Chapter summary imageWhat do we store in the “filing cabinet” of the brain?

HOW IS MEMORY ORGANIZED?

  • Memory is the brain’s system for filing away new information and retrieving previously learned data.
  • There are three different types of memory: sensory memory, working memory, and long-term memory.
  • Sensory memory is a type of memory lasting no more than a few seconds in which the impression of a sensory stimulus is stored.
  • Working memory is a type of memory in which information for short-term use is stored.
  • Long-term memory is a type of memory in which information that can last a lifetime is stored.
  • According to the information-processing model, our brains encode information, store it as a memory, and retrieve it when we need to remember it.

WHAT ARE THE CHARACTERISTICS OF SENSORY, WORKING, AND LONG-TERM MEMORY?

  • Sensory memory consists of sights, sounds, smells, and other information that the senses transmit to the corresponding sensory cortices in the brain. Sensory memories last for no more than a few seconds.
  • Iconic memory is the type of sensory memory that comes from visual stimuli.
  • Eidetic memory is not truly photographic.
  • Echoic memory is the type of sensory memory that comes from auditory stimuli.
  • Working memory contains memories that we can access immediately. Images, sounds, and meanings can all be encoded in working memory. We can store approximately seven pieces of information in our working memory.
  • Long-term memory includes both implicit and explicit memories. Meaningful or emotional information is often encoded into long-term memory. Long-term memories can last a lifetime but can be difficult to retrieve.

HOW ARE MEMORIES ENCODED, STORED, AND RETRIEVED?

  • Attention enables us to consciously or unconsciously encode memories.
  • We use rehearsal, mnemonics, chunking, and other organizational strategies to store memories.
  • The frontal lobe, hippocampus, basal ganglia, and cerebellum are active in memory encoding and storage.
  • Retrieval cues such as the context effect help us move long-term memories into working memory, where stored information is “at the ready.”
  • Forgetting can be due to interference, cued forgetting, pseudoforgetting, storage decay, or memory mishaps, such as amnesia or too much stress.

WHAT ARE THE WEAKNESSES AND LIMITATIONS OF MEMORY?

  • Memory is not perfect. Our memories, and our abilities to store and retrieve memories, change.
  • Stress can inhibit memory storage and recall.
  • Brain damage can lead to retrograde and anterograde amnesia.
  • Memories are easily forgotten and prone to distortion, and they can persist even when we try to forget them.