Question

Discuss how neuroimaging techniques can provide information about the brain’s structure and function.

Answer 1

Answer:

Neuroimaging, or brain scanning, includes the use of various techniques ( Four of the most common types of brain scans are EEG, PET, MRI, and fMRI )to directly or indirectly image the structure, function, or pharmacology of the brain

Explanation:

Electroencephalography (EEG) is used to show brain activity under certain psychological states, such as alertness or drowsiness.

Positron emission tomography (PET) scans show brain processes by using the sugar glucose in the brain to illustrate where neurons are firing.

Magnetic resonance imaging (MRI) scans use echo waves to discriminate among grey matter, white matter, and cerebrospinal fluid.

Functional magnetic resonance imaging (fMRI) scans are a series of MRIs measuring brain function via a computer’s combination of multiple images taken less than a second apart. With this different scan it is possible for the function and structure of the brain to be determined.

Answer 2

Answer:

These are different techniques of viewing the brain activities and possible anomalies without the usual open surgeries.

Example of these techniques are;

Functional magnetic resonance imagine ; (fMRI) is used to detect how blood and oxygen flow during neural activity to active areas of the brain. Since increased activity in particular cells of the brain area requires increase consumption of oxygen. fMRI can be used to identify and mapped out active areas of the brain during different cognitive tasks, and when the brain is at rest.  

This sensitivity to oxygenation of the blood, makes it idea for detection of large drop in blood oxygen levels (ISCHEMIA in the brain .

Computed tomography (CT) scanning; the operation of CT is based on the degree of absorption of X-rays by different in parts of the brain.As the head passes through the hollow cylinder of beam, of X-rays, bones,soft tissues, body fluid, air lodged in the brain, they absorbs X-ray beams. The scan gives detail picture the the gross structure of the brain. All though they can be used to detect some diseases  internal bleeding.; they can not accurately detect cancer tissues in the brain.Although they can be used for detection of

Positron Emission Tomography(PET) This techniques involved the use of injected short-lived radio active materials into the brain,and map out the activities of the brain from the picture produced by the decay of the radio active materials. Positron with short half life and rapid metabolism is usually used, to emits radiation.The radiation is picked up by the detectors, and transmitted to the screen for visualization. An area of high neural activity emits more radiation and this can be used for mapping activities of the brain. The emission of radiation by PET, makes it less preferable to fMRI with no radiation.

Electroencephalography (EEG)  makes use of the  electrical signals received from electrodes connected to different part of the scalp to map out activities  of different brain parts.  Thus the amount  of current  produced can be used to measure the degree of activities of the part of the brain.The potential produced by these parts of the brain are pick by detectors and recorded as electroencephalogram.

It is therefore idea for detection of diseases or anomalies, that relates to disruptions of the synaptic transmission in the brain; e.g seizures, epilepsy, brain tumor, insomnia  can be detected.  and recorded as Electroencephalography

Magnetoencelography  uses the value of  oscillation produced in the magnetic field of the current from electrical activity of a brain part, to determine functions of different brain parts,its pathology and  structure.

It is very expensive.

Near infrared spectroscopy (NIRS) .This optical technique is used to map out brain activities by measuring  the concentration of oxygen in the cerebral flow.it is carried out by shining infrared light through the skull and measure the amount of light is absorbed by the  brain based on the amount  that reemerged. Since infrared will be absorbed by  oxygen.This measure  brain activity, because, high oxygenation indicate high neural activity.  High reemerged light indicates low oxygenation  reduced activity of the brain which may be due to  anomalies.