Can you find any pattern in the two signals, green and blue? The blue signal is the brain wave (measured by NIRS) of a person when he is pressing some buttons (the timing of button pressing is shown i
Wavelet transform coherence (WTC) is a method for analyzing the coherence and phase lag between two time series as a function of both time and frequency (Chang and Glover 2010). Here I played with it
SVM is mostly commonly used for binary classifications. But one branch of SVM, SVM regression or SVR, is able to fit a continuous function to data. This is particularly useful when the predicted varia
Update 2021/2/27: If you find griddata3 not working, try to change griddata3 to griddata. I was asked where to get nirs2img script. Here it is. The download link is at the bottom of this article. nirs2img is to create an image file from the input data. Then theimage file can be viewed by a
One of the advantages of NIRS is that it measure two values at a time – both oxy- and deoxy-Hb concentration, while fMRI measure only one value, called BOLD. (See a comparison between NIRS and fMRI.) However, what is the use of measuring two va
I usually report a group-level T-test image in the final publications or presentations. But in the early stage of a project when only one or a few subjects have been scanned, I often need to report an activation map for an individual subject after ge
The following script is to determine is a channel (or voxel) survives the FDR corrected threshold. Assume you have 48 channels and you already calculated the (uncorrected) p-value of each channel. You put it into an array called p. Now you want to kn
Finger tapping is probably the most used task in brain imaging studies (fMRI and NIRS). The task is simple and elicits robust brain signal in the motor cortex. We always use it to test new devices or develop a new method. If you want to control your
Below is sample hyperscanning data from one subject (myself). For detailed information please refer to http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3254802 Name Email
This is a guest post by Andrew Gundran and Paul Mazaika, both working with NIRS in Stanford University. They did an interesting experiment comparing the light power between NIRSport and Octamon. We ran experiments to compare the emission signal stren
Back in 2010 we ran a simultaneous fMRI-NIRS experiment (see publication here). At that time we borrowed a 10m long optical fibers from Hitachi (Thank them!). The participants had to wear a NIRS cap (with probes) while lying in a fMRI scanner. And th
It’s often said that dark hair is bad for NIRS experiment because it absorbs more light. I heard this on day one when I started using NIRS back in 2008. I never got a chance to do a systematic experiment to compare hair colors and their effect
