The Sol Braiding Method for Handling Thick Hair During Transcranial Magnetic Stimulation: An Address for Potential Bias in Brain Stimulation

The question we are addressing is whether braiding hair can solve the age-old problem in neuroscience of dealing with thick, curly, dense hair that is typical of minorities. As a leading TMS lab, we have a responsibility to promote inclusion. While our research on self-deception and self-awareness is recognized, we also strive to explore ways to increase diversity.

Our survey research revealed that participants with the care were excluded or not efficiently tested. We offer an easy and quick method to stimulate the brain in these cases. To begin, monitor the temperature of the 70-millimeter figure of eight coil.

Have backup coils prepared and accessible for immediate replacement if needed. Then, using an erasable magic marker, mark the Cz, nasian, or inian line region and the midpoint. Also, measure and mark the ear lobe or preauricular points.

Measure one-third down the right hemisphere line to locate the optimal location for activating abductor pollicis brevis, or APB. Using the coil trigger and foot switch, activate the TMS device and disengage the safety from the front of the machine. Position the TMS coil at a 45-degree angle for all searches and TMS deliveries.

Now, using the dial on the front of the machine, start the stimulation output at 30%of the total machine output. Incrementally increase the intensity by 2%until movement is noted. To facilitate accurate placement before starting motor threshold determination, mark the coil tip site on the swim cap.

Using a magic marker, outline the entire anterior portion of the coil. For the visual inspection method, use the dial to start at 20%of the machine's intensity and deliver around 20 pulses. Once 50%of the responses have been obtained, record the intensity as the individual's motor threshold.

For the motor evoked potential method, attach disposable electrodes to the APB and the tendon of the thumb, with a ground electrode around the back of the wrist. Instead of visual inspection, ensure a positive motor evoked potential is observed on the recording unit. Define a positive motor evoked potential response as one with a peak-to-peak amplitude of 50 microvolts or more.

To begin, try various brushes, combs, and paints, as preferences for these tools can vary among researchers. Describe the braiding methods to the participant using photographs during the consent process. Identify the target points prior to starting the braiding process.

To transfer the 10-20 coordinates onto the scalp to guide the braiding, use a standard ERP or EEG cap, a gel syringe, and a blunt needle with GFP. Apply the cap and mark the target points with a small dab of GFP. Then start from the marked point on the head and pull the hair away with fingers or a pick to clear the surrounding skin area.

Ensure the skin around the mark is visible. To begin the first cornrow, part a small section of hair from any side of the marked point. Use both hands to divide this initial clump of hair into three equal sections in terms of hair quantity.

Then hold the left section in the left hand and the right section in the right hand. Use one or both index fingers to hold down the middle section. If done correctly, the original right section should now be in the middle, and the original middle section should have moved to the right.

Now lift the leftmost section of hair and cross it over between the middle and right sections. Take the right section of hair and repeat the crossing over process, adding some new hair from the scalp underneath the piece. Keep cornrowing until you reach the end of the clump of hair.

Repeat this process six to eight times to create a sun-like shape with the cornrow. Significant improvements were observed in amplitude and AUC following braiding, potentially reducing motor threshold in TMS.