biological perspective behavior has a physical explanation

Biological Perspective

Behavior has a physical explanation

Biological Approach Reductionist Assumptions:

• Behavior can be boiled down to:– Genetics – Nervous System – Endocrine system (hormones)– Some other organic problem. (Cancer or other

disorder…)

NERVOUS SYTEM!!!! One of the keys to the biological approach in Psychology.

Brain Research

• Brain scans (MRI especially) show brain activity

• Lesions are brain injuries.

• Lesions often show behavior changes

Brain Anatomy

• Frontal lobe (pink) – Original thought

– Decision making

– Planning

– Problem solving

– Ability to talk is located here too! (on the left side)

Phineas Gage

Gage began to have startling changes in personality in mood. He became extravagant and anti-social. Also a foulmouthed liar with bad manners. He could no longer hold a job or plan his future.  "Gage was no longer Gage", said his friends of him. He died in 1861, thirteen years after the accident, penniless and epileptic, and no autopsy was performed on his brain.

Others• Egaz Moniz: Won the Nobel Prize for lobotomy

procedure… eww. (needles through the corner of the eyes to scramble the prefrontal cortex…)

Voice in the field:

• Paul Broca found the ability to talk was located in the left frontal lobe. He was one of the first to show LOCALIZATION OF FUNCTION! (The brain is divided into parts that have specific tasks like language or vision.)

Broca’s area

Brain Anatomy

• Temporal lobe (blue)– Memory, emotion,

hearing, language

– The left temporal lobe is the area that helps you understand speech.

Brain stuff you can impress your friends with:

• Wernicke’s area in the left temporal lobe helps you understand speech (understanding the talk!).

Wernicke’s area

Brain Anatomy

• Parietal lobe (yellow)– Senses and movement

Parietal lobe up close

Paralysis is a condition of parietal lobe damage

Brain Anatomy

• Occipital lobe (green)– vision

Occipital lobe processes what the eye sees. Note cat story…

Art piece called “Struck by Blindness”. Why is this a great name for this piece?

Are you right brained or left brained?

• Left side of the brain is good at language, math, analysis, and logic. Operates the right side of the body…

• Right side of the brain is good at nonverbal stuff like identifying faces, recognizing facial expressions, music, and spacial skills. Operates the left side of the body.

Lets review:

Left frontal lobe? Talkin’ the talk! The ability to speak…

Left temperal lobe? Understandin’ the talk! The ability comprehend the speak…

Left side of the brain? Math, logic, language, analysis…

Right side of the brain? Music, spacial skills, ID of face and expressions…

Other Bio biggies• Wilder Penfield: took electronic probes and mapped

the cortex of the brain (the big thing we usually think of as the brain.) He did this so that he could treat epilepsy by destroying the parts of the brain that were causing the seizures… He didn’t want to destroy good tissue, so he would stimulate a section to see what it was used for.

• Roger Sperry and Michael Gazzaniga: split brain people (again with the localization of function!)

Lobes of the brain-review• Occipital lobe: in the back of the brain and it is

the vision center• Frontal lobe: The front of the brain. This is

what makes you you. This is where you interpret and control emotions, make decisions and carry out plans. In the back of the frontal lobe, you work the voluntary muscles.

• Parietal lobe: behind the frontal lobe. Somatosensory (senses are here)

• Temporal lobe: ear and below. Hearing processes. Music/tone,

Vision? Original Thought? Talking? Hearing/Understanding? Feeling with your fingers?

Vision = occipital lobe

Original thought = frontal lobe

Talking = frontal lobe

Hearing = temporal lobe

Touch of fingers = parietal lobe

Lookin’ at the brain

• PET scans and MRI scans can look at the brain while the brain is working! (MRI has more resolution, however.)

• CAT scans are x-rays of the brain.

• EEG’s measure brain wavelengths or the brain’s electrical activity.

What kind of scan?

PET Scan

fMRI scan of a person and a face

Looking at a face

Asked to think about the face (hippocampus –memory thing lights up!)

Asked to compare a new face to the face shown previously.

Flexing the hand either rhythmically or rhythmically to a metronome and going back and forth…What kind of scan?

What kind of image is this?

EEG

Red is ‘high’ activity, blue is ‘low’ activity.

1 and 2 are children without ADD, 3 and 4 have been diagnosed with ADD

It looks like #4 isn’t looking at the object!

Neurons, the cells of the nervous system

• They send chemical signals to:– Other neurons– Muscles– Organs– glands

Neurons• The action of a neuron is electrical, yet the

neuron sends a chemical signal called a neurotransmitter.

neurotransmitter

Neurotransmitters:Chemicals that neurons use to

talk to each other!

Neurotransmitter: Acetylcholine

• Works on the voluntary muscles

• Also abundant in the brain.

• Nicotine reacts with the receptors that respond to acetylcholine.

• Alzheimer’s patients lose neurons that release Acetylcholine.

Dopamine• Thought (generally) to control pleasure and

motivation

• Controls movement, so Parkinson’s patients have benefited from dopamine-type medicines

• Too much dopamine has been linked to psychosis… limit the dopamine, limit the psychosis.

• Might regulate hormones through the pituitary gland.

Serotonin

• Linked to sleep, depression, and anxiety.• Prozac is a serotonin reuptake

inhibitor. (Not intuitive, but it is thought that a lack of serotonin is a cause of depression. If you keep it in the synapse longer, it is more active.)– Used to treat obsessive-compulsive disorder– Used to treat depression.

Nervous System

Central Nervous System Peripheral Nervous System

Divided into:

Brain

Spinal Chord

Nervous System