Core - Chapter 2 - The Brain and Behavior Flashcards
Describe a longitudinal study done on brain damages
Dr John Harlow: The Study of Phineas Gage, 1848
Paul Broca 1861
Paul Broca, 1861
People suffering from damage in the left frontal lobe of brain (Broca’s area) were unable to understand and make grammatically complex sentences. Had problems producing speech, able to understand, a condition now called Broca’s aphasia. Case study on patient Tan - could only say “tan”
Carl Wernicke 1874
Carl Wernicke, 1874
Area crucial for language comprehension - left posterior superior temporal gyrus. Ability to produce speech but not understand it - condition known as Wernicke’s aphasia.
What is a post-mortem study?
A study on a passed away person
Describe a study on pleasure carried out on humans
Robert Heath, 1950s
Describe a study on pleasure carried out on rats
James Olds, 1950s
Describe two invasive techniques
Ablation - removing brain tissue
Lesioning - scarring brain tissue
Describe a study where lesioning was used
Heatherington and Ranson, 1942
What is EEG and how does it work?
Electroencephalogram - EEG printout thought of as “brainwaves”
When neurons transport information through the brain, they have an electrical charge. The EEG registers patterns of voltage change in the brain.
What has EEG been used for and what are the limitations?
Through EEG psychologists have been able to gain better understanding of behaviors as diverse as sleep, emotion and epilepsy.
However, EEG provides the researcher with limited information - it cannot reveal what is happening in deeper brain regions; nor can it show the actual functioning of the brain
What are PET scans used for?
Has been used to diagnose abnormalities like tumors, or changes as in Alzheimer’s; to compare brain differences in normal individuals and those with psychological disorders (e.g. neural activity is different in people with schizophrenia); and to compare sex differences
What study was made on sex differences using PET scan?
Gur et al., 1995
Found more active metabolism in primitive brain centers controlling violence in men than in women.
What is fMRI and how does it work?
Functional magnetic resonance imaging
Provides three-dimensional pictures of brain structures, using magnetic fields and radio waves. The fMRI shows actual brain activity and indicates which areas of the brain are active when engaged in a behavior. These scans have higher resolution than PET scans and are easier to carry out. One of the most frequently used technologies in biopsychological research today.
What are “invasive techniques”?
Removing (ablating) or scarring (leisoning) brain tissue in order to study behavioral changes
Criticism towards invasive techniques
The harm cannot be undone, and the potential harm to the animals cannot be determined. Pain to the animals may occur
What is PET scan and how does it work
Positron Emission Topography scan. Monitors glucose metabolism in the brain. The patient is injected with a harmless dose of radioactive glucose, and the radioactive particles emitted by the glucose are detected by the PET scanner. Can record ongoing activity in the brain such as thinking.
Dr John Harlow; the Study of Phineas Gage (1848)
- 25 year old railroad foreman, serious accident, tried to blast through a rocky cliff - an explosion sent a metal pole through his skull, entering Gage’s left cheek, pierced the base of the skull, went through the front of his brain, exited at high speed through the top of his head. The pole landed more than 100 feet away, covered in blood and brains.
- Phineas was awake and alert, was carried to an ox cart and sent to the local hotel. Lost vision in his left eye but right eye remained intact. No paralysis nor noticeable difficulty with language or speech. Became impatient and indulgent, could make plans but never follow then through. Pornographic language.
- longitudinal study of the damage to his frontal lobe provided evidence that the brain affects personality and social behaviors.
Robert Heath (1950s)
Electrically stimulating specific parts of the brain of depressed patients, making them experience pleasure. Let the patients themselves press the buttons. (one person stimulated himself 1500 times during a 3h session, had to be removed)
James Olds (1950s)
Rats received electrical stimulation of the nucleus accumbens by pressing a lever. Rats were willing to walk across electrified grids to get the “pleasure lever”. Preferred stimulation over eating and drinking.
Heatherington and Ranson (1942)
Lesioned the ventromedial hypothalamus in rats. Result: rats increased food intake drastically, often doubled their weight.
Could have a role in acting as a brake on eating, does play a role in the regulation of hunger but the exact role is not yet understood
Give an example of researchers disproving the brain of being unchangeable
Hubel and Wiesel (1965)
Hubel and Wiesel (1965)
The brain can change as a response to environmental input. Based on laboratory experiments on rats but has now become generally accepted that environmental enrichment can modify the brain, especially the cerebral cortex, which is the area of higher cognitive functioning. It seems like the brain is always changing as a result of experience throughout the lifespan.
