Investigation of the Causal Relationship between Different Brain Areas and Behavior




Our knowledge of the relationship between activity in a particular area of the brain and a specific behavior comes from the examination of patients with an injury to their brain who suffer from cognitive and behavioral problems. Based on studies of different areas of the brain, we now know that some areas are correlated with cognitive and behavioral patterns. However, as a researcher aims to study the relationship between a particular area of the brain and behavior or a cognitive component, it is very difficult and frustrating to wait for a patient with an injury to the desired area of the brain.  But no worries if you want to work on such a hypothesis because we are living in an era when one can study the brain by using one of the most promising emerging tools in neuroscience.

Transcranial magnetic stimulation (TMS) was invented by Dr. Anthony Barker at the University of Sheffield, England, in 1985. Soon after, it became a powerful tool for brain studies. This technique creates a focal magnetic field on a patient's skull through a coil and changes the activity of a set of neurons beneath the coil's surface, allowing manipulattion of the brain function. By increasing or decreasing cortical excitability, TMS can make changes to the stimulated cortical area or the surrounding areas related to the stimulated area. If you seek an answer to the same basic question (whether the X area of the brain is related to a Y particular behavioral or cognitive component), TMS is able to cause a virtual lesion in the brain so that you can disable an area for a short time and see if that area is related to the intended behavior. 

The review of the literature on TMS can reveals how much this technique has developed over the past years. A review study on papers about this field published from 1988 to 2017 showed that 17,492 papers have been published in this field so far with an annual mean of 583 papers. This study also indicated that the annual growths of papers in this field was 127.18% from 1988 to 1992, 30.95% from 1993 to 1997, 16.36% from 1998 to 2002, 13.04% from 2003 to 2007, 9.31% from 2008 to 2012, and 3.06% from 2013 to 2017. The following figure shows the growing trend of science production in this field:


Recently, the combination of TMS with other neuroimaging modalities has augmented the strength of this method. The combination of TMS with an electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) has provided extremely useful tools for the examination of neural circuits. These tools allow us to have an online picture of what happens in the brain and monitor the TMS-caused behavioral and neurological changes.

Brain Stimulation Facilities of Atieh NeuroLab

Our lab is equipped with one of the most advanced TMS devices (Mag Venture X 100). This device allows you to apply many stimulation protocols such as single pulse, repetitive, and Theta Burst. Equipped with a powerful cooling system, this device allows therapists to stimulate the brain with a pulse rate of 4000 to 6000 at high frequency and intensity.


NEURO PRAX is an amplifier system for TMS-EEG studies. This device has an online TMS-associated noise removal algorithm that allows you to separately remove the noise and analyze your records.