Neuroscience and Biological Foundations

1. Neuroscience and Biological Foundations Neuroscience: Interdisciplinary field studying how biological processes relate to behavioral and mental processes.

2. Neuron

3. Neuron • Dendrites—branching structures that receive neural impulses from other neurons and convey impulses toward the cell body • Cell Body—contains the cell nucleus, as well as other structures that help the cell carry out its functions • Axon—a long, tubelike structure that conveys impulses away from the neuron’s cell body toward other neurons or to muscles or glands

4. Neuron Communication • Action potential—neural impulse that carries information along the axon of a neuron. (electrical impulse) • Neurotransmitter—chemicals manufactured and released by neurons that alter activity in other neurons • Synapse—junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; during an action potential, neurotransmitters are released and flow across the synaptic gap

5. Neurotransmitters • Endorphins—chemical substances in the nervous system that are similar in structure and action to opiates and are involved in pain control, pleasure and memory • Linked to disease—Parkinson’s Disease (too little dopamine), schizophrenia (excessively high dopamine), depression (too little serotonin)

6. Neurotransmitters and Drugs • Drugs act as agonists (“contest, struggle”) or antagonists (“members of the opposing team”) • i.e., nicotine is an agonist for acetylcholine whereas amphetamines act as agonists for norepinephrine

7. Hormones • Chemicals manufactured by endocrine glands and circulated in the bloodstream to produce bodily changes or maintain normal bodily functions • Endocrine System—a collection of glands located throughout the body that manufacture and secrete hormones into the bloodstream

8. Hormones • Like neurotransmitters, hormones activate cells in the body • Pituitary Gland—the master gland of the body

9. The Nervous System • Central Nervous System • The Brain—directs mental processes and maintains basic life functions • The Spinal Cord—receives sensory input, sends information to the brain, responds with motor output

10. The Nervous System • Peripheral Nervous System • Somatic nervous system—conveys sensory information to the central nervous system and sends motor messages to muscles (voluntary) • Autonomic nervous system—serves basic life functions, such as heartbeat and response to stress (involuntary) • Sympathetic—readies the body to respond to threat • Parasympathetic—calms the body down and maintains energy

11. Phineas Gage • Different parts of the brain must control different physical, emotional, thinking processes • Phineas could survive physically because the part of his brain that controlled breathing, heart, etc. was untouched • His injuries effected the emotions, motivation, impulse control, etc.

13. The Brain • Brainstem—area at the base of the brain in front of the cerebellum responsible for automatic, survival functions • Midbrain—neural centers located near the top of the brainstem involved in coordinating movement patterns, sleep and arousal

14. The Brain • Pons—structure at the top of the brainstem involved in respiration, movement, waking, sleep, and dreaming • Medulla—structure at the base of the brainstem responsible for automatic functions such as breathing and heart rate

15. The Brain • Cerebellum—structure at the base of the brain, behind the brainstem, responsible for maintaining smooth movement, balance, and some aspects of perception and cognition • Thalamus—a brain structure at the top of the brainstem that relays sensory messages to the cerebral cortex

16. The Brain • Hypothalamus—a small brain structure beneath the thalamus that maintains the body’s internal environment and regulates emotions and drives, such as hunger, thirst, sex and aggression

17. The Brain • Limbic System—An interconnected group of lower-level brain structures involved with the arousal and regulation of emotion, motivation, memory and many other aspects of behavior and mental processes • Amygdala—an almond-shaped lower-level brain structure that is part of the limbic system and is involved in emotion

18. The Brain’s Higher Functions • The Cerebral Cortex—the bumpy, convoluted area on the outside of the two cerebral hemispheres that regulates most complex behavior, including receiving sensations, motor control and higher mental processes (i.e., thinking, personality, emotion, memory, motivation, creativity, self-awareness, reasoning, etc.)

19. Cerebral Cortex—Four Lobes • Frontal Lobes—receive and coordinate messages from other lobes as well as motor control, speech and higher functions • Parietal Lobes—receives information about pressure, pain, touch and temperature

20. Cerebral Cortex—Four Lobes • Temporal Lobes—hearing, language comprehension, memory and some emotional control • Occipital Lobes—vision and visual perception

21. Brain Hemispheres • The Cerebral Cortex is divided into two hemispheres connected by the Corpus Collosum • Each hemisphere receives and sends information to the opposite side of the body • Each hemisphere also specializes in certain functions

22. The Left Hemisphere (or Left Brain) • Language Functions (speaking, reading, writing, and understanding language) • Analytical Functions (mathematics, physical sciences) • Right-hand touch

23. The Right Hemisphere (or Right Brain) • Non-verbal abilities (music, art, perceptual and spatial manipulation, facial recognition) • Some language comprehension • Left-hand touch

24. Genetics and Evolution • Gene—a segment of DNA that occupies a specific place on a particular chromosome and carries the code for hereditary transmission • Chromosome—Threadlike strands of DNA molecules that carry genetic information • Behavioral genetics—the study of the effects of heredity on biolgical, behavioral and mental processes

25. Study Methods • Heritability—the measure of the degree to which a characteristic is related to genetic factors (think correlation rather than cause-effect) • Twin studies—studies of identical (monozygotic) and fraternal (dizygotic) twins. What traits or behaviors do we see the same in identical twins that are not in fraternal twins • Adoption studies—what traits or behaviors do we observe in families even when the child has been adopted

26. Study Methods • Family studies—are there increased incidents of a particular trait or behavior within family units? • Genetic abnormalities—traits or disorders that are linked to chromosomal problems (i.e., Down syndrome)

27. Things to Remember • Genetic traits are not fixed or inflexible • Heritability estimates DO NOT apply to individuals • Genes, individuals and the environment are inseparable

28. Evolutionary Psychology • A branch of psychology that studies evolutionary principles, like natural selection and genetic mutations, which affect adaptation to the environment and help explain commonalities in behavior