Mapping the Cortex

To be human, more does matter

Brains of Mammals

More cortical surface areaKW 2-2

Hemispheres

Two brains in one

Lobes

Based on skull bones

Phrenology

Franz Gall

Broca’s discovery

• Neuorologist working in Paris in 1860’s

• Patient called “Tan”• Understood

commands• Couldn’t speak• After Tan’s death,

Broca found area of damage in frontal lobe

Tan’s Brain

• Broca presented case study on Tan in 1862

Korbinian Brodmann

• 1868-1918• Neurologist• Research suggested by

Alois Alzheimer• Mapped the cell

structure of the brain• 52 discrete areas• First complete and

accurate map (1909)

Brodmann Areas of Cortex

Numbered areas to changes in cell structureKw 2-21

Penfield’s Neurosurgery

Wilder Penfield:

A pioneer in neurosurgery

Temporal lobe epilepsy

First studies of living, reacting brain

Motor and Sensory Cortex

Motor and Sensory strips

One of Penfield’s

discoveries

KW 2-22

Note difference in cell structure:

Brodmann maps

Motor and Sensory Strips

Homunculus

Sensory strip contains

• Skin Sensations– pressure– warmth– cold– pain

Also on sensory strip are• Kinesthesis

– the system for sensing the position and movement of individual body parts

• Vestibular Sense– the sense of body movement and position

– including the sense of balance

Motor and Sensory Strips

Homunculus

Contralateral Control

KW 2-32

Sensory and Motor Strips

• Contralateral control• Amount of cortex

related to abilities not size of body area

• Sensory and motor side by side

Visual Areas

KW 8-17

Visual cortex responds

• Functional MRI scan of the visual cortex activated by light shown in the subject’s eyes`

Auditory Areas

KW 9-12

Broca’s area

Broca’s located next to motor strip area for face

(light blue)

KW 9-17

Broca’s area

Carl Wernicke

• 1848-1904• Born in Poland• Educated in Germany• Psychiatry and

neurology• Studies on receptive

aphasia in 1874• Wernicke’s area in

temporal lobe

Wernicke’s area

• Patient unable to comprehend commands

• Able to speak but speech lacked meaning

• Wernicke’s area next to auditory area on temporal lobe

Thought to Spoken Word

KW 9-17

Prefrontal Lobes

Area just behind the forehead

Frontal lobes

Prefrontal Cortex

KW 11-16

Prefrontal Cortex and Limbic System

KW 11-15

Limbic and Frontal Lobes

KW 11-15

Limbic system and fontal lobes interact to control behavior

Egas Moniz

• 1875-1955• Portuguese neurologist

and politician• Developed angiogram

to visualize blood supply to brain

• Frontal lobe surgery• Nobel prize in 1949

Lobotomy

• First lobotomy in US preformed in 1937 by Walter Freeman

• Calming effect• Less anxious• Lack of care and

concern• Loss of motivation

KW 11-24

Phineas Gage

Gage’s rock drilling

Gage Recreated

• New imaging techniques allow us to see how rod passed through Gage’s frontal lobes.

KW 1-5

Visiting Gage Site

For directions, visit Gage website at

www.hbs.deakin.edu.au/gagepage/pgage.htm  

PET Scanner

KW 9-20

PET Scan Images

KW 9-21

That’s all folks.