The Brain CNS BRAIN SPINAL CORD PNS somatic autonomic sympathetic and arasympathetic Methods of Neural Research Brain damage case studies Phineas Gage Used to be only way Lesion studies in animals Imaging Electroencephalogram EEG Positron Emission Tomography Active areas have increased blood flow Radioactive isotopes small amounts are placed in the blood Sensors detect radioactivity Different tasks show distinct activity patterns Magnetic Resonance Imaging Magnetic fields align certain ions and compounds When field is removed these molecules release energy as radio waves Kind of like an X ray Provides clear 3D images Vital involuntary functions such as sneezes breathing hanging Hindbrain Midbrain The primitive inner core Medulla Pons Sleep and arousal Cerebellum Learning acquired reflexes Motor coordination alcohol Reticular formation Screens incoming information and arouses higher brain centers when nee ded Forebrain the Limbic System emotions memory and learning Thalamus Amygdala Sensory relay station All but smell Fear anger aggression Story of Elliot Hippocampus Memory formation Story of H M Page 10 Hypothalamus Regulates glands autonomic NS release of hormones Limbic System emotions memory and learning Hypothalamus Regulates glands autonomic NS release of hormones Basic Needs Four F s Fighting Fleeing Feeding Mating Hypothalamus Regulates glands autonomic NS release of hormones Basic Needs Four F s Fighting Fleeing Feeding Fornicating Lobes of the Cerebral Cortex Lobes of the Brain Temporal Lobes Auditory Perception Categorization Essential for social i nteraction Occipital Lobes Contain the visual cortex associations related to visual st imuli Parietal Lobes Sensory integration and then project to frontal lobes Ment al manipulation Cross modal matching Frontal Lobes star of brain Contain controls for speech production thin king planning reasoning impulse control motivation Phineas Gage The Case of Phineas Gage Two Hemispheres Language mostly in left hemisphere Detecting emotion spatial abilities music are in right Right controls and received input from left side of body and vice versa The Corpus Callosum Provides a pathway for communication between the hemispheres Sperry s Split Brain Experiment Split brain subjects could not name objects shown only to the right hemis phere If asked to select these objects with their left hand they succeeded The right side of the brain doesn t control speech Plasticity in Brain Behavior Some rats are housed alone in empty cages Their littermate twins are group housed in cages with toys which are cha nged frequently Richer environments led to heavier thicker brains more synapses and b etter learning Page 11 Sensation and Perception How do people navigate through the world Sensation Receive signals from the environment Perception Organizing and interpreting these signals Sometimes we don t immediately perceive what we sense An Overview of Sensation to Perception An age old question If a tree falls in the forest and no one is there to hear it does it make a so und Transduction The process of translating physical information into neural impulses Five Senses At least e g equilibrium pain Each sense perceives certain types of info e g light Has different structures e g rods and cones in eyes Thresholds Absolute Threshold Absolute Thresholds The smallest amount of stimulation that can be detected The lowest level of stimulation that can be detected 50 of the time Absolute Thresholds The Five Senses Difference Thresholds and Weber s Law Why can weightlifters perceive the difference between lighter and heavier weights Sensory Adaptation the tendency for our sensory receptors to have decreasing responsive ness to stimuli that continue without change Auditory adaptation occurs much more slowly than adaptation to odor s tastes and skin sensations We adapt to smells very quickly with the perceived magnitude of odo r decay occurring at the rate of about 2 5 each second Cain 1978 The Visual Stimulus Light Light travels in waves with two important properties Wavelength perceived as color Amplitude perceived as brightness Page 12 The Electromagnetic Spectrum and Visible Light The electromagnetic spectrum ranges from cosmic rays through X rays and ultraviolet light to TV and radio waves The Anatomy of the Eye Parts of the Eye Pupil small opening through which light enters the eye Lens transparent part of eye inside pupil that focuses light Retina lining of the eye containing receptor cells that are sensitive to ligh t The Retina Rods Cones Mostly in the periphery More light sensitive detect light and dark Take 20 30 minutes to fully adapt to darkness Mostly in the fovea Less light sensitive detect colors Have best detail vision Adapt fully to darkness in 2 3 minutes Visual Pathways Color vision The Young Helmholtz trichromatic theory Trichromatic Theory of Color Vision After Image Effect The Opponent Process Theory Cells are connected so as to place sensations of Page 13 Perception of color is based on the response rates of three kinds of cones After Image Effect Our receptor cells become over stimulated and then send less information into our brain for a short while afterwards Opponent color is thus seen more Color Vision The trichromatic theory explains perception at the receptor level The opponent process theory explains it at higher brain levels Colorblindness Perception Bottom up versus top down Bottom up processing use bits of information e g color brightness Top down processing use prior information Perception is affected by context and expectations True for auditory perception as well Chicago Police door study Attention The link between sensation perception and our experiences Directs our sensory systems toward certain stimuli Selects specific information for further processing Allocates the mental energy needed for that processing Regulates the flow of resources needed to perform tasks and coordinat e several tasks Critical Role of Attention We are surrounded by stimuli all the time Perception depends on attention Preconscious Processing The processing that occurs prior to the filtering process Exp dichotic listening task Cocktail party effect Exp sensitivity to sound while sleeping Klinger Change Blindness Illusion of Memory We tend not to notice unexpected changes in our environments We think we perceive and remember more of our world than we actually d o Perceiving visual forms Gestalt Psychology whole is more than the sum of its parts Page 14