Learning and memory Flashcards
What is flashbulb memory?
The phenomenon of vivid memories of important, stressful events
- a class of memories that are more frequently rehearsed or more strongly encoded
What are the components of learning and memory and how do hormones play into it?
- Entering information into storage
- retaining the information
- retrieving the information
Hormones can affect each of these components, or they can affect learning directly and thus memory indirectly - Role for psychological components, as well: motivation, attention, arousal
How does arousal affect learning?
If it is too low, performance is not as good
If it is too high, performance is also not as good
There is a sweet spot in the middle that helps to create optimal learning performance
What is learning?
A process that expresses itself as an adaptive change in behavior in response to experience
- the stages of learning include: acquisition, consolidation, retrieval and extinction
What is memory?
The encoding, storage and retrieval (or forgetting) of information about past experience–is necessary if learning is to take place
What are the two types of non-associative learning?
Sensitization (results in progressive amplification of a response after multiple exposures)
Habituation (reduces a response after repeated exposures)
What is non-associative learning?
The change in the strength of a response after repeated exposures
All animals appear to be capable of changing their behavior as a result of experience
What is associative learning?
Learning about relationships, or the process by. which an association between two stimuli is established
What is classical conditioning?
Not-purposefully paired stimuli–unconscious relations between stimuli and reaction
What is operant conditioning?
Purposefully exhibiting behavior for a response –> nose poke for door to open
What is active avoidance?
Animal learns to move to other side to avoid shock when it hears the sound
What is passive avoidance?
Cage is lit on one side with an electrified grid on the other:
Animal would rather not be in the light, but they also have to avoid shock–> refrain from going to “comfort” bc of shock
What is fear conditioning?
Can be used to test for effects of hormones on learning and memory (learned quickly and remembered for a long time)
What is extinction in learning and memory?
(different from forgetting)
This is when an individual stops responding to a stimulus following a series of non-reinforced experiences or trials
(Keep playing just the tone and not shocking –> learn that the tone is no longer associated with a shock so don’t need response anymore)
How does memory affect behaviors?
Memory is required in order for adaptive changes in behavior to result from experience
- testing memory tests for the permanence of learning
What are different types of memory?
Short-term memory persists for seconds to minutes
Rehearsing moves items from short-term to long-term memory
Describe the taxonomy of memory
Long-term memory can become either
-declarative (explicit): episodic or semantic
-procedural (implicit): skill learning, priming, or conditioning
How does epinephrine effect learning and memory?
enhances memory in a dose- and time-dependent way
- the mechanism for enhancing memory isn’t clear
- could be affecting the encoding or storing processes since those happen rather quickly
- does not easily pass the blood-brain barrier
1. it could be activating peripheral receptors that directly influence brain function
2. It could affect memory via its effect on blood glucose levels
How does insulin affect learning and memory?
- There is a strong relationship between glucose regulation and cognitive impairment; some cognitive impairments have been seen in diabetics (with more severe issues in aged patients)
- Even in healthy individuals, dysregulated glucose metabolism (which happens with age) can affect memory
What are the effects of glucose on learning?
Similar to arousal, there is a sweet spot where too low is not enough and too high is too much
How does insulin relate to Alzheimer’s Disease?
Impaired insulin signaling has been proposed as an important factor in the development of Alzheimer’s Disease
- Abnormal insulin levels and low brain insulin receptors are common in Alzheimer’s patients with severe memory impairments
- Treatment of these patients with insulin significantly improves memory, which may be aiding in neural transmission
How does insulin affect learning and memory in animal models?
using animal models has shown that disruption of brain insulin receptors in mice impairs memory
- treating animals with streptozotocin destroys insulin-secreting B-cells of the pancreas, rendering the animal diabetic
- These animals do significantly worse in passive avoidance learning and Morris water maze
How do Glucocorticoids affect learning and memory?
- Similar to stressful events, administering glucocorticoids to people (acute stress) enhances memory consolidation
- Acute stress impairs memory retrieval in a water maze
- Chronic stress impairs the acquisition of spatial learning as well as the memory (long-term storage) for a radial arm maze
What are some sex differences in learning and memory?
In general, female rats learn active avoidance tasks faster than males, but males do better with passive avoidance
- could just reflect differences in general activity levels
- males are less active in open field so “easier” for them to inhibit movement?
- Indeed, the increases errors when females do mazes is sometimes attributed to increased exploratory behavior and not to poor L&M
What are spatial memory sex differences?
- Spatial ability: males can be better with the learning of the maze, but they are equal upon recall/memory
- Sometimes its not that males or females are better or worse, but that they use different strategies to solve the mazes
- Landmark versus global cues
- Organization effects of hormones are a strong contributing factor
What are sex differences in the affect of stress on memory?
Generally, acute stressors increase performance for both; long-term impairs male performance but sometimes doesn’t affect or even improves female performance
What are the effects of estrogens on learning and memory?
- Estradiol enhances several aspects of L&M in both human and nonhuman animals, and enhances spatial memory
- Estradiol’s effect is transient, and can be seen across an estrous cycle in female rats
- for ex: female rats perform better during the cycle when estradiol is high compared to when its low
- These rapid effects can be seen in increased spine density in the CA1 region of the hippocampus
What are the effects of testosterone on learning and memory?
Gonadal androgens have an effect on L&M through organizational effects, but don’t appear to have any activational effects on L&M
