Studying The Brain

Lesson 6-2

Objectives

• Identify the structure and functions of the human brain

• Discuss the different ways psychologists study the brain

Introduction

• Early Greeks thought the heart was the source of feelings and thought

• Hippocrates observed the effects of head injuries on people’s thoughts.

The Three Brains

• Hindbrain– at base of the skull– controls most life processes (eating, sleep,

appetite, thirst, mating)– includes cerebellum, medulla and pons

Brain

Hindbrain

– cerebellum- controls posture and balance– medulla- controls breathing– pons- bridges messages between brain

and spinal cord

Brain

Midbrain

• Integrates sensory information and relays it

Brain

Forebrain

• Includes thalamus- integrates sensory information, except smell

• hypothalamus- controls hunger, thirst, body temperature, and sexual behavior

Brain

Forebrain

• Allows for higher level thinking

• Outer layer is called cerebral cortex

• Inner layer is the cerebrum

Brain

Activity

• Color the brain according to hindbrain, midbrain, and forebrain

• Label structure and function: – thalamus - cerebellum– pituitary gland -cerebral cortex– pons -spinal cord– medulla

HIND

MID

FORE

Lobes of the Brain

• Cerebrum is two sides

• Corpus Callosum is a band of fibers that connects the two sides

• Deep grooves that forms lobes

Lobes of the Brain

• Occipital Lobe- processes visual info

• Parietal Lobes- Sensory information

• Temporal Lobe- hearing, memory, emotion, speaking

• Frontal Lobe- organization, planning, creative thinking, and personality

Psychosurgery

• A prefrontal lobotomy has been preformed many times to alter psychopathic behavior

– are very controversial when preformed on prisoners

• informed consent

• role of prisons

Brain and Criminal Behavior

• Recent studies show that men convicted of violent crimes are more likely to have abnormalities of their frontal lobe and their right hemisphere.

Activity

• Color and label the lobes of the brain

Left and Right Hemispheres

• Are almost mirror images

• Left brain controls the right side of the body

– controls speech for most people

– controls mathematical ability and logic

Left and Right Hemispheres

• Right hemisphere controls left side of the body

– visual and spatial ability

• puzzles

– recognizing patterns

• music and art

– creativity and intuition

Split Brain Operations

• Corpus Callosum- lets right brain know what left brain is doing

• right brain- sees the sunset

• left brain- describes the sunset

Split-Brain Operations

• In Epileptics, split the corpus callosum to decrease number of seizures

• seizure is massive uncontrolled electrical activity that begins in either hemisphere and spreads to the other

Split-Brain Operations

• Roger Sperry did experiments on people with split brain operations– Nobel Peace prize in 1981

• Holds ball in right hand can say it is a ball, but put in left hand, can’t say it is a ball.

• Showed each half had specialized functions

Activity

• Right brain or left brain??

How Psychologists Study the Brain

• Physiological Psychologists or Psychobiologists study the role of the brain in behavior

Recording

• Electrodes- can be inserted into the brain to record electrical activity

• electroencephalograph- EEG records electrical activity from whole areas of the brain

• See p. 167

Stimulation

• Electrodes can be used to set off the firing of neurons

• Stimulate brains of patients during surgery to find out what function they perform

• have been used to relieve pain of terminally ill cancer patients

• experimented with use to control violent emotional behavior

Lesions

• Cut or destroy a small portion of an animals brain

• They then monitor the animal for changes in behavior

• Assume those changes are controlled by that part of the brain

• Rhesus monkey study

– no longer fearful and aggressive

Accidents

• 1848- Phineas Gage– RR foreman– showed good judgement, restraint, worked

well with others

• tamping iron enters Gage’s head right below left eye (13 pounds, 3 feet long)

• survived, but personality changed greatly

Accidents

• Dr. Paul Broca discovered the connection between left brain and speech

– area now called Broca’s area

Images

• Computer Axial Tomography (CAT)

– xrays pass around and through a person’s head

– radiation absorbed based on density of brain tissue

– transforms into a 3 dimensional picture

Images

• Positron Emission Topography (PET)– captures a picture as different parts are

being used– Uses a radioactive solution into the blood

and then measures the amount absorbed by blood cells.

Images

• Magnetic Resonance Imaging (MRI)

– study both structures and activity

– pass radio frequencies through the brain

– used to identify tumors or brain damage

Closure

• Web activity from prentice hall site

• Read articles on brain injury on prentice hall site and report to class. Each student reads a different one.

• Web activity- Probe the brain

• Research a brain disorder