Brain activity involves the measurement and analysis of the electrical, chemical, and metabolic processes that occur in the brain as a person engages in various cognitive tasks or experiences different emotions. This research area typically involves the use of imaging techniques such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and positron emission tomography (PET) to monitor and study brain activity in real-time. Researchers use these techniques to better understand how different regions of the brain are involved in various functions, such as perception, memory, language processing, and decision-making. By studying brain activity, researchers hope to gain insights into how the brain works, how it changes over time, and how it may be altered in neurological and psychiatric disorders.