Brain Scanning Techniques A look inside the Brain

G Neurology is a very new part of Psychology. G Neuroscientists must use many specialized techniques to look into the brain.

Ways to Look Inside the Brain G Electric Recordings G Lesioning G Electrical Stimulation of the Brain G Brain-Imaging Procedures G CT Scan G PET Scan G MRI Scan G fMRI Scan G Electric Recordings G Lesioning G Electrical Stimulation of the Brain G Brain-Imaging Procedures G CT Scan G PET Scan G MRI Scan G fMRI Scan

Electrical Recordings G Recordings of the electrical activity in the brain G Electroencephalograph (EEG) -a device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp G Identifies patterns of activity G Recordings of the electrical activity in the brain G Electroencephalograph (EEG) -a device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp G Identifies patterns of activity

EEG Hookup

EEG Readings

Lesioning G Involves destroying a piece of the brain G Done by inserting an electrode into a brain structure and by using a high- frequency electric current through it to burn the tissue

Electrical Stimulation G Involves sending a weak electrical current into a brain structure to activate it G Most of this type of research is done with animals, however, recently it has been done on humans for medical purposes G Involves sending a weak electrical current into a brain structure to activate it G Most of this type of research is done with animals, however, recently it has been done on humans for medical purposes

Brain-Imaging Procedures G These are the newest and most useful techniques in brain exploration G Have led to spectacular advances in science G We can now look at not only the STRUCTURE but also the FUNCTION of the parts of the brain G These are the newest and most useful techniques in brain exploration G Have led to spectacular advances in science G We can now look at not only the STRUCTURE but also the FUNCTION of the parts of the brain

CT Scans G Stands for Computerized Tomography G Computer-enhanced X-ray G Shot from many angles

CT Scan Migraine Headache

PET Scans G Positron Emission Tomography G This kind of imaging explores the function and maps actual activity in the brain G Done by injecting radioactive chemicals into body - serving as a marker for blood flow in the brain G Positron Emission Tomography G This kind of imaging explores the function and maps actual activity in the brain G Done by injecting radioactive chemicals into body - serving as a marker for blood flow in the brain

Examples of PET Scans

MRI Scan G Magnetic Resonance Imaging G Uses magnetic fields, radio waves, and computerized enhancement to map out brain structure G Provide much better images than CT Scans

MRI Normal Brain

CT vs. MRI

fMRI Scans G Functional Magnetic Resonance Imaging G Several new variations to MRI scans G Monitor blood and oxygen flow in the brain to identify areas of high activity G Functional and structural information in the same image G Red/Orange - High Activity G Blue/Black - Low Activity G Functional Magnetic Resonance Imaging G Several new variations to MRI scans G Monitor blood and oxygen flow in the brain to identify areas of high activity G Functional and structural information in the same image G Red/Orange - High Activity G Blue/Black - Low Activity

fMRI Scan Examples

Examples of Brain Scans from Real People

Normal Brain

Normal Aging - 76 yr. old

Chronic Subdural Hematoma

Chronic Subdural Hematoma Function

Glioma (Low Grade Brain Tumor)

Glioma Function

Metastatic Adenocarcinoma

Cerebral Hemorrhage

Fatal Stroke

MALIGNANT (WHO Grade 3 of 3) OLIGODENDROGLIOMA

G This teenager presented to an Emergency Department with progressive headaches, vomiting, and memory impairment. G A. MRI scan of the brain showed a very large and infiltrative brain tumor (T; white and grey areas in red circle) located in the "dominant" temporal lobe, with considerable brain swelling (oedema). It was causing life-threatening compression of the brainstem (green arrow head). The mass encroaches upon regions serving memory & learning, hearing and language, field of vision, and limb movement, G B. The boy's preoperative imaging included MR tractography, in order to assess the proximity of the tumor to his critical "limb movement" and "visual field" pathways deep within the brain. G C. The boy was taken to the operating room, and while awake and comfortable ("awake craniotomy"), the tumor (T) was nearly totally removed while his language and movement functions were repetitively assessed in real-time by the anaesthetic team during the surgery. The tumor was infiltrative and malignant (a brain cancer) and therefore every tumor cell could not be removed surgically. G D. However, the postoperative MRI scan showed near-complete removal of the tumor mass (now just a surgical cavity outlined by the red circle). The is no longer any compression of the brainstem (green arrow head). The child's symptoms all resolved, he was completely neurologically intact within a few days of surgery, and he returned to school within a few weeks of completing post- operative brain radiotherapy. G This teenager presented to an Emergency Department with progressive headaches, vomiting, and memory impairment. G A. MRI scan of the brain showed a very large and infiltrative brain tumor (T; white and grey areas in red circle) located in the "dominant" temporal lobe, with considerable brain swelling (oedema). It was causing life-threatening compression of the brainstem (green arrow head). The mass encroaches upon regions serving memory & learning, hearing and language, field of vision, and limb movement, G B. The boy's preoperative imaging included MR tractography, in order to assess the proximity of the tumor to his critical "limb movement" and "visual field" pathways deep within the brain. G C. The boy was taken to the operating room, and while awake and comfortable ("awake craniotomy"), the tumor (T) was nearly totally removed while his language and movement functions were repetitively assessed in real-time by the anaesthetic team during the surgery. The tumor was infiltrative and malignant (a brain cancer) and therefore every tumor cell could not be removed surgically. G D. However, the postoperative MRI scan showed near-complete removal of the tumor mass (now just a surgical cavity outlined by the red circle). The is no longer any compression of the brainstem (green arrow head). The child's symptoms all resolved, he was completely neurologically intact within a few days of surgery, and he returned to school within a few weeks of completing post- operative brain radiotherapy.

The Newest Brain Scanning Technique G MagnetoEncephalography G - an imaging technique used to measure the magnetic fields produced by electrical activity in the brain via extremely sensitive devices such as superconducting quantum interference devices (SQUIDs). MEG offers a very direct measurement neural electrical activity The advantage of measuring the magnetic fields produced by neural activity is that they are not distorted by surrounding tissue, unlike the electric fields measured by EEG (particularly the skull and scalp). G MagnetoEncephalography G - an imaging technique used to measure the magnetic fields produced by electrical activity in the brain via extremely sensitive devices such as superconducting quantum interference devices (SQUIDs). MEG offers a very direct measurement neural electrical activity The advantage of measuring the magnetic fields produced by neural activity is that they are not distorted by surrounding tissue, unlike the electric fields measured by EEG (particularly the skull and scalp).