Questions: Question 4 1 pts Which of the following is a brain imaging technique? transcranial direct current stimulation microdialysis transcranial magnetic stimulation positron emission tomography

The answer is the fourth one: positron emission tomography.

Explanation for each option:

1. Transcranial direct current stimulation (tDCS): This is a form of neuromodulation that uses constant, low direct current delivered via electrodes on the head. It is not a brain imaging technique but rather a method to stimulate brain activity.

2. Microdialysis: This is a technique used to measure the concentration of chemicals (such as neurotransmitters) in the extracellular fluid of tissues. It is not a brain imaging technique but a method for sampling chemical substances in the brain.

3. Transcranial magnetic stimulation (TMS): This is a non-invasive method used to stimulate small regions of the brain. It is used for both research and therapeutic purposes but is not a brain imaging technique.

4. Positron emission tomography (PET): This is a brain imaging technique that uses radioactive tracers to visualize and measure changes in metabolic processes, and other physiological activities including blood flow, regional chemical composition, and absorption.

Summary: Positron emission tomography (PET) is the correct answer as it is a brain imaging technique, unlike the other options which are methods for brain stimulation or chemical measurement.