The overall goal of this study is to evaluate the use of a fibrous, functional, near infrared spectroscopy system to monitor frontal lobe, hemodynamic, and oxygenation changes induced by a cognitive task. This method can help answer key questions about prefrontal cortex function that are most optimally studied in naturalistic settings rather than in the laboratory. Ner sufferers.
The advantages of being non-invasive, portable wearable with minimally restrictions make it suitable to monitor brain functional activation in freely moving subjects in naturalistic environments, such as in the center of London. This technique can potentially be used to detect rostral prefrontal cortex abnormalities, which avail themselves in naturalistic tasks, but not in the laboratory. It can also be applied to clinical settings like neuro rehabilitation to investigate the neural effect of training procedures.
Demonstrating the procedure will be a fin lead, a research assistant here at UCL and Beth Wickler, Sarah Power postgraduate students here at UCL Begin by setting up a camera on the experimenter's chest in order to follow the participant's movements. Then mount a head camera onto the functional near infrared spectroscopy or F nears shading cap, which is used to protect the device from sunlight and to track where the participant looks during the experiment, prepare and turn on a camera for the second experimenter who follows the first experimenter and the participant around for the entire session. Finally, clean the F N'S headset with a sanitizing wipe.
Before the experiment begins, have the participant sign the consent form. Use the 10 20 system to digitize the optos and use the 10 20 standard positions to achieve consistent FNE R'S headset placement across all the participants. Use a washable marker to mark the Nasion and Ian and measure the distance between these two points.
Then mark the left and right preauricular points, and measure the distance over the head between these points. Mark the FPZ and FZ points based on the 10 20 system. Next place the F Ns headset on the participant's head and align channels eight and nine to the FPZ fz line and overlap.
Channel nine to FPZ ensure the probe is securely attached to the participant's head. The F N'S headset needs to be well attached to the end in order to prevent any displacement during natural walking, which can cause motion artifacts that corrupt the measurement. After digitization, place the shading cap with the mounted head camera over the F NS headset.
In order to protect the device from the sunlight, The shedding cap is necessary to reduce the risk of saturating the optical detectors, which is caused by sunlight. Finally, explain the experimental rules to the participant. Inform them that no running is allowed and that they must stay within the designated outside area.
Go outside to begin the experiment. Begin by pressing the power button on the portable box and put the F ns into the wireless mode. Then open the F NS acquisition software on the F Ns laptop and establish a connection with the portable box.
Press the probe adjustment button to optimize the detector's gain on the base of the detected light. Next, press the ready button and then start to acquire data for a minute. Check if a heartbeat is visible on the concentration signals, which ensures a good signal quality.
Press the power button on the portable box to turn off the wireless mode. Additionally, press the power button and the mode button on the portable box to put the F nears in standalone mode. Next, turn on the head camera and both the experimenter's cameras.
To start filming, press the probe adjustment button on the F N'S portable box to optimize the detector's gain. Then press the play stop button on the portable box to start the F N'S acquisition. Finally, manually add a marker to the F n's data by using the mark button on the F N's portable box in conjunction with an audio trigger, which must be clearly recorded on all video cameras.
Then start the experiment to assess frontal cortex function, have the participant complete a perspective memory task. Begin by having the participant stand stationary on a street where the test is conducted, and count the number of stimuli on a piece of paper. Then have the participant walk a short distance at a normal walking pace.
For the baseline condition, have the participant walk around the street where the experiment is conducted. Next, have the participant walk around the experimental area and count the occurrence of certain items to complete the uncontaminated ongoing condition. For the non-social perspective memory condition, have the participant give a fist bump to each parking meter as he comes within a specified distance of it.
At the same time, the participant must count the number of dates and opening hours affixed to the buildings. Next, for the social perspective memory condition, have the participant give a fist bump to a Confederate who moves to pre-specified locations in the experimental area. At the same time, have the participant count the number of doorbells.
Then have the participant count the number of unobstructed stairways within the testing area to complete the contaminated ongoing condition. Repeat the two rest conditions in the opposite order. Finally, watch the synchronized video stream and annotate the start and the end of each experimental condition of the cognitive task.
Obtain timestamps for the point at which each perspective memory target is reached. Finally, pre-process the F NS data. Remove physiological noises with a band pass filter and correct for motion artifacts.
A fibrous, wearable functional, near infrared spectroscopy system was used to measure frontal cortex activity during an ecological prospective memory task. The color maps shown on the brain cortex indicate the amplitude changes in concentration of oxyhemoglobin and deoxyhemoglobin across all the measurement channels, while the participant executes social and non-social perspective memory tasks. This profile of hemodynamic changes demonstrates increments of oxyhemoglobin and decrements of deoxyhemoglobin that are typical of functional activation.
This is shown in response to non-social and social perspective memory tasks. Higher oxyhemoglobin increases and deoxyhemoglobin decreases to social perspective. Memory tasks are localized both on the left and right prefrontal cortex, whereas similar hemodynamic changes during non-social perspective memory tasks are mainly localized in the left prefrontal cortex.
In this video, we have demonstrated how to perform functional experiments using a portable wearable device to assess brain activity to life-based cognitive tasks. So the current experiment can take up to one hour and 30 minutes, which includes both the experimental setup and the execution of the functional task. While attempting this procedure, it's important to remember to stabilize and protect the instrumentation and synchronize All the recordings.
The percentage results are preliminary and refer to one participant. Statistical analysis are required to localize functional activation. In addition to analyzing a larger sample by including more participants following this procedure, the analysis of the video recordings has to be Performed in order to recover functional events.
Behavioral analysis of the video recordings can help us link the F nears neuro imaging data to the participant's performance. It's also possible to monitor systemic changes such as heart rated breathing rate, and investigate how these physiological changes can affect our ethne neuro imaging. This technology can pave the way for cognitive neuroscience researchers to study brain function in naturalistic and open-ended settings.
