Story of Psychology - Morton Hunt [347]
FIGURE 41
One portrayal of the long-term semantic memory network
This is only a minuscule sample of the semantic memory network. Every node shown here is connected to many other chains of nodes not shown: “Swim” might be linked to “cetaceans,” “human swimmers,” “sports,” “healthful exercises,” and each of those to other instances, characteristics, traits, and so on, and on.
A much later and much more detailed representation of the memory network relating to birds is bewilderingly complex; it is on page 612, as FIGURE 42, for those who care to puzzle it out.
Memory research has been so far-ranging and multifaceted over the last several decades that we must limit ourselves now to a handful of brief reports of major research findings and theories, and then move on.
Memory systems: The memory system portrayed in FIGURE 40, on p. 608, is now seen as too simple. According to the results of many studies, there are a number of interacting memory systems that encode and store different kinds of information in different ways. The memories stored about how to swim, drive a car, or sail a boat are very different from those concerning the names and identities of people you know, how to perform arithmetical procedures, or what a collie looks like. Each of these kinds of memory, and many others, require their own forms of processing and storage, and differ in the amount and kinds of effort required to enter and retain it in long term memory.
FIGURE 42
Network and connectionist representations of concepts relating to birds
Moreover, memory researchers distinguish among types of memory in other ways: Explicit memory refers to information or knowledge that we can bring to mind and to personal experiences, and implicit memory to information that is available without conscious effort, including motor skills and automatic responses (such as avoiding bumping into others on the sidewalk), built-in attitudes and reactions to people, objects, and situations—all of these requiring different memory systems.41
Other studies have investigated the differing process of recognition and recall—a distinction familiar enough in everyday experience (we all recognize a great many words that we cannot easily or at all summon up voluntarily). In a socially valuable application of the difference, a series of studies tested whether witnesses to a crime (a staged one before groups of students who were not told what was going on until later) would be more likely to identify the actual culprit in a lineup or by seeing a number of suspects one at a time. The latter method proved so much the better that many police departments are now changing their standard lineup procedures.42
Cognitive neuroscientists have lately done brain scans during different kinds of memory activity and come up with an answer to an old question: Where are memories stored? The answer, in the past, has vacillated between “locally” and “widely distributed.” Brain scans now show that “widely distributed” is the answer—and that different kinds of memories are differently distributed.43
Categorization: Much research indicates that the human mind has a tendency to spontaneously group similar objects in memory and, from their similarities, develop general concepts or categories. Even infants only a few months old seem to do simple categorizing. One research team showed four-month-old babies patches of varied blues, greens, yellows, and reds. After seeing a number of patches of one color group, the babies showed a preference for a patch of any other color. The conclusion: Hue categorization is either innate or develops soon after birth.44
Many other studies have documented how, as children acquire language, they gradually develop such categories as “animal” after experiences of dogs, cats, squirrels, and others. Parents, to be sure, teach these concepts to their children, but in part the tendency seems to be built in. It is so general among all people as to be presumed an innate human trait. The anthropologist Brent Berlin found that people in