Copyright © 2010 by Worth Publishers. Memories Can Involve All Your Senses Think back to a...


Memories Can Involve All Your Senses Think back to a particularly memorable experience from your high school years. Can you conjure up vivid memories of smells, tastes, sounds, or emotions associated with that experience? In the years to come, these teenagers may remember many sensory details associated with this summer gathering at the beach.


Figure 6.1 Overview of the StageModel of Memory


The Interaction of Memory Stages in Everyday Life Imagine driving on a busy street in pouring rain. How might each of your memory stages be involved in successfully navigating the wet streets? What kinds of information would be transferred from sensory memory and retrieved from long-term memory?


George Sperling Sperling carried out hisresearch on the duration of sensorymemory while still a graduate studentat Harvard. Now at the University ofCalifornia–Irvine, he continues to studyperception, attention, and cognition.


Figure 6.2 Sperling’s Experiment Demonstrating the Duration of Sensory Memory In George Sperling’s (1960) classic experiment, (1) subjects stared at a screen on which rows of letters were projected for just one-twentieth of a second, then the screen went blank. (2) After intervals varying up to one second, a tone was sounded that indicated the row of letters the subject should report. (3) If the tone was sounded within about one-third of a second, subjects were able to report the letters in the indicated row because the image of all the letters was still in sensory memory.


Perception and Sensory Memory Traces Because your visual sensory memory holds information for a fraction of a second before it fades, rapidly presented stimuli overlap and appear continuous. Thus, you perceive the separate blades of a rapidly spinning windmill as a smooth blur of motion. Similarly, you perceive a lightning bolt streaking across the sky as continuous even though it is actually three or more separate bolts of electricity.


Demonstration of Short-Term Memory Capacity


Figure 6.3 Baddeley’s Model of Working Memory: How Do I Get to Marty’s House? Suppose you are trying to figure out the fastest way to get to a friend’s house. In Baddeley’s model of working memory, you would use the phonological loop to verbally recite the directions. Maintenance rehearsal helps keep the information active in the phonological loop. You would use the visuospatial sketchpad to imagine your route and any landmarks along the way. The central executive is the conscious part of your mind, which actively processes and integrates information from the phonological loop, the visuospatial sketchpad, and long-term memory.


“The matters about which I’m being questioned, Your Honor, are all things I should have included in my long-term memory but which I mistakenly inserted in my short-term memory.”


Figure 6.4 The Role of Sensory and Short-Term Memory in the Stage Model of Memory


Types of Information Stored in Long-Term Memory A memorable skateboard ride involves all three types of long-term memory. Remembering how to steer and balance on a skateboard are examples of procedural memory. Knowing the names of the different parts of a skateboard and the different kinds of skateboards available would be examples of semantic memory. And, if this young man forms a vivid memory of the day he rode his skateboard in a huge drainpipe, it will be an example of an episodic memory.


Culture and Earliest Memories Psychologist Qi Wang (2006, 2001) found that the earliest memories of Chinese and Taiwanese adults tended to focus on routine activities that they shared with other members of their family or social group rather than individual events. Perhaps years from now, these children will remember walking with their preschool friends to play in the park.


Figure 6.5 Types of Long-Term Memory


Figure 6.6 Clustering Demonstration Study the words on this list for one minute. Then count backward by threes from 108 to 0. When you’ve completed that task, write down as many of the words from the list as you can remember.


Figure 6.7(a) Demonstration of Retrieval CuesSource: Bransford & Stein (1993).


Figure 6.7(b) Demonstration of Retrieval CuesSource: Bransford & Stein (1993).


A Demonstration of the Serial Position Effect Without singing them, try to recite the words of “The Star-Spangled Banner.” If you’re like most people, you’ll correctly remember the words at the beginning and the end of “The Star-Spangled Banner” but have difficulty recalling the words and phrases in the middle—the essence of the serial position effect.


Flashbulb Memories? Can you remember where you were when you heard about the terrorist attacks on the World Trade Center and the Pentagon? The Oklahoma City bombing? Shocking national events can supposedly trigger highly accurate, long-term flashbulb memories. Meaningful personal events, such as your high school graduation or wedding day can also produce vivid flashbulb memories.


Memories of Traumatic Events If you are like most Americans, you have vivid memories of watching media coverage of the terrorist attacks on September 11, 2001. Although such “flashbulb” memories are emotionally charged, they are not necessarily more accurate than memories of more common events (Talarico & Rubin, 2007).


Hermann Ebbinghaus (1850–1909) Afterearning his Ph.D. in philosophy in 1873,Ebbinghaus worked as a private tutor forseveral years. It was during this time thathe conducted his famous research on thememory of nonsense syllables. In 1885, hepublished his results in Memory: A Contributionto Experimental Psychology. In thattext, Ebbinghaus observed, “Left to itself,every mental content gradually loses itscapacity for being revived. Facts crammedat examination time soon vanish, if theywere not sufficiently grounded by otherstudy and later subjected to a sufficient review.”Among his other notable contributions,he developed an early intelligencetest, called the Ebbinghaus CompletionTest (Lander, 1997).


Figure 6.8 The Ebbinghaus Forgetting Curve Ebbinghaus’s researchdemonstrated the basic pattern of forgetting: relatively rapid loss of some information, followed by stable memories of the remaining information.Source: Adapted from Ebbinghaus (1885).


Figure 6.9 Test for Memory of Details of a Common Object Which of these drawings is an accurate picture of a real penny?


Eyewitness Misidentification: Convicting the Wrong Man Four months after being attacked, kidnapped, and raped, an Oklahoma woman picked Arvin McGee out of a photographic lineup and identified him as the attacker. She claimed he had tied her up and carried her over his shoulders to a car. Then, she said, he drove her to a secluded area where he raped her. Based solely on the victim’s eyewitness identification, McGee was arrested for the brutal crime. His first trial was declared a mistrial. His second ended in a hung jury. His third trial resulted in a guilty verdict. Despite the fact that McGee had an alibi and was also suffering from an abdominal hernia that would have made it virtually impossible for him to commit the crime, he was convicted and sentenced to 365 years in jail. Thirteen years after his conviction, DNA testing finally proved what McGee had maintained throughout his trials and years in prison—that he was innocent of the crime. Scores of studies have shown that eyewitness misidentification is the leading cause of wrongful convictions (see Garrett, 2008; Gross & others, 2004; Wells & Loftus, 2003).


The Misinformation Effect in Action In October 2002, the Washington, D.C., area was terrorized by a series of random sniper attacks. Early on, the police issued an alert that an eyewitness reported a white van speeding from the scene of a shooting. Later attacks brought more eyewitness reports of a white van or truck. Hundreds of white vans were pulled over and searched by the police. In reality, the killers, John Alan Muhammed and John Lee Malvo, were traveling in a dark blue Chevrolet Caprice. Ironically, several people had reported seeing a blue Caprice near different shooting scenes, but these reports were largely ignored because of the misinformed fixation on a white van.


Psychological studies have shown thatit is virtually impossible to tell the differencebetween a real memory andone that is a product of imaginationor some other process. Our job asresearchers in this area is to understandhow it is that pieces of experienceare combined to produce whatwe experience as “memory.”ELIZABETH LOFTUS (2002)


Which is the Real Photo? The photograph of an unknown young man bravely defying oncoming tanks in an antigovernment protest in China’s Tiananmen Square has become an iconic image of individual courage and the global struggle for human rights. But after people who remembered the original image correctly were shown the doctored image on the right, their memories changed to incorporate the crowds of onlookers in the fake photo (Sacchi & others, 2007).


False Memories of a Psychology Professor’sOffice After briefly waiting in the psychologyprofessor’s office shown below,participants were taken to another roomand asked to recall details of the office—the real purpose of the study. Many participantsfalsely remembered objects thatwere not actually in the office, such asbooks, a filing cabinet, a telephone, alamp, pens, pencils, and a coffee cup.Why? The details that the participantserroneously remembered were all itemsthat would be consistent with a typicalprofessor’s office (Brewer & Treyens, 1981).Schemas can cause memory errors byprompting us to fill in missing detail withschema-consistent information (Kleider &others, 2008).


Can Real Photos Create False Memories? Psychologist Stephen Lindsay and his colleagues (2004a, 2004b) had participants look at their first-grade class photo and read a description of a prank that they were led to believe had occurred in the first grade—putting slime in their teacher’s desk. After a week of trying to remember the prank, 65% of the participants reported vivid, detailed memories of the prank. In contrast, only about a quarter (23%) of participants who tried to remember the prank but did not view a school photo developed false memories of the pseudoevent. Viewing an actual school photo, Lindsay believes, added to the legitimacy of the pseudoevent, making it seem more probable. It also provided vivid sensory details that blended with the imagined details to create elaborate and subjectively compelling false memories. Real photos can lend credibility to imaginary events (Garry & Gerrie, 2005).


Karl S. Lashley (1890–1958) Lashley wastrained as a zoologist but turned to psychologyafter he became friends with John B. Watson, the founder of behaviorism. Interested in discovering the physical basis of the conditioned reflex, Lashley focused his research on how learning and memory were represented in the brain. After years of frustrating research, Lashley (1950) humorously concluded, “This series of experiments has yielded a good bit of information about what and where memory is not. It has discovered nothing directly of the real nature of the engram. I sometimes feel in reviewing the evidence on the localization of the memory trace, that the necessary conclusion is that learning just is not possible.”


Richard F. Thompson (b. 1930) Like Karl Lashley, Richard Thompson (1994, 2005), sought to discover the neurobiological basis for learning and memory. But, unlike Lashley, Thompson (2005) decided to use a very simple behavior—a classically conditioned eye blink—as a model system to locate a memory trace in the brain. He succeeded, identifying the critical region in the cerebellum where the memory of the learned behavior was stored.


Aplysia, the Supersnail of Memory Research Eric Kandel holds Aplysia, the sea snail that is used to study how neurons change when simple behaviors are learned and remembered. Kandel was awarded the Nobel Prize in 2000 for his discoveries on the neural basis of memory.


Figure 6.10 How Neurons Change as Aplysia Forms a New Memory When Aplysia is repeatedly squirted with water, and each squirt is followed by a mild shock to its tail, the snail learns to withdraw its gill flap if squirted with the water alone. Conditioning leads to structural and functional changes in the three neurons involved in the memory circuit.


Creating New Synaptic Connections Forming new memories involves strengthening existing synaptic connections and creating new synaptic connections between neurons in the brain. Neuroscientist Michael Colicos and his colleagues at the University of California–San Diego (2001) photographed structural changes in a single hippocampus neuron that occurred in response to repeated electrical stimulation. The spidery blue lines in the photo are physical changesin the neuron’s structure that represent the first steps toward the formation of new synaptic connections with other neurons.


Picture

Sound

Perception Recall

(a) (b)

(c) (d)

Retrieving the Memory of a Sensory ExperienceTop row: (a) Perceiving a picture activates areas of the visual cortex. (b) When the memory of the picture is recalled, it reactivates some of the same areas of the visual cortex (arrow) that were involved in the initial perception of the picture. Bottom row: (c) Perceiving a sound activates areas of the auditory cortex. (d) When the memory of the sound is recalled, it reactivates some of the same areas of the auditory cortex (arrow) that were involved in the initial perception of the sound. Source: Wheeler & others (2000).


Disrupting the Consolidation of MemoriesHead injuries are common in football andmany other sports. In one study, footballplayers who were questioned immediatelyafter a concussion or other head injurycould remember how they were injuredand the name of the play just performed.But if questioned 30 minutes later for thesame information, they could not. Becausethe head injury had disrupted the memoryconsolidation process, the memories werepermanently lost (Yarnell & Lynch, 1970).


Brenda Milner Born in England in 1918, Milner studied at Cambridge and immigrated to Canada shortly after World War II. Her groundbreaking research at the Montreal Neurological Institute—including the more than 25 years she spent working with the famous patient, H.M.—helped establish the field of neuropsychology.


Suzanne Corkin Since the mid-1960s, MITneuropsychologist Suzanne Corkin has evaluated different aspects of H.M.’s memory abilities. In looking back on H.M.’s life, Corkin (2002) commented, “We all understand the rare opportunity we have had to work with him, and we are grateful for his dedication to research. He has taught us a great deal about the cognitive and neural organization of memory. We are in his debt.”


Figure 6.11 Brain Structures Involved in Human Memory Shown here are some of the key brain structures involved in encoding and storing memories.

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