Chapter 12 - Quiz 5 Flashcards
12.1: Localized Representations of Memory
What are the two types of learning? Who invented one of them?
-classical (Pavlov) and instrumental conditioning
-animals have specialized methods of learning beyond these two
12.1: Localized Representations of Memory
What is the basic premise of classical conditioning? What are the steps? (5)
-learning to associate a neutral stimulus with a meaningful stimulus, resulting in a new learned process
Steps:
1. The experimenter presents a conditioned stimulus first which is a neutral stimulus that eventually becomes meaningful once paired with the UCS. This is the bell.
2. Next they immediately present the unconditioned stimulus UCS. This is a stimulus that naturally and automatically triggers a response without any prior learning. This is the food.
3. This triggers the unconditioned response which is the salivation. UCR
4. After a while of pairing these two together the individual begins making a new, learned response to the CS called a conditioned response CR. This is the dog salivating to the sound of the bell.
12.1: Localized Representations of Memory
Explain what is instrumental conditioning.
-a response leads to a reinforcer or punishment where behavior is influenced by its consequences
-behaviors followed by a favorable consequence are more likely to be repeated than behaviors followed by unfavourable consequences
12.1: Localized Representations of Memory
What is a reinforcer and punishment? (2)
-reinforcer is any event that increases the future probability of the response
-punishment is an event that suppresses the frequency of the response
12.1: Localized Representations of Memory
Give an example of instrumental conditioning and explain the example with both reinforcer and punishment. (2)
-when a rat is going through a particular arm of a maze and find a treat they are more likely to enter that area in the future
-however, if they recieve an electric shock they are less likely
12.1: Localized Representations of Memory
Describe the differences between classical and instrumental conditioning. (2)
-in instrumental conditioning, the individual’s response determines the outcome
-wheras in classical conditioning, the conditioned stimulus which is the bell and the unconditioned stimulus which is the food occur independetly of the individual’s actions. The learnign process involces forming associations between these stimuli reather than between behaviors and consequences
12.1 Lashley’s search for the Engram
How did Pavlov believe classical conditioning worked in the brain?
-he believed it reflected a strengthened connection between a CS center (bell) and a UCS center (food) so when the CS was excited it would excite the UCS and the UCR automatically
-now we know this hypothesis does not fit all behavioral observations
12.1 Lashley’s search for the Engram
What is an engram?
-a physical representation of what has been learned
Chat GPT: a theoretical concept that refers to the physical or biochemical trace of memory within the brain. It’s the means by which memories are stored as biophysical or biochemical changes in the brain (and other neural tissue) in response to external stimuli
12.1 Lashley’s search for the Engram
What two experiments did Lashley complete to try to find the Engram? (2)
- Trained rats then made deep cuts in their cerebral cortices. However, no knife cut significantly impaired the rats’ performances.
- He also would try cutting out large portions of the cortex to see how well rats navigated the maze. He found that no particular cortical area impaired performance more than another.
12.1 Lashley’s search for the Engram
What are the two concepts Lashley theorized based on his experiments? (2)
-define the
-equipotentiality: all parts of the cortex contribute equally to complex behaviors such as learning, and any part of the cortex can substitute for any other
-mass action: the cortex works as a whole and more cortex is better
-however, these rest on assumptins. The first is that the cerebral cortex is the best or only place to search for an engram and that studying one example of learning is just as good as studying any other one
12.1 The Modern Search for the Engram
Describe Thompson’s experiment looking for the Engram and highlight the difference to Lashley’s. (3)
-looked in the cerebellum not the cerebral cortex
-studied classical conditioning of blinking to a puff of air in rabbits
-think of the chart that starts with a -> b-> c -> d. This thinking allowed him to precisely figure out which part of the brain was actually doing the learning, as if he stopped that part from working that the muscles wouldn’t respond but we would see evidence of the learning of the animal later
12.1 The Modern Search for the Engram
Which area of the brain did Thompson’s research identify as essential for learning?
-lateral interpositus nucleus (LIP)
12.1 The Modern Search for the Engram
How did Thompson know that LIP was the correct area where the learning was happening, not just an area after the learning? (2)
-while the LIP was suppressed, the training had no effect on the rabbit
-they tried suppressing the red nucleus an area that recieves input from the cerebellum and the rabbit did learn after the suppression of the red nucleus wore off showing that the learning did not require activity in the red nucleus or any area after it
12.1 The Modern Search for the Engram
What do people with damage to the cerebellum show when doing Thompson’s experiment?
-either no conditioned eyeblinks or only weak inaccurately timed ones
-damage to the cerebellum impairs learning only when a discrete response needs to be made with precise timing
12.1 Types of Memory: Short and Long-term memory
What two types of memory did Hebb propose? (2)
-short-term memory for events that have just occurred
-long-term memory of events from further back
12.1 Types of Memory: Short and Long-term memory
What three types of evidence support the idea that there is short and long-term memory? (3)
-you can remember a lot of information in long-term memory but very little in short term memory. For example, repeating a random number sequence would be challenging after a certain number of letters.
-short-term memory requires rehearsal. You can recall long-term memories you haven’t thought about in years
-once you have forgotten something from short-term memory it is lost but with long-term memory often a hint will allow you to remember something you’ve forgotten
12.1 Types of Memory: Short and Long-term memory
How did Hebb suggest short-term memories are held in our brains in a simple way?
-through a reverbrating circuit in which neuron A excites neuron B which excites neuron C with then reexcites neuron A.
12.1 Types of Memory: Short and Long-term memory
How did Hebb propose we make short-term memories into long-term ones?
-storing something in short-term memory for long enough makes it possible for the brain to consolidate it into long-term memory, presumably by building new synapses or other structural change
12.1: Our Changing views of consolidation
Does holding onto a memory for a long enough time automatically turn it into a permenant memory? Give an example with your answer. (2)
-no
-emotionally significant memories form quickly like if someone told you a snake was in the house you would remember that immediately but if you try to memorize flashcards those take a lot longer
-flashbulb memories are when you remember something before and after a major event happened
-also, your brain tags a weak new memory for later stabilization if a similar more important event soon follows
12.1 Working Memory
What does the term that Baddeley and Hitch introduced, working memory, refer to?
-the way we store information while we are working on it
12.1 Working Memory
What is a common test of working memory? Explain it. (2)
-delayed response task
-you look at a dot and light flashes in your periphery and later a beep sounds and once the beep sounds you look towards where the light flashed
-results show memory was distributed over many cells in an alternating pattern
12.1 Working Memory
How does the cortex store a working memory during a delay?
-Occasional bursts of gamma oscillations (45 to 100 Hz) occur in cells that responded to a stimulus, but the bursts alternate among cells instead of persisting throughout the delay in any one cell.
12.1 Korsakoff’s Syndrome
What is Korsakoff’s syndrome? What is it caused by? What does prolonged thiamine deficiency result in in the brain? (3)
-AKA Wernicke-Korsakoff
-brain damage caused by prolonged thiamine deficiency
-since the brain needs thiamine to metabolize glucose, going for long periods without vitamins such as in alcohilism will cause this
-loss of neurons throughout the brain, especially in the dorsomedial thalamus
12.1 Korsakoff’s Syndrome
What is a distinctive symptom of Korsakoff’s syndrome?
-confabulation: in which patients fill in memory gaps with guesses
-most likely to do this with questions about their own lives
12.1: Alzheimers
Discuss scientists findings on genes linked to Alzheimers. What is their finding for early vs. late-onset? (2)
-some genes have been linked to early-onset Alzheimers, a gene on chromosome 21
-however, many late-onset cases relate to epigenetic changes in certain genes
12.1 : Alzheimers
What are the two proteins that scientists propose cause Alzheimers? (2)
-amyloid-B
-tau protein
12.1: Alzheimers
Describe how amyloid-B is believed to result in Alzheimers? Start from where the protein goes, what it does and why that is damaging. (3)
-the genes controlling early-onset cause this protein to accumulate inside and outside neurons and spread from cell to cell
-this protein then damages axons and dendrites, decreases synaptic input and decreases plasticity
-these damaged axons cluster into plaques that damage the brain
-many researchers are not convinced that Amyloid-B is the sole causer of Alzheimers as many people have high levels of amyloid-B without alzheimers disease and vice versa
12.1 Alzheimers
How do scientists believe the tau protein causes Alzheimers? (3)
-this protein is in the intracellular support structure of axons
-high levels of amyloid-B cause more phosphate groups to attach to tau proteins
-the altered tau cannot bind to its usual targets within axons, so it starts spreading into the cell body and dendrites
-the altered tau is responsible for tangles, structures formed from degeneration within neurons
-the areas of cell damage in the brain correlate better with tau levels than with amyloid-B levels
12.1 Alzheimers
Is any drug highly effective for Alzheimer’s disease?
-no
12.1 Infant Amnesia
What is infant amnesia?
-when children, teens, and adults cannot recall memories from when they were a baby
12.1 Infant Amnesia
What do researchers believe causes infant amnesia?
-the formation of new neurons facilitates new learning, which displace the old learning in infants because there is only so many neurons in an infant
12.1: Memory loss after damage to the hippocampus
What is the hippocampus important for?
-it is active during the formation of memories and recall of them
12.2: Anterograde and retrograde amnesia
What two types of amnesia did the patient who had severe epilepsy experience after the lobotomy?
-anterograde amnesia and retrograde
12.2: Anterograde and retrograde amnesia
What is anterograde amnesia?
-the inability to form memories for events that happened after the brain damage
12.2: Anterograde and retrograde amnesia
What is retrograde amnesia?
-loss of memory for events that occured before the brain damage
12.2: Intact working memory
Which type of memory did the patient H.M still have, so long as he wasn’t distracted?
-working memory or short term memory
12.2 Impaired storage of long-term memory
Describe H.M’s impaired storage of long-term memory. What was the discrepancy? (2)
-he was severely impaired from learning new long-term memories, like his age or what he looked like in a photo
-however, he could remember semantic memories, factual information, such as famous singers who became famous after his lobotomy
12.1: Severe impairment of episodic memory
Define semantic memory and episodic memory (2)
-semantic memory: is being able to remember factual information
-episodic memory: are memories of personal events
-through patients with damage we can see that the brain treats episodic memory different from other memories
12.2: Severe impairment of episodic memory
Why is episodic memory so important?
-because it allows us to imagine the future
12.2: Better implicit than explicit memory
What is explicit memory? What falls under it? Give an example. (3)
-deliberate recall of information that one recognizes as a memory
-episodic and semantic memory
-remembering details about your graduation day, like what you wore and what you did
-AKA as declarative memory
12.2: Better implicit than explicit memory
What is implicit memory? What falls under it? Give an example. (3)
-an influence of experience on behavior, even if you do not recognize that influence
-procedural memory, priming and classical conditioning
-your subconcious influencing you, like if you have biases like racism from your family messaging and subtle stay away from certain ethnicities
12.2 Procedural memory
What is procedural memory? Give an example. (2)
-the development of motor skills and habits
-like riding a bike
12.2 Procedural memory
Sum up the patterns of patients with amnesia. (5)
-normal working memory, unless distracted
-severe anterograde amnesia for declerative memory (difficulty forming explicit memories)
-severe loss of episodic memories, including most of those from before the damage
-better implicit memory than explicity memory
-nearly intact procedural memory
12.2: Theories of the function of the hippocampus
What is delayed matching-to-sample task?
-an animal sees an object and after a delay, gets a choice between two objects, from which it must choose the one that matches the sample
12.2: Theories of the function of the hippocampus
What is delayed-nonmatching-to-sample task?
-the procedure is the same as the matching task except that the animal must choose the object that is different from the sample
12.2: Theories of the function of the hippocampus
What does hippocampal damage in animals cause in the matching or nonmatching sample tasks?
-it strongly impairs performance
12.2: Theories of the function of the hippocampus
If the hippocampus is a coordinator that reconstructs the context of a memory, describe how hippocampal damage impairs recent memories more than distant memories?
-Recent memories include details of context, and the hippocampus is essential for memory of context. Most old memories include only the gist of the event, and the hippocampus is less important for memories of that type.
12.2: Navigation
What two mazes demonstrate the importance of the hippocampus and nearby areas for spatial memory?
-radial maze and Morris water maze
12.2: Navigation
What is the radial maze? Briefly describe how researchers test rats spatial memory with this?
-a maze with several arms, typically eight, where some or all have food in them
-rats may learn that the arm with a window behind it always has no food and rats with damage to the hippocampus can learn to avoid these never-correct arms, but even after much training they often enter a correct arm twice
-they forget which arms they have already tried
12.2: Navigation
What is the Morris water maze
-there is murky water and rats have to swim to it and find a rest platform hidden underneath the water
12.2: Navigation
What are place cells? When do they respond best? (2)
-hippocampal neurons tuned to particular spatial locations,
-responding best when an animal is in a particular place and looking in a particular direction
-researchers can watch the brain activity of the rat as it imagines trying each route in a maze, the cells become active in the proper order as if the rat were actually walking down one path or the other
12.2: Navigation
What do many of the place cells also function as? What are these? (2)
-time cells
-respond at a particular point in a sequence of time
12.2: Navigation
What are grid cells? How do they work? How do these cells differ from ventral (front) levels to dorsal levels (back)? (3)
-type of neuron found in the entorhinal cortex that help us understand our position in space
-the cells always respond in a hexagon shape
-moving dorsals to ventral, the grid cells respond to larger areas
12.2 The Striatum
What composes the striatum?
-caudate nucleus and the putamen
12.2 The Striatum
Compare the hippocampus and the striatum for these:
1. Speed of learning
2. Type of behavior
3. Based on what type of feedback
4. Explicit or implicit learning
5. What happens after damage?
- H: can learn in a single trial. S: learns gradually over many trials.
- H: flexible responses. S:habits
- H: sometimes connects information over a delay. S: generally requires prompt feedback
- H: explicit. S: Implicit
- H: impaired long-term memory (declerative), especially episodic. S: impaired learning of skills and habits
12.2: Other brain areas and memory
What happens to people with parietal lobe damage?
-the process of associating one piece of information with another is impaired
12.2: Other brain areas and memory
What do people with damage in the anterior temporal cortex struggle with?
-semantic dementia
12.3: Learning and the Hebbian synapse
What did Hebb propose about how learning is influenced by neurons?
-that an axon that has successfully stimulated cell B in the past becomes even more successful in the future
-cells that fire together wire together
12.3: Learning and the Hebbian synapse
Define a Hebbian synapse
-a synapse that can increase its effectiveness as a result of simultaneous activity in the presynaptic and postsynaptic neurons
12.3: Aplysia as an experimental animal
What is Aplysia? What research has been done? (2)
-a marine invertebrate related to the slug, that has been popula for studies of learning
-research has been done on the withdrawal respobse as this creature has fewer neurons and the neurons are identical
12.3: Habituation in Aplysia
What is habituation? Give an example. Why does it happen? (3)
-a decrease in response to a repeated stimulus that is accompanied by no change in other stimuli
-a sudden noise may startle you but you respond less after repeated presentations if they occur frequently or at predictable intervals
-it happens because there is a change in the synapse between the sensory neuron and the motor neuron
12.3: Sensitization in Aplysia
What is sensitization?
-an increase in response to mild stimuli as a result of exposure to more intense stimuli
12.3 Sensitization in Apylasia
How does sensitization occur in the neurons?
-when strong stimulation excites a facilitating interneuron to release serotonin onto the presynaptic terminals of sensory neurons, blocking potassium channels and causing prolonged neurotransmitter release. Repeated stimulation leads to the synthesis of new proteins in the sensory neuron, resulting in long-term sensitization.
12.3 Long-term Potentiation in Vertebrates
What is long-term potentiation? (LTP) (2)
-when one or more axons connected to a dendrite bombard it with a rapid series of stimuli
-the burst of intense stimulation leaves some of the synapses potentiated (more responsive to new input of the same type ) for minutes, days, or weeks
12.3 Long-term Potentiation in Vertebrates
What three properties does LTP show that make it an attractive candidate for a cellular basis of learning and memory? (3)
-specificity: if some of the synapses onto a cell have been highly active and others have not, only the active ones become strengthened
-cooperativity: nearly simultaneous stimulation by two or more axons produces LTP more strongly than does repeated stimulation by just one axon
-associativity: pairing a weak input with a strong input enhances later response to the weak input, matching Hebbian synapses
12.3 Long-term Potentiation in Vertebrates
What is long-term depression?
-a prolonged decrease in response at a synapse occurs for axons that have been less active than others
-You can think of this as a compensatory process. As one synapse strengthens, another weakens. If learning produced only a strengthening of synapses, then every time you learned something, your brain would get more and more active, constantly burning more and more fuel!
12.3: AMPA and NMDA Synapses
What two receptors are involved in LTP?
-AMPA and NMDA
12.3 AMPA and NDMA Synapses
Explain the AMPA receptor, including whether it is ionotropic and which molecule it responds to or metabotropic and what its function is. (2)
-ionotropic glutamate receptor that responds to both glutamate and AMPA
-When glutamate binds to AMPA receptors, they open and allow the flow of sodium (Na+) ions into the neuron. This influx of Na+ ions causes depolarization of the postsynaptic membrane, which can lead to the generation of an action potential if the depolarization is strong enough.
12.3 AMPA and NMDA Synaspses
Explain the NMDA receptor, including whether it is ionotropic or metabotropic and what it opens under. Highlight why this receptor is of particular importance once it is depolarized (3)
-ionotropic glutamate receptor which responds to both glutamate and also NMDA
-only opens under two conditions: glutamate must bind to the receptor and the postsynaptic membrane must be sufficiently depolarized to remove the magnesium (Mg2+) ion that normally blocks the receptor channel at resting membrane potential.
-once NMDA receptors open, calcium ions enter into the neuron and this is import for synaptic plasticity and signaling
12.3 AMPA and NMDA Synaspses
Explain the route that calcium goes through that can explain long-term memory. Start when the calcium enters through the NMDA channel. (3)
-calcium enters the NMDA chanell and activates a protein called CaMKII
-this eventually releases CREB
-CREB goes to the nucleus of the cell and regulates the expression of several genes and this altered gene expression can last for years
-the effects of CaMKII are necessary for LTP and for certain types of learning, it is responsible for the specificity aspect of LTP because it does not diffuse
12.3 AMPA and NMDA Synaspses
The effects of CaMKII and CREB are magnified by what?
-BDNF
12.3 Presynaptic changes
What is one of the most important retorograde transmitters in the context of LTP?
-nitric oxide
12.3 Presynaptic changes
Explain what retrograde transmitters are and how they play a role in LTP. (2)
-Unlike traditional neurotransmitters, which travel from the presynaptic to the postsynaptic neuron, retrograde transmitters travel in the opposite direction. They are released from the postsynaptic neuron in response to synaptic activity and act on the presynaptic neuron to modulate neurotransmitter release.
-By modulating presynaptic function, retrograde transmitters help to sustain the enhanced synaptic strength characteristic of LTP.
12.3 Stop and Check pg 411
Before LTP: In the normal state, what is the effect of glutamate at the AMPA receptors? At the NMDA receptors?
-Before LTP, glutamate stimulates AMPA receptors but usually has little effect at the NMDA receptors because magnesium blocks them.
12.3 Stop and Check pg 411
During the formation of LTP, when a burst of intense stimulation releases much more glutamate than usual at two or more incoming axons, what is the effect of the glutamate at the AMPA receptors? At the NMDA receptors?
-During the formation of LTP, the massive glutamate input strongly stimulates the AMPA receptors, thus depolarizing the dendrite. This depolarization enables glutamate to excite the NMDA receptors also.
12.3 Stop and Check pg 411
After the neuron has gone through LTP, what is now the effect of glutamate at the AMPA receptors? At the NMDA receptors?
-After LTP has been established, glutamate stimulates the AMPA receptors more than before, mainly because of an increased number of AMPA receptors. At the NMDA receptors, it is again usually ineffective.
12.4: Intelligence
What is g?
-it symbolizes a theoretical underlying factor of general intelligence
12.4: Intelligence: Comparing species
What comparison has shown the most promise in how functional elements relate to intelligence?
-the total number of neurons
-In primates, however, the species with larger brains have the same size neurons as those with smaller brains, and so humans’ neuron total is much elevated
12.4: Intelligence: Size comparison
How do researchers explain why males and females are equal in intelligence despite differences in brain size?
-same number of neurons as men’s brains. Also, women’s brains have different patterns of connections.
