Biological Bases of Behavior AP Psych – Chapter 3 Biological Foundations of Behavior Alice F. Short Hilliard Davidson High School

Chapter Preview Nervous System Neurons Brain Endocrine System Damage, Plasticity, and Repair Genetics and Behavior Biological Foundations and Health and Wellness

Nervous System Neuroscience…study of the body’s electrochemical communication circuitry Characteristics of the nervous system complexity (metaphor = multitasking) integration adaptability (plasticity) electrochemical transmission

Nervous System: Pathways Afferent Nerves carry information  spinal cord and brain Efferent Nerves carry information  muscles

Nervous System: Divisions The Two Main Divisions of the Nervous System: 1. Central Nervous System (CNS) brain and spinal cord 2. Peripheral Nervous System (PNS) somatic nervous system – sensory nerves muscular activity autonomic nervous system – internal organs sympathetic nervous system – arouses parasympathetic nervous system – calms Nervous System: Divisions

1. Central Nervous System 1. Central Nervous System (CNS) brain and spinal cord

2. Peripheral Nervous System 2. Peripheral Nervous System (PNS) – composed of all the sensory and motor nerves somatic nervous system – sensory nerves muscular activity allows you to move in cases of emergency allows you to move when you want to move autonomic nervous system – internal organs sympathetic nervous system – arouses kicks into overdrive in cases of emergency parasympathetic nervous system – calms medication techniques elicit response

Nervous System: Cells Neurons Glial Cells information processing about 100 billion in brain mirror neurons (in primates) – imitating behaviors of someone else mimicking the movements of a coach or dancer, etc. Glial Cells provide support and nutrition carries nutrients from blood vessels  neurons

Neurons: Structure neuron – the type of cell that is the basic unit of the nervous system – the nervous system contains over 11 billion neurons cell body (soma) – contains the nucleus dendrites – branched appendages that carry information to the cell body axon – conveys information away from the cell body myelin sheath – covers the axon and aids in neural transmission

Neurons: Structure dendrite  cell body  axon

Neurons: 3 Types Neuron – the type of cell that is the basic unit of the nervous system – the nervous system contains over 11 billion neurons sensory neurons are located in the body’s sense organs (for example, the eye, ear, or nose) and send information from these organs to the brain motor neurons– convey information from the nervous system to the body’s organs, glands, and muscles interneurons (association neurons) transmit information from one neuron to another within the nervous system

Neural Impulse Axons Resting Potential Action Potential ions/ion channel negatively/positively charged semipermeable membrane polarization Resting Potential stable charge of an inactive neuron a negative charge on the inside of the cell membrane and a positive charge on the outside Action Potential depolarization (ion channel opens) sodium ions flow into the membrane repolarization ion exchange sweeps along length of axon all-or-none principle – intensity of the action potential is not effected by depolarizing and greater levels once initiated, cannot be stopped

Transmission of Nerve Impulse

Synapses and Neurotransmitters Synapse / Synaptic Gap space between sending axon’s terminal buttons and the receiving dendrite or cell body the neural message being delivered in a synaptic transmission is carried across the synaptic gap by chemical substances Synaptic Transmission electrical impulse is converted into a chemical signal axon vesicle releases neurotransmitter into gap dendrite receptor site detects neurotransmitter

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

Neurotransmitters Neurotransmitters carry information across the synaptic gap to next neuron. (chemical) Acetylcholine muscle actions, learning, memory black widow venom ↑ Ach levels botox (botulin) ↓ Ach levels Alzheimer’s disease: ↓ Ach levels GABA anxiety: ↓ GABA levels Glutamate excitatory learning & memory involved in many psychological disorders Norepinephrine stress and mania: ↑ norepinephrine levels depression: ↓ norepinephrine levels regulates sleep states in conjunction with ACh

Neurotransmitters (cont.) Dopamine voluntary movement reward anticipation stimulant drugs: activate dopamine receptors Parkinson’s disease: ↓ dopamine levels schizophrenia: ↑ dopamine levels Serotonin regulation of sleep, mood, attention, learning depression: ↓ serotonin levels prozac: ↑ serotonin levels Endorphins natural opiates mediate feelings of pleasure and pain Oxytocin both a hormone and a neurotransmitter related to onset of lactation in new mothers related to attachment/emotional bonds

Neurotransmitters Note: Drugs can interfere with neurotransmitters mimics or enhances NT effects blocks effects of NT

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

Studying the Brain Brain Lesioning Electrical Recording naturally occurring or induced Electrical Recording electroencephalograph (EEG) single-unit recording

Brain Imaging X-Ray CT Scan PET MRI fMRI TMS

Areas of the Brain Hindbrain Midbrain forebrain Reminder: any part of the brain is a part of the central nervous system (CNS), which is a part of the nervous system in general

Areas of the Brain: 1. Hindbrain Brainstem medulla – control breathing, regulate reflexes pons – sleep & arousal Cerebellum motor coordination

Areas of the Brain: 2. Midbrain Substantia Nigra Parkinson disease Reticular Formation stereotyped behavior patterns like walking manipulates neurotransmitters

Brain: Structure and Function

Areas of the Brain: 3. Forebrain Limbic System 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 Basal Ganglia coordination of voluntary movements Hypothalamus eating, drinking, sexual behaviors regulate body’s internal state emotion, stress, reward

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)

Cerebral Cortex

Are Brains Wired to Recognize Faces? prosopagnosia fusiform face area (FFA) FFA – specifically for processing faces?

Somatosensory, Moor, 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

Split-Brain Research Corpus Callosum W.J., the Split Brain Patient Large bundle of axons that connects the two hemispheres of the brain W.J., the Split Brain Patient

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 Hemispheres of the Cortex

Happy Brains Happiness: Prefrontal Lobe Asymmetry Biofeedback positive emotional responses more left prefrontal lobe activity negative emotional responses more right prefrontal lobe activity Biofeedback Mindfulness (Awareness) Meditation

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

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

Genetics and Behavior chromosomes, genes, and DNA Human Genome Project dominant-recessive genes principle molecular genetics selective breeding behavior genetics and adoption studies

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

Biological Foundations and Health and Wellness stressors …circumstances and events that threaten individuals and/or tax their coping abilities stress …our response to those stressors causes/effects of acute and chronic stress

Chapter Summary

Chapter Summary Discuss the nature and basic function of the nervous system. Explain what neurons are and how they process information. Identify the brain’s levels and structures and summarize the function of those structures. Identify the endocrine system and describe how it affects behavior.

Chapter Summary Describe the brain’s capacity for recovery and repair. Explain how genetics increases understanding of behavior. Describe the role of the biological foundations of human psychology in the body’s stress response.

Chapter Summary The Nervous System Brain: Structure and Function structure and function of the nervous systems structure of a neruon electrochemical communication neurotransmitters and their effects Brain: Structure and Function brain imaging techniques hindbrain, midbrain, forebrain cerebral lobes and functions

Chapter Summary Brain Damage and Plasticity Genetics and Behavior collateral sprouting, substitution of function, neurogenesis, brain tissue grafts Genetics and Behavior “genes v. environment” and adoption studies Biological Foundations & Health and Wellness acute and chronic stress