The Stage Model of Memory
will recognize its primary caregivers within its first days of life regardless of experiences in the womb. So although there is increasing evidence that fetuses develop memories and are more sensitive to sensory stimuli than scientists once thought (e.g., Del Giudice, 2011), it is not yet clear if any specific kind of prenatal stimulation is beneficial for development.
Section Review Using an information processing approach, explain how cognition advances.
7.6 The Stage Model of Memory Because the information-processing model involves the encoding, storage, and retrieval of information, understanding how memory processes work is an essential part of the theory. Psychologists understand that there must be some physical (brain) representation of almost every experience, but there is not a unified idea of how we actually store the information, either physiologically or behaviorally. One way to conceptualize where memories live is the stage model of memory (see Figure 7.9). This traditional theory describes how we can con- nect daily life to three separate memory processes: sensory memory, short-term memory, and long-term memory (Atkinson & Shiffrin, 1968). They represent different types of storage sys- tems where information is encoded.
Figure 7.9: The stage of model memory
In this model, there are three stores of memory, each with its own characteristics.
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Section 7.6 The Stage Model of Memory
Sensory Memory When you surf the Internet, there are dozens of ads designed to make you pay attention to them. However, most people do not “see” them all. Images are part of your field of vision, but your eyes just sweep over them in an unfocused way. That experience is part of sensory memory (Atkinson & Shiffrin, 1968). This initial stage of memory acts as a filter. Before your brain can encode something and store it for later retrieval, you first need to perceive the stimulus. That is, you must first notice a stimulus in order to encode it.
To demonstrate this process for yourself, take a moment to describe in detail what is behind you without turning. What do you remember? Now turn around and find something behind you that you did not describe before turning around. Even if it is simply a blank wall behind you, there are likely to be imperfections in the paint or marks that you did not “notice” before. At one time, though, images of what is behind you fell onto your retina. Even though you do not remember every detail about what is behind you, at one time it was part of your sensory memory.
Short-Term Memory Now that you have turned around and attended to a stimulus, it is part of your short-term memory. This storage system is like a temporary “holding area” where information waits for further processing. It can consist of phone numbers, the title of a book, or names that will rapidly decay unless they make it into long-term memory.
Contrary to what many think, short-term memory remains relatively efficient as we age. Some aspects of short-term memory become less efficient, but other areas of cognition compensate by becoming more efficient. For example, there is no decline in short-term visual recogni- tion, so rather than memorizing a short grocery list, older shoppers may take a practiced, visual “walk” around the store (Secular, McLaughlin, Kahana, Wingfield, & Yotsumoto, 2006). With age, we become better at recognizing organizational strategies that may assist memory, and we become more proficient at employing them. On the other hand, when there is the added task of mentally juggling multiple bits of information, like performing several mental math operations simultaneously, adults show deterioration beginning in middle adulthood (Kausler, 1994; Schaie, 2005). Visit the following website to participate in the kind of short- term memory task that researchers use in an experimental setting (http://faculty.washington .edu/chudler/stm0.html).
Do you have an accurate visual representation of the information processing approach to cognition? If so, you probably looked at Figure 7.9 until you understood the concept. How you stored the information was an active interchange between what you already knew and the fresh information that was presented. Because there is a conscious processing of attention and mental work, we now conceptualize short-term memory better as working memory (Baddeley, 2007). Working memory temporarily stores and manages information, similar to RAM or flash memory in a computer. Like solving a multiple-step puzzle or mentally remem- bering a string of numbers, working memory provides storage for some bits while manipulat- ing others.
Although practice improves the efficiency of working memory, its growth depends more on maturational gains than increased knowledge (Cowan, Ricker, Clark, Hinrichs, & Glass, 2015).
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Section 7.6 The Stage Model of Memory
This physical development of the brain coincides with an increase in sophistication, and allows people to more efficiently manage their own thinking and behavior. That is, we become better at self-analysis and reflection. This kind of “thinking about thinking” is called meta- cognition. It involves the ability to plan, hypothesize about possible outcomes, and make reasonable, informed decisions regarding cognitive–behavioral strategies (Flavell, 1976). For instance, when deciding how to guess on a multiple-choice exam, you might consciously ana- lyze all the possible answers and consider multiple sources (e.g., lectures, readings, notes) simultaneously. There is a conscious interchange between momentary thought and long-term storage (McCabe, Roediger, McDaniel, Balota, & Hambrick, 2010).
Long-Term Memory We lose anything we process in short-term memory unless we encode or place it in long-term storage in some way. Sometimes that happens automatically, like the events surrounding a special occasion, a traumatic incident, or even the object behind you that you still remember. When that occurs, it becomes part of long-term memory (see Figure 7.10). These memo- ries are relatively permanent, like the name of a first-grade teacher or your Social Security number. When long-term memory increases, we can utilize more information resources for working memory. This is why encoding information about favorite academic interests, music groups, or social concerns is much easier than learning a new subject. In familiar subjects, there are more anchors to old memory files to help store and later retrieve memories.
Explicit and Implicit Memory Long-term memory can be further divided into the separate components of explicit memory and implicit memory (see Figure 7.10). Explicit memory refers to information that is con- sciously available, like favorite foods, typical weather, the name of your best friend, and the events surrounding a graduation party are all examples of explicit memory. These memories consist of both episodic and semantic memories. Episodic memories attach to a specific time and place—episodes of life—such as a wedding, first kiss, or trip to the beach. Episodic memories are often visual, where we “see” images of an old house or a favorite park. On the other hand, when we specifically encode memories in words, like the rules of Monopoly or the definition of the word “cognition,” we are using semantic memory. It includes factual information like the meanings of social customs, historical details, and names of phone apps.
Whereas explicit memory stores episodes and facts that can be encoded (and recalled) in words, there is a lack of conscious awareness for implicit memory. A key component of implicit memory is procedural memory. We sometimes call this “muscle memory,” and it includes activities like riding a bicycle or making a peanut butter sandwich. When we first learn how to play a musical instrument, we have to consciously think about moving specific leg or hand muscles. After a while, the body remembers how to move without consciously thinking about it. Fingers go to the correct keys seemingly without cognitive effort—just as recalling an address from semantic memory does not take effort.
In addition to body memories, we are often implicitly predisposed by unintentional or unplanned memories, what psychologists refer to as priming. For instance, early exposure to specific genres of music causes us to continue liking what we were exposed to and find other categories less favorable. People who enjoy listening to rap and hip-hop often dislike country music, and vice versa. Cognitively, we are primed by the familiar sound that is embedded in memory.