b). It should be noted that the patterns here follow the characteristic inverse relationship between power and frequency (f), with falloff at 1/f. Figure 1c shows the power spectrum taken from this same subject following hypnotic induction and a deepening technique. Attenuation of power can be seen in EEG theta and beta subbands, and the overall plot no longer follows 1/f. Figure 2 shows our schematic for an MRI compatible temperature sensor, which uses LM34/LM35 precision temperature sensors&#160;coupled to an Arduino device.
<img alt="Figure 1" src="/files/ftp_upload/3298/3298fig1.jpg" /> 
Figure 1. Electroencephalogram (EEG) power spectrum in a single subject for a representative electrode channel. (a) 255 channel EEG electrode array with the spatial location of the channel selection for the power analysis marked in blue (b) EEG power spectrum prior to hypnotic induction, and (c) power spectrum in the same electrode channel following hypnotic induction and a deepening technique. The bar at the top, right corner of Figure 1c indicates the legend for each EEG subband with frequencies: delta (0.1-4 Hz), theta (4-8Hz), alpha (8-12 Hz), beta (12-20 Hz), and gamma (frequencies above 20 Hz).
<img alt="Figure 2" src="/files/ftp_upload/3298/3298fig2.jpg" /> 
Figure 2. Schematic of the MRI compatible differential temperature sensor configuration. (above) Differential thermometry circuit, (below) overview of thermometry measurement process.

Watch this Scientific Journal Video about Method for Simultaneous fMRI/EEG Data Collection during a Focused Attention Suggestion for Differential Thermal Sensation at JoVE.com

Method for Simultaneous fMRI/EEG Data Collection during a Focused Attention Suggestion for Differential Thermal Sensation

We present a protocol for concurrent collection of EEG/fMRI data, and synchronized MR clock signal recording. We demonstrate this method using a unique paradigm whereby subjects receive &#x2018;cold glove&#x2019; instructions during scanning, and EEG/fMRI data are recorded along with hand temperature measurements both before and after hypnotic induction.

In the present work, we demonstrate a method for concurrent collection of EEG/fMRI data. In our setup, EEG data are collected using a high-density ...

method-for-simultaneous-fmrieeg-data-collection-during-focused

Research

JoVE Journal

Behavior

Best Current Practice for Obtaining High Quality EEG Data During Simultaneous fMRI

Simultaneous EEG-fMRI allows the excellent temporal resolution of EEG to be combined with the high spatial accuracy of fMRI. The data from these two modalities can be combined in a number of ways, but all rely on the acquisition of high quality EEG and fMRI data. EEG data acquired during simultaneous fMRI are affected by several artifacts, including the gradient artefact (due to the changing magnetic field gradients required for fMRI), the pulse artefact (linked to the cardiac cycle) and movement artifacts (resulting from movements in the strong magnetic field of the scanner, and muscle activity). Post-processing methods for successfully correcting the gradient and pulse artifacts require a number of criteria to be satisfied during data acquisition. Minimizing head motion during EEG-fMRI is also imperative for limiting the generation of artifacts.
Interactions between the radio frequency (RF) pulses required for MRI and the EEG hardware may occur and can cause heating. This is only a significant risk if safety guidelines are not satisfied. Hardware design and set-up, as well as careful selection of which MR sequences are run with the EEG hardware present must therefore be considered.
The above issues highlight the importance of the choice of the experimental protocol employed when performing a simultaneous EEG-fMRI experiment. Based on previous research we describe an optimal experimental set-up. This provides high quality EEG data during simultaneous fMRI when using commercial EEG and fMRI systems, with safety risks to the subject minimized. We demonstrate this set-up in an EEG-fMRI experiment using a simple visual stimulus. However, much more complex stimuli can be used. Here we show the EEG-fMRI set-up using a Brain Products GmbH (Gilching, Germany) MRplus, 32 channel EEG system in conjunction with a Philips Achieva (Best, Netherlands) 3T MR scanner, although many of the techniques are transferable to other systems.

Simultaneous electroencephalography (EEG) and functional Magnetic Resonance imaging (fMRI) is a powerful neuroimaging tool. However, the inside of an MRI scanner forms a difficult environment for EEG data recording and safety must be considered whenever operating EEG equipment inside a scanner. Here, we present an optimised EEG-fMRI data acquisition protocol.

Simultaneous  EEG-fMRI allows the excellent temporal resolution of EEG to be combined with the  high spatial accuracy of fMRI. The data  from these two ...

Simultaneous EEG Monitoring During Transcranial Direct Current Stimulation

Transcranial direct current stimulation (tDCS) is a technique that delivers weak electric currents through the scalp. This constant electric current induces shifts in neuronal membrane excitability, resulting in secondary changes in cortical activity. Although tDCS has most of its neuromodulatory effects on the underlying cortex, tDCS effects can also be observed in distant neural networks. Therefore, concomitant EEG monitoring of the effects of tDCS can provide valuable information on the mechanisms of tDCS. In addition, EEG findings can be an important surrogate marker for the effects of tDCS and thus can be used to optimize its parameters. This combined EEG-tDCS system can also be used for preventive treatment of neurological conditions characterized by abnormal peaks of cortical excitability, such as seizures. Such a system would be the basis of a non-invasive closed-loop device. In this article, we present a novel device that is capable of utilizing tDCS and EEG simultaneously. For that, we describe in a step-by-step fashion the main procedures of the application of this device using schematic figures, tables and video demonstrations. Additionally, we provide a literature review on clinical uses of tDCS and its cortical effects measured by EEG techniques.

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has shown initial therapeutic effects in several neurological conditions. The main mechanism underlying these therapeutic effects is the modulation of cortical excitability. Therefore, online monitoring of cortical excitability would help guide stimulation parameters and optimize its therapeutic effects. In the present article we review the use of a novel device that combines simultaneous tDCS and EEG monitoring in real time.

Transcranial  direct current stimulation (tDCS) is a technique that delivers weak electric  currents through the scalp. This constant electric current ...

The 5-Choice Serial Reaction Time Task: A Task of Attention and Impulse Control for Rodents

This protocol describes the 5-choice serial reaction time task, which is an operant based task used to study attention and impulse control in rodents. Test day challenges, modifications to the standard task, can be used to systematically tax the neural systems controlling either attention or impulse control. Importantly, these challenges have consistent effects on behavior across laboratories in intact animals and can reveal either enhancements or deficits in cognitive function that are not apparent when rats are only tested on the standard task. The variety of behavioral measures that are collected can be used to determine if other factors (i.e., sedation, motivation deficits, locomotor impairments) are contributing to changes in performance. The versatility of the 5CSRTT is further enhanced because it is amenable to combination with pharmacological, molecular, and genetic techniques.

This protocol describes the 5-choice serial reaction time task, which is an operant based task used to study attention and impulse control in rodents. Test day challenges, which are modifications of the standard task, increase flexibility of the task and can be combined with other manipulations to more fully characterize behavior.

This protocol describes the 5-choice serial reaction time task, which is an operant based task used to study attention and impulse control in rodents. ...

Transcranial Direct Current Stimulation and Simultaneous  Functional Magnetic Resonance Imaging

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp to manipulate cortical excitability and, consequently, behavior and brain function. In the last decade, numerous studies have addressed short-term and long-term effects of tDCS on different measures of behavioral performance during motor and cognitive tasks, both in healthy individuals and in a number of different patient populations. So far, however, little is known about the neural underpinnings of tDCS-action in humans with regard to large-scale brain networks. This issue can be addressed by combining tDCS with functional brain imaging techniques like functional magnetic resonance imaging (fMRI) or electroencephalography (EEG).
In particular, fMRI is the most widely used brain imaging technique to investigate the neural mechanisms underlying cognition and motor functions. Application of tDCS during fMRI allows analysis of the neural mechanisms underlying behavioral tDCS effects with high spatial resolution across the entire brain. Recent studies using this technique identified stimulation induced changes in task-related functional brain activity at the stimulation site&#160;and also in more distant brain regions, which were associated with behavioral improvement. In addition, tDCS administered during resting-state fMRI allowed identification of widespread changes in whole brain functional connectivity.
Future studies using this combined protocol should yield new insights into the mechanisms of tDCS action in health and disease and new options for more targeted application of tDCS in research and clinical settings. The present manuscript describes this novel technique in a step-by-step fashion, with a focus on technical aspects of tDCS administered during fMRI.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique. It has successfully been used in basic research and clinical settings to modulate brain function in humans. This article describes the implementation of tDCS and simultaneous functional magnetic resonance imaging (fMRI), to investigate the neural basis of tDCS effects.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp ...

Methods to Test Visual Attention Online

Online data collection methods have particular appeal to behavioral scientists because they offer the promise of much larger and much more representative data samples than can typically be collected on college campuses. However, before such methods can be widely adopted, a number of technological challenges must be overcome &#8211; in particular in experiments where tight control over stimulus properties is necessary. Here we present methods for collecting performance data on two tests of visual attention. Both tests require control over the visual angle of the stimuli (which in turn requires knowledge of the viewing distance, monitor size, screen resolution, etc.) and the timing of the stimuli (as the tests involve either briefly flashed stimuli or stimuli that move at specific rates). Data collected on these tests from over 1,700 online participants were consistent with data collected in laboratory-based versions of the exact same tests. These results suggest that with proper care, timing/stimulus size dependent tasks can be deployed in web-based settings.

To replicate laboratory settings, online data collection methods for visual tasks require tight control over stimulus presentation. We outline methods for the use of a web application to collect performance data on two tests of visual attention.

Online data collection methods have particular appeal to behavioral scientists because they offer the promise of much larger and much more representative ...

A Method for Remotely Silencing Neural Activity in Rodents During Discrete Phases of Learning

This protocol describes how to temporarily and remotely silence neuronal activity in discrete brain regions while animals are engaged in learning and memory tasks. The approach combines pharmacogenetics (Designer-Receptors-Exclusively-Activated-by-Designer-Drugs) with a behavioral paradigm (sensory preconditioning) that is designed to distinguish between different forms of learning. Specifically, viral-mediated delivery is used to express a genetically modified inhibitory G-protein coupled receptor (the Designer Receptor) into a discrete brain region in the rodent. Three weeks later, when designer receptor expression levels are high, a pharmacological agent (the Designer Drug) is administered systemically 30 min prior to a specific behavioral session. The drug has affinity for the designer receptor and thus results in inhibition of neurons that express the designer receptor, but is otherwise biologically inert. The brain region remains silenced for 2-5 hr (depending on the dose and route of administration). Upon completion of the behavioral paradigm, brain tissue is assessed for correct placement and receptor expression. This approach is particularly useful for determining the contribution of individual brain regions to specific components of behavior and can be used across any number of behavioral paradigms.

This protocol describes how to temporarily and remotely silence neuronal activity in discrete brain regions while rats are engaged in learning and memory tasks. The approach combines pharmacogenetics (Designer-Receptors-Exclusively-Activated-by-Designer-Drugs) with a behavioral paradigm (sensory preconditioning) that is designed to distinguish between different components of learning.

This protocol describes how to temporarily and remotely silence neuronal activity in discrete brain regions while animals are engaged in learning and ...

Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects

Tests that allow the precise determination of psychophysical thresholds for vibration and grating orientation provide valuable information about mechanosensory function that are relevant for clinical diagnosis as well as for basic research. Here, we describe two psychophysical tests designed to determine the vibration detection threshold (automated system) and tactile spatial acuity (handheld device). Both procedures implement a two-interval forced-choice and a transformed-rule up and down experimental paradigm. These tests have been used to obtain mechanosensory profiles for individuals from distinct human cohorts such as twins or people with sensorineural deafness.

Here, we present protocols to determine vibration detection thresholds and tactile acuity using psychophysical methods in man.

Tests that allow the precise determination of psychophysical thresholds for vibration and grating orientation provide valuable information about ...

Protocol for Data Collection and Analysis Applied to Automated Facial Expression Analysis Technology and Temporal Analysis for Sensory Evaluation

We demonstrate a method for capturing emotional response to beverages and liquefied foods in a sensory evaluation laboratory using automated facial expression analysis (AFEA) software. Additionally, we demonstrate a method for extracting relevant emotional data output and plotting the emotional response of a population over a specified time frame. By time pairing each participant's treatment response to a control stimulus (baseline), the overall emotional response over time and across multiple participants can be quantified. AFEA is a prospective analytical tool for assessing unbiased response to food and beverages. At present, most research has mainly focused on beverages. Methodologies and analyses have not yet been standardized for the application of AFEA to beverages and foods; however, a consistent standard methodology is needed. Optimizing video capture procedures and resulting video quality aids in a successful collection of emotional response to foods. Furthermore, the methodology of data analysis is novel for extracting the pertinent data relevant to the emotional response. The combinations of video capture optimization and data analysis will aid in standardizing the protocol for automated facial expression analysis and interpretation of emotional response data.

A protocol for capturing and statistically analyzing emotional response of a population to beverages and liquefied foods in a sensory evaluation laboratory using automated facial expression analysis software is described.

We demonstrate a method for capturing emotional response to beverages and liquefied foods in a sensory evaluation laboratory using automated facial ...

A Protocol of Manual Tests to Measure Sensation and Pain in Humans

Numerous qualitative and quantitative techniques can be used to test sensory nerves and pain in both research and clinical settings. The current study demonstrates a quantitative sensory testing protocol using techniques to measure tactile sensation and pain threshold for pressure and heat using portable and easily accessed equipment. These techniques and equipment are ideal for new laboratories and clinics where cost is a concern or a limiting factor. We demonstrate measurement techniques for the following: cutaneous mechanical sensitivity on the arms and legs (von-Frey filaments), radiant and contact heat sensitivity (with both threshold and qualitative assessments using the Visual Analog Scale (VAS)), and mechanical pressure sensitivity (algometer, with both threshold and the VAS). The techniques and equipment described and demonstrated here can be easily purchased, stored, and transported by most clinics and research laboratories around the world. A limitation of this approach is a lack of automation or computer control. Thus, these processes can be more labor intensive in terms of personnel training and data recording than the more sophisticated equipment. We provide a set of reliability data for the demonstrated techniques. From our description, a new laboratory should be able to set up and run these tests and to develop their own internal reliability data.

The goal of this procedure is to demonstrate a battery of quantitative techniques for sensory and pain measurement in humans. The equipment and techniques described are commonly found in pain clinics or are easy to obtain.

Numerous qualitative and quantitative techniques can be used to test sensory nerves and pain in both research and clinical settings. The current study ...

Simultaneous Transcranial Alternating Current Stimulation and Functional Magnetic Resonance Imaging

Transcranial alternating current stimulation (tACS) is a promising tool for noninvasive investigation of brain oscillations. TACS employs frequency-specific stimulation of the human brain through current applied to the scalp with surface electrodes. Most current knowledge of the technique is based on behavioral studies; thus, combining the method with brain imaging holds potential to better understand the mechanisms of tACS. Because of electrical and susceptibility artifacts, combining tACS with brain imaging can be challenging, however, one brain imaging technique that is well suited to be applied simultaneously with tACS is functional magnetic resonance imaging (fMRI). In our lab, we have successfully combined tACS with simultaneous fMRI measurements to show that tACS effects are state, current, and frequency dependent, and that modulation of brain activity is not limited to the area directly below the electrodes. This article describes a safe and reliable setup for applying tACS simultaneously with visual task fMRI studies, which can lend to understanding oscillatory brain function as well as the effects of tACS on the brain.

Transcranial alternating current stimulation (tACS) is a promising tool for noninvasive investigation of brain oscillations, though its effects are not completely understood. This article describes a safe and reliable setup for applying tACS simultaneously with functional magnetic resonance imaging, which can increase understanding oscillatory brain function and effects of tACS.