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PSYC205 Test 2 Review:
Memory: the mental processes of acquiring and retaining information for later retrieval
Learning Vs. Memory
- Learning = acquisition
- Memory = Retention
- Ebbinghaus pioneered early memory studies by asking participants to memorize
- Early memory studies associative method; Later studies information
- Memory and learning should be studied as one phenomenon.
- Evolutionary advantages of memory survival & reproduction
- Memory uses a lot of brain power and resources that could be dedicate elsewhere
- Evolution favours behavioural change based on experience because our
environments are always changing
- Difficult to compare memory between species.
oAlternative approach: measuring whether the type of information they
remember matches the ecological constraints of their environment (or
Ex. Squirrels have better spatial memory (caching)
Ex. Humans have better memory for stimuli associated with bugs
and snakes than guns and electrical outlets.
-Memory Retention Curve: how long memory lasts. Should mimic the course of
survival events in the environment. (ex. Male crustacean remembering his female
only as long as she nurtures their offspring. After, save brown power)
- Same-species memory in different habitats Huntingford & Wright high-predator
vs. low-predator water fish experiment. High-predator showed memory focused
on escaping and predicting predator actions. Low-predator focused on finding
food. Specialized memories passed on genetically.
- Memory is not just a series of stored past events. It is a cognitive process that
allows you to adjust your behaviour in an ever-changing world.
- Memory isn’t static. It takes time to form. Time between memory formation and
behavioural change can vary from a few seconds to decades depending on the
oMemory is sequential – 3 stages: formation, storage, retrieval
Encoding (1 st
-Encoding: conversion of incoming information into neural signals that will be
used for later processing
- Only sensations that require our attention will be encoded. Stronger attention =
stronger encoding. Salient & surprising events more likely to be encoded.
-Elaboration: the process of adding meaning, images, or other complex info to
sensory input. The greater the level of processing, the stronger & more durable the
memory. (ex. Remember meaningful words vs. upper/lower case words)
oMore complex cognitive processes = greater encoding
- Natural tendency to remember things relating to survival in ancestral
- Limit on amount of info nervous system can process. Solution = Chunking
-Chunking (Miller): reorganize sensory input into larger units, reducing amount of
information that is encoded. Creating larger units from smaller units requires
cognitive processing – but this conversion process gets easier with practice
(explains why it becomes easier for us to read full words instead of just sounding
out letters with practice).
- Encoding facilitated by: attention, elaboration, chunking
Consolidation (2 nd
-Consolidation: the process of modifying encoded representations so that they
become more stable over time
- Takes time, memories are not stable until this process is complete
- ‘Flashbulb Memories’ very detailed & vivid snapshots of the moment an
individual receives emotional arousing news. Are sometimes more reliable than
other memories because very detailed & permanent. People more confident in
these being more accurate.
oStress hormones released & travel to amygdala. Increased activity in
amygdala improves accuracy of memory
oHigher arousal = higher chances of being remembered
oEvolutionary significance: high arousal events usually signal important
events, so adaptive to remember conditions under which these occurred
- 2 stages of Consolidation:
o1st – occurs within minutes/hours protein synthesis. Disruption of protein
synthesis disrupts memory formation.
o2nd - occurs within weeks/years & only in mammal Structural changes in
synaptic connections between neurons, and shift in brain areas that store
memory related information.
- All memories are open to change/alteration before they become fully consolidated
- Evolutionary purpose of memory taking time to stabilize keeps from
overloading the nervous system with useless information and saves cognitive
energy. Also provides a timeframe for memory to be modified, allowing
associations between events and generalizations across conditionings to be
incorporated into the memory.
oOR just biology? Protein synthesis & structural rewiring takes time
Retrieval (3 rd
-Retrieval: the mental activity of accessing stored information
- 2 retrieval mechanisms:
oRecognition: identifying information as familiar, even if unsure why its
oRecall: generating information from memory stores in the absence of
familiar cues or “reminders”
- Both mechanisms work better if they occur in same context the memory was
encoded. Context can include sensory signals, emotional, or hormonal states
oGolden hamsters didn’t remember which environment they had received
electric shock in, if the shock and subsequent testing occurred at different
times of day (circadian cues)
oEvolutionary value of circadian cues: biologically relevant events often
occur at the same time of day
oBetter memory retrieval in one context and not another supports idea that
forgetting is a failure of retrieval, not a decay of the memory
- Bartlett found that memory retrieval combines elements of both encoded
information and existing knowledge (Ex. Subjects recalled the same story they
had all read, but retold them differently based on their perceptions or beliefs)
- Retrieval is a reconstruction of past events, influenced by preexisting knowledge
as well as current emotional state
- Retrieval can be distorted by suggestion, when false/misleading info is introduced
after a memory is encoded, altering how original event remembered
- False Memories:
oLoftus’ Eyewitness Memory Testing question wording influenced
responses. Some participants ‘remembered’ never-occurring details.
oMore thinking about false memories = the more detailed they become
oArgues that eyewitness testimonies unreliable. Memory reconstruction
- Retrieval is an active process that modifies stored information
- Since retrieved memories can still be modified, to become stable, they must
undergo a 2nd consolidation phase called ‘reconsolidation’ [different biological
mechanisms] - Necessary to further stabilize memory!
-Short-Term Memory: time-dependent process with limited capacity. Information
is held in immediate consciousness
- Keeping information in conscious awareness involves mental effort
-Working Memory: the process of maintaining information in short-term store so
that it can be used in other cognitive processes. An ongoing mental computation
using recently encoded information & retrieved info from long-term store to make
decisions, navigate in space, or communicate.
-N-Back Test letters presented visually or vocally. Participants remember and
match letters to those presented earlier in the sequence. The greater the distance
between matching letters (N) the harder the task.
oPoor performance in Alzheimer’s & damaged prefrontal cortex. Indicates
distinct difference between long & short-term memory
- Key feature of memory tasks unpredictability. Information must change from
trial to trial to avoid pattern recognition.
- Distractions in delay period between matching stimuli cause loss of working
memory (key element of ‘attention’- necessary for encoding – disrupted)
- Working memory longer and higher capacity in humans than animals