CT scans are not useful for studying cognitive processes because these processes

occur in real time or occur in regions of the brain not accessible to CT scans

Please explain.

CT scans, also known as computed tomography scans, use X-ray technology to create detailed cross-sectional images of the body. While they are valuable for diagnosing structural abnormalities in the brain, they have limitations when it comes to studying cognitive processes.

One limitation is that cognitive processes occur in real time. CT scans provide static images, capturing a single moment in time. They do not allow for the observation of the dynamic and rapid changes that happen during cognitive processing. For example, when someone is solving a complex problem or engaging in attentional tasks, multiple brain regions are constantly interacting and changing their activity patterns over milliseconds. CT scans are unable to capture this real-time activity.

Additionally, cognitive processes often occur in regions of the brain that are not easily accessible by CT scans. CT scans generate images by detecting X-ray absorption, and structures with higher density, such as bones, appear brighter in the images. However, this technique is less effective for studying soft tissues, like the brain. The brain is made up of complex networks of neurons and glial cells, which do not have enough density contrast to be clearly visualized by CT scans. This makes it difficult to study the specific regions and networks involved in cognitive processes.

In contrast, other imaging techniques like functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) are better suited for studying cognitive processes. fMRI measures changes in blood flow to infer brain activity, while EEG records electrical signals generated by brain activity. These methods provide insight into the real-time dynamics of cognitive processes and offer better spatial resolution to identify specific brain regions involved.