The Nervous System

Introduction to the BRAIN

Mind Brain

?Question?

How are we able to determine which region(s)

of the brain perform a specific task?

Imaging the Living Brain

•CAT•fMRI•PET

Computerised Axial Tomography (CAT)

• X-ray• 2D horizontal

sections• Used to diagnose

tumours, blood clots, degenerative disease & location of strokes

Magnetic Resonance Imaging (MRI)

• strong magnetic field

• radiation from hydrogen molecules present in all brain tissue in different concentrations.

• Sagittal, horizontal and frontal images

Carlson (1994) p 120

Positron Emission Tomography (PET)

• Radioactive glucose is taken up by active cells in the brain.

• As the radioactive isotopes decay, they emit positrons which are detected by the scanner.

• I.D. areas for specific mental operations

Interpreting PET Images Highest Activity

Lowest Activity

A B

C D

SET

1

QUESTIONS

Write the answers in complete sentence in your lab book.

1.Why are 4 images shown in each set?

1.SET 1 is the control set of images. Why is it important to have a control set?

Create the following table in your notebook and fill out

Set #

Image w/greatest change

Description of Location(s)

Subjects Task Region of the Brain

2

3

4

5

6

A B

C D

SET

2

A B

C D

SET

3

A B

C D

SET

4

A B

C D

SET

5

A B

C D

SET

6

PET IMAGE TASK • SET 1- Resting

• SET 2- Listening to Music• SET 3 – Looking at picture

showing both color & pattern

• SET4 – Thinking task• SET 5- Remembering an

image for later recall• SET 6- Hopping up and

down on the right foot.

The task that the subject performed during each of the PET scan are as follows:

HAVE MS. B. CHECK YOUR TABLE

Check Your WorkSet # Image w/greatest

change Description of Location(s) Subjects Task Region of the Brain

2 b There is more red on the right side of thebrain, mainly near the center in terms offront-to-back direction. There is also redon the left side, but it is not as strong asit is on the right side.

Listening to music

Auditory cortex*Temporal Lobe

3 b The main activation is in the back of thebrain on both sides of the midline.

Looking at a picture

Primary visual cortex*Occipital Lobe

4 c The main activation is at the front of thebrain near the periphery on both sides ofthe midline.

Thinking task

Frontal cortex*Frontal Lobe

5 d The main activation is in four areas, twoon each side of the brain. Two are verynear the back of the brain, and two arefarther forward.

Remembering

Hippocampus*Temporal Lobe

6 a The main areas of activation are a spoton the left side of the brain and asmaller spot near the front of thebrain on the midline.

Hopping up and down

Motor cortex*Frontal Lobe