BRAIN MAPPINGEMMA COLEMAN

INITIAL THOUGHTS

• The predominant reason that I selected this topic was that we had previously

discussed some of its basic medical applications in AP Biology this year. Due to

the fact that my class did not have the opportunity to closely examine brain

mapping in its entirety at that point in time, I hoped that my research for this

project would help me to gain a better understanding of the concept.

• Prior to my research, I do not feel as though I had any bias regarding the topic

because it is inherently non-polarizing. That said, I viewed brain mapping as a

beneficial method of study for neurology and biopsychology, which I now

realize is contested in the psychological community.

BACKGROUND• Brain Mapping: “a visual

representation which illustrates

the different brain regions and

the specific functions assigned to

each. Much of the information

used in creating these maps come

from brain imaging, recorded

electrical activity, and studies on

localized brain

lesions”(Psychology Dictionary) A brain map of a healthy adult

human brain

BACKGROUND: LOCALIZATION

• Localization of Function: the notion that different physiological parts of the

brain complete different actions; this concept is central to brain mapping

initiatives; originates to the creation of phrenology, by Franz Joseph Gall in

1796

• Though Gall’s phrenology was later disregarded by the scientific

community, the idea of neurological localization continues to persist as an

important concept in the field

• Later proven by the speech studies of Carl Wernicke and Paul Broca;

Broca’s area controls the production of speech whereas Wernicke’s area

controls speech comprehension

LOCALIZATION

• Cerebral cortex contains numerous regions with specific functions due to

unique structural, functional, and connective properties

• Scientists currently categorize these regions into three distinct

subdivisions: primary sensory areas, sensory association areas, and

higher order association areas

• Brain mapping seeks to relate brain structure to function with a high

degree of specificity using the principle of localization of function

DIAGRAM: LOCALIZATION OF FUNCTION

This diagram represents

some of the most

important neural regions

in the context of

localization of function

theory.

METHODS OF BRAIN MAPPING: IMAGING • Computer axial tomography (CAT)

scan: X-rays of the brain are taken

from several angles to depict structural

abnormalities

• Structural magnetic resonance

imaging: creates high resolution

images using water in the brain

• Diffusion tensor-MRI (DTI): images of

neuron "tracts" that connect brain

regions by following water movement in

the brain

BRAIN MAPPING METHODS: ACTIVITY • Positron Emission Topography (PET): traces

radioactive glucose is injected into the brain

and absorbed by neurons

• Data synthesized into a color-coded

image of the brain

• Transcranial magnetic stimulation

(TMS): noninvasively stimulates parts of the

brain using an magnetic field generator (coil)

to elicit particular behaviors

• Also helps to determine how muscles

connect to the brainPET scan of brain during

different cognitive processes

BRAIN MAPPING METHODS: ACTIVITY

• Electroencephalography (EEG): indicates electrically active locations in the brain using either internally or externally applied detectors (galvanometers)

• Functional MRI (fMRI): shows brain activity while subjects work on various tasks by measuring changes in blood flow and neuron activation

• Pharmacological functional MRI (phMRI): shows brain activity after drugs are administered

fMRI representing brain activity during several activities.

HISTORY OF BRAIN MAPPING: BLOOD FLOW

• 19th Century: Angelo Mosso pioneered the

idea that blood flow in the brain relates to

different specific tasks

• 1890: Physiological connection

between blood flow and function in the

brain proven by Charles Roy and

Charles Sherrington

• John Fulton reaffirmed Masso’s hypothesis

with his experimentation regarding the

relationship between activity in the visual

cortices and brain blood flow, which

concluded that the flow differed for

different visual stimuli

A fundamental concept used

in brain mapping is that the

brain exhibits different

patterns of blood flow when

completing different

neurological functions.

HISTORY OF BRAIN MAPPING: BLOOD FLOW

• 1940s: Seymour Kety introduced in vivo

tissue autoradiographic measurement of

regional blood flow in animals, which later

helped inspire techniques used in PET scans

• David Ingvar and Neils Lassen

extrapolated this technique to humans

Seymour Kety

HISTORY OF BRAIN MAPPING: METHODOLOGY• 1971: Godfrey Hounsfield introduced X-

ray computed tomography (CT scans) ;

major advancement in safely producing

accurate anatomical images

• 1951: PET scan technology first created by

a group of scientists at Washington

University's Mallinckrodt Institute of

Radiology

• First used at Hammersmith Hospital in

1955

Godfrey Hounsfield

HISTORY OF BRAIN MAPPING: METHODOLOGY

• 1946: Felix Bloch and Edward Purcell

concurrently discovered the principles of MRIs

• 1973: Paul Lauterbur adapted Bloch and

Purcell’s discoveries to create the earliest

version of an MRI

• 1990:A group of researchers led by Ken

Kwong, Sieji Ogawa, David Tank, Kamil

Ugirbil,and Ravi Menon created the fMRI

• 1991: the same group extended the fMRI

technique to task based brain mapping

Felix Bloch (left) and

Edward Purcell (right)

HISTORY OF BRAIN MAPPING: APPLICATIONS• 1908: Horsley and Clarke created stereotaxy, a

method of objectively relating the functional

imaging data from PET imaging to brain

anatomy

• 1868: Franciscus Donders studied the

connection between thought processes and

reaction time, thus contributing to the idea that

cognitive psychology and information-processing

brain imaging techniques can be used together

• Aided study of human cognition with PET

scans and TMS

Franciscus

Donders

RECENT RESEARCH• BOLD fMRI: Specialized type of fMRI created by a

group led by Sieji Ogawa that measures oxygen

levels in different parts of the brain; this feature

complements MRIs and PET scans in order to give

researchers a more complete picture of neural

activity

• Clarity: Technique created by Karl Deisseroth that

allows scientists to directly see neuron structures

inside an intact brain, which could otherwise be

blocked by lipids in the brain

• Currently only works on sections of the brain, but

will likely be adapted in the future to be used on

a whole human brain

Image created using

the Clarity technique

FUTURE DEVELOPMENTS• Uncovering more distinct areas of the brain to be paired with specific

neurological activities

• More highly specialized brain maps that allow scientists to view the

exact arrangement of cells and nerve fires within an intact brain

• Focus cellular resolution to one or two micrometers as opposed to the

current 20 micrometers

• Ability to use create brain maps in real time; would allow researchers to

create continuous series of images to depict changes in mental activities as

they occur

UTILITY • Medicine:

• Provides insights into how humans adapt

• Allows for more precise, less invasive surgical methods

• Improved diagnosis of degenerative illnesses

• Better treatment for brain damage following trauma

• Psychology:

• Helps identify brain abnormalities that correlate with

mental illnesses such as depression and schizophrenia,

thereby improving diagnosis and treatment

• Government:

• In 2014, former president Barrack Obama allocated federal

funds to Brain Research through Advancing Innovative

Neurotechnologies and other organizations that use brain maps

• Improve quality of life of citizens with physical or mental

disorders

• Opportunities for technological advancement

The fundamental function

of brain mapping is

acquiring greater, more

detailed knowledge of

the exact structure of the

brain and each neural

region’s specific functions.

This information has many

practical applications that

benefit doctors,

psychologists, and the

government.

REVIEW QUESTIONS

• True or False

A. Brain mapping relates structure to

function.

B. Wernicke’s area controls the

production of speech whereas

Broca’s area controls speech

comprehension.

C. Blood flow and electrical activity

are good indicators of brain

activity.

• Matching

Scientist Technique

Godfrey Houndfield A.Stereotaxy

Paul Lauterber B.Clarity

Horsley and Clark C. CT scan

Sieji Ogawa D. MRI

Karl Deisseroth E.BOLD fMRI

ANSWERS

• True or False

A. TRUE: Brain mapping produces

anatomical images that demonstrate

the activity level of the brain while

completing specific functions, thus

connecting structure to function

B. FALSE: should be vice versa

C. TRUE: Brain mapping relies on using

blood flow and electrical activities as

markers of brain function

• Matching

A. Horsley and Clark

B. Karl Deisseroth

C. Godfrey Houndfield

D. Paul Lauterber

E. Sieji Ogawa

DISCUSSION QUESTION

Is brain mapping an effective

strategy for studying the human

brain? Why or why not?

DISCUSSION RESPONSE

• I believe that brain mapping is an effective strategy for studying the

human brain. Specifically, this approach encompasses many distinct

factors, such as oxygen absorption, electrical activity, and the flow of

water and blood within the brain. Together, these markers help provide

detailed understanding of the anatomical structure of the brain as

differentiated into many unique regions while also providing insights

into the specific functions that they carry out. Furthermore, these results

can be adapted for a variety of necessary practical applications,

spanning from medicine to psychology.

BIBLIOGRAPHY

BIBLIOGRAPHY

Finger, S. "Birth of Localization Theory." NCBI, National Center for Biotechnology Information, U.S. National

Library of Medicine, www.ncbi.nlm.nih.gov/pubmed/19892113.

Humphries, Courtney. "Brain Mapping." MIT Technology Review,

www.technologyreview.com/s/526501/brain-mapping/.

"Localization of the Function." Indiana University, www.indiana.edu/~p1013447/dictionary/localiz.htm.

Nasr, Susan L. "How Brain Mapping Works." How Stuff Works, InfoSpace Works,

science.howstuffworks.com/life/inside-the-mind/human-brain/brain-mapping.htm.

Raichle, Marcus E. "A Brief History of Human Brain Mapping." Trends in Neurosciences, vol. 32, no. 2, Feb.

2009, pp. 118-26. Cell, doi:10.1016/j.tins.2008.11.001.

Rilling, James. "Broca's and Wernicke's Areas." Center for Academic Research and Training in Anthropogeny,

CARTA, carta.anthropogeny.org/moca/topics/brocas-and-wernickes-areas