ABSTRACT
In recent years, noninvasive brain stimulation (NIBS) has been embraced as an increasingly popular method of both investigating and enhancing human cognitive abilities. Two main methods include transcranial magnetic stimulation and transcranial electrical stimulation, which includes the subtypes of transcranial direct current stimulation, transcranial alternating current stimulation, and transcranial random noise stimulation. Such techniques utilize external sources (e.g., magnetic pulses or electrical current) to remotely modulate the local electromagnetic properties of neuronal populations within the brain. By varying factors of the stimulation such as frequency, amplitude, duration, and location of application, these versatile methods can induce suppression or enhancement of targeted cortical areas. By systematically modulating localized neuronal activity, NIBS can establish causation in relationships between neuronal function and behavior that previously could only be observed in correlation. Additionally, NIBS can be used for neuroenhancement of cognitive abilities.
In this chapter, we first outline the current understanding of the neuromodulatory mechanisms behind these techniques and subsequently discuss how they have been used in recent years to illuminate diverse fields of human cognition. We discuss details of practical use and the stimulation parameters that researchers may wish to choose based on experimental design. Last, we touch on the future of NIBS and areas in which it shows particular promise, such as cognitive development, aging-related neurorehabilitation in populations with cognitive decline, and enhancement in congenital cognitive disabilities.
