Chapter 2 Biological Foundations and the Brain

Copyright © 1999 by The McGraw-Hill Companies, Inc. 2 The Genetic Perspective Chromosomes threadlike structures located in the nucleus of each human cell Deoxyribonucleic Acid (DNA) a complex molecule that contains genetic information Genes short segments of DNA that are the units of heredity information

Copyright © 1999 by The McGraw-Hill Companies, Inc. 3 Perspectives on Nature and Nurture Environment –all of the surrounding conditions and influences that affect the development of living things Nurture –an organism’s environmental experiences Nature –an organism’s biological inheritance

Copyright © 1999 by The McGraw-Hill Companies, Inc. 4 Perspectives on Nature and Nurture Dominant-recessive genes principle –the principle that if one gene of a pair is dominant and the other is recessive, the dominant gene exerts its effect, overriding the potential influence of the recessive gene. A recessive gene exerts its influence only if both genes of the pair are recessive

Copyright © 1999 by The McGraw-Hill Companies, Inc. 5 The Evolutionary Perspective Natural selection –the evolutionary process that favors the individuals within a species that are best adapted to survive and reproduce in their particular environment Evolutionary psychology –emphasizes the roles of evolution and psychological mechanisms in adaptive behavior

Copyright © 1999 by The McGraw-Hill Companies, Inc. 6 The Nervous System

Copyright © 1999 by The McGraw-Hill Companies, Inc. 7 The Nervous System Neurons Central Nervous System (CNS) Peripheral nervous system Somatic nervous system Autonomic nervous system

Copyright © 1999 by The McGraw-Hill Companies, Inc. 8 The Nervous System Sympathetic nervous system –the division of the autonomic nervous system that arouses the body Parasympathetic nervous system –the division of the autonomic nervous system that calms the body

Copyright © 1999 by The McGraw-Hill Companies, Inc. 9 Neural Transmission Afferent nerves –sensory nerves that carry information to the brain Efferent nerves –motor nerves that carry the brain’s output Interneurons –CNS neurons that mediate sensory input and motor output

Copyright © 1999 by The McGraw-Hill Companies, Inc. 10 Structure of the Neuron Cell body Dendrite Axon Myelin sheath

Copyright © 1999 by The McGraw-Hill Companies, Inc. 11 The Nerve Impulse Ions Resting potential Action Potential All-or-none principle

Copyright © 1999 by The McGraw-Hill Companies, Inc. 12 Synapses and Neurotransmitters Synapses Neurotransmitters –dopamine –serotonin –endorphins

Copyright © 1999 by The McGraw-Hill Companies, Inc. 13 The Central Nervous System Hindbrain –Medulla –Cerebellum –Pons

Copyright © 1999 by The McGraw-Hill Companies, Inc. 14 The Central Nervous System Midbrain –Reticular Formation –Basal ganglia Forebrain –Thalamus –Hypothalamus

Copyright © 1999 by The McGraw-Hill Companies, Inc. 15 The Central Nervous System Endocrine system –Hormones –Pituitary gland Limbic system –Amygdala –Hippocampus

Copyright © 1999 by The McGraw-Hill Companies, Inc. 16 The Central Nervous System

Copyright © 1999 by The McGraw-Hill Companies, Inc. 17 The Central Nervous System Cerebral Cortex (Cerebrum) –Occipital lobe –Temporal lobe –Frontal lobe –Parietal lobe Association cortex

Copyright © 1999 by The McGraw-Hill Companies, Inc. 18 The Central Nervous System

Copyright © 1999 by The McGraw-Hill Companies, Inc. 19 Split-Brain Research and the Cerebral Hemisphere Split-brain research –Corpus Callosum Hemispheric specialization His brain and her brain Aphasia Localization and integration of function –phrenology

Copyright © 1999 by The McGraw-Hill Companies, Inc. 20 Brain Damage, Plasticity, and Repair The brain’s plasticity and capacity for repair –collateral sprouting –substitution of function Brain tissue implants –the implantation of healthy tissue into damaged brains

Copyright © 1999 by The McGraw-Hill Companies, Inc. 21 Techniques for Studying the Brain Electroencephalograph (EEG) Computer-assisted Axial Tomography (CAT scan) Positron-Emission Tomography (PET scan) Magnetic Resonance Imaging (MRI) Superconducting Quantum Interference Device (SQUID)