Sept 6Psy 360

Webpage: http://psych.umb.edu/faculty/adams

Then click on the Jane Adams, PhDThen the next page will have a link that says

“students click here”

History of Approaches/Questions

1. Where does knowledge come from?

Nativism – body, soul, knowledge come from God –

from B.C. to 1500s

• illness or strangeness due to evil spirits

• treatments focused on driving out the evil spirits

spells, potions, incantations

drill into skull to release demons

use electric fish to shock out evil

2. Do body and soul interact?

Descartes - French scientist - 1600s

Suggested that body and soul are 2 separate things - one physical, one spiritual.

Dualism – the physical body and spiritual soul are 2 separate things

• Descartes suggested that they communicate in brain area

• Still believed that all knowledge came from god - Nativism

• Put focus on the brain as the most important organ for behavior

Modern day relevance – beliefs about what happens when we die? Does a soul separate? (near death experiences – look down on self; see white light)

3. Then where does knowledge come from? Not God?

John Locke - late 1600s - 1700s

Suggested that all knowledge comes from experience

Empiricism - mind is a blank slate at birth (tabula rasa) and all knowledge comes from experience

• directed attention to brain and how it works

4. How does the brain work and what does it do?

People in history - 1700s-1900s

• Gall - suggested that certain areas of the brain involved in certain behavioral traits. Phrenology - not very scientific: bumps on skull (due to brain size of the part underneath) related to personality traits

• Broca - 1st scientific evidence relating brain structure to function The Case of Tan - man who lost ability to speak; Broca found

tumor in left frontal area of brain.

Broca’s area - important for speech

• Fechner, Helmholtz, Wundt - 1700s-1800s - scientists studying sensation and perception (is what I hear and see etc the same as what you hear and see?)

Studied physical stimulation and the psychological experience of it – psychophysics.

• William James - late 1800s – argued that consciousness is a property of the nervous system that should be studied through biology of nervous system

4. How does the brain work and what does it do? This remains as the central question

People in history - 20th century

• Ebbinghaus, Thorndike, Pavlov - research on learning and memory

• Franz and Lashley - location of memory via brain lesion studies

• Hebb - learning and memory occur in complex networks of brain cells whereby connections are strengthened through use

People in history – 20th-21st century

• Rosenzweig (1961), Greenough (1976) – experience alters brain anatomy and physiology

• Terje Lomo (1966) - process of long term potentiation; changes in connections between brain cells that are thought to underlie memory formation

• Fred Gage (1998) - discovery that adult brain cells have regenerative ability; stem cells in nervous system

Key Concepts in 20th and 21st Century –

Neural Plasticity

- the ability of the brain to be changed by the environment and by experience

- the interactions between brain, environment, and behavior

Has replaced old debates about relative roles of soul, mind, genetics, brain in controlling behavior

Zeitgeist - general attitudes during a particular period of time

20th century - still some dualism.

21st century – still some dualism in beliefs of general public, but not among neuroscientists.

(Examples: flute, but then near death experience)

Current zeitgeist is that our nervous system represents an interaction between genetics and developmental experience. Nervous system controls behavior which is also influenced by the immediate environment (the situation), and one’s interpretation of the situation.

Modern Approaches to Examining Brain-Behavior Relationships

• still study the behavioral characteristics of people with disease, disorder or injury

• still manipulate brain anatomy or physiology and look at effects on behavior (surgery; drugs)

• still examine at autopsy the brains of people of interest

• still manipulate behavior and examine neurophysiological and anatomical changes, but through new techniques

Modern Imaging Tools

• MRI - magnetic resonance imaging

• fMRI - functional magnetic resonance imaging

• PET scan - Positron Emission Tomography

• Evoked Potentials - averaged EEG

MRI - 3 dimensional image of brain structure created by bouncing radio waves off of the brain’s hydrogen ions and recording inside a magnetic field

Provides an image of anatomical structure

Sagittal view

Coronal view

Transverse view

fMRI - provides picture of cortical activity by measuring changes in oxygen levels in the brain which represent blood flow to active areas

Image based on blood flow dynamics and oxygen use.

fMRI Image – metabolic activity

Dyslexics do not show activationin the area of the brain that specializes in movement detection.

PET scan - metabolic activity measured by brain’s use of radioactive material that is injected or inhaled.

Commonly used radioactively-labeled material includes oxygen, fluorine, carbon and nitrogen. When this material gets into the bloodstream, it goes to areas of the brain that use it.

Inject with radioactive material, perform task, measure activity in specific brain areas

PET SCAN IMAGE

From the Neuroscience for Kids webpage http://faculty.washington.edu/chudler/image.html

A combination of PET and MRI techniques:

Thalamus Cortex

• These 2 images show the averaged data from 14 subjects who received a painful injection of the chemical capsaicin into the upper arm. The colored part of the images show increased blood flow (the PET) to the thalamus and primary somatosensory cortex after the injection. The gray areas of the images (the MRI) show the brain anatomy. So using this method one can identify the areas of the brain that are active during specific conditions. This technique could be used to study just about any other cognitive function.

• (These two PET/MRI images were provided by Dr. Robert C. Coghill at Wake Forest University School of Medicine.

• PET alone is also used to study different cognitive functions.

Evoked Potentials - changes in EEG in response to stimulus processing. Can be done to examine response to sensory stimuli or brain activity while engaged in a cognitive task. Offers msec by msec information about brain activity.

Other new research tools:

• manipulate genetics by creating a knock-out or knock-in mouse (without or with a certain gene) and examine effects

• examine the neurochemistry of the brain through the use of radioactive antibodies or antibodies attached to a dye – labels a particular neurochemical and allows examination of how it is different across group or behavioral conditions under which it is used most

• anesthetize or stimulate an area of the brain and see what happens (Wada technique; electrical stimulation)

• single cell recording to determine what areas process what kind of stimuli (awake animals)

All research is multidisciplinary!

• Comparative psychology

• Behavioral genetics

• Developmental neuroscience

• Neuropsychology

• Cognitive neuroscience