Chapter 1 Introduction lecture 05 08 2014 Why do we study the brain nervous sys Makes possible everything tht we do experience and perceive It makes us different from the rest of the animal kingdom Its complexity is enormous and far from being completely It allows interaction between the outer world and mind process of understood thinking The ultimate function of the brain is to Output in external pathway from motor sys Physiological Psychology Beh neuroscience the study of the physiological evolutionary and developmental mech of beh and exp Beh neuroscience seeks to describe the physical mech of the body that mediate our movements and mental activity o We want to be able to describe what occurs o But the ultimate aim is to be able to explain o Why do we act the way we do Y are we diff from each other Y some of us become scientists and others poets Relationship between the mind and body Two major views of the mind body problem o Dualism mind and body are separate but interacting Body is physical mind is not From the belief that spirits can inhabit a body o Monism mind is a property of the physical nervous sys body an emerging property of the brain is the mind Everything in the universe consists of matter and energy mind is a result of working cns Only one single entity Consciousness Refers to self awareness and the ability to communicate our thoughts perceptions feelings and memories Physiological approach consciousness can be affected by drugs brain trauma illness o Thus conscious is a physiological fn just like our other forms of beh perception motivation emotions memory motor control Consciousness and blind sight Damage to the visual sys on one side of the brain will produce blindness in the opposite contralateral visual field Blind sight blind patients are unable to see but are able to reach for objects placed in their blind visual field o Implies tht we need not be conscious of a stimulus in order to act on tht stimulus o Is able to happen to blind patients bc of residual vision Eye primitive visual sys a person is not aware of vis info by the sys prmitive beh mech eye and head movements reaching movements w hands other simple beh Eye mamalin visual sys damage abolishes perception and awareness of visual stim more recently evolved beh mech speech and thinking in words and consciousness other complex beh Split brain procedure Corpus callosum contains bundles of axon fibers that connect one hemisphere to the other Epilepsy frequent seizures the hippocampus is extremely susceptible to being hyperactive and is capable of sending overstimulation to other parts of the brain as soon as that overstimulation reaches the frontal cortex initiates seizure Collotomy cutting the corpus callosum to alleviate epileptic seizures o The surgeon opens the skull lays back brains coverings exposes corpus callosum w cerebral retractor cuts through the corpus callosum W out a corpus callosum the left and right cerebral hemispheres are unable to directly communicate Info that doesn t reach the left hemi Left language does not enter consciousness the person therefore cannot verbalize it o Info tht enters the right hemi cannot be translated into lang Testing a split brain The olfactory sys is unilateral thus if a person smells a flower w right nostril it will stay in the right hemi if split brain is not named bc does not go to left hemi Will however pick the flower w left hand when asked what was smelled bc right hemi controls left side of body has not been able to reach consciousness o the activity of the brain results in the mind the idea of consciousness This is what the brain does o beh neuroscience studies this phenomena explain find the mech that underlie these phenomena Research Goals The goal of science is to explain the phenomena under study Explanation involves 2 processes o Generalization deduction of general laws using results from experiments laws to exp individ beh o Reduction the use of simple phenomena to explain more complicated phenomena ex lang is due to act of left hemi Create models tht could simulate what is happening in the brain Roots of phys psych 3000 bc the dawn of neurology first descriptions of the brain and brain injuries surgical papyrus Hippocrates the father of medicine All of our emotions are based on the activity of the brain Learning and knowledge likes and dislikes come from the brain Hippocratic corpus provided 1st statement about the brain as a controlling center for the body Believed that the heart was the seat of intellectual and perceptual functions Brain served to cool the heart Aristotle Galen Performed dissections anatomical description of nerves cerebrum v cerebellum animal spirits were stored in ventricles cavities within the brain Renaissance Rene Descartes Three cavities within the brain 17th century French philosopher dualist mind unique human attribute that is not subject to the laws of the was first to suggest connection between mind and its physical universe housing brain viewed world as mechanic and viewed human beh in terms of reflexive mech elicited by stimuli in the env o proposed tht the mind interacted w the physical body thru the pineal body not brain tissue not within brain tissue o viewed hydraulic pressure within nerves as the basis for movement Era of cortical localization Franz joseph gall Localization of function phrenology individual development of cortex was reflected in bumps and depressions of the skull localization of fn of the brain Muller 1808 1858 noted that specific nerves carry messages from different sensations Doctrine of Specific Nerve Energies o ex stimulation of the retina will always produce a visual image seeing stars every line is labled Florens used ablation removal of discrete brain areas in animals to asses the role of the brain in control of beh o Caveat may reach the wrong conclusion may be removing a central part of the sys for fn but may not be esp roach o Flourens reported discrete brain areas that controlled heart rate and breathing purposeful movements and visual Paul Broca blood o Demonstrated tht cancer cells can spread throughout the o Leborgne Tan patient w paralysis on the right side of the body progressive loss of speech o Showed major deficit in stroke aphasia o Broca s autopsy of Tans brain noted damage in the left hemi o Broca s area Electrical stim of the brain Fritsch and hitzig applied electrical stim to cortex in dogs to elicit muscle contraction on the opposite side of the body contralateral o
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