1. Chapter 3 Biological Foundations of Behavior
© 2011 The McGraw-Hill Companies, Inc.

2. Chapter Preview Nervous System Neurons Brain Endocrine System
Damage, Plasticity, and Repair
Genetics and Behavior
Biological Foundations and Health and Wellness
© 2011 The McGraw-Hill Companies, Inc.

3. Nervous System
Neuroscience…study of the body’s electrochemical communication circuitry
Characteristics of the nervous system
complexity
integration
adaptability (plasticity)
electrochemical transmission
© 2011 The McGraw-Hill Companies, Inc.

4. Nervous System: Pathways
Afferent Nerves
carry information  spinal cord and brain
Efferent Nerves
carry information  muscles
© 2011 The McGraw-Hill Companies, Inc.

5. Nervous System: Divisions
Central Nervous System (CNS)
brain and spinal cord
Peripheral Nervous System (PNS)
somatic nervous system – sensory nerves
muscular activity
autonomic nervous system – internal organs
sympathetic nervous system – arouses
parasympathetic nervous system – calms
© 2011 The McGraw-Hill Companies, Inc.

6. Nervous System: Divisions
© 2011 The McGraw-Hill Companies, Inc.

7. Nervous System - Cells Neurons Glial Cells information processing
about 100 billion in brain
mirror neurons (in primates)
Glial Cells
provide support and nutrition
© 2011 The McGraw-Hill Companies, Inc.

8. Neurons: Structure cell body dendrites axon myelin sheath
© 2011 The McGraw-Hill Companies, Inc.

9. Neurons: Structure
© 2011 The McGraw-Hill Companies, Inc.

10. Neural Impulse Axons Resting Potential ions/ion channel
negatively/positively charged
semipermeable membrane
polarization
Resting Potential
stable charge of an inactive neuron
© 2011 The McGraw-Hill Companies, Inc.

11. Neural Impulse Action Potential depolarization (ion channel opens)
repolarization
ion exchange sweeps along length of axon
all-or-none principle
once initiated, cannot be stopped
© 2011 The McGraw-Hill Companies, Inc. 11

12. Synapses and Neurotransmitters
Synapse/Synaptic Gap
space between sending axon’s terminal buttons and the receiving dendrite or cell body
Synaptic Transmission
electrical impulse is converted into a chemical signal
axon vesicle releases neurotransmitter into gap
dendrite receptor site detects neurotransmitter
© 2011 The McGraw-Hill Companies, Inc.

13. Synapses and Neurotransmitters
© 2011 The McGraw-Hill Companies, Inc.

14. Neurotransmitters Neurotransmitters carry information
across the synaptic gap to next neuron.
Acetylcholine
muscle actions, learning, memory
black widow venom ↑ Ach levels
botox (botulin) ↓ Ach levels
Alzheimer’s disease: ↓ Ach levels
GABA
anxiety: ↓ GABA levels
© 2011 The McGraw-Hill Companies, Inc.

15. Neurotransmitters Glutamate Norepinephrine excitatory
learning & memory
involved in many psychological disorders
Norepinephrine
stress and mania: ↑ norepinephrine levels
depression: ↓ norepinephrine levels
regulates sleep states in conjunction with ACh
© 2011 The McGraw-Hill Companies, Inc.

16. Neurotransmitters Dopamine voluntary movement reward anticipation
stimulant drugs: activate dopamine receptors
Parkinson’s disease: ↓ dopamine levels
schizophrenia: ↑ dopamine levels
© 2011 The McGraw-Hill Companies, Inc.

17. Neurotransmitters Serotonin Endorphins
regulation of sleep, mood, attention, learning
depression: ↓ serotonin levels
prozac: ↑ serotonin levels
Endorphins
natural opiates
mediate feelings of pleasure and pain
© 2011 The McGraw-Hill Companies, Inc.

18. Neurotransmitters Oxytocin
both a hormone and a neurotransmitter
related to onset of lactation in new mothers
related to attachment/emotional bonds
Note: Drugs can interfere with neurotransmitters
mimics or enhances NT effects
blocks effects of NT
© 2011 The McGraw-Hill Companies, Inc.

19. Neural Networks interconnected pathways of nerve cells
integrate sensory input and motor output
take years to develop
a given piece of information embedded in multiple connections between neurons
© 2011 The McGraw-Hill Companies, Inc.

20. Studying the Brain Brain Lesioning Electrical Recording
naturally occurring or induced
Electrical Recording
electroencephalograph (EEG)
single-unit recording
© 2011 The McGraw-Hill Companies, Inc.

21. Brain Imaging X-Ray CT Scan PET MRI fMRI TMS
© 2011 The McGraw-Hill Companies, Inc.

22. Brain: Structure and Function
© 2011 The McGraw-Hill Companies, Inc. 22

23. Hindbrain Brainstem Cerebellum
medulla – control breathing, regulate reflexes
pons – sleep & arousal
Cerebellum
motor coordination
© 2011 The McGraw-Hill Companies, Inc.

24. Brain: Structure and Function
© 2011 The McGraw-Hill Companies, Inc. 24

25. Midbrain Substantia Nigra Reticular Formation Parkinson disease
stereotyped behavior patterns like walking
© 2011 The McGraw-Hill Companies, Inc.

26. Brain: Structure and Function
© 2011 The McGraw-Hill Companies, Inc.

27. Forebrain Limbic System Thalamus memory and emotion amygdala
- discrimination of objects needed for survival
- emotional awareness and expression
hippocampus
- formation and recall of memories
Thalamus
relay station for much sensory information
© 2011 The McGraw-Hill Companies, Inc.

28. Forebrain (cont’d) Basal Ganglia Hypothalamus
coordination of voluntary movements
Hypothalamus
eating, drinking, sexual behaviors
regulate body’s internal state
emotion, stress, reward
© 2011 The McGraw-Hill Companies, Inc.

29. Brain: Structure and Function
© 2011 The McGraw-Hill Companies, Inc. 29

30. Cerebral Cortex Neocortex: outermost layer Four Lobes:
occipital (vision)
temporal (hearing, language processing, memory)
frontal (intelligence, personality, voluntary muscles)
parietal (spatial location, attention, motor control)
© 2011 The McGraw-Hill Companies, Inc.

31. Cerebral Cortex
© 2011 The McGraw-Hill Companies, Inc.

32. Somatosensory, Motor, and Association Cortex
Somatosensoy Cortex (in parietal lobe)
body sensations
Motor Cortex (in frontal lobe)
voluntary movements
Point-to-Point Mapping
Association Cortex (75% of cortex)
not sensory or motor, but associations between
© 2011 The McGraw-Hill Companies, Inc.

33. Split-Brain Research W.J., the Split Brain Patient Corpus Callosum
Large bundle of axons that connects the two hemispheres of the brain
W.J., the Split Brain Patient x X
© 2011 The McGraw-Hill Companies, Inc.

34. Hemispheres of the Cortex
Hemispheric Specialization of Function
left hemisphere
verbal processing, speech, grammar
Broca’s Area
Wernicke’s Area
right hemisphere
spatial perception, visual recognition, emotion
© 2011 The McGraw-Hill Companies, Inc.

35. Endocrine System
set of glands that regulate the body by secreting hormones into the bloodstream
hormones = chemical messages
relatively slow communication system
interconnected with the nervous system
pituitary, thyroid, parathyroid, adrenal glands, pancreas, ovaries, testes
© 2011 The McGraw-Hill Companies, Inc.

36. Brain Damage and Plasticity
Recovery from brain damage depends on
age of the individual
extent of the damage
Repairing the damaged brain
collateral sprouting
substitution of function
neurogenesis
brain tissue grafts
© 2011 The McGraw-Hill Companies, Inc.

37. Genetics and Behavior chromosomes, genes, and DNA
dominant-recessive genes principle
Besides the brain, many other aspects of ourselves affect our psychological functioning.
We have trillions of cells.
The nucleus of each cell contains 46 chromosomes
23 pairs of chromosomes with one of each pair coming from each parent.
Chromosomes contain deoxyribonucleic acid, or DNA.
DNA is the molecule that carries a person’s genetic information.
Genes are the segments of chromosomes that are composed of DNA.
Genes carry the heredity information of the individual.
According to the dominant-recessive genes principle, if one of the genes of a pair is dominant over the other, the dominant gene resides over the recessive one.
For example, if a person inherits the blue-eyed gene from his or her mother and the brown-eyed gene from the father and the blue-eyed gene is dominant, the person will have blue eyes.
Other characteristics do not come from one specific gene.
Polygenic inheritance describes how multiple genes influence other aspects of self like behavior, personality, intelligence, etc.
© 2011 The McGraw-Hill Companies, Inc. 37

38. Genetics and Behavior molecular genetics selective breeding
behavior genetics and adoption studies
Gregor Mendel first started the research on genetics in the mid-nineteenth century when he studied heredity in pea plants by cross breeding them and seeing what the plant offspring looked like.
He realized that some genes are more likely to show up in offspring.
These are the dominant genes.
Modern researchers use Mendel’s techniques to study genetics today.
Molecular genetics involves the manipulation of genes.
The term genome refers to the instructions for making an organism.
Selective breeding occurs when organisms are chosen for reproduction based on how much of a particular trait they display.
Research has been done with rats by breeding those good at running mazes and those not so good to see whether the offspring were good.
Behavior genetics is the study of the degree and nature of heredity’s influence on behavior.
In twin studies, behavior genetics studies the extent to which individuals are shaped by their heredity and the influence of the environment on them.
The behavioral similarity of identical twins is compared to the behavioral similarity of fraternal twins.
Identical twins are found to be consistently more similar so it seems likely that genes play a role in behavioral expression.
Even in studies of twins reared apart they have found similarities which gives further evidence to show the role of genes in behavior.
© 2011 The McGraw-Hill Companies, Inc. 38

39. Genes and the Environment
Genotype – genetic heritage
+ the effects of experience =
Phenotype – observable characteristics
environment alters how genetic traits develop
both physical & psychological characteristics
genetic expression
© 2011 The McGraw-Hill Companies, Inc.