Memory and Cognition - APSY101 Notes

How We Remember

• Encoding: Taking in information.
• Storage: Keeping information.
  • Maintenance rehearsal.
• Retrieval: Accessing information.
• Attention is crucial for encoding.
• Sensory Input leads to Sensory Memory.
• Short-Term Memory (STM) follows sensory memory.
• Long-Term Memory (LTM) is the final stage; unrehearsed information is lost from STM, and some information is lost from LTM over time.

Long-Term Memory (LTM)

• The last stage in the Modal Model of Memory.
• Only a minority of initially attended to and processed information reaches LTM.
• Retains abstracted semantic information.
• Information may need to be kept indefinitely and is retrievable.

Retrieval

• The process of reactivating information that has been stored in memory.
• Tip-of-the-tongue phenomenon: Knowing something but not able to recall it, illustrating retrieval failure.

Context-Dependent Memory

• Memory is improved when we have consistent environments at the time of encoding and retrieval.

State-Dependent Memory

• Memory is improved when we have consistent internal states and moods at the time of encoding and retrieval.
• The brain encodes associations between experiences and the world, allowing us to make predictions about our environment, even if associations are incidental.

Serial Position Effect

• People better retrieve items at the beginning and end of a list than items in the middle.
  • Illustrates a U-shaped recall performance when given a long string of numbers to repeat.
• Primacy effect: People better retrieve beginning items.
• Recency effect: People better retrieve end items.
  • The tendency to remember information presented earlier in a sequence.
  • The tendency to remember information presented at the end of a sequence.

Neurological Differences in STM and LTM

• Behavioral differences between STM and LTM suggest that they may be distinct memory systems.
• Amnesia: Severely impaired long-term memory due to brain trauma.
• Retrograde Amnesia: Difficulty remembering events that occurred leading up to the event.
• Anterograde Amnesia: Difficulty remembering any new information they encounter.
  • Retrograde Amnesia: Memory loss of before event.
  • Anterograde Amnesia: Memory loss after event.

Structure of LTM

Categories

• Networks of associated memories that have features in common.
• Associated concepts in a category are connected through spreading activation.
• Some categories have defining features true of all category members.
• The prototype is the most typical category member.

Schemas

• Patterns of knowledge in long-term memory that help us organize information.
• Stereotypes are schemas about social groups.

Biology of Memory

• Long-term potentiation:
  • The strengthening of synaptic connections between neurons as a result of frequent stimulation.
  • Examples: Practicing an instrument, learning a new language.

Brain Areas Involved in Memory

• Hippocampus: Preprocessor and elaborator of information.
• Cerebellum: Involved in implicit memory, such as learning procedures.
• Amygdala: Stores important emotional memories, especially those associated with fear.

Types of Amnesia

• Retrograde amnesia: An inability to retrieve events that occurred before a given time.
• Anterograde amnesia: The inability to store new events.

Neurotransmitters and Hormones Involved in Memory

• Glutamate: Perhaps the most important neurotransmitter in memory.
• Epinephrine: Secreted during stress; may aid memory.
• Serotonin: Secreted during learning.
• Estrogen: Decreases during menopause and may be related to memory difficulties.

Key Takeaways

• Information is better remembered when it is meaningfully elaborated.
• Context- and state-dependent learning, as well as primacy and recency effects, influence long-term memory.
• Memories are stored in connected synapses through the process of long-term potentiation.
• Brain areas including the hippocampus, cerebellum, and the amygdala, also play important roles in memory.
• Damage to the brain may result in retrograde amnesia or anterograde amnesia.
• Case studies of patients with amnesia can provide information about the brain structures involved in different types of memory.
• Memory is influenced by chemicals including glutamate, serotonin, epinephrine, and estrogen.

Accuracy and Inaccuracy in Memory and Cognition

• Cognitive biases: systematic errors in memory or judgment.

Cognitive Processes Posing Threats to Accuracy

• Source confusion: Forgetting the source of a memory.
• Confirmation bias: The tendency to verify and confirm our existing beliefs rather than to challenge and disconfirm them.
• Functional fixedness: When schemas prevent us from seeing and using information in new and nontraditional ways.
• Misinformation effect: Errors in memory that occur when new but incorrect information influences existing accurate memories.
• Overconfidence: When we are more certain than we should be that our memories and judgments are accurate.
• Representativeness heuristic: The tendency to make judgments according to how well the event matches our expectations.
• Availability heuristic: The idea that things that come to mind easily are seen as common.
• Counterfactual thinking: When we “replay” events such that they turn out differently.

Schematic Processing: Distortions Based on Expectations

• Confirmation bias: The tendency to verify and confirm our existing memories rather than to challenge and disconfirm them.
• Functional fixedness: Schemas prevent people from using an object in new and nontraditional ways.
  • Example: In the candle-tack-box problem, functional fixedness may lead us to see the box as only a box, not a potential candleholder.

Misinformation Effects

• Errors in memory that occur when new information influences existing memories.
• Misinformation may not only distort our memories of events that actually occurred but may also lead us to falsely remember events that never happened.
• Loftus and Palmer’s participants viewed a film of a traffic accident and then answered a question about the accident.
• The verb in the question was “hit,” “smashed,” or “contacted.”
  • The wording of the question influenced the participants’ memory of the accident.

Overconfidence

• The tendency for people to be too certain about their ability to accurately remember events and to make judgments.
• Eyewitnesses to crimes are often overconfident.
• There is a very small correlation between an eyewitness’ confidence and the accuracy of the eyewitness’ memory.
• Flashbulb memory:
  • A vivid and emotional memory of an unusual event that people believe they remember very well.
  • Example: One’s memory of the start of the COVID-19 epidemic.
  • Flashbulb memories are less accurate than we believe them to be.

Heuristic Processing

Representativeness

• We base our judgments on information that seems to match our expectations and ignore potentially more relevant statistical information.

Availability

• The tendency to make judgments concerning an event’s frequency or likelihood on the basis of the ease with which the event can be retrieved from memory.

Counterfactual Thinking

• The tendency to think about and experience events according to “what might have been.”
• Often, the bronze medalist in one of the Olympic Games look happier than the silver medalist does.

Key Takeaways

• Our memories fail in part due to inadequate encoding and storage and the inability to accurately retrieve stored information.
• The human brain is wired to develop and make use of schemas.
• Schemas help us remember new information but may also lead us to falsely remember things that never happened to us and distort or misremember things that did.
• A variety of cognitive biases influence the accuracy of our judgments.