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BIO 435
Learning and Memory
Question | Answer | |
---|---|---|
What are the two types of memory | 1. Declarative 2. Nondeclarative | |
Define declarative memory | Memory that is available to consciousness (words and memories/ history) | |
Define nondeclarative memory | Memories that are generally not available to consciousness (motor skills, associations, priming clues, puzzle-solving skills) | |
What do long-term declarative memories require? | consolidation (the process by which a temporary memory is transformed into a more stable, long-lasting form) | |
Describe the two types of amnesia | 1. Retrograde amnesia = some memory loss of events that occurred before the time of trauma 2. Anterograde amnesia = all memory loss of events occurs after the time of trauma | |
What are some things that can cause amnesia? | Trauma, strokes, brain tumors, chronic alcoholism | |
What were the results of Lashley's studies that looked at the neurobiology of memory? | Larger lesions in the brain resulted in rats having a harder time learning mazes and remembering them. It was even more difficult if the maze was more complex | |
What did Hebb propose? | He proposed a mechanism for memory consolidation-neurons that fire together wire together and memories are stored in the areas of the cortex that process sensory modality | |
What did Penfield believe about memory? | Penfield thought that the temporal lobe might be involved in memory because during stimulation of the temporal lobe, some were able to describe past events | |
What did research on H.M. further support? | H.M. research further supported idea that the temporal lobe is involved in memory | |
Describe H.M. case study | The amygdala, hippocampus, and medial temporal lobe cortex was removed. This causes severe loss of declarative memory (severe anterograde amnesia and some retrograde amnesia) | |
What task did H.M. complete that made it clear that he could still learn procedural tasks? | The mirror drawing task where he was not good at on the first day but by day 3 he was really good at it (even though he didn't remember ever completing the task) | |
Describe the pathway of sensory information in the medial temporal lobe | 1. Cortical association areas 2. parahippocampal and rhinal cortical areas 3. hippocampus (may go back to cortical association areas) 4. [via the fornix from the hippocampus] thalamus and hypothalamus (may go back to cortical association areas) | |
Which task was used to test recognition memory (declarative memory) | Delayed Non-Match to Sample (DNMS) task | |
Describe the results of the DNMS task | Monkeys with entire MTL (medial temporal lobe) lesions performed poorly on the DNMS task which showed that the hippocampus and the MTL cortex are important for DNMS performance (amgydala lesion did not have as much of an impact) | |
Describe the Win-Shift task | Rats have to remember which of the 8 arms of the maze they previously visited so they could collect food. When the fornix (between the hippocampus, HC, and the thalamus) was lesioned, the rats made more mistakes | |
What do the radial arm maze (win-shift task) and morris water maze results signify? | They signify that the HC is important for navigational learning and memory | |
What type of cells in HC might be important for navigational learning? | Place cells; these cells have action potentials whenever subject is in a particular place | |
Describe the plasticity of place cells | Place fields for each place cell can change/expand/shrink based on changing environments | |
What cells may exist in the MTL and could contribute to navigational learning/memory? | Grid cells; these grid cells show action potentials when animal is in multiple places in cage and these APs form a grid. Place cells might arise due to convergence from multiple grid cells | |
Describe hippocampus and hippocampal lesions of taxi drivers | - Taxi drivers that had been driving for more months had larger hippocampus -Taxi driver with hippocampal damage could navigate using main streets but not smaller ones | |
Describe the hippocampal pathway | 1. temporal lobe 2. dentate gyrus 3. CA3 neurons 4. CA1 neurons | |
Where does long-term potentiation occur in the hippocampus pathway | between CA3 and CA1 neurons (Schaffer collateral) | |
What happens if CA1 neurons have an action potential shortly before the CA3 neuron? | long-term depression occurs | |
What happens if CA3 neurons have an action potential shortly before CA1 neurons | long-term potentiation occurs | |
Is a tetanus required to induce LTP in hippocampus? | NO | |
What type of antagonists interfere with learning? | NMDA antagonists; animals with more NMDA receptors learn faster | |
What type of knockout animals have trouble learning | CAMKII knockouts | |
What occurs during late LTP that helps with learning? | Synapses change; they are formed or eliminated as you learn | |
What area of the brain is important for memory storage? | All parts of the cortex are important for memory storage; each cortical area stores memories relevant to its sensory function | |
Describe a hypothesis for memory consolidation and storage | 1. Hippocampus neurons activate specific cortical neurons 2. Over time, hippocampus facilitates LTP between cortical neurons | 3. Hippocampus strengthens cortical connections between neocortical cells when one of the cortical neurons is activated later, it activates the entire network and helps you remember that event |
What study suggests that the hippocampus/medial temporal lobe is not important for all types of memory? | H.M. case study | |
What type of learning does the basal ganglia seem to be important for? What experiment suggests this? | Basal ganglia seems to be important for habit or stimulus response learning. Rats in the win-stay task were required to respond to visual cues instead of remembering where they had already previously gone. | Rats with lesions in the caudate ( a part of basal ganglia) were unable to do this |
What type of disease do people have that makes forming habits/stimulus response learning difficult? | Parkinson's disease (because they have damage in their basal ganglia) | |
What part of the brain is important for working memory? | prefrontal cortex | |
What does damage to prefrontal cortex result in? | 1. Monkeys in DNMS task perform poorly when short delay is given 2. Impairs ability to change strategies and learn from mistakes (especially for working memory related to organizing behaviors) [example | |
What happens to neurons in the prefrontal cortex during the DNMS task? | There's an increase in the number of action potentials after the cue period and during the delay period in order to increase memorization of what they just learned | |
What type of memories does the amygdala play a role in consolidating? | Emotional memories | |
What types of receptors do amygdala (basolateral amygdala, BLA) neurons typically have? | glucocorticoid and norepinephrine receptors | |
Where do BLA neurons project to? | hippocampus, basal ganglia, and cortex | |
What does activation of BLA neurons induce? | LTP | |
What does emotional memory formation require? | Norepinephrine and the amygdala | |
What three things does the hippocampus do? | 1. Declarative memory consolidation 2. Spatial memory and navigational learning 3. Binds sense together (creates associations; similar to Hebb's theory) |