Chapter 8
Source amnesia:
attributing to the wrong source an event we have experienced, heard about, read about, or imagined. (Also called source misattribution.) Source amnesia, along with the misinformation effect, is at the heart of many false memories. (p. 346)
Imagine being a jury member in a trial for a parent accused of sexual abuse based on a recovered memory. What insights from memory research should you offer the jury?
It will be important to remember the key points agreed upon by most researchers and professional associations: Sexual abuse, injustice, forgetting, and memory construction all happen; recovered memories are common; memories from before age 3 are unreliable; memories claimed to be recovered through hypnosis or drug influence are especially unreliable; and memories, whether real or false, can be emotionally upsetting.
If you try to make the material you are learning personally meaningful, are you processing at a shallow or a deep level? Which level leads to greater retention?
Making material personally meaningful involves processing at a deep level, because you are processing semantically—based on the meaning of the words. Deep processing leads to greater retention.
Massed practice
Massed practice (cramming) can produce speedy short-term learning and a feeling of confidence. But to paraphrase early memory researcher Hermann Ebbinghaus (1885), those who learn quickly also forget quickly.
What—given the commonality of source amnesia—might life be like if we remembered all our waking experiences and all our dreams?
Real experiences would be confused with those we dreamed. When meeting someone, we might therefore be unsure whether we were reacting to something they previously did or to something we dreamed they did.
How can you use memory research findings to do better in this and other courses?
Rehearse repeatedly. Make the material meaningful. Activate retrieval cues. Use mnemonic devices. Minimize interference. Sleep more. Test your own knowledge, both to rehearse it and to find out what you don't yet know.
Short-term memory:
activated memory that holds a few items briefly, such as the seven digits of a phone number while calling, before the information is stored or forgotten. (p. 320)
self-reference effect
We have especially good recall for information we can meaningfully relate to ourselves. Asked how well certain adjectives describe someone else, we often forget them; asked how well the adjectives describe us, we remember the words well. This tendency, called the self-reference effect, is especially strong in members of individualist Western cultures (Symons & Johnson, 1997; Wagar & Cohen, 2003). Information deemed "relevant to me" is processed more deeply and remains more accessible. Knowing this, you can profit from taking time to find personal meaning in what you are studying. The point to remember: The amount remembered depends both on the time spent learning and on your making it meaningful for deep processing.
Anterograde amnesia:
an inability to form new memories. (p. 338)
Retrograde amnesia:
an inability to retrieve information from one's past. (p. 338)
Long-term potentiation (LTP):
an increase in a cell's firing potential after brief, rapid stimulation. Believed to be a neural basis for learning and memory. (p. 332) The sending neuron now needs less prompting to release its neurotransmitter, and more connections exist between neurons. This increased efficiency of potential neural firing, called long-term potentiation (LTP), provides a neural basis for learning and remembering associations
Shallow processing:
encoding on a basic level based on the structure or appearance of words. (p. 326)
Deep processing:
encoding semantically, based on the meaning of the words; tends to yield the best retention. (p. 326) The deeper (more meaningful) the processing, the better our retention.
Effortful processing:
encoding that requires attention and conscious effort. (p. 321)
Testing effect:
enhanced memory after retrieving, rather than simply rereading, information. Also sometimes referred to as a retrieval practice effect or test-enhanced learning. (pp. 13, 326) The point to remember: Spaced study and self-assessment beat cramming and rereading. Practice may not make perfect, but smart practice—occasional rehearsal with self-testing—makes for lasting memories.
Chunking:
organizing items into familiar, manageable units; often occurs automatically. (p. 324)
Serial position effect:
our tendency to recall best the last (a recency effect) and first (a primacy effect) items in a list. (p. 336) explains why we may have large holes in our memory of a list of recent events.
Implicit memory:
retention of learned skills or classically conditioned associations independent of conscious recollection. (Also called nondeclarative memory.) (p. 321)
At which of Atkinson-Shiffrin's three memory stages would iconic and echoic memory occur?
sensory memory
Déjà vu:
that eerie sense that "I've experienced this before." Cues from the current situation may unconsciously trigger retrieval of an earlier experience. (p. 346) (French for "already seen"). Two-thirds of us have experienced this fleeting, eerie sense that "I've been in this exact situation before." It happens most commonly to well-educated, imaginative young adults, especially when tired or stressed (Brown, 2003, 2004a,b; McAneny, 1996). Some wonder, "How could I recognize a situation I'm experiencing for the first time?" Others may think of reincarnation ("I must have experienced this in a previous life") or precognition ("I viewed this scene in my mind before experiencing it"). The key to déjà vu seems to be familiarity with a stimulus without a clear idea of where we encountered it before (Cleary, 2008). Normally, we experience a feeling of familiarity (thanks to temporal lobe processing) before we consciously remember details (thanks to hippocampus and frontal lobe processing). When these functions (and brain regions) are out of sync, we may experience a feeling of familiarity without conscious recall. Our amazing brains try to make sense of such an improbable situation, and we get an eerie feeling that we're reliving some earlier part of our life. After all, the situation is familiar, even though we have no idea why. Our source amnesia forces us to do our best to make sense of an odd moment.
Parallel processing:
the processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions. (pp. 96, 246, 320)
Long-term memory:
the relatively permanent and limitless storehouse of the memory system. Includes knowledge, skills, and experiences. (p. 320)
Automatic processing:
unconscious encoding of incidental information, such as space, time, and frequency, and of well-learned information, such as word meanings. (p. 321)
Retrieval:
the process of getting information out of memory storage. (p. 320) later get the information back out
Storage:
the process of retaining encoded information over time. (p. 320) retain that information
What are three ways we forget, and how does each of these happen?
(1) Encoding failure: Unattended information never entered our memory system. (2) Storage decay: Information fades from our memory. (3) Retrieval failure: We cannot access stored information accurately, sometimes due to interference or motivated forgetting.
Several lines of evidence confirm that LTP is a physical basis for memory:
-Drugs that block LTP interfere with learning (Lynch & Staubli, 1991). -Mutant mice engineered to lack an enzyme needed for LTP couldn't learn their way out of a maze (Silva et al., 1992). -Rats given a drug that enhanced LTP learned a maze with half the usual number of mistakes (Service, 1994). One approach to improving memory focuses on drugs that boost the LTP-enhancing neurotransmitter glutamate (Lynch et al., 2011). Another approach involves developing drugs that boost production of CREB, a protein that also enhances the LTP process (Fields, 2005). Boosting CREB production might trigger increased production of other proteins that help reshape synapses and transfer short-term memories into long-term memories. Sea slugs, mice, and fruit flies with enhanced CREB production have displayed enhanced learning.
To explain our memory-forming process, Richard Atkinson and Richard Shiffrin (1968) proposed a three-stage model:
-We first record to-be-remembered information as a fleeting sensory memory. -From there, we process information into short-term memory, where we encode it through rehearsal. -Finally, information moves into long-term memory for later retrieval.
Without conscious effort you also automatically process information about:
-space. While studying, you often encode the place on a page where certain material appears; later, when you want to retrieve the information, you may visualize its location on the page. -time. While going about your day, you unintentionally note the sequence of its events. Later, realizing you've left your coat somewhere, the event sequence your brain automatically encoded will enable you to retrace your steps. -frequency. You effortlessly keep track of how many times things happen, as when you realize, "This is the third time I've run into her today."
electroconvulsive therapy (ECT)
After long-term potentiation has occurred, passing an electric current through the brain won't disrupt old memories. But the current will wipe out very recent memories. Such is the experience both of laboratory animals and of severely depressed people given electroconvulsive therapy (ECT).
Which strategies are better for long-term retention: cramming and rereading material, or spreading out learning over time and repeatedly testing yourself?
Although cramming may lead to short-term gains in knowledge, distributed practice and repeated self-testing will result in the greatest long-term retention.
state-dependent memory
Closely related to context-dependent memory is state-dependent memory. What we learn in one state—be it drunk or sober—may be more easily recalled when we are again in that state. What people learn when drunk they don't recall well in any state (alcohol disrupts storage). But they recall it slightly better when again drunk. Someone who hides money when drunk may forget the location until drunk again.
better long-term recall.
Distributed practice produces better long-term recall. After you've studied long enough to master the material, further study at that time becomes inefficient. Better to spend that extra reviewing time later—a day later if you need to remember something 10 days hence, or a month later if you need to remember something 6 months hence (Cepeda et al., 2008).
Your friend has experienced brain damage in an accident. He can remember how to tie his shoes but has a hard time remembering anything told to him during a conversation. What's going on here?
Our explicit conscious memories of facts and episodes differ from our implicit memories of skills (such as shoe tying) and classically conditioned responses. Our implicit memories are processed by more ancient brain areas, which apparently escaped damage during the accident.
infantile amnesia
Our implicit memory system, enabled by the cerebellum and basal ganglia, helps explain why the reactions and skills we learned during infancy reach far into our future. Yet as adults, our conscious memory of our first three years is blank, an experience called infantile amnesia
Why are reports of repressed and recovered memories so hotly debated?
Sexual abuse happens. Injustice happens. Forgetting happens. Recovered memories are commonplace. Memories of events before age 3 are unreliable. Memories "recovered" under hypnosis or the influence of drugs are especially unreliable. Memories, whether real or false, can be emotionally upsetting.
amygdala
Stress provokes the amygdala (two limbic system, emotion-processing clusters) to initiate a memory trace in the frontal lobes and basal ganglia and to boost activity in the brain's memory-forming areas. Our emotions trigger stress hormones that influence memory formation.
basal ganglia
The basal ganglia, deep brain structures involved in motor movement, facilitate formation of our procedural memories for skills (Mishkin, 1982; Mishkin et al., 1997). The basal ganglia receive input from the cortex but do not return the favor of sending information back to the cortex for conscious awareness of procedural learning. If you have learned how to ride a bike, thank your basal ganglia.
retrieval cues and visual cues
The best retrieval cues come from associations we form at the time we encode a memory—smells, tastes, and sights that can evoke our memory of the associated person or event. To call up visual cues when trying to recall something, we may mentally place ourselves in the original context.
Which parts of the brain are important for implicit memory processing, and which parts play a key role in explicit memory processing?
The cerebellum and basal ganglia are important for implicit memory processing and the frontal lobes and hippocampus are key to explicit memory formation.
cerebellum
The cerebellum plays a key role in forming and storing the implicit memories created by classical conditioning. With a damaged cerebellum, people cannot develop certain conditioned reflexes, such as associating a tone with an impending puff of air—and thus do not blink in anticipation of the puff (Daum & Schugens, 1996; Green & Woodruff-Pak, 2000). When researchers surgically disrupted the function of different pathways in the cerebellum of rabbits, the rabbits became unable to learn a conditioned eyeblink response (Krupa et al., 1993; Steinmetz, 1999). Implicit memory formation needs the cerebellum.
Sleep and positive transfer
The hour before sleep is a good time to commit information to memory (Scullin & McDaniel, 2010), though information presented in the seconds just before sleep is seldom remembered (Wyatt & Bootzin, 1994). If you're considering learning while sleeping, forget it. We have little memory for information played aloud in the room during sleep, although the ears do register it (Wood et al., 1992). Old and new learning do not always compete with each other, of course. Previously learned information (Latin) often facilitates our learning of new information (French). This phenomenon is called positive transfer.
Retaining Information in the Brain
The point to remember: Despite the brain's vast storage capacity, we do not store information as libraries store their books, in single, precise locations. Instead, brain networks encode, store, and retrieve the information that forms our complex memories.
hierarchies
When people develop expertise in an area, they process information not only in chunks but also in hierarchies composed of a few broad concepts divided and subdivided into narrower concepts and facts. (Figure 8.12 ahead provides a hierarchy of our automatic and effortful memory processing systems.) Organizing knowledge in hierarchies helps us retrieve information efficiently, as Gordon Bower and his colleagues (1969) demonstrated by presenting words either randomly or grouped into categories. When the words were grouped, recall was two to three times better.
retrieval cues
When you encode into memory a target piece of information, such as the name of the person sitting next to you in class, you associate with it other bits of information about your surroundings, mood, seating position, and so on. These bits can serve as retrieval cues that you can later use to access the information. The more retrieval cues you have, the better your chances of finding a route to the suspended memory.
Flashbulb memory:
a clear memory of an emotionally significant moment or event. (p. 331) Our flashbulb memories are noteworthy for their vividness and our confidence in them. But as we relive, rehearse, and discuss them, these memories may come to err.
recall
a measure of memory in which the person must retrieve information learned earlier, as on a fill-in-the-blank test. (p. 319)
recognition
a measure of memory in which the person need only identify items previously learned, as on a multiple-choice test.
relearning
a measure of memory that assesses the amount of time saved when learning material again. learning something more quickly when you learn it a second or later time. When you study for a final exam or engage a language used in early childhood, you will relearn the material more easily than you did initially.
Echoic memory:
a momentary sensory memory of auditory stimuli; if attention is elsewhere, sounds and words can still be recalled within 3 or 4 seconds. (p. 323)
Iconic memory:
a momentary sensory memory of visual stimuli; a photographic or picture-image memory lasting no more than a few tenths of a second. (p. 323)
Hippocampus:
a neural center located in the limbic system; helps process explicit memories for storage. (pp. 71, 329) a temporal-lobe-neural center located in the limbic system, is the brain's equivalent of a "save" button for explicit memories (FIGURE 8.9). The hippocampus and nearby brain networks are active as people form explicit memories of names, images, and events (Squire & Wixted, 2011). The network that processes and stores your explicit memories for facts and episodes includes your frontal lobes and hippocampus. Sleep supports memory consolidation. During deep sleep, the hippocampus processes memories for later retrieval. After a training experience, the greater the hippocampus activity during sleep, the better the next day's memory will be
Working memory:
a newer understanding of short-term memory that focuses on conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory. (p. 321)
Reconsolidation:
a process in which previously stored memories, when retrieved, are potentially altered before being stored again. (p. 343)
Repression:
in psychoanalytic theory, the basic defense mechanism that banishes from consciousness anxiety-arousing thoughts, feelings, and memories. (pp. 343, 575)
The neural basis for learning and memory, found at the synapses in the brain's memory-circuit connections, results from brief, rapid stimulation. It is called _________-__________ _________.
long-term potentiation
Mnemonics [nih-MON-iks]:
memory aids, especially those techniques that use vivid imagery and organizational devices. (p. 325) The peg-word system harnesses our superior visual imagery skill. This mnemonic requires you to memorize a jingle: "One is a bun; two is a shoe; three is a tree; four is a door; five is a hive; six is sticks; seven is heaven; eight is a gate; nine is swine; ten is a hen." Without much effort, you will soon be able to count by peg words instead of numbers: bun, shoe, tree ... and then to visually associate the peg words with to-be-remembered items.
Explicit memory:
memory of facts and experiences that one can consciously know and "declare." (Also called declarative memory.) (p. 321)
Encoding:
the processing of information into the memory system—for example, by extracting meaning. (p. 320) get information into our brain.
Priming:
the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response. (pp. 231, 334) Priming is often "memoryless memory"—invisible memory, without your conscious awareness. Priming can influence behaviors as well (Herring et al., 2013). In one study, participants primed with money-related words were less likely to help another person when asked (Vohs et al., 2006). In another, people primed with money words or images expressed more support for free-market capitalism and social inequality (Caruso et al., 2013). In such cases, money may prime our materialism and self-interest rather than the social norms that encourage us to help (Ariely, 2009).
Which brain area responds to stress hormones by helping to create stronger memories?
the amygdala
Retroactive interference:
the backward-acting disruptive effect of new learning on the recall of old information. (p. 341) occurs when new learning disrupts recall of old information. If someone sings new lyrics to the tune of an old song, you may have trouble remembering the original words. It is rather like a second stone tossed in a pond, disrupting the waves rippling out from the first.
Proactive interference:
the forward-acting disruptive effect of prior learning on the recall of new information. (p. 341) occurs when prior learning disrupts your recall of new information. If you buy a new combination lock, your well-rehearsed old combination may interfere with your retrieval of the new one.
Encoding specificity principle:
the idea that cues and contexts specific to a particular memory will be most effective in helping us recall it. (p. 335)
Sensory memory:
the immediate, very brief recording of sensory information in the memory system. (p. 320)
Memory consolidation:
the neural storage of a long-term memory. (p. 330)
Spacing effect:
the tendency for distributed study or practice to yield better long-term retention than is achieved through massed study or practice. (p. 325)
Mood-congruent memory:
the tendency to recall experiences that are consistent with one's current good or bad mood. (p. 336)
connectionism
views memories as products of interconnected neural networks. Specific memories arise from particular activation patterns within these networks. Every time you learn something new, your brain's neural connections change, forming and strengthening pathways that allow you to interact with and learn from your constantly changing environment.
Misinformation effect:
when misleading information has corrupted one's memory of an event. (p. 344) In many follow-up experiments around the world, others have witnessed an event, received or not received misleading information about it, and then taken a memory test. Digitally altered photos have also produced this imagination inflation. Misinformation and imagination effects occur partly because visualizing something and actually perceiving it activate similar brain areas