CHAPTER 8

MEMORY

Studying and Encoding Memories

8-1 What is memory, and how is it measured?

Memory is learning that has persisted over time, through the encoding, storage, and retrieval of information. Evidence of memory may be recalling information, recognizing it, or relearning it more easily on a later attempt.

8-2 How do psychologists describe the human memory system?

Psychologists use memory models to think and communicate about memory. Information-processing models involve three processes: encoding, storage, and retrieval. Our agile brain processes many things simultaneously (some of them unconsciously) by means of parallel processing. The connectionism information-processing model focuses on this multitrack processing, viewing memories as products of interconnected neural networks. The three processing stages in the Atkinson-Shiffrin model are sensory memory, short-term memory, and long-term memory. This model has since been updated to include two important concepts: (1) working memory, to stress the active processing occurring in the second memory stage; and (2) automatic processing, to address the processing of information outside of conscious awareness.

8-3 How do explicit and implicit memories differ?

The human brain processes information on dual tracks, consciously and unconsciously. Explicit (declarative) memories—our conscious memories of facts and experiences—form through effortful processing, which requires conscious effort and attention. Implicit (nondeclarative) memories—of skills and classically conditioned associations—happen without our awareness, through automatic processing.

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8-4 What information do we process automatically?

In addition to skills and classically conditioned associations, we automatically process incidental information about space, time, and frequency.

8-5 How does sensory memory work?

Sensory memory feeds some information into working memory for active processing there. An iconic memory is a very brief (a few tenths of a second) sensory memory of visual stimuli; an echoic memory is a three- or four-second sensory memory of auditory stimuli.

8-6 What is the capacity of our short-term and working memory?

Short-term memory capacity is about seven items, plus or minus two, but this information disappears from memory quickly without rehearsal. Working memory capacity varies, depending on age, intelligence level, and other factors.

8-7 What are some effortful processing strategies that can help us remember new information?

Effective effortful processing strategies include chunking, mnemonics, hierarchies, and distributed practice sessions. The testing effect is enhanced memory after consciously retrieving, rather than simply rereading, information.

8-8 What are the levels of processing, and how do they affect encoding?

Depth of processing affects long-term retention. In shallow processing, we encode words based on their structure or appearance. Retention is best when we use deep processing, encoding words based on their meaning. We also more easily remember material that is personally meaningful—the self-reference effect.

Storing and Retrieving Memories

8-9 What is the capacity of long-term memory? Are our long-term memories processed and stored in specific locations?

Our long-term memory capacity is essentially unlimited. Memories are not stored intact in the brain in single spots. Many parts of the brain interact as we encode, store, and retrieve memories.

8-10 What are the roles of the frontal lobes and hippocampus in memory processing?

The frontal lobes and hippocampus are parts of the brain network dedicated to explicit memory formation. Many brain regions send information to the frontal lobes for processing. The hippocampus, with the help of surrounding areas of cortex, registers and temporarily holds elements of explicit memories before moving them to other brain regions for long-term storage. The neural storage of long-term memories is called memory consolidation.

8-11 What roles do the cerebellum and basal ganglia play in memory processing?

The cerebellum and basal ganglia are parts of the brain network dedicated to implicit memory formation. The cerebellum is important for storing classically conditioned memories. The basal ganglia are involved in motor movement and help form procedural memories for skills. Many reactions and skills learned during our first three years continue into our adult lives, but we cannot consciously remember learning these associations and skills, a phenomenon psychologists call “infantile amnesia.”

8-12 How do emotions affect our memory processing?

Emotional arousal causes an outpouring of stress hormones, which lead to activity in the brain’s memory-forming areas. Significantly stressful events can trigger very clear flashbulb memories.

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8-13 How do changes at the synapse level affect our memory processing?

Long-term potentiation (LTP) appears to be the neural basis of learning. In LTP, neurons become more efficient at releasing and sensing the presence of neurotransmitters, and more connections develop between neurons.

8-14 How do external cues, internal emotions, and order of appearance influence memory retrieval?

External cues activate associations that help us retrieve memories; this process may occur without our awareness, as it does in priming. The encoding specificity principle is the idea that cues and contexts specific to a particular memory will be most effective in helping us recall it. Returning to the same physical context or emotional state (mood congruency) in which we formed a memory can help us retrieve it. The serial position effect accounts for our tendency to recall best the last items (which may still be in working memory) and the first items (which we’ve spent more time rehearsing) in a list.

Forgetting, Memory Construction, and Improving Memory

8-15 Why do we forget?

Anterograde amnesia is an inability to form new memories. Retrograde amnesia is an inability to retrieve old memories. Normal forgetting can happen because we have never encoded information (encoding failure); because the physical trace has decayed (storage decay); or because we cannot retrieve what we have encoded and stored (retrieval failure). Retrieval problems may result from proactive (forward-acting) interference, as prior learning interferes with recall of new information, or from retroactive (backward-acting) interference, as new learning disrupts recall of old information. Some believe that motivated forgetting occurs, but researchers have found little evidence of repression.

8-16 How do misinformation, imagination, and source amnesia influence our memory construction? How do we decide whether a memory is real or false?

In experiments demonstrating the misinformation effect, people have formed false memories, incorporating misleading details, after receiving wrong information after an event, or after repeatedly imagining and rehearsing something that never happened. When we reassemble a memory during retrieval, we may attribute it to the wrong source (source amnesia). Source amnesia may help explain déjà vu. False memories feel like real memories and can be persistent but are usually limited to the gist of the event.

8-17 How reliable are young children’s eyewitness descriptions?

Children are susceptible to the misinformation effect, but if questioned in neutral words they understand, they can accurately recall events and people involved in them.

8-18 Why are reports of repressed and recovered memories so hotly debated?

The debate (between memory researchers and some well-meaning therapists) focuses on whether most memories of early childhood abuse are repressed and can be recovered during therapy using “memory work” techniques using leading questions or hypnosis. Psychologists now agree that (1) sexual abuse happens; (2) injustice happens; (3) forgetting happens; (4) recovered memories are commonplace; (5) memories of things that happened before age 3 are unreliable; (6) memories “recovered” under hypnosis or the influence of drugs are especially unreliable; and (7) memories, whether real or false, can be emotionally upsetting.

8-19 How can you use memory research findings to do better in this and other courses?

Memory research findings suggest the following strategies for improving memory: Study repeatedly, make material meaningful, activate retrieval cues, use mnemonic devices, minimize interference, sleep more, and test yourself to be sure you can retrieve, as well as recognize, material.

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