ABSTRACT
In the last two decades, the advent of noninvasive brain stimulation (NBS) techniques has allowed us to systematically study the functionality of various brain regions in great detail. NBS methods such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) not only can function as
Summary ................................................................................................................ 279 11.1 What Is NBS? ...............................................................................................280 11.2 Brief Historical Background of Brain Stimulation ....................................... 282 11.3 Mechanism of Action Underlying TMS and tDCS ...................................... 282
11.3.1 TMS .................................................................................................. 282 11.3.2 tDCS ................................................................................................. 283
11.4 Using NBS to Study Brain Function ............................................................284 11.4.1 Measures from NBS: What Do They Represent? .............................284 11.4.2 Combining NBS with Neuroimaging Techniques ............................287
11.5 NBS as a Rehabilitative to Improve Brain Function .................................... 289 11.5.1 Alzheimer’s Disease ......................................................................... 289 11.5.2 Depression ........................................................................................290 11.5.3 Neurological Disorders ..................................................................... 291 11.5.4 Brain Injuries and Stroke .................................................................. 293
11.6 Can Nutrition and NBS Be Complimentary? ...............................................294 11.7 Future Direction for NBS .............................................................................296 References ..............................................................................................................297
a tool to establish the interconnectivity of different brain networks (i.e. cognitive, motor, executive and inter-hemispheric) but can also be used as an interventional non-pharmacological means of treating various mental health and neurological disorders. The mechanism of action of NBS is centred on modulating neurophysiological processes that underpin brain plasticity, which is vital for the brain to adapt to the external environment (i.e. learning), injury or disease. The effects of TMS and tDCS are thought to primarily act upon the release of excitatory and inhibitory neurotransmitters at the synaptic junction and the polarity of the neuronal membrane that ultimately impacts upon the strength of communication between neurons. Particularly intriguing is that the neuro-modulatory effects of TMS and tDCS may outlast the period of stimulation. Thus NBS techniques have the potential as adjunctive or stand-alone treatments for various mental health and neurological conditions. This chapter provides an overview of the history and evidence regarding the use of NBS to measure brain function and will explore the interventional effects of NBS on cognition in healthy and clinical populations. Lastly, this chapter will discuss the strengths and limitations of current NBS systems and the potential for combining micronutrients (using the example of caffeine) and NBS to improve cognitive function.
