Why Study the brain?- Is it necessary for psychologoists to understand the biology fo the brain?o Yes – the brain is the organic matter underlying the mind- The Mind-body problemo Monism: Mind and brain are the same thingo Dualism: Mind and brain are different entitieso Current research rejects strict dualismHow does the Brain Work at the Cellular Level?- Neurons: cells in the nervous system that communicate to perform information processing taskso 3 main parts Cell Body Dendrites-- Receives information from other neurons axons Axons- - Transmits informationo 3 Major Types Sensory Neurons-- Sensory information transferred to the brain Motor Neurons-- Receive information from the spinal cord to direct movement Inter Neurons-- Connect neuronso Approximately 100 billion neurons in the brain- Neurotransmitters: Chemicals that transmit information across the synapse to a receiving neuron’s dendriteso Acetylcholine (Ach): involved in voluntary motor control, memory, regulation of attention, learning, sleeping and dreaming.o Dopamine: regulates motor behavior, motivation, pleasure, and emotional arousalo GABA: involved in stoppingo Norepinephrineo Serotonino Endorphins- The Brain communicates via electrochemical processes o Conductiono Transmission- A major debate in the 1800so Equipotentiality: All parts of the cortex contribute equally to all mental abilitieso Functional Localization: different parts of the cortex underlie different mental processes Phrenology: Assessing personality and abilities by measuring bumps on the skull (functional localization) Broca’s area: 1861: Broca described a patient who had lost the capacity to produce spoken language but not the ability to understand language. Excellent evidence for functional localization and challenged Descartes notion of dualism Can be studied with Transcranial Magnetic Simulation (TMS)- Brainstem: Basic survival…o Midbraino Ponso Medulla- Cerebellum (“little brain”): fine motor movement- Pituitary gland: “master gland” produces and releases hormones- Thalamus: Relays & filters sensory information- Hypothalamus: Regulates drives. o The four F’s—Feeding, fighting, fleeing, and Sex- Cerebral Cortex (Cerebrum): Specialized into four lobeso The occipital lobe Structure- Back of head Functions include:- Visiono The Temporal lobe Structure- Near the temples Funcitons- Hearing- Memoryo The Parietal lobe Structure- Top, rear of the brain Funcitons include: - Spatial abilities - integrate sensory info- Sense of touch Somatosensory cortexo The Frontal Lobe Structure- Front of the brain - Huge in humans Funcions include:- Planning- Rational, directed activity- Self-control- Socialy appropriate behavior- Movement / motor control Motor Cortex- Somatosensory and Motor Homunculi (“little men”)- Phineas Gageo 25 year old railroad construction foreman in Vermonto An explosion blew a tamping iron clear through his heado The tamping iron was long and heavy Landed 80 ft awayo Physical and Intellectual consequences He was able to walk and talk immediately - To the doctor “Here is business enough for you” He fully recovered – physically – within two months Intelligence, memory, language, etc were intacto Personlaity consequences Before he was most efficient and a capable employee After: Gage was no longer Gage- He got really mean afterwardso Personality is controlled by the frontal lobe Corpus Callosum: 200 million nerve fibers that connect the twohemispheres- Controlateral pereption and controlo Each hemisphere perceives information from the opposite side of the bodyo Each hemisphere controls the opposite side of the bodyo Each Hemisphere controls the opposite side of the body- Hemispheric Lateralization: The hemispheres specialize in different thingso Left hemisphere Verbal processing: language, speech, reading, writingo Right Hemisphere Nonverbal processing: spatial, musical, visual recognition- Split-brain patientso In extreme epilepsy, treatment sometimes includes cutting the corpus callosumo Patient can still function, but information cant cross from one side of the brain to the other- The Split brain tasko Hemispheric Lateralization & Vision The right visual field goes to the left side of the brain and vice