How can scientists study the living brain if it is protected by the skull? The textbook notes several methods for this type of study. Describe the different techniques that have been used to explore the workings of the brain

What will be an ideal response?

Answer: A good answer will include the following key points.
? Electroencephalogram (EEG)—recording brain waves through electrodes attached to the scalp.
? Event-related potentials (ERP)—a technique that isolates the neural activity associated with a specific stimulus or event.
? Transcranial magnetic stimulation (TMS)—a method of stimulating brain cells, using a powerful magnetic field produced by a wire coil placed on a person's head; it can be used by researchers to temporarily inactivate neural circuits
? Transcranial direct current stimulation (tDCS)—a technique that applies a very small electric current to stimulate or suppress activity in parts of the cortex; it enables researchers to identify the functions of a particular area.
? Positron-emission tomography (PET scan)—records biochemical changes in the brain, often after injection of radioactively-labeled glucose allowing researcher to "see" which areas of the brain are most active.
? Magnetic resonance imaging (MRI)—using powerful magnetic fields to produce vibration in the nuclei of atoms, then recording the vibrations and converting them into a high-contrast image of the brain.
? Functional MRI (fMRI)—an ultrafast MRI allowing visualization of second-to-second changes in the brain. In fMRI, the receivers detect levels of blood oxygen in different brain areas. Because neurons use oxygen as fuel, active brain areas produce a bigger signal.