Chapter 8 Memory
Answers to Before You Go On Questions
1. What are encoding, storage, and retrieval? Simply put, memory is the faculty for recalling past events and past learning. Psychologists generally agree that it involves three basic activities: (1) encoding (getting information into a form appropriate for storage in memory in the first place), (2) storage (retaining memories for future use), and (3) retrieval (recapturing memories when we need them).
2. What are the three memory stores suggested by the information-processing model of memory?The information-processing model of memory has its roots back in early computer science (Atkinson Shiffrin, 1968) and was intended to chart the ways that, like computers, humans process information from their senses into memory. There are three suggested memory stores used by the information-processing model of memory: (1) sensory memory (holds sensory information, lasting up to half a second for visual inputs and 2–4 seconds for auditory inputs; has a large capacity), (2) working memory (holds information temporarily for analysis, lasting up to 30 seconds without rehearsal, with a limited capacity for about 5–9 items, and (3) long-term memory (permanent storage with a relatively unlimited capacity).
3. How does increased attention affect automatic and effortful processing? Automatic processing (encoding of information with little conscious awareness or effort) and effortful processing (encoding information through careful attention and conscious effort) are both variations on our ability to process information. There are key differences between these two kinds of processing. First, the encoding of information by effortful processing tends to be disrupted when a person is forced to perform other tasks or to attend to other information while trying to encode the information at hand (think about playing an intense video game and talking on the phone). In contrast, automatic processing is disrupted only slightly by the performance of other tasks (think about pouring a cup of coffee while talking on the phone). Therefore, increasing the amount of attention focused upon a particular task has a much larger and positive effect on effortful processing than automatic processing, which is not significantly enhanced by a person’s extra efforts to attend and encode.
4. Why is it more effective to study all term long, rather than in one massive session right before a final exam? Information passes into long-term memory best when our rehearsal sessions are spread out over a period of time rather than attempting to take in a great deal of information all at once. This phenomenon is known as the spacing effect. Thus, distributed practice, such as studying material weekly followed by reviews closer to the time of an exam, is usually more profitable than massed practice, such as studying in one “cram” session just before an exam.
5. Which type of coding would most people use to remember someone’s face? Which type would most people use to remember a person’s name? To remember someone’s face, typically we would use visual code, or photographic memories. To remember a person’s name we would likely employ the use of a phonological code, the repetition of the sounds of the letters to form the name. Research suggests that people tend to favour phonological codes (as if they were spoken) when recording verbal information, such as numbers, letters, and words. We rely more on visual codes for non-verbal information, such as a person’s face or a speeding car (Just & Carpenter, 2002).
6. What is chunking, and why would you want to use it? Chunking is one way of organizing information to help enhance memory. If you watch a lot of hockey, you might chunk or organize strings of single-digit numbers into times for goals in a game—1, 3, 4, 5, 2 might become a goal at 13:45 of the second period. Chunking pieces of information together into larger units enables us to encode more information in our working memory system, and it also enables our working memory to store more information at a given moment.
7. What kind of information is stored in semantic memory and episodic memory? Are semantic and episodic memories implicit or explicit memories? Semantic memory typically is a person’s memory of general knowledge of the world. This includes both facts as well as seemingly general knowledge (for example, bananas are yellow, there are 12 months in a year, spiders have eight legs). Episodic memory, on the other hand, relates to a person’s memory of personal events or episodes from his or her life (our memory of our high school graduation, the birth of our first child, etc.). Both semantic and episodic memories are considered explicit memories, that is, memories with conscious recall.
8. If researchers show people several pictures of small rodents, then find that a lot of people include hamsters and mice when asked to name animals that make good pets, what has happened? Why did it happen? The pictures of the small rodents had a priming effect on the participants’ memories. As such, the pictures served as cues to recall similar memories, making it more likely people would think of other small rodents (hamsters and mice) when asked later about pets.
9. Why do many educators believe it is helpful to take an exam in the same room where you learned the material? The retrieval of information from memory is facilitated by retrieval cues—words, sights, or other stimuli that remind us of the information that we need. Essentially, when we come across a retrieval cue, we enter our long-term memory system and activate a relevant piece of information. Because the pieces of information in this memory system are linked to each other in a network of associations, the activation of the first piece of information will trigger the activation of related pieces until a complete memory emerges. This is known as context (encoding [context] specificity). The original location where you first learned a concept or idea is rich with retrieval cues that will make it more likely you will be able to recall that information later if you are in the same location or context.
10. How do strong emotions affect our memory processes? Some theorists suggest that strong emotions may enhance memories by leading to increased rehearsal, elaboration, and organization of a particular event, or that intense emotions may trigger a special memory mechanism, producing emotional memories. What were you doing at 9:00 a.m. on Tuesday May 2, 2006? Can’t remember off the top of your head? That’s not surprising. What were you doing on Tuesday, September 11, 2001, at 9:00 a.m.? That memory is probably quite easy to access.
11. How does the decay theory explain forgetting? The decay theory of forgetting suggests that memories fade over time because of neglect or failure to access them over long periods of time. This theory is built on the notion that memories leave a physical trace in the brain—a so-called memory trace—when they are acquired. Theoretically, these traces fade away over time if the person does not use them.
12. What is repression? Sigmund Freud’s theory of repression is a process in which we unconsciously prevent some traumatic events from entering our awareness, so that we do not have to experience the anxiety or blows to our self-concept that the memories would bring. According to Freud, the repressed material is not lost, but rather hidden from consciousness. He believed that this hidden material may influence later decisions or interpretations of events, even though we are not aware of its impact in such cases. In short, the repressed information takes on the form of an implicit memory.
13. A late night TV comedy show host suggests that supporters of one political party have happier lives than members of the others. Although this person is obviously unqualified to know, your friends have started to tell you it’s proven that members of this party have more fun, so they’re thinking of switching parties. What might be happening to your friends’ memories? Just as retroactive interference causes us to forget something when we are later exposed to new competing information, so too can exposure to new misinformation. This new “information” that is inaccurate or misleading can distort our recall or lead us to manufacture new memories.
14. The saying, “Elementary, my dear Watson,” did not appear in any of the writings of Sir Arthur Conan Doyle, the author of the Sherlock Holmes series, yet millions of fans vividly remember reading these words. What processes can explain this manufactured memory? We often forget or are confused about where we have gathered information that is now stored in our long-term memory system. This is known as source misattribution (remembering information but not the source it came from, leading us to remember information as true from unreliable sources). These source misattributions can render our memories of certain events distorted or, in some cases, manufactured (Lindsay et al., 2004).
15. Which parts of the brain are most active in memory? How are these parts related to neurotransmitters involved in memory? Based on a number of studies, researchers have concluded that there is no specific place—no storehouse—in the brain where memories reside (Dudai, 2011). Information in the brain is encoded across various neurons throughout the brain. Among the most important structures of working memory, for example, is the prefrontal cortex, a key structure within the neocortex; among the most important structures in long-term memory are the hippocampus and other parts of the neocortex.
16. What is a neural network and how might long-term potentiation contribute to its formation? Remembering that communication throughout the brain proceeds from neuron to neuron, when we talk about certain pieces of information being closely linked to other pieces of information in the long-term memory system, we are really saying that certain neurons in the brain become predisposed to trigger other neurons. It appears that the repeated stimulation of certain neurons greatly increases the likelihood that these neurons will respond to future stimulation of the same kind, a phenomenon called long-term potentiation (LTP) (Nicholl & Roche, 2013; Wixted, 2004). LTP affects not just single neurons, but the networks of neurons that make up neural circuits. The effects of LTP can last quite a long time (hence the name long-term potentiation), long enough to be a key factor in the formation and retrieval of information.
17. Why are toddlers able to effectively remember faces, places, objects, and certain skills, but are not able to remember the events of their lives very well? Brain regions holding different types of memories do not develop at the same rate. That is, the brain circuits responsible for storing memories of events seem to develop more slowly than the brain regions responsible for storing information about language, motor skills, and simple associations. We know that many memories about life events, often called episodic memories, are initially stored in the hippocampus; the hippocampus is a late-developing brain structure, and this late development might contribute to the inability to form episodic memories early on.
18. Why do the memories of elderly people tend to decline and what techniques seem to help prevent or slow down memory problems? Certain parts of the brain, such as the hippocampus, begin to shrink beginning in our twenties. A study of the brains of elderly individuals found that the hippocampus was about 20 percent larger in those with excellent memories than those suffering from Alzheimer’s disease, a finding that may also have implications for the memory losses that accompany normal aging (Winningham, 2010; Erten-Lyons et al., 2009). Brain fitness approaches—using computer exercises and mental games to keep the mind “in shape”—have become popular and are often recommended to elderly patients by health-care professionals. Research has also demonstrated repeatedly that physical exercise also seems to help prevent or slow down deficiencies and impairments of memory and other forms of cognitive functioning (Hoveida et al., 2011; Smith et al., 2011).
19. Compare and contrast retrograde and anterograde amnesia. What are the likely causes of both? Retrograde amnesia is an inability to remember things that occurred before the organic disorder (known as an amnestic disorder) or event that triggered the amnesia. Anterograde amnesia is an ongoing inability to form new memories after the onset of the disorder or event. So in retrograde amnesia old memories are lost and new memories are formed, and in anterograde amnesia old memories are maintained but there is an inability to form new memories. Anterograde amnesia is often the result of damage to the brain’s temporal lobes or mammillary bodies, areas that play a role in transferring information from working to long-term memory. Head injuries are a common cause of amnestic disorders; although mild head injuries, for example, a mild concussion, rarely cause memory loss, almost half of all severe head injuries do cause some permanent learning and memory problems (Sadock & Sadock, 2007). Another cause of amnestic disorders are brain surgeries.
20. What changes happen in the brains of people with Alzheimer’s disease? This gradually progressive disease sometimes appears in middle age, but most often it occurs after the age of 65. People with Alzheimer’s disease form far more than ordinary numbers of neurofibrillary tangles and senile plaques, brain changes that are normal features of aging up to a point (Selkoe, 2002, 2000, 1991). Neurofibrillary tangles are twisted protein fibres found within the cells of the hippocampus and several other brain areas. Senile plaques are sphere-shaped deposits of a protein known as beta-amyloid protein that form in the spaces between cells in the hippocampus, cerebral cortex, and several other brain regions, as well as in some nearby blood vessels. The presence of so many tangles and plaques indicates that enormously destructive processes take place in the brains of people with Alzheimer’s disease (Meyer-Luehmann et al., 2008; O’Connor et al., 2008).