Name: Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis (Video) | JoVE Journal
Uploaded: 2012-06-20T12:00:00.000+00:00
Duration: 10 min 33 s
Description: Learn to correlate behavioral responses with fMRI signals from the human prefrontal cortex using emotional Stroop tasks. This method reveals activation in the inferior frontal gyrus during attentional processing.

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5 minutes

Funded by the National Science and Engineering Research Council (NSERC) to JFXD, Faculty of Health, York University and author SO has PhD funding by The Ontario Problem Gambling Research Centre (OPGRC).

1. Before Entering the MRI Room
<ol>
	<li>Participants complete a consent form explaining all the experimental risks (e.g. pacemaker, claustrophobia, metallic implants, chance of pregnancy, etc), and benefits of their participation.</li>
	<li>All participants are required to fill out the MRI safety and screening questionnaire (brief medical history, previous surgical procedures etc.) Participants with contraindications must be excluded.</li>
</ol>
2. Task Overview and Training
<ol>
	<li>Provide training on task performance on anti-saccade.
	<ol>
		<li>Green fixation indicates a pro-saccade trial. Instruct participants to look to the target appearing in the periphery of the screen, at a visual angle of 8-10°.</li>
		<li>Red fixation indicates an anti-saccade trial. Instruct participant to look to the mirror opposite of target appearing in the periphery of the screen, at a visual angle of 8-10° (e.g. for right target, look to the left).</li>
	</ol>
	</li>
	<li>Provide training on task performance for the emotional Stroop outside the scanner.
	<ol>
		<li>Include 15 practice trials with different combinations of face-word expressions on a computer outside the scanner. The purpose of the practice is for the participants to learn the task and what is expected of them in pressing the appropriate button in the MRI scanner. Instruct participants as to which buttons are pressed for reporting a happy expression/word, neutral expression/word and sad expression/word. Additionally, when inside the scanner, remind participants of which emotion each button represents.</li>
		<li>Descriptive words indicating the expressions (Happy, Neutral, Sad) are superimposed over the pictures of individual faces. These words are either congruent or incongruent with the emotion depicted by the face in the picture (Figure 1). Begin each scan with a written instruction on the screen reminding the participants to either report the "FACE EXPRESSION (happy, neutral, sad)" or the "WRITTEN WORD (happy, neutral, sad)" by pressing the corresponding button as quickly as possible.</li>
		<li>The instruction is displayed for 1 second, followed by a fixation cross, which the participants fixated on for another 1 sec. The fixation cross is followed by the face stimuli presented for 250 milliseconds and then followed by the response image for 2 seconds. The response image is used to give the participants time to report their responses by pressing the appropriate button. The next visual presentation of the fixation cross begins after the end of this response image. Each participant repeats the experimental scan in one of the two instruction groups (i.e. face expression OR written word). All stimuli were created and presented using Presentation 12.1 (<a href="http://www.neurobs.com" target="_blank">www.neurobs.com</a>).</li>
	</ol>
	</li>
</ol>
3. Scanner and Eye Tracking Setup
<ol>
	<li>To begin the set up of the experiment, start by projecting the computer stimulus as a focused image onto the screen in the MRI with a digital projector.</li>
	<li>Participants are asked to get up from their chair in the control room and walk into the scanner room. Earplugs and/or head phones are provided and subjects place them in their ears canals.
	<ol>
		<li>The subject lies supine with their head position to the centre of the head coil. We stabilize participant's body and head position with pillows or foam inserts to make them as comfortable as possible but also to aide in restricting their movement of the head since head motion during scanning causes loss of data. Especially if the head motion is greater than 1 mm in any direction.</li>
		<li>Slide/place the headcoil over the participant's head and have them tilt their head as comfortably as possible while looking straight ahead to view the mirror that reflects the projector's screen. The eyes must be as close to primary position as possible8 in order to maintain the participant's comfort over the scanning session which can last up to two hours.</li>
	</ol>
	</li>
	<li>Ask the participant how the focus of the projected image is once they are in the scanner. If it is not sharp, re-adjust the lens to improve the image on the screen.</li>
	<li>The eyetracker is now tested by means of a calibration to ensure that the IRED camera is in the correct location. If the reflection on the cornea is not ideal or working properly, the IRED source must be adjusted, or the mirror reflecting the IRED source near the participant's head position must be realigned/adjusted. If the participant's head was adjusted, ask the subject if more padding/foam or pillows are needed to maintain this head/body position. During scanning monitor and record participants' horizontal and vertical eye positions using an infrared eye tracker (i.e. Sensomotoric Instruments, Needham/Boston, MA) and correlate these with the behavioral paradigm when analyzing brain activity.5,7</li>
</ol>
4. Scanning Procedures
<ol>
	<li>Place the emergency contact squeeze ball on the participant's abdomen in their left hand and the joystick/button box in the right hand. Place a vitamin E capsule on the right side near the head. This will be viewable on the anatomical scans which will make certain an error will not flip the images from left to right. Raise and slide the bed into the centre of the MRI.</li>
	<li>Ensure all of the experimenters leave the MRI room and close the door to the MRI.</li>
	<li>Communicate with the participant through the intercom in the control room and confirm that they are prepared to begin scanning and are as comfortable as possible. If not, readjust as needed.</li>
	<li>Remind the participant that the noises in the scanner will be loud and this is normal.
	<ol>
		<li>The first scan collects a few brain images along the sagittal region to be able to localize/prescribe the exact orientation of the slices for the full anatomical and functional data. The participants are told this scan will take a few minutes.</li>
		<li>Once the experimenters view the results of the localizer scan, we prescribe a series of anatomical slices that cover the whole brain. In our cases we typically scan axial oblique slices that encompass the whole brain (170 to 256 slices). Tell the participant that this scan will take around 6 to 10 minutes depending on the prescribed number of slices. In some cases the anatomical scan can be done after the functional scans. There are some advantages of the latter; usually in long experiments subjects will experience fatigue. Thus, the anatomical scan needs no attention by the subjects so they may close their eyes. It might be useful to do these scans at the end of the imaging session.</li>
		<li>Once anatomical scans are completed the participant is reminded of the specific instructions of the upcoming scan through communication via the microphone/speaker system.</li>
	</ol>
	</li>
	<li>In this example, a pseudo event-related design2 is used to identify the brain regions activated by the emotional stroop task but any sensory, internal perception9 or motor stimulus10 could be directed for use when needed. After these are scanned then we will instruct the subject that the anti-saccade paradigm will be scanned next. Depending on the imaging parameters chosen the scan will be close to 6 minutes long. We find that scans longer than this induce subjects to fall asleep.</li>
	<li>The total imaging session takes approximately 60 to 120 of minutes, depending on the total scans needed for the analysis.</li>
</ol>
5. fMRI Analysis
<ol>
	<li>Analyze the data using BrainVoyager QX software (or any analysis package such as AFNI or SPM).</li>
	<li>Begin by superimposing functional data statistical maps onto anatomical brain images. Functionally define the brain regions of interest (ROIs) using the general linear model (GLM), with separate predictors (i.e. congruent and incongruent, face instruction and word instruction, anti-saccade, pro-saccade) for each of the conditions in the task during the two types of scans2.</li>
	<li>Examine the signal intensity in all the activated frontal regions from the GLM contrasts (i.e. all incongruent versus all congruent to produce a map of areas), compute the standardized BOLD signal across all participants and compare the incongruent word/face expression with the congruent word/faces expressions for both conditions2.</li>
	<li>Correlate the reaction times collected on the trials that were used for the GLMs, then correlate brain activity across each individual with their own reaction times for the specific trials2 as in Figure 4.</li>
</ol>
6. Representative Results
After the analysis we show brain regions that correlate with the emotional stroop and anti-saccade tasks recorded during scanning. The results from the emotional stroop paradigm showed an interaction effect between all three factors of expression, instruction, and brain region but there was no main effect of expression and no main effect of instruction2. We found that when the expression of the face was incongruent to the superimposed emotional word, this incongruency produced from reporting the written word showed higher BOLD signal intensity in the left IFG2 (Figure 2). The larger signal intensity on the incongruent expressions compared to the congruent expressions was statistically significant, with happy congruent showing the largest difference2.
Most importantly the RTs for the three incongruent conditions tested (sad, happy and neutral) predicted an increased BOLD signal within left IFG compared to all the congruent conditions (Figure 3). For this analysis we specifically examined the reaction times and conducted a regression analysis to test whether RT for the incongruent and congruent conditions were predictive of the BOLD signal activity within this brain region (Figure 3). We found that RT accounts for 81% of the variation in left IFG activity when reporting the word expressions of Happy, Neutral, and Sad during the incongruent and congruent conditions2. Higher RT is predictive of larger left IFG activation, with the incongruent sad condition yielding the greatest RT/signal intensity ratio compared to all other expression conditions. We analyzed the anti-saccade paradigms using similar methods as above to be able to compare the two networks of activity. In this example, we found that there was no increased signal in left IFG for the anti-saccade compared to the pro-saccade task. For more details, we refer the readers to Ford et al. (2007).
<img alt="Behavioral response experiment diagram with trial sequence, timing, and visual stimuli." src="/files/ftp_upload/3237/3237fig1.jpg" data-altupdatedat="1788235205000" data-alt="Figure 1"> 
Figure 1. An example of an incongruent trial (face with a happy expression superimposed by the word SAD). The experiment will begin with the fixation dot (1 second), proceeding by the face stimulus (250 ms) and the masked image (2 seconds) which requires the participant's button response.
<img alt="Bar chart comparing incongruent and congruent expressions' signal change in left inferior frontal gyrus." src="/files/ftp_upload/3237/3237fig2.jpg" data-altupdatedat="1788235205000" data-alt="Figure 2"> 
Figure 2. All fixation volumes were used as the baseline. Error bars signify the standard error of mean (SEM). Incongruent expressions (Happy, Neutral, Sad) showed significantly larger BOLD signal change compared to congruent expressions2. The inset image shows left inferior frontal gyrus (IFG) that was functionally localized using the contrast describe in section 5.2 for the incongruent emotional stroop versus the congruent condition during the attend to word instruction set.
<img alt="Correlation graph of behavior and BOLD signal, reaction time vs. % signal change, r=0.81, p&lt;0.05." src="/files/ftp_upload/3237/3237fig3.jpg" data-altupdatedat="1788235205000" data-alt="Figure 3"> 
Figure 3. During the "Attend to Word" instruction, incongruent-congruent contrast showed a positive correlation between the RTs and BOLD signal intensity. This graph is an average of all 10 subjects' RTs and BOLD signal during each of the six conditions. Error bars signify the standard error of mean (SEM)2 .
<img alt="Hemodynamic Response Function diagram with HRF delay curves, timing sequences, and response graphs." src="/files/ftp_upload/3237/3237fig4.jpg" data-altupdatedat="1788235205000" data-alt="Figure 4"> 
Figure 4. Two repetitions of each expression were displayed to the subjects. Top row is an schematic illustration of a trial sequence from one block of trials. Bottom section is a depiction of the Two-Gamma hemodynamic response function (HRF) used to discover brain regions involved in the emotional face expressions.

<ol><li>Stroop, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Studies+of+interference+in+serial+verbal+reactions%5BTitle%5D)+AND+%22Journal+of+Experimental+Psychology%22%5BJournal%5D)">Studies of interference in serial verbal reactions.</a> Journal of Experimental Psychology. 18, 643-662 (1935).</li>
<li>Ovaysikia, S., Tahir, K. A., Chan, J. L., DeSouza, J. F. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Word+wins+over+face%3A+emotional+Stroop+effect+activates+the+frontal+cortical+network%5BTitle%5D)+AND+%22Front+Hum.+Neurosci%22%5BJournal%5D)">Word wins over face: emotional Stroop effect activates the frontal cortical network.</a> Front Hum. Neurosci. 4, 234(2011).</li>
<li>Hallett, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Primary+and+secondary+saccades+to+goals+defined+by+instructions%5BTitle%5D)+AND+%22Vision+Res%22%5BJournal%5D)">Primary and secondary saccades to goals defined by instructions.</a> Vision Res. 18, 1279-1296 (1978).</li>
<li>Connolly, J. D., Goodale, M. A., DeSouza, J. F. X., Menon, R. S., Vilis, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+comparison+of+frontoparietal+fMRI+activation+during+anti-saccades+and+anti-pointing%5BTitle%5D)+AND+%22J.+Neurophysiol%22%5BJournal%5D)">A comparison of frontoparietal fMRI activation during anti-saccades and anti-pointing.</a> J. Neurophysiol. 84, 1645-1655 (2000).</li>
<li>DeSouza, J. F. X., Menon, R. S., Everling, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Preparatory+set+associated+with+pro-saccades+and+anti-saccades+in+humans+investigated+with+event-related+FMRI%5BTitle%5D)+AND+%22J.+Neurophysiol%22%5BJournal%5D)">Preparatory set associated with pro-saccades and anti-saccades in humans investigated with event-related FMRI.</a> J. Neurophysiol. 89, 1016-1023 (2003).</li>
<li>Everling, S., DeSouza, J. F. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Rule-dependent+activity+for+prosaccades+and+antisaccades+in+the+primate+prefrontal+cortex%5BTitle%5D)+AND+%22J.+Cogn.+Neurosci%22%5BJournal%5D)">Rule-dependent activity for prosaccades and antisaccades in the primate prefrontal cortex.</a> J. Cogn. Neurosci. 17, 1483-1496 (2005).</li>
<li>Ford, K. A., Goltz, H. C., Brown, M. R. G., Everling, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Neural+processes+associated+with+antisaccade+task+performance+investigated+with+event-related+fMRI%5BTitle%5D)+AND+%22J.+Neurophysiol%22%5BJournal%5D)">Neural processes associated with antisaccade task performance investigated with event-related fMRI.</a> J. Neurophysiol. 94, 429-440 (2005).</li>
<li>DeSouza, J. F. X., Nicolle, D. A., Vilis, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Task-dependent+changes+in+the+shape+and+thickness+of+Listing%27s+plane%5BTitle%5D)+AND+%22Vision+Res%22%5BJournal%5D)">Task-dependent changes in the shape and thickness of Listing's plane.</a> Vision Res. 37, 2271-2282 (1997).</li>
<li>Hadjikhani, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Mechanisms+of+migraine+aura+revealed+by+functional+MRI+in+human+visual+cortex%5BTitle%5D)+AND+%22Proc.+Natl.+Acad.+Sci.+U.S.A%22%5BJournal%5D)">Mechanisms of migraine aura revealed by functional MRI in human visual cortex.</a> Proc. Natl. Acad. Sci. U.S.A. 98, 4687-4692 (2001).</li>
<li>DeSouza, J. F. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Eye+position+signal+modulates+a+human+parietal+pointing+region+during+memory-guided+movements%5BTitle%5D)+AND+%22J.+Neurosci%22%5BJournal%5D)">Eye position signal modulates a human parietal pointing region during memory-guided movements.</a> J. Neurosci. 20, 5835-5840 (2000).</li>
</ol>

We have nothing to disclose.

Identifying brain regions relies on creating an accurate contrast between the tasks scanned (i.e. in either the Stroop, incongruent versus congruent emotion and facial expression; or anti-saccade versus pro-saccade) in order to produce a map of activation related to the task. These functional maps can be more refined when behavior is collected in the scanner to remove trials where the subject made errors. These errors can be removed and if there was enough numbers of errors than functional maps could be made of these<sup...

A correction was made to <a href="http://http://www.jove.com/video/3237">Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis</a>. Joseph DeSouza and Laura Pynn middle initials were omitted at publication.
These have been corrected to:
Joseph F.X. DeSouza Laura K. Pynn

A correction was made to <a href="http://http://www.jove.com/video/3237">Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis</a>. Some of the authors middle initials were omitted.

Erratum: Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis

<table><tbody><tr><td>3-Tesla MRI machine</td><td>Siemens Magnetom Trio (Erlangen, Germany)</td><td></td><td></td></tr><tr><td>iViewX Eye Tracking </td><td>SensoMotoric Instruments, Inc.</td><td></td><td></td></tr><tr><td>BrainVoyager QX software </td><td>Brain Innovation, Maastricht, The Netherlands</td><td></td><td></td></tr><tr><td>Four-button Joystick</td><td>Current Designs, Inc., Philadelphia, PA, USA</td><td></td><td></td></tr><tr><td colspan="4">&lt;strong&gt;Table 1. &lt;/strong&gt; Specific Reagents and Equipment.</td></tr></tbody></table>

correlating behavioral responses to fmri signals from human prefrontal cortex: examining cognitive processes using task analysis

Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis

The aim of this methods paper is to describe how to implement a neuroimaging technique to examine complementary brain processes engaged by two similar tasks. Participants' behavior during task performance in an fMRI scanner can then be correlated to the brain activity using the blood-oxygen-level-dependent signal. We measure behavior to be able to sort correct trials, where the subject performed the task correctly and then be able to examine the brain signals related to correct performance. Conversely, if subjects do not perform the task correctly, and these trials are included in the same analysis with the correct trials we would introduce trials that were not only for correct performance. Thus, in many cases these errors can be used themselves to then correlate brain activity to them. We describe two complementary tasks that are used in our lab to examine the brain during suppression of an automatic responses: the stroop1 and anti-saccade tasks. The emotional stroop paradigm instructs participants to either report the superimposed emotional 'word' across the affective faces or the facial 'expressions' of the face stimuli1,2. When the word and the facial expression refer to different emotions, a conflict between what must be said and what is automatically read occurs. The participant has to resolve the conflict between two simultaneously competing processes of word reading and facial expression. Our urge to read out a word leads to strong 'stimulus-response (SR)' associations; hence inhibiting these strong SR's is difficult and participants are prone to making errors. Overcoming this conflict and directing attention away from the face or the word requires the subject to inhibit bottom up processes which typically directs attention to the more salient stimulus. Similarly, in the anti-saccade task3,4,5,6, where an instruction cue is used to direct only attention to a peripheral stimulus location but then the eye movement is made to the mirror opposite position. Yet again we measure behavior by recording the eye movements of participants which allows for the sorting of the behavioral responses into correct and error trials7 which then can be correlated to brain activity. Neuroimaging now allows researchers to measure different behaviors of correct and error trials that are indicative of different cognitive processes and pinpoint the different neural networks involved.

The goal of our research is to correlate behavior to brain activity. Accurate behavioral measures and imaging techniques allow us to elucidate brain-behavior relationships.

The aim of this methods paper is to describe how to implement a neuroimaging technique to examine complementary brain processes engaged by two similar ...

The overall goal of the following experiment is to study the MRI signals related to the attentional responses to visual stimuli. This is achieved by scanning subjects while they attend to emotional stroop stimuli. At the same time button, press responses to the stimuli are recorded, which are the measure of behavior that will be correlated to the signals in the brain.Additionally, the subject's eye movements are recorded within an eye tracker within the scanner in order to obtain a measure of attentional selection. Results are obtained that show inferior frontal gyrus activation based on analysis of the correlations of behavior and FMRI signal during the stimulus response task. The main advantage of this technique over other ones such as positron emission tomography, is that subjects can be scanned for up to two hours.This system helps us understand a little bit more about frontal cortex inhibition. Dysfunction of this system is implicated in various neuropathology, such as a DHD and Tourette syndrome. Before beginning this experiment, potential participants should complete a study consent form as well as a standard MRI screening questionnaire subjects.With any contraindications to MRI must be excluded. Once paperwork is complete, provide the subject with a training session on the antis task. Here, a green fixation indicates a pro secod trial.Instruct the participant to look at the target appearing in the periphery of the screen at a visual angle of eight to 10 degrees. A red fixation indicates an antis COD trial instruct the participant to look into the mirror opposite of the target appearing in the periphery of the screen again at a visual eight to 10 degrees. For example, if a right target appears, the subject should look to the left.Next, provide training for the emotional stroop task. This is a pseudo event related paradigm in which descriptive words indicating the expressions are superimposed over pictures of individual faces. The words are either congruent or incongruent with the emotion depicted by the face.In the picture, instruct participants as to which buttons are pressed for reporting a happy expression or word, a neutral expression or word or a sad expression or word. The task should begin with a one second written instruction screen reminding the participants to either report the face expression or the written word by pressing the corresponding button as quickly as possible. This is followed by one second of a fixation cross, then by the face stimuli for 250 milliseconds, and then a response image for two seconds.The response image serves to give the participants time to report their responses. The next visual presentation of the fixation cross begins after the end of the response image. Include 15 practice trials with different combinations of face word expressions.To begin set up for scanning. First turn on a digital projector to display the computer stimulus as a focused image on a screen in the MRI bore. Then bring the participant into the scanner room and provide earplugs and headphones to provide hearing protection.Have the subject lie supine and position the head in the center of the head.Coil.Cradle. Stabilize participant's body and head position with pillows or foam inserts to provide comfort while restricting movement of the head. Now, place the head coil.Then have the subject tilt his or her head comfortably while looking straight ahead to view the mirror, reflecting the projected image, the eyes should be as close to primary position as possible in order to maintain the participant's comfort over the scanning session, which can last up to two hours. Ask the participant if the projected image is in focus. If it is not sharp, readjust the lens to improve the image clarity.Then calibrate the eye tracker to ensure that the infrared camera is in the correct location. If the reflection on the cornea is not ideal, the infrared source should be adjusted or the mirror reflecting the infrared source near the participant's head position should be realigned. Also, ask the subject if more foam padding or pillows are needed to maintain this position.Once equipment set up is complete, place an emergency contact squeeze ball in the participant's right hand and the response box in the left hand. Also place a vitamin E capsule on the right side of the headphones as this will be visible in anatomical scans and can help assure images are not flipped from left to right. Finally, raise and slide the bed into the center of the MRI.Once in the control room, use the intercom to confirm that the participant is prepared to begin the scanning session and is as comfortable. Also, remind the participant that the scanner noises will be loud. Begin by acquiring a localizer scan.Then prescribe a series of anatomical slices that cover the whole brain. Typically axial oblique slices should be used. Let the participant know about how long the anatomical scan will take.This can be around six to 10 minutes depending on the prescribed number of slices. Alternatively, the anatomical scan can be acquired after the functional scans. Once anatomical scans are completed, prescribe a functional sequence and remind the participant of the task instructions for the stroop paradigm.Then begin the scanner and paradigm synchronously recording all button presses. Be sure to monitor and record the participant's horizontal and vertical eye positions using the infrared eye tracker so that these data can be correlated with the behavioral paradigm. Next, instruct the subject that the anti Scho paradigm will be performed during the next scan.Then start the scan with the synced paradigm. Depending on the imaging parameters chosen, the scan will be close to six minutes long. Avoid longer scans as subjects may fall asleep.This entire imaging session can take 60 to 120 minutes depending on the time needed for setup and subject specific adjustments and the number of functional scans required for the analysis. The data obtained from this experiment can be analyzed using any FMRI analysis package, such as brain voyage or qx. Seen here.A acne or SPM are other commonly used FMRI analysis programs. Statistical maps derived from the functional data should be superimposed onto anatomical brain images. To do this, first, use the general linear model or GLM to functionally define the brain regions of interest with separate predictors for each of the conditions in the task.During the two types of scans, use the following predictors, congruent and incongruent face instruction and word instruction, antis, secod, and pros secod. Next, examine the signal intensity in all the activated frontal regions from the GLM contrasts. Then compute the standardized bold signal across all participants and compare the incongruent word face expression with the congruent word faces.Expressions for both conditions finally correlate the reaction times collected on the trials that were used for. The GMs then correlate brain activity across each individual with their own reaction times for the specific trials. The image seen here shows left inferior frontal gyrus or IFG that was functionally localized using the contrast for the incongruent emotional stroop versus the congruent conditioning.During the attend to word instruction set. Here we see that when the expression of the face was incongruent to the superimposed emotional word, the incongruency produced from reporting the written word produced higher bold signal intensity. In the left, IFG incongruent expressions showed significantly larger bold signal change compared to congruent expressions.During the attend to word instruction, incongruent congruent contrast showed a positive correlation between the reaction times and bold signal intensity. This graph is an average of 10 subjects reaction times and bold signal during each of the six conditions. Here the top row is a schematic illustration of a trial sequence from one block of trials.Bottom section is a depiction of the two gamma hemodynamic response function used to discover brain regions involved in the emotional face expressions. While attempting this procedure, it's important to remember to check on the subject in between scans and remind them to remain as still as possible to reduce motion artifact Following this procedure. Other techniques such as magne ence biography can be used to examine the timing effects within the inferior frontal gyrus.

correlating-behavioral-responses-to-fmri-signals-from-human

Research

JoVE Journal

Neuroscience

This article demonstrates an experimental design in which whole-body animated characters are used in conjunction with functional magnetic resonance imaging (fMRI) to investigate the neural correlates of observing virtual social interactions.

Brain Imaging Investigation of the Neural Correlates of Observing Virtual Social Interactions

We present a protocol that allows investigation of the neural mechanisms mediating the detrimental impact of emotion on cognition, using functional magnetic resonance imaging. This protocol can be used with both healthy and clinical participants.

Brain Imaging Investigation of the Impairing Effect of Emotion on Cognition

This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data.

A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

Transferring a paradigm with a history of use in EEG experiments to an fMRI experiment is considered. It is demonstrated that manipulating the task demands in the visual oddball task resulted in different patterns of BOLD activation and illustrated how task design is crucial in fMRI experiments.

Transferring Cognitive Tasks Between Brain Imaging Modalities: Implications for Task Design and Results Interpretation in fMRI Studies

Monitoring brain activity outside the lab without physical constraints presents methodological challenges. A fiberless, wearable functional Near Infrared Spectroscopy (fNIRS) system was used to measure brain activity during an ecological prospective memory task. It was demonstrated that this system could be used to monitor brain activity during non-lab based experiments.

Using Fiberless, Wearable fNIRS to Monitor Brain Activity in Real-world Cognitive Tasks

The present protocol describes how to perform concurrent EEG and fNIRS recordings and how to inspect the relationship between the EEG and fNIRS...

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

Presented here is a video analysis pipeline that overcomes challenges in behavioral monitoring within MRI environments, allowing for the detection of uninstructed behavioral responses to external cues. This analysis will facilitate a more comprehensive understanding of evoked internal state changes and brain-wide activity.

Profiling Maternal Behavior Responses During Whole-Brain Imaging

We introduce a protocol for exploring the neural correlates of a cognitive emotion regulation task, namely cognitive reappraisal, using functional magnetic resonance imaging. This protocol was used in patients with obsessive-compulsive disorder and healthy controls but can also be used in other clinical samples.

Exploring the Neural Correlates of Cognitive Reappraisal in Obsessive-Compulsive Disorder Using Task-based Functional Magnetic Resonance Imaging

We have developed two methods for studying effects of visual cues on behavior in the absence of tactile and chemical cues.  One method involves videotaping responses of crayfish to reflective walls in an aquarium; the other examines effects of visual inputs provided by a live crayfish behind a transparent partition.

Recording Behavioral Responses to Reflection in Crayfish

We describe a novel approach for simultaneous analysis of brain function and structure using magnetic resonance imaging (MRI). We assess brain structure with high-resolution diffusion-weighted imaging and white-matter fiber tractography. Unlike standard structural MRI, these techniques allow us to directly relate anatomical connectivity to functional properties of brain networks.

Co-analysis of Brain Structure and Function using fMRI and Diffusion-weighted Imaging

Learn to correlate behavioral responses with fMRI signals from the human prefrontal cortex using emotional Stroop tasks. This method reveals activation in the inferior frontal gyrus during attentional processing.

Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis (Video) | JoVE Journal

Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis

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