Brain and Behavior Exam 4 Study Guide LEARNING AND MEMORY Learning relatively permanent change in an organism s behavior as a result of experience Memory the ability to recall or recognize previous experience o Implies a mental representation of the experience is stored in neural pathways Plasticity the brain s ability to change as a result of experience o Changes in neural pathways and synapses o Brain changes throughout life allows us to modify our behavior to adapt learn o Brain changes that occur as a result of learning NOT localized to one region of the brain Can occur anywhere in the brain Strengthen weaken synapse connections Neurons change their structure response to changing experiences More dendrites more connections Build new synapse connections circuits Difficult to study directly Observe behavior to gain insight How it is studied o It is challenging to get the animal to reveal what it has learned o Match the species analyzed with a test appropriate for abilities Rats mice mazes swimming pools lever pressing Birds singing Monkeys observe environment choose objects Humans paper and pencil tests Training Models o Pavlovian Conditioning Classical Conditioning Associate 2 stimuli and give same response to both Unconditioned Stimulus Unconditioned Response US Conditioned Stimulus Un Conditioned Response CS CR Example Air puff US blink UR Tone CS No response Air puff Tone blink UR Tone blink CR UR CR eventually become the same o Operant Conditioning Instrumental Conditioning Associate actions w consequences which changes the probability of the animal repeating the action in the future How you measure learning in positive reinforcement tests o Time to complete task decreases w repetition o of trials required for task to be completed in time frame o Positive stimulus applies stimulus o Negative stimulus removes stimulus o Reinforcement increases frequency of desirable behavior o Punishment decreases the frequency of undesirable behavior Positive reinforcement increased behavior Negative reinforcement increased behavior Positive punishment decreased behavior Negative punishment decreased behavior applies good stimulus removes bad stimulus applies bad stimulus removes good stimulus o Conditioned place preference test No preference before trials left side right side Rat receives rewards punishments on one side only and learns to prefer that side other side o Morris Water Maze Assesses spatial learning and memory Associate the location of the submerged platform with the visual cues distinguishing the regions of water maze Hippocampus functioning o Radial Arm Maze Subject placed in center of eight arm radial maze Four randomly chosen arms have food Subject visits and collects food Tests short long term memory Used to test effects of marijuana usually short term memory affected impaired o Novel Object Recognition Rats tend to spend more time interacting with a new object than a previously observed object Measure the amount of time spent with Object A previous vs Object B novel Tests hippocampal function o Extinction Used in drug rehab Gradual decrease of learned behavior over time Subjects can unlearn previously learned behaviors Pavlovian Operant o No US w CS o No reward or punishment with action Categories of Memory o Short term sensory motor cognitive o Long term Explicit conscious subjects can retrieve an item from memory and indicate that they know the retrieved memory is correct Implicit unconscious subjects demonstrate knowledge such as a skill conditioned response or recalling events on prompting but can t explicitly retrieve information Declarative explicit medial temporal lobe diencephalon Episodic includes a record of event and your role in event Tulving said it s a marvel of nature Transforms brain into a time machine that allows us to dwell on the past and make plans for the future Semantic record of facts meaning concepts knowledge Non declarative implicit Procedural basal ganglia Priming neocortex Simple classical conditioning amygdala cerebellum Habituation sensitization reflex pathways Encoding Implicit tasks passive role Explicit tasks active role Priming using a stimulus to sensitize the nervous system to a later presentation of the same or a similar stimulus often used to measure implicit memory Amnesia partial or total loss of memory o What makes I E memory different The way they store memories Info from each sensory system visual auditory etc is processed and stored in different neural areas No single place in the brain is the location of learning and memory every part of the brain can learn Emotional memory is both conscious and unconscious remember event but not his her role in it inability to store new memories after an event inability to retrieve memories formed prior to an event o Retrograde o Anterograde o Episodic o Impaired explicit memory new memories since surgery but procedural memory intact Parkinson s disease impaired ability to perform tasks he d done all his life Patient J K basal ganglia damage due to o Impaired explicit memory Patient H M medial temporal lobe damage no Korsakoff s Syndrome o Permanent loss of the explicit memory Inability to learn new info anterograde amnesia and to retrieve old info retrograde amnesia o Caused by diencephalic damage from chronic alcoholism or malnutrition that produces a vitamin B deficiency Modifying Synapses Plasticity o Habituation a repeated stimulus leads to a decrease in the normal response o Sensitization a stimulus to one pathway enhances reflex strength in another o LTP long term potentiation long lasting enhancement in signal transmission o LTD long term depression long lasting reduction in signal transmission o Neurogenesis evidence that neurogenesis growth of new neurons does occur between two neurons between two neurons in the mammalian brain Olfactory bulb hippocampal formation and possibly the neocortex Reason for neurogenesis is still unclear o Raising rats in enriched enclosures is associated with higher dendrite length astrocyte processes vascular volume synapses neurons aka plasticity o Higher hormone levels also helps with plasticity o Glucocorticoids released from the adrenal cortex in times of stress Chronic increased levels of these from prolonged stress may be neurotoxic Stress can damage hippocampal cells used in memory o Nerve growth factor Neurotropic factor that stimulates neurons to grow dendrites and synapses and in some cases promotes the survival of neurons o Brain Derived