Chapter 6: Memory

Intro to Psychology

Measuring Memory

  • Explicit memory: intentional recollection of information.
    • Recall: the ability to retrieve previous information.
    • Recognition: the ability to identify information you’ve seen before.

Models of Memory

  • Memory moves from sensory register to working memory (~30 seconds unless you focus hard) to long-term memory.
    • sensory register: visuals retain for 0.5 seconds, auditory signals for up to 10 seconds
    • working memory: retains for 30 seconds
      • Remembering a sentence as it’s being spoken is remembered in “chunks”, not individual words.
    • long-term memory: evidence suggests things are grouped by category (furniture, fruits).
      • Explicit memory - hippocampus
        • Semantic memory: internal representations of the world.
        • Episodic memory: internal representations of events you experienced.
      • Implicit memory - striatum
  • Parallel distributed processing (PDP) model (connectionist model): memory is connections in a vast network of processing units.

The Biology of Memory

  • In working memory, neurons temporarily alter their ability to release neurotransmitters.
  • In long-term memory, there are structural changes to the brain.
    • Long-term potentiation: a long-lasting change to the strength of synaptic responsiveness as a result of long-term memory.
  • Hippocampus is critical to forming and recalling long-term memories.
  • Memories may be stored in the same places where they were originally perceived (when recalling a visual memory, the visual parts of the brain become active).

Hormones, Emotion, and Memory

  • In traumatizing or stressful moments, hormones such as epinephrine (adrenaline) and norepinephrine are released, which enhance memory.
    • Arousal tells the brain that this is important to remember.
    • Hormones bind to amygdala, which signals hippocampus to increase memory incoding.


Rehearsal: repeating information in your head until you remember it.

  • Maintenance rehearsal: rote repetition of material.
  • Elaborative rehearsal: associating new information with things you already have in your memory.
  • Deep processing: learning more about the meaning of something helps with memory.


Four ways of forgetting:

  1. Decay
  2. Replacement
  3. Interference
    • Retroactive interference: recently learned material interferes with previously learned material.
    • Proactive interference: material you learned before interferes with trying to remember new information.
  4. Cue-Dependent Forgetting
    • Cue-dependent forgetting: inability to retrieve stored information because of insufficient cues.
    • “Tip of the tongue” is an example of this.

Forgetting your childhood

People don’t remember things before the age of 2. Why?

  1. Brain isn’t well-developed, and also may be focusing on all the new events and unable to focus on one event.
  2. Children don’t have a sense of self, and don’t have the language to encode their own experiences.
  3. Children don’t know what’s normal and what’s not, so they focus on ordinary things.


There isn’t much evidence that people can “repress” memories and completely forget about them.

Instead, usually these people recall false memories because of the power of suggestion from a psychotherapist.

False Memories

DRM Paradigm: a way to study false memories.

  • False memories are correlated with:
    • Inconsistencies in people’s reports of past events.
    • Reports of memories of past lives or alien abductions.
    • Age (old = more errors)

Some false memories are caused by spreading activation of your semantic memory network — related things are activated.

  • False memories are more common than you think.
  • They often grow out of normal tendencies and processes (e.g. semantic memory).

Why do we get false memories?

  • Memory is a constructive process - we fill in the edges.
  • We’re easily influenced.
  • Post-event information affects your memory.