Methods, Inventions, & Technologies

Quantitative Electroencephalography (QEEG)

Most of our studies involve quantitative electroencephalography (QEEG).  These digital recordings of  brain electrical activity employ six to 36 electrodes focused either on a limited brain region (such as the frontal cortex), or distributed to record activity from all major brain regions.  We utilize several QEEG measures including cordance, a measure developed in our Laboratory. [hot button leading to cordance pubs]  Cordance has been studied in adult and elderly subjects with major depression.  Cordance is calculated utilizing:  1) a new reference electrode method for calculating absolute and relative QEEG power, and 2) a method for integrating absolute and relative power measures into a single measurement.  As a means of validating the cordance algorithm, we studied subjects with simultaneous ¹⁵O PET and QEEG measurements.  These studies examined the association between QEEG measurements at each electrode and perfusion underlying the electrode, and determined that cordance shows stronger associations with cerebral perfusion than traditional power measurements.  Cordance values can be calculated for any frequency band, and our pilot data and prior reports from others indicate that alterations related to depression might be best detected in the theta band (4-8 Hz).  Because of these prior studies, most of our work focuses on cordance values in the theta band.

Genotyping

Some work has shown that genetic polymorphisms, such as those in the promoter region of the serotonin transporter gene, are related to the outcomes of antidepressant treatment.  We therefore collect blood samples from subjects in many of our studies to examine the relationships among brain function, genotype, and treatment outcome.  The genes of interest include those coding for the serotonin transporter and certain serotonin receptors, as well as genetic targets in the dopamine and norepinephrine systems