PSYC 311 1st EditionLecture 10Lecture 10 - February 24 (slide 79-105)- Sensory systems, cont.o Complex NS – frequent change/choice of responses is required  Very flexible, emphasizes learning - High cost of glucose/oxygen requirements  Advanced vertebrates have a combination of complex responses, but do have “semi-automatic” pre-wired set-ups/simple reflexes- Dedication of advanced brain structures follows/allows species-specific sensory capabilities - Human visual/auditory/tactual brain areas are highly developed (big)- Olfactory structures used for memory o Approaches to increasing conduction velocity of neurons Size of neurons: bigger = faster Myelination: encasing axon in a sheath - Saltatory conduction: jumping from gap/node to gap/node (nodes of Ranvier)- More heavily myelinated = faster o Heavily myelinated = “A” fibers  “B” are partially myelinated “C” are slow conduction neurons - Need for miniaturization in higher animalso Human optic nerve contains one million + A fibers Nerve is 2 millimeters in diametero Squids have giant axons (1 mm each) Neurons are specialized for conducting info from one part of the body to another - Neurotransmitters responsible for transferring information from one neuron to the next - Types of Nervous Systems o Any type is adequate for the organismo Vertebrates NS  Progressive Encephalization – gradual increase in size/complexity/importance of brain  Structure does not follow function – smell analysis in humans used for verbal purposes o Mammalian CNS  Telencephalon – cortex- Cell bodies of most neurons are located in outer surface area of thecortex- Neocortex: six layers (located on outside)- Brain complexity related to number of neurons in CNS- To increase numbers of neurons, must increase surface area of the cortex o Brain folds present to increase cortical surface area withoutincreasing brain size (for birthing purposes) Localization of function - More posterior lobes are involved in analyses of sensory info including high-level capabilities o Central analyses (visual, auditory, tactical)o Brocca, Flourens, Fritsch, Hitzig o Occipital, parietal, temporal- Anterior (frontal lobes) are motor in nature, including areas responsible for o Evaluation of outcome probabilities associated with variouschoice between available responseso Evaluation of signals concerning emotions o Response sequencing (motor speech, eye movement)o Actually carrying out response  Diencephalon - Hypothalamus (endocrine system)o Densely packed nuclei – bilaterally symmetrical  Ventromedial vs. lateral (feeding vs. emotion)  Dorsomedial – emotional  Preoptic – gender related differences  Suprachiasmic – rhythmic cycles (diurnal)o Limbic system – loosely interconnected structures (Brocca) Role in emotions (Papez) Emotional feeling vs. emotional behavior  Autonomic Nervous System - Homeostasis – regulation of internal environment of body (digestion, HR, BP) Endocrine System – produces hormones- Chemical messengers released into bloodstreamo Adrenaline: NT and hormoneo Specificity vs. spread - Activation effects: hormones start a process that changes the animalo Changes in sexual attraction - Organizational effects: start a reorganizing process in body o Metamorphosis o Preoptic nucleus – mammals default female  One male can fertilize a bunch of women, but only females can give birth  Testosterone in embryonic stage – produces changes in hypothalamus- Much larger in males o If testosterone is present  male brain (even if female)o If testosterone is not present  female brain (even if