Last night, IEEE’s Computational Intelligence Society hosted a talk by Dr. Bharat Biswal about his latest imaging research on brain connectivity. He first explained the difference between a traditional MRI image and a functional MRI (fMRI) image and compared them to information obtained from a digital camera. A digital picture is one moment in time and has a high resolution – similar to a single MRI image. A video taken from a digital camera is lower resolution but gives information about what happens over time – similar to fMRI. An MRI image resolution is 1mm3 and takes about 5-7 minutes to produce while fMRI resolution is 3.75mm3 and takes about 2 seconds. You can then overlay your findings from the fMRI onto an MRI image to see the regions of activation.
He has run a variety of imaging experiments using fMRI to find areas of activation and connectivity. Resting state used a black screen to attempt to be a baseline (though it is difficult to baseline subjects’ brains since you can’t control what someone is thinking or feeling while looking at the black screen). He then imaged subjects while performing various exercises like finger tapping and also exposed subjects to increased CO2 levels to change their hemodynamics. He was able to find reliable, reproducible areas of connectivity across patients.
Since much work has been done using fMRI to image brains, he also collected data from other researchers to increase sample size. With over 1,000 subjects, he was able to break subjects into categories for comparisons. He looked at young and old persons, male and female, those with mental illness and those without. In every comparison, he found differences and correlations between groups. Much more research must be done before brain connectivity is fully understood since activations only accounts for 7% of brain activity.
It was a very interesting presentation, and I’m glad that I went!
*The talk was also hosted by Fordham University’s Information Fusion class taught by Dr. Frank Hsu. A big thank you to Dr. Hsu, his class, Dr. Biswal for his presentation, and Dr. Ravi Rao (chair of IEEE’s New York chapter of CIS) for allowing me to attend.
