Psych 210: Exam 3Touch: Ch. 11- somatosensory system: relays information about the bodyo touch, temperature, body position= proprioception, organic senses (heart burn), pain=nociception - Labeled Line System- receptors are neurons that transduce or change a physical stimulusinto neural eventso In the skin, each receptor has a specialized ending that responds to a specific attribute of the stimulus o Labeled line= different receptors for different qualities have different line to the brain. Such as: Ruffini’s ending- stretch Pacinian corpuscle- vibration- When deformed (skin vibrate) sodium channels are opened which depolarizes the endings, if its depolarizes enough it creates an action potential Meisssner’s corpuscle- touch Merkel’s disc- touch Free nerve endings- pain and temperature o Plays factor on receptive field- exhibit adapting The region of the receptor surface that excites or inhibits a sensory neuron. (smallest in the fingertips, larger in the hand, larger in the arm) The receptive fields size varies with use- Adaption- loss of sensitivity to continuous presence of stimuluso If you don’t change pressure then your brain doesn’t need to know- Somatosensory pathways- information ascends in the dorsal columns to the medulla, then to thalamus and then to somatosensory cortex.o information coming in through the bottomo Reaches medulla, sensory information crosses overo Goes to thalamus then somatosensory cortex. - Dermatomes- you have axons coming in your sacral region, all the wayup your spinal cord until medulla. o If you were to cut off any part of the spinal cord, you would severall the way down from where you cut. o Coccygeal, sacral, lumbar, thoracic, cervical  No need for face muscles to go to spinal cord- Somatosensory cortex is just posterior to the central sulcus o Plastic, changing type of information to the brain after trainingMovement: Ch. 11- muscle receptors:o Golgi tendons organs- contractiono Muscle spindle receptors- stretch Primary sensory endings- innervate the central region of the muscle spindle Secondary sensory endings- innervate thethin ends of the muscle spindle- Sensory information enters spinal cord via dorsal root- Motor information exits spinal cord via ventral root- Muscle receive neural input from motor neurons in thespinal cord- Motor neurons release acetylcholine (ACh)- There is multiple sights of synaptic contact. - Cidocoline activates muscle- Stretch reflex- the position of the muscle is set by thebrain, the tap on the patella tendon creates an error andthe error signal to try to return the limb to its originalpositiono The activation pattern of spine and brain- Babinski sign- underdeveloped motor system. Damage to motor cortex, corticospinal track. Baby doesn’t have fully developed nervous system- Major components of movement o Spinal cordo Cerebellum- basic coordination of limbs, eye movements, balance, muscle tone Flocculonodular lobe- vestibular control  Vernis and anterior lobe- motor coordination, limb control Posterior lobe- initiation/planning, timing  Damage: Right arm was right on time to point target and back to his nose.Left arm could not focus on target and difficulty pointing at his nose.o Behavioral traits- depends upon the region damaged  Depends on the behavioral trait- depend upon the region damagedo Three layers- molecular layer (top), purkinje cell layer, granular layer o Two inputs- climbing fibers, mossy finers One output- Purkinje cell- form large planar dendritic trees in molecular layer - guides movements by inhibiting neurons- cerebellum is fine tuning motor movementso in order for control over motor movement (smooth)o climbing fibers- form many synaptic connections with 1-10 purkinje cells all way up to molecular level then wrap around purkinje cells, as it wraps around it is making synapseso mossy fibers- form synaptic contact with many granule cells  if you stimulate one mossy fiber it stimulate handful of parallel o granule cells- project into molecular layer and form parallel fibers parallel fibers- long lateral projections form synaptic contacts with multiple purkinje cells- 1 parallel fiber wouldn’t activate- Levels of motor control o Spinal cordo Cerebellumo Cerebral cortex- primary/ secondary motor cortex- Motor cortex: three regionso Primary motor cortex - encode force and direction Lesion cause weakness  Recorded neuronal activity in primary motor cortex while monkeys make arm movements o Supplementary motor area- planning movements  Lesions result in loss of voluntary movements Recorded neuronal activity while monkey moves arm toward an object  Doesn’t respond until an activation signal knows when it can moveo Premotor cortex- planning and control of limb movements - Basal ganglia- consists of the caudate nucleus, putamen, globus pallidus subthalamic nucleus , substantia nigrao Encodes the amplitude, direction and initiation of movement - Parkinson’s Disease- 1% of US population over the age of 65o Caused by a loss of dopamine from the substantia nigra (midbrain) to the basal gangliao Phenotypic traits: Body tremors when at rest Muscle rigidity Bradykinesia (slow movements) and akinesia (no movement)- Huntington’s Chorea: incidence of 5-10/100,000o Phenotypic traits: Sudden jerky, involuntary movements (chorea) throughout your body Severe problems with balance and coordination Jerky, rapid eye movementso An inherited condition caused by a single abnormal geneo Resulting in a degeneration of cells in the basal gagliaDeclarative Memory: p. 481-516- Henry Gustav Molaison (HM)o When he was very young he fell and hit the back of his head. Had seizures and got worse with age. o Doctor said he would check which part of the brain was over acting Medial temporal lobe 2/3 hippocampus removed  Amygdala removed Removed cortex around hippocampus- Helped reduce seizureo After his surgery he had severe amnesiao Outcome: hippocampus-----memory - Amnesia- memory losso Retrograded Amnesia: loss of memory for the past HM- lfor about 10 years before surgeryo Anterograde amnesia: inability to form new memories HM- for long term storage of new memories- Hypothesis of memory process: information comes in, sensory buffers, encoding, short term storage(-consolidation) -working memory-retrieval ---- performance, long term storage. Loss of