Psychology Biological Basis of Behavior Biological Basis of
Psychology Biological Basis of Behavior
Biological Basis of Behavior ¡ “DNA, by itself, does nothing at all” l Denis Noble, Genes and Causation ¡ The expression of genotype is completely dependent on molecular, physiological, behavioral, and environmental conditions. ¡ The gene is not an infallible unit of heredity, but rather part of an extremely complex, reciprocally-determined developmental system
Biological Basis of Behavior ¡ Heredity and Behavior l Darwin’s Theory of natural selection has been applied to the development of species-typical behaviors ¡ ¡ Certain behaviors, that would serve to the survival and reproduction of the organism would become geneticallydetermined over many generations This theory, while appealing, is generally frowned upon by developmental scientists l The development of species-typical behavior is determined by the organism’s ontogenetic niche: a complex system of hierarchically-organized environmental and biological constraints that an organism would typically “inherit” ¡ The ontogenetic niche includes genes, epigenetics, physical forces (gravity, temperature) and social experience.
Biological Basis of Behavior ¡ Genotype: the genetic structure an organism inherits; DNA ¡ Phenotype: The individual organism’s characteristics, resulting from the interaction between genetics and environment ¡ Epigenenome: a series of molecular mechanisms (methyl groups and histones) that alter the expression of the genome as a result of environmental stimuli l MZ or identical twins, who share 100% DNA, can have vastly different epigenomes, based on experience, and therefore can have vastly different developmental outcomes l Epigenetic tags can be inherited ¡ Your behavior can effect your epigenome and the epigenome of your children/grandchildren.
Neurology ¡ Central Nervous System (CNS): Brain and spinal cord l l ¡ Communication Reflexes Peripheral Nervous System (PNS): the nerve fibers that connect the CNS to the rest of the body. The peripheral nervous system is composed of two subsystems: l Autonomic Nervous System: regulates basic life processes and survival; unconscious; responds to threats (fight or flight) ¡ ¡ l Sympathetic division: EMERGENCY!! Parasympathetic: routine, homeostasis Somatic Nervous System: regulates conscious actions of skeletal muscle
Neurology ¡ Sensory Neuron: carry messages from sense receptor cells toward the CNS l There are different kinds of sensory neurons specializing in different senses ¡ ¡ Photoreceptors Chemoreceptors Nociceptors Ect… ¡ Motor Neuron: carry messages from the CNS to muscles and glands ¡ Interneuron: part of the intermediate network between sensory, motor, and other interneurons. ¡ Mirror Neurons*: a neuron that responds when an individual observes another performing a motor action or experiencing a sensation, has implications for social imitation and empathy; only observed in nonhuman primates. ¡ Glia cell: “support cells” or scaffolding for neurons
Neurology ¡ Plasticity: The malleability of neural structures in response to experience.
Neurology http: //www. youtube. com/watch? v=TKG 0 Mt. H 5 crc
Neurology ¡ Neurotransmitters: chemical messengers from one neuron to the next l Influenced by stimuli, behavior, and drugs l Problems occur when there is too much or too little
Neurology Common Neurotransmitters l Acetylcholine: skeletal muscles, attention, memory l Dopamine: voluntary movement, “reward system” l Norepinephrine: mood and arousal l Serotonin: sleep & wake cycle, aggression l GABA: regulation of anxiety l Glutamate: learning and memory l Endorphins*: pain relief and stress response l Oxytocin*: social bonding
Brain Imaging ¡ ¡ ¡ PET (positron emission tomography) CAT or CT (computerized axial tomography) EEG (electroencephalogram) MRI (magnetic resonance imaging) f. MRI (functional magnetic resonance imaging)
Brain Imaging: Your Professor’s Brain!
Neuroanatomy: Brain Stem ¡ Medulla: regulates breathing, blood pressure, and heartbeat ¡ Pons: “bridge” between spinal cord and brain; regulates sleep ¡ Thalamus: relays sensory information
Neuroanatomy: Limbic System ¡ Hippocampus: explicit memory ¡ Amygdala: emotion, aggression, fear, and related memories ¡ Hypothalamus: motivated behavior and homeostasis ¡ Olfactory Bulb: smells
Neuroanatomy: The BRAINS (Cortex)!!
Neuroanatomy: BRAINS!! ¡ Cerebrum: the region of the brain that controls higher cognitive and emotional processes (the brain-looking part). Divided into left and right hemispheres: l Left and right hemispheres are connected by the corpus collosum, anterior and posterior commissures. l Cerebral cortex: the outer surface of the brain ¡ ¡ ¡ Sulci: the trenches in the cortex Gyri: the folds of the cortex Cerebellum: attached to the brainstem and controls motor coordination, posture, and balance
More BRAINS!! http: //www. youtube. com/watch? v=j. Hxy. P-n. Uh. UY
¡ The sensory and motor cortex strips are bilateral, with the left hemisphere controlling the right side of the body, and the right hemisphere controlling the left side of the body ¡ The sensory and motor cortex strips allocate space based on complexity and sensitivity
“Split Brain” Patients ¡ http: //www. youtube. com/watch? v=ZMLz. P 1 VCANo
Endocrine System & Behavior ¡ The endocrine system uses hormones to supplement the work of the nervous system l ¡ The endocrine system regulates metabolism, and influences body growth, mood, and sexual characteristics Pituitary: the “Master Gland” in the brain that regulates the endocrine system l Endocrine glands include: ¡ ¡ ¡ Thyroid Adrenals Pancreas Ovaries Testes
Take Away ¡ The brain is super complicated! l ¡ No one spot is “in charge” of any process; it’s all about the connections and interactions between areas Experience effects neurology and neurology effects experience l Either chemical (drugs) or environmental (behavior) can break and change the entire cycle