Week 12 - Memory, Cognition, and Learning Flashcards
Explain why previous theories of learning are flawed, and what do new theories need to uncover?
Previous theories are just methods for studying learning (controlled ways), changing the behaviour of animals with various techniques, such as classical and instrumental conditioning. They fail to explain what the brain is doing, and any other types of learning outside of this, which is most (how humans learn in a lecture).
New theories need to capture any long-term changes in behaviour that depends on interacting with the world (perceive, feel, think and behave).
Explain how neural changes and learning relate, and List 3 kinds of neural changes that have been demonstrated to underpin learning?
Many synaptic changes exists when learning (rewiring - the only way behaviour can actually change). They make new connection, or alter strength of existing, or removes existing. These underpin learning new processes, motor patterns, people and objects.
Strengthening existing
(1) Pre-synaptic neuron produces more neurotransmitters, making a stronger connection.
(2) Pre-synaptic neuron sprouting a new terminal button, making an extra connection to the post-synaptic neuron, strengthening the connection (more neurotransmitter).
(3) Inter-neuron modulation, where the pre-synaptic neuron is modulated by an extra neuron (3rd), increasing the PSP (post-synaptic potential). (graph)
Weakening Connection also occurs which may impact learning. Breaking of connection, or decreased amount of neurotransmitter.
New synapses
(4) New synapses forming (pre-SN sprouts new terminal button and send to an empty post-synaptic button) - number of receptors increases.
(5) rearranging of synaptic input, making a more efficient and stronger potential.
These have been documents in the cerebellum and hippocampus.
Explain what anterograde amnesia (HM’s case) is, and what it reveals about the brain and outline the brains interconnectedness for memories?
Anterograde amensia is the inability to lay down to episodic and semantic memories (declarative/explicit). Where they have the ability to learn procedural memory tasks over time, despite never having memories of doing it (and not impaired in implicit memory test, HM learnt to do the tower of Hanoi). But, they don’t learn in trace conditioning experiments - puff of air, interval of time between CS and UCS - classical conditioning.
Parahippocampul gyrus (cortex that surrounds/near the hippocampus) are intimately involved in making new connection for long-term episodic memories, with the Fornix as the output end point for the episodic memory process:
(1) There is a whole bunch of structures involved in laying down new episodic memories
(2) They are all intimately interconnected (go both ways). They form new connections between other parts of the brain to make neural changes to lay down episodic memories (event memories are just connection).
This means that memories are not stored events that you sift through and recall, they are connection between parts of the brain that were active when the event want happening, and it is reactivated.
Explain some of the ways declarative memory is studied in non-humans and humans?
In non-humans, using Monkey with a sample, delay and choice phase, or in rats with milky water and a platform (remember if they don’t have hippocampus damage).
In Humans, Recall and Recognition tests (MC and short answer), Item and context tests (list of 20 words, or 2 list and get them to recall and also which list they were in), and semantic memory tests (ask questions about facts).
Outline the role of frontal lobes in declarative memory? What role do the hemisphere’s play in recall?
Permits the ability to judge whether a memory is true or not (meta-cognitive ability). Damage to the frontal lobes shows that patients mis-attribute facts (inaccurate memories - answer incorrectly to obvious questions).
The hemisphere also play a role in recall (“remember” - have to be able to say it), where Left PFC is associated with recollection (“remember” - able to say it), and Right PFC associated with familiarity (‘know” - but unable to produce answer by saying it).
Explain the role of hippocampus in processing space?
In Rats, the hippocampus knows where the rat is in space by different neuronal firing patterns.
In humans, when learning a new environment and navigating space, their is high hippocampus activity. Shown to grow in Taxi driver’s.
Illustrate the importance and existence of spatial memory within nature?
In foraging ecology, species of bird are shown to have outstanding spatial memory when refinding their hidden food, not visual, only spatial (larger hippocampus - evolutionary adaptation).
But does the hippocampus code spatial location, or relationships between things (yes to both). (1) Encoding where you are in space is done by hippocampal place cells that fire when you go from one place to another. (2) Also, learning where you are using spatial relationships of location/objects - which is basically what an episodic memory is, put memories into a temporal order - evolved to be able to make episodic memories. e.g. monkeys with hippocampal damage cannot identify the biggest item out of three (no relationship identification).
Outline some Spatial Adaptions in birds when foraging nectar, and in Rodents when Mating?
The best foraging strategies for bird who feed on nectar is to avoid places they have been before - win-shifting (at least until the nectar has regenerated). E.g. Honey-eaters tested at long and short delays showed appropriate evolved bias towards shifting, as should be in nature.
Rodents when mating differ in spatial abilities depending on their mating patterns and territory needs. Monogamous rodents have less ability than polygynous males in breeding-season (who need to remember their territory)
Explain human spatial differences for males and females?
Silverman & Eals (1992) proposed a Hunter/Gatherer theory.
Hunting was primarily a male activity, and required tracking in unpredictable directions and unfamiliar terrain (orienting using distance navigational landmarks, and encode space allocentrically)
Gathering was primarily a female activity, and required retracing previously successful routes, and what is where when (local landmark emphasis, and encoding space egocentrically).
Evidence using a navigation game simulation which relied on both allocentric and egocentric spatial encoding supported this. This is cross-culturally supported, and performance is affected by hormone levels.
Explain Working memory and the correlating neural activity?
WM is keeping things in mind, neural activity (single cell, fMRI, and ERP) peaks when encoding and responding (and high activity between - during the delay between whilst trying to keep the WM active) - neurons continuing to fire. Much of this happens at the PFC areas, for example, you undertake an auditory/visual memory task, then this shows activity in the corresponding part of the brain (keeping those neurons firing) - unless distracted, and stopping the firing momentum.
Outline the relationship between WM and attention?
WM seems to involve maintaining sustained activity of neurons (keep in mind), where attention may be responsible for the boosting responsiveness of the neurons during WM - activated in both parietal lobes and frontal cortical areas.
Evidence of this is seen within hemispatial neglect patients. (damage to the parietal lobe making attentional deficits). patients with right parietal damage do not experiences anything in the left visual space, shown in various drawing tasks, pictures, lines, clocks. Also, ignoring things on the left hand side of the body for touch, unless the limbs was moved into the right visual space, where they were now able to respond (when in the attentional part of the world - no sensory deficit, somatosensory cortex working fine, but parietal prevents).
This implies without attention we cannot perceive things, which is shown in change blindness also (looking at a picture and no seeing it unless we are aware of it).
***WE only see what we are consciously attending to. So for WM and LT memories are only activated when attended to (retention and cues), thus attention drives your perception and remembering of the world
