Memory & Intelligence Flashcards
What is known as the “mental glue” that binds one moment to the next?
Memory
What’s memory?
The process of using information that was obtained in the past in order to generate some cognitive function in the present
Memory is any cognitive process that involves what 3 fundamental components (memory processing stages)?
- Encoding
- Storage
- Retrieval
What’s encoding?
- The initial processing of information by the nervous system -> process of inputting info into memory
- Creating separate memory traces to represent experiences
- This may be in the form of a short-term transduction of a physical stimulus into a neural code or a structural change in the brain that encodes a fact or event about the world
- This process is the necessary predecessor of storage and retrieval -> if something isn’t encoded in the nervous system, it can never be remembered
- Here, a memory trace is formed as a hippocampal-cortical activity pattern
- Encoding is when information from the short term is transformed into the long term
What’s storage?
- The retention of information in the nervous system beyond initial processing (retention of encoded information or encoded memory traces)
- Encoded information by the nervous system remains encoded in some form for a longer duration than immediate processing
- Here, via consolidation, a memory is transformed into a stable cortical pattern
What’s retrieval?
- The access and use of stored information by the nervous system for some cognitive purpose
- A memory is recovered when a cue activates part of a stored memory trace
- That memory trace then enters conscious experience
- Here, part of a memory trace is activated by a cue that triggers pattern completion
- When LTM retrieves info from STM or WM
What happens if any of the links in the chain of memory (encoding, storage, retrieval) is broken?
Memory can’t function
What’s analogous to human memory?
Computer memory
Why are human memory and computer memory analogous?
- Both human and computer memory require the same basic elements to function: a means of encoding, storing and retrieving information
- Like human memory, a failure at any stage of this process will lead to a memory “loss”
What is one of the most important recent advances with regard to the emergence of a highly computer-connected human society?
The development of powerful search engines that enable successful (human-driven) retrieval of information from the “memory” of the internet
Describe how encoding, storage and retrieval can be used when describing to a friend that you saw a mutual acquaintance at an event last week
- This requires initial encoding at the event, where your brain processed the light and images entering via your eyes’ retinas. This allows you to see your surroundings and mutual acquaintance
- This visual processing by the brain leads to a cascade of storage activities involving multiple cortical and subcortical brain regions that can store the information for both short and longer-term durations
- Finally, retrieval of that stored memory allows you to describe the event, activating your language and motor areas in order to produce the speech you use to tell your friend what you saw
What are 2 basic dimensions of memory that we can measure with behavioral research?
- We can measure how much information a memory system can hold (its capacity)
- We can measure how long information remains in memory (its duration)
- Considering and contrasting these 2 dimensions across different conditions has been sufficient for investigators to draw firm conclusions that there are different kinds of memory that exist in the human brain
What’s the memory’s capacity?
- A measure of how much information a memory system can hold
- Some types of memory appear to have much higher capacity than others
- Ex: there’s a very limited amount of numbers or letters that you can hear & repeat verbatim -> a task that requires short-term memory (no such limit for the amount of more general info you can retain in long term memory)
What’s the memory’s duration?
- A measure of how long information can be held in memory
- Some types of information are very quickly lost from memory while other information may be retained for a lifetime
What’s one of the most important and influential concepts in the history of cognitive psychology?
The idea that memory isn’t one kind of function but that instead there are different types of memory
Who was the first person to formally articulate the idea that there may be 2 kinds of memory stores and what were those 2 kinds of memory stores?
- William James
- One for information related to the current task or environment
- One for longer-term storage
- However, these were based on casual observation rather than experimental research
What was the first substantial theoretical model of memory that attempted to account for experimental data?
Atkinson & Shiffrin’s (1968) multi-store/modal model of memory
Describe Atkinson & Shiffrin’s (1968) multi-store/modal model of memory
- An influential model of human memory that posited 3 distinct memory stores: sensory, short-term, long-term
- All of these different memory stores work in conjunction with one another during everyday cognition
- This model proposed that each of these memory stores have their own duration and capacity
- The modal model was created in a new era of computer science
- It likens our processing of information to encoding and storing information into a computer
- AKA information processing model
What’s the first stage in the modal model of memory?
Sensory memory
What’s sensory memory?
- 1st and “temporary” stage in the modal model of memory
- Holds information before it can be processed
- Has a high capacity and short duration
- It briefly stores the info just encoded by the sensory organs
- The purpose of this form of memory is simply to hold the information in place before it can be selected, via attention, for further processing
- Only a fraction of the information stored in sensory memory ends up being selected by attention and passed along to short-term memory (STM)
- Under some conditions, sensory memory may actually be directly observed in action (ex: persistence of vision phenomena)
- Duration ~1 second
- Important for when we have to make quick decisions about what’s in our environment
What’s short-term memory (STM)?
- 2nd stage of the modal model of memory
- Serves to hold processed information for rehearsal or to produce a behavior
- Has a much smaller capacity than sensory memory (magical number seven plus or minus two”) but a considerably longer duration (approx. 15-30 secs)
- Unlike sensory memory, STM is capable of producing a behavioral output, such as repeating a phone number someone has just told you or responding to a recall task
- STM has the capacity for reactivating information stored within it through a process called maintenance rehearsal
- Involves the prefrontal cortex
- Attended information moves from sensory to short term memory
What’s maintenance rehearsal?
- The mental repetition of information in short-term memory that allows information to be regenerated in order to prolong its duration
- This process essentially reactivates the initial encoding
- Once information is rehearsed, it can restart the clock on the duration of the memory
- A technique for encoding information in long-term memory (LTM)
- Without any distractions, people are able to engage in maintenance rehearsal
- If you have absolutely nothing else to do, information can theoretically persist in STM for as long as you can keep rehearsing. However, in the real world, this isn’t possible
- Some research has found that such repetition can lead to a modest bump in retention in LTM
- However, simple repetition isn’t as effective as techniques in which we go beyond the simple repetition of the info in STM and consider the meaning of the info
What’s long-term memory (LTM)?
- The final stage of the modal model of memory
- Serves as cold? storage of information for retrieval into short-term memory
- Because of the nature of how LTM is encoded, there’s no agreed-upon method for measuring its capacity, but it’s clear that only a small fraction of STM is encoded as LTM
- LTM comprises anything that’s remembered from beyond roughly 15-30 secs (duration of STM) up to a lifetime
- We know that at least some memories can last a lifetime but that many decay over time as well
- The duration and capacity of LTM have no quantified limit
- Theoretically LTM is infinite -> lifetime memory and no known capacity limit
- The lack of duration and capacity limits of LTM doesn’t mean that all of the information in STM makes its way to and is retained for a long period in LTM -> most of the info we encounter in our lives doesn’t seem to be stored in LTM, at least not for very long
- According to the modal model, STM items gradually transfer to LTM
- Unlike STM, LTM doesn’t seem to depend on continuous activation of the original activation used to encode the stored info
There’s evidence that after the initial transduction of sensory information, it’s retained within our nervous system for how long?
A brief period of around 250 ms