chapter 8 notes - memory

• memory is an information processing system, consisting of encoding, storage, and retrieval

encoding

• encoding, the input of information into the memory system,

  • once we receive sensory information from the environment, our brains code it

  • we organize this info with other similar information and connect new concepts to existing concepts

  • occurs by automatic and effortful processing

    • automatic processing

      • the encoding of details like time, space, frequency, and the meaning of words

      • done without any conscious awareness

    • effortful processing

      • encoding that requires a lot of work and attention

• semantic encoding

  • encoding of words and their meaning

  • first demonstrated by William Bousfield, in an experiment where he asked people to memorize words already split into four categories, but were randomly told to the people. the people, without even knowing the proper groupings, recited them back in groups, suggesting they paid attention to the meaning of the words as they learned them

• visual encoding

  • encoding of images

  • you can recall images (mental pictures) more easily than words alone

  • high-imagery words, encoded both visually and semantically and builds a stronger memory than abstract words

• acoustic encoding

  • encoding of sounds, words in particular

  • we encode the sounds words make

• Fergus Craik and Endel Tulving study about which type of encoding is memorized the best

  • words that had been encoded semantically were better remembered than those encoded visually or acoustically

  • semantic encoding involved a deeper level of processing than the shallow visual or acoustic coding

  • concluded that we process verbal information best through semantic encoding, especially if we apply the self-reference effect

• self-reference effect, is the tendency for an individual to have a better memory for information that relates to oneself in comparison to material that has less personal relevance

storage

• is the creation of a permanent record of information

• in order for memory to go into storage (long term memory), it has to pass through three different stages, sensory memory, short term memory, and finally, long term memory

• model of human memory by Richard Atkinson and Richard Shiffrin (Atkinson and Shiffrin’s model

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  • not the only model for memory, Baddeley and Hitch proposed a working memory model is like opening different files on a computer and adding information

    • working memory holds a limited amount of information, this type of short term memory (file) depends on the information received

      • visual spatial form as well as memories of spoken or written material, stored in three short term systems, a visuospatial sketchpad, an episodic buffer, and a phonological loop

      • a central executive part of memory supervises of controls the flow of info to and from the three short term systems, central executive responsible for moving info into long term memory

• sensory memory

  • In the Atkinson Shiffrin model, stimuli from the environment are processes first in sensory memory, storage of brief sensory events, such as sights, sounds, and tastes

  • very brief, cannot absorb most of it

  • if we view something as valuable the info moves to our short term

• short term memory

  • STM, is a temporary storage system that processes incoming sensory memory

  • component of working memory

  • takes info from sensory memory and sometimes connects that memory to something already in long term memory

  • lasts 15-30 seconds

• rehearsal moves info from short term memory to long term memory

  • active rehearsal is a way of attending to info to move it from short term to long term, in which you repeat (practice) the info to be remembered, if repeated enough, it can be moved into long term

  • elaborative rehearsal, act of linking new info you are trying to learn to existing info you already know

• Craik and Lockhart proposed the levels of processing hypothesis that states the deeper you think about something, the better you remember it

• George Miller reviewed most of the research on the capacity of short term memory, and found most people can retain between 5 and 9 items, capacity of short term memory was the magic number 7 ±2

  • more contemporary research has found the working memory capacity is 4 ±1

• recall is better for random numbers than for random letters, and slightly better for info we hear (acoustic) than info we see (visual)

• memory decay and interference

  • Peterson and Peterson investigated short term memory using three letter sequences called trigrams that had to be recalled between 3-18 seconds

  • participants remembered about 80% of trigrams after a 3 second delay but only 10% after a delay of 18 seconds

  • short term decayed in 18 seconds

  • during decay, memory trace becomes less activated over time and info is forgotten

• Keppel and Underwood examined only the first trials of the trigram task and found that proactive interference also affected short term memory retention

  • during proactive interference, previously learned info interferes with the ability to learn new info\

• both memory trace decay and proactive interference affect short term memory

• once info reaches long term memory, it has to be consolidated at both the synaptic level, which takes a few hours

long term memory (LTM)

• continuous storage of information

• believed to be unlimited

• all the things you can remember

• memories are organized in semantic (or associative) networks

  • semantic network consists of concepts, which are categories or groupings of linguistic information, images, ideas, or memories, such as life experiences

  • concepts believed to be arranged hierarchically in the mind where related concepts are linked and the strength of the link depends on how often two concepts have been used

• semantic networks differ depending on personal experiences

  • activating any part of a semantic network also activates the concepts linked to that part to a lesser degree, spreading activation

    • if one part of a network is activated, it is easier to access the associated concepts because they are already partially activated

  • when you remember something, you have several routes to get the information you are trying to access, the more links you have to a concept, the better chance you have to remember

• explicit and implicit

  • aging, types of brain trauma, and certain disorders can impact explicit and implicit memory in diff ways

    • explicit memories are those we consciously try to remember, recall, and report, like memories you have on hard drive, but not on your desktop (short term memory)

      • not all long term memories are strong memories, some memories can only be recalled using prompts

      • sometimes referred to as declarative memory because it can be put into words

      • divided into episodic and semantic memory

    • episodic memory is information about events we have personally experiences (an episode) (aka autobiographical memories

      • first proposed in the 1970s. since then, Tulving and others have reformulated the theory and scientists believe that episodic memory is memory about happenings in particular places and particular times (what, where, and when of an event)

      • involves recollection of visual imagery as well as feeling of familiarity

    • semantic memory is knowledge about words, concepts, and language-based knowledge and facts

      • typically reported as facts

      • having to do with language and knowledge about language

    • implicit memories are long term memories that are not part of our consciousness

      • learned outside of our awareness and cannot be consciously recalled

      • demonstrated in the performance of some task

      • studied with cognitive demand task, such as performance on artificial grammars, word memory, and leaning unspoken and unwritten contingencies

      • like a program running in the background, you are not aware of their influence

      • influence observable behaviors as well as cognitive tasks

      • you cannot put the memory into words that adequately describe the task

      • include procedural, priming, and emotional conditioning

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  • implicit procedural memory, often studied using observable behaviors and stores information about the way to do something and it is the memory for skilled actions, such as brushing your teeth, riding a bicycle, or driving a car

  • implicit priming, another type of implicit memory

    • priming exposure to a stimulus affects the response to a later stimulus

    • stimuli can vary and may include words, pictures, and other stimuli to elicit a response or increase recognition

  • implicit emotional conditioning, the type of memory involved in classically conditioning emotion responses

    • cannot be reported or recalled but can be associated with different stimuli

retrieval

• the act of getting information out of memory storage and back into conscious awareness

  • vital to our everyday functioning

  • recall, accessing info without cues

  • recognition, happens when you identify info that you have previously learned after encountering it again

    • process of comparison

  • relearning, learning info that you have previously learned

8.2 parts of the brain involved in memory

• engram, group of neurons that serve as the physical representation of memory

• Karl Lashley tried to find this by creating lesions in the brain of different animals, but he was unable to find evidence of the engram

  • equipotentiality hypothesis, if part of one area of the brain involved in memory is damaged, another part of the same area can take over that function

  • although Lashley did not confirm the existence of an engram, modern psychologists are making progress locating it

• many psychologists believe the entire brain is involved with memory

  • however they have argued that memory is located in specific parts of the brain and specific neurons can be recognized for their involvement in forming memories

• main parts of brain involved with memory are the amygdala, the hippocampus, the cerebellum, and the prefrontal cortex

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• the amygdala

  • main function is to regulate emotions like fear and regression

  • plays a part in memory storage b/c storage is influenced by stress hormones

  • a researcher experimented with rats and fear response by using pavlovian conditioning

    • researcher, after enforcing a fear response in the rats, would induce cell death in neurons in the lateral amygdala that is responsible for fear memories and found the fear memory had become extinct.

  • involving also in memory consolidation, which is the process of transferring new learning into long-term memory

  • facilitates encoding memories at a deeper level when the event is emotionally arousing

• the hippocampus

  • group of researchers also experimented on rats to learn how the hippocampus functions in memory processing by creating lesions on the hippocampi of rats and found the rats demonstrated memory impairment on various tasks like object recognition and maze running

  • concluded hippocampus is involved in memory, specifically normal recognition memory as well as spatial memory

  • also projects info to cortical regions that give memories meaning and connect them with other memories

  • plays a part in memory consolidation which is the process of transferring new learning into long term memory

  • injury to this area leaves us unable to process new declarative memories

    • one famous patient (“H.M.”) has both his left and right temporal lobes (hippocampi) removed in an attempt to help control his seizures

    • as a result, his declarative memory was significantly affected and he could not form new semantic knowledge and lost the ability to form new memories, but could still remember info and events that occurred prior to surgery

• cerebellum and prefrontal cortex

  • more of a processing area for explicit memories, you could lose it and still be able to create implicit memories (procedural memory, motor learning, and classical conditioning) thanks to the cerebellum

  • one classical conditioning experiment is to accustom subjects to blink when they are given a puff of air to the eyes

    • when researchers damaged the cerebellums of rabbits, they discovered that the rabbits were not able to learn the conditioned eye blink responed

  • other researchers have used brain scans, including PET scans to learn how people process and retain info

    • it seems the prefrontal cortex is involved because after a PET scan in a specific study, there was much more activation in the left inferior cortex in the semantic tasks

  • encoding is associated with left frontal activity while retrieval is associated with the right frontal region

• neurotransmitters

  • epinephrine, dopamine, serotonin, glutamate, and acetylcholine

  • we know that communication among neurons via neurotransmitter is critical for developing new memories

  • repeated activity by neurons leads to increased neurotransmitters in the synapses and more efficient and more synaptic connections, which is how memory consolidation occurs

  • strong emotions trigger the formation of strong memories and vice versa, which is arousal theory

    • strong emotional experiences can trigger the release of neurotransmitters and hormones which strengthen memory

    • memory for emotional event > emotional for non emotional event

  • when humans are stressed, the brain secretes more of the neurotransmitter glutamate, which helps us to remember the stressful event

    • flashbulb memory, exceptionally clear recollection of an important event

      • ex. how many people can remember where they were and how they learned of tragic events like 9/11

      • widely known event not required

      • positive events can also elicit flashbulb memories

      • flashbulb memories have decreased accuracy with the passage of time

    • memory reconstruction, components that have to be put back together for the complete memory

8.3 problems with memory

• amnesia, the loss of long term memory that occurs as the result of disease, physical trauma, or psychological trauma

  • Endel Tulving and others studied K.C., a pt who suffered a traumatic head injury in a motorcycle accident and have severe amnesia in which he was only able to remember the last one or two minutes of his life

• anterograde amnesia, commonly caused by brain trauma in which you cannot remember new info, but can remember info and events that happened prior to your injury

  • hippocampus usually affected

  • damage to the brain has resulted in the inability to transfer info from short to long term memory

  • inability to consolidate memories

  • unable to form new episodic or semantic memories

  • able to form new procedural memories

• retrograde amnesia loss of memory for events that occurs prior to the trauma

  • cannot remember some of even all of their past

  • difficulty remembering episodic memories

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memory construction and reconstruction

• construction, formulation of new memories

• reconstruction, process of bringing up old memories

• as we retrieve memories, we also tend to alter and modify them

  • distortion of facts can happen in the process of retrieving old memories and combining them with new memories

suggestibility

• describes the effects of misinformation from external sources that leads to the creation of false memories

• we are vulnerable to the power of suggestion

eyewitness misidentification

• can lead to wrongful conditions

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the misinformation effect

• misinformation effect paradigm, which holds that after exposure to additional and possibly inaccurate info, a person may misremember the original event

• an eyewitness’s memory of an event is very flexible due to the misinformation effect

controversies over repressed and recovered memories

• false memory syndrome, recall of false autobiographical memories

  • relates to events that do not have independent witnesses

  • one one side, some researchers believe that some people have has such traumatizing experiences, they must be locked away in order to have some semblance of a normal life

    • recovered memory project was created so that victims of childhood sexual abuse can recall these memories and allow the healing process to begin

  • on the other side, Loftus has challenged the idea that individuals can repress memories of traumatic events from childhood

  • social scientists, police officers, therapists, and legal practictioners have been aware of the flaws in interview questions and steps have been taken to decrease suggestibility of witnesses with less leading language

forgetting

• refers to the loss of info from long term memory

• memory is fragile, but why do we forget?

  • encoding failure

    • memory loss happens before actual memory process beings, which is encoding failure, cant remember something if it was never stored to begin with

    • in order to remember something, we must pay attention to the details and actively work to process the info (effortful encoding)

memory errors

• Psychologist Daniel Schacter, well known memory researcher, offers 7 ways our memories fail, seven sins of memory and categorizes them into three groups: forgetting, distortion, and intrusion

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  • transience, memories fade over time. unused info fades with the passage of time

• storage decay, the average person will lose 50% of memorized info after 20 minutes and 70% on info after 24 hours. memory for new info quickly decays and eventually levels out

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• absentmindedness, describes lapses in memory caused by breaks in attention or our focus being somewhere else

• blocking, inability to access stored info

• misattribution, when you confuse the source of your info

• suggestibility, similar to misattribution, false memory comes from someone else like a police interviewer asking leading questions

• bias, memories can be affected by this, final distortion error

  • stereotypical bias, involves racial and gender biases

  • egocentric bias involves enhancing our memories of the past

  • hindsight bias, we think an outcome was inevitable after the fact (“i knew it all along”)

• persistence, last memory error, a failure of our memory system when we involuntary recall unwanted memories

interference

• info is stored in memory but for some reason it is inaccessible, this is known as interference

  • proactive interference, old info hinders the recall of newly learned info

  • retroactive interference, happens when info learned more recently hinders the recall of older info

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8.4 ways to enhance memories

• memory enhancing strategies

  • rehearsal, conscious repetition of info to be remembers

  • chunking, you organize info into manageable bits or chunks

    • useful when trying to remember info like dates and phone numbers

  • elaborative rehearsal, a technique in which you think about the meaning of new info in relation to knowledge already stored in memory

    • involves both linking the info to knowledge already stored and repeating the info

  • mnemonic devices

    • memory aids that help us organize info for encoding

    • useful when we want to recall larger bits of info such as steps, stages, phases, and parts of a system

    • more vivid or unusual the mnemonic, the easier it is to remember

  • expressive writing and saying words out loud which helps boost short term memory

• how to study effectively

  • use elaborative rehearsal

    • levels of processing, if we want to remember a piece of info, we should think abt it more deeply and link it to other info and memories to make it more meaningful

  • self reference effect

    • make it personally meaningful to you, write notes in your own words, relate something to something that applies to you, etc

  • use distributed practice

    • study across time in short duration rather than trying to cram

  • rehearse, rehearse, rehearse

    • review material over time, in spaced and organized study sessions

  • study efficiently

    • use index cards

  • be aware of interferences

    • study during a quiet time without interruptions or distractions

  • keep moving

    • regular aerobic exercise is beneficial for memory

    • promotes neurogenesis, growth of new brain cells in the hippocampus, an area of the brain known to play a role in memory and leaning

  • get enough sleep

    • during sleep, the brain organizes and consolidates info to be stored in long term memory

  • make use of mnemonic devices