Transcript Overview of the Day

Overview of the
Day
Neuroscience - Part 2
The Brain
The Brain and Behavior
Genetics and Behavior
Why Has the Brain Been so
Difficult to Study?
Most of it is enclosed in the skull
It just sits there and makes no obvious
movements [electrical/chemical, not
mechanical, like the heart or skeleton]
Appears undifferentiated (all of it looks
about the same
Ethics of studying human brains
Differences between human an animal
brain function
How Can We Figure out
How the Brain Works ?
Clinical observations of illnesses and
damage to brain
injuries in war or work
damage to back of brain disrupted vision
 Phinous Gage, damage to frontal cortex resulted in DPC
 Manipulating the brain

create brain injuries
destroy parts of brain (lesions) and see what happens [ethical on
humans?--when done for other reasons: e.g., split brain, corpus
callosum to ameliorate epilepsy]
stimulate it chemically or eclectically (Delgato and bulls)
 Observe it
What about the Brain
Would You Observe?
What it looks like (3D, X-ray)
brain structure, shapes of different types of
people
Brain activity
what parts of the brain are firing when
people are engaged in different tasks
Brain Imaging Techniques:
Technologies for Observing the Brain
CT
(computed tomograph) scan
X-rays of brain in 3d
PET (positron emission tomograph) scan
Depicts activity of different brain areas by showing each area's
consumption of its chemical fuel (glucose). Active areas
consume most fuel
MRI (magnetic resonance imaging) scan
Detects signals from atoms in brain to give detailed picture of
brain's soft tissue
Major Parts of the Brain
Brainstem (oldest, evolved first)
Thalamus
Cerebellum
Limbic system
Cerebral Cortex (evolved last)
Brainstem
Since it evolved first, what functions do
you think it controls?
Medulla
Heartbeat and breathing
Reticular formation
arousal and sleep
relays information to other areas of the brain
Thalamus
Switchboard
receives information from sensory neurons
and routes it to the higher brain regions that
deal with seeing, hearing, tasting, and
touching.
Cerebellum
Coordinates voluntary movement
Limbic System
Primarily deals with emotion
Amygdala (aggression, fear)
Would psycho-surgery for violent criminals (modifying amygdala) be a good
idea?
• Varied results: brain parts not completely isolated in terms of function
• Easy to err when trying to localize brain functions
Hypothalamus (hunger, thirst, body
temperature, and sexual behavior, pleasure
center)
Hippocampus (memory)
Cerebral Cortex
Layer of cells on the top of the brain
structure: body's control and informationprocessing center. that part of the brain
most associated with our humanity
(thought, planning, language, symbols)
Motor cortex (fine voluntary movements)
Sensory cortex (this is where incoming
messages reach the cortex)
Association areas (integrate
information)
the more intelligent the animal, the greater
the amount of uncommitted association areas
electrically probing these areas does not
trigger any specific response
Association areas
Frontal lobe
judging, planning, personality, social skills
(Phinehas Gage-DPC)
Auditory and visual cortexes
Divided Brain
Right Half of the brain
controls which side of the body?
Pictures, faces, visual-spatial
What percentage of gifted artists are-left
handed
Left Brain
language, numbers, analysis
Corpus callosum (connects right and left
hemispheres of the brain)
Genetics and Behavior
Basic Units
Genes: biochemical units of heredity
Chromosomes: egg and sperm cells each have
23 chromosomes: when they combine, the 46
chromosomes contain master plan for an individual's
development
Genes and Human
Development
Genes influence (G x E)
Physical development: height, hair color,
skin color, ear lobe, curl tongue, bend thumb back
Behavioral tendencies: personality (anxiety,
sensation seeking, shyness, physical and mental
abilities
Individual differences (behavior genetics)
Universal human characteristics (evolutionary
psychology)
Behavior Genetics
Hereditary influences on individual
differences
How we differ from one another (personality and
ability)
To what extent are we a product of our
genes vs. our environment?
Estimate heritability: the extent to which differences
among individuals is due to genes
Adoption studies
Identical and fraternal twins, siblings (natural
and adopted)
reared together and reared apart (separated at birth)
Identical twins reared apart are more similar
than natural or adopted siblings reared together
in:
intelligence and personality
Evolutionary Psychology
Why we are all the same: universal
human tendencies
just as our bodies were designed by natural
selection, so to natural selection designed they way
people tend to think and behave--particularly with
respect to behaviors and thinking that affects
reproduction and survival
universal behavioral tendencies passed on through
adaptive genes we all share
Study commonalties among people raised in
different cultures
preference for sweets, fats, salt
fear of snakes and spiders
women's preference for men who have status and wealth; men’s
preference for young, attractive females
men in groups (coordinated action to achieve a goal, dominance
hierarchies); women in groups (independent, less competitive,
more egalitarian)
strong bond between biological parents and their children
(children with stepparents 40 more likely to be abused than
children who are raised by both biological parents)
Summary
Studying the brain
Parts of the brain
Parts of the brain and behavior
Divided brain
Genetics and behavior
behavior genetics
evolutionary psychology