Emi’s 9.00 Midterm Review SheetThe Brain• Disorders associated with damage to very specific areas– Broca’s area: region of left front lobe. Damage causes nonfluent aphasiaswhere the patient has trouble speaking; there is great loss of vocabulary, speechis labored, finding/articulating words takes special effort.– Wernicke’s area: region borders on the auditory primary projection area. Damagecauses fluent aphasias, where the patient can produce speech but do not un-derstand what is said to them. Reasonably grammatical sentences are produced,but are “word salad” and mostly little filler words, provide little information.– prefrontal area: responsible for response inhibition; use of rules to control behav-ior.• Other Disorders– prosopagnosia: a complex form of agnosia, where one cannot identify familiarobjects using the sense that has b e en affected. I n this particular case, a person isunable to identify human faces. it involves areas of temporal and parietal lobes.– apraxia: produced by lesions in the frontal lobe of the cortex. Disturbance ininitiation or organization of voluntary action. Sometimes patient is unable tosalute, wave goodbye when asked to do so. Trouble putting actions in correctsequence.– agraphia: inability to write• Hemispheres– Difference between two seems related to language.– Right-handed people with lesions in left hemisphere tend to have aphasia.– Left-handed people with lesions in right hemisphere have difficulty in the compre-hension of various aspects of space and form; right-handers with the same lesionssee details but not the overall picture.– (Note: aphasia is not really a matter of speaking or hearing; is the result ofdisruption in specific processing steps needed for language.)• Structures– Hindbrain∗ Medulla: lies directly above the spinal chord. Regulates cardiovascular andrespiratory systems.1∗ pons: regulate brain’s level of attentiveness, sleep, dreaming. Other partsintegrate movements and sensations from facial muscles, tongue, eye, ear.∗ Cerebellum: Skilled movement, balance, timing, all intuitive me mory–musclememory.– Midbrain: Tracking small movements–this part of the brain is large in birds.– Forebrain∗ Thalamus: Relay stations for nearly all the sensory information going to thecortex.∗ Hypothalamus: regulatory organ–responsible for hunger, thirst∗ Basal Ganglia: Regulating muscular contractions; keep us from jerking around(think of the gangly teenager).∗ Cortex: The outermost layer of the cerebral hemisphere, most developed inprimates and higher order mammals.∗ Medial Forebrain Bundle (MFB): Pleasure center of the brain, perhaps. Ittriggers the activity of cells that rely on dopamine as a neurotransmitter,which some believe is a positive reinforcer.– Myelin is only found in vertebrates, which move much faster than invertebrates.They are specialized glial cells that help neurons communicate faster. Made offatty substances, wrapped around long axons.• Action-Potentials and nerve cells– Action-potential refers to the whole destabilization-stabilization process the cellgoes through.– Stimulus is not detected by strength of action-potential; nerve firing folllows theall-or-nothing rule; if a stimulus is over the threshold, the action-potential occurs.Intensity is detected by the number of nerves that end up firing.• afferent pathway: information (bottom-up) lots of stuff in front of you, not lookingfor anything in specific.• efferent pathway: information (top-down) searching specifically for something– “whereare my pants?”Motivation• Schools of thought (I’m not sure if this really belongs here)– Dualists: Plato, believed that there is a body and a soul– Gestalt: Nothing is caused by individual neurons; everything is a sum of lots ofneurons’ activity.– Behaviorists: There is only behavior to be seen.2Vision• Color Vision– Light mixes additively: We see the sum of the wavelengths. Remember that thewavelengths of each color being mixed does not change! I f we took a spectrometer,we would see a mixture of the constituent wavelengths. More than two colors inthe right proportions forms white. The complements turn into gray (ie blue andyellow light).– Paint mixes subtractively: Each pigment or filter absorbs its own set of wave-lengths, and the only wavelengths that emerge are those absorbed by none of thepigments or filters. So a mixture of three different paints/filters is a dark gray.– Hue distinguishes blue from green from red; corresponds to our word for “color.”– Brightness is dimension that differentiates amount of black.– Saturation is the purity of a color; extent to which it is chromatic rather thanachromatic. The lesser the saturation, the more gray a color.Memory• “Disordered Memories”– anterograde amnesia: caused by lesions in the temporal cortex (hippocampus andsubcortical regions). One common cause is malnutrition associated with alco-holism: Korsakoff’s syndrome. Symptoms are inability to form new memories–ie H.M.. Working memory but no ability to add to long-term memories.– retrograde amnesia: Patient suffers loss of memory for some period prior to braininjury. Perhaps related to trace consolidation? Maybe trace consolidation is amore drawn out process than thought to be? (Since some memories lost in thisway go back years or so.)• Memory Errors– Bias: Your general knowledge intrudes on specific memories and reshapes them–iethe European children hearing about the Native American stories and retellingthem slightly altered, changing the parts they didn’t understand.– Context: ie leading questions; example about the car crash using the words bump,hit, smash causes the subjects to put different estimates of the car’s speed.– False memories:– Failure in source monitering:– Becoming plastic again: Retelling of memories causes subjects to become confusedabout what actually happened and what they made up later. This may happenwith flashbulb memories; you have heard it retold by so many people.3– Hypnosis does not reliably summon up old memories; we do not retain everybit of sensory knowledge that we have encountered. Hypnosis simply makes usmore likely to believe the person giving us hypnosis; we are convinced we arereliving childhood, but really it is just a pretense (comparison of “recreated”child’s drawing and actual child’s drawing.)Child Development• Piaget’s four stages–