http://www.nature.com/news/2008/080411/full/news.2008.751.htmlHaynes and his colleagues imaged the brains of 14 volunteers while they performed a decision-making task. The volunteers were asked to press one of two buttons when they felt the urge to. Each button was operated by a different hand. At the same time, a stream of letters were presented on a screen at half-second intervals, and the volunteers had to remember which letter was showing when they decided to press their button.
When the researchers analysed the data, the earliest signal the team could pick up started seven seconds before the volunteers reported having made their decision. Because of there is a delay of a few seconds in the imaging, this means that the brain activity could have begun as much as ten seconds before the conscious decision. The signal came from a region called the frontopolar cortex, at the front of the brain, immediately behind the forehead.
A brain scan, also known as a brain imaging technique, is a medical procedure that uses technology to create images of the brain. This can be done through various methods such as magnetic resonance imaging (MRI), computed tomography (CT) scan, positron emission tomography (PET) scan, or electroencephalography (EEG). These techniques use different forms of energy, such as magnetic fields or radio waves, to produce detailed images of the brain's structure and function.
A regular scan, such as an X-ray or ultrasound, is used to image parts of the body such as bones or organs. A brain scan, on the other hand, specifically targets the brain and allows for detailed images of the brain's structure and function. It can also be used to diagnose and monitor various brain disorders and diseases.
The duration of a brain scan can vary depending on the type of scan being performed. For example, an MRI can take anywhere from 20 minutes to an hour, while a PET scan can take up to 2 hours. However, advancements in technology have allowed for faster brain scans, with some techniques now taking only a few minutes to complete.
Brain scans are generally considered safe and non-invasive. However, some techniques, such as PET scans, involve the injection of a radioactive substance which may carry some risks. It is important to discuss any potential risks with your doctor before undergoing a brain scan.
While brain scans can provide valuable information about the brain's structure and function, they may not be able to detect all types of brain disorders. Some disorders, such as depression or anxiety, do not have specific physical markers that can be detected through brain imaging. Additionally, brain scans are just one tool used in diagnosing brain disorders, and a comprehensive evaluation by a medical professional is necessary for an accurate diagnosis.