He responded: I was sitting there, and my Chief of Staff—well, first of all, when we walked into the classroom, I had seen this plane fly into the first building. There was a TV set on.
And you know, I thought it was pilot error and I was amazed that anybody could make such a terrible mistake. Greenberg, , p. The first plane was not videotaped because it was a normal Tuesday morning in New York City, until the first plane hit.
However, there is a much more benign explanation: human memory, even flashbulb memories, can be frail. In fact, memory can be so frail that we can convince a person an event happened to them, even when it did not.
In studies, research participants will recall hearing a word, even though they never heard the word. The researchers who discovered this named the theory after themselves and a fellow researcher, calling it the Deese-Roediger-McDermott paradigm. Summary Beginning with Karl Lashley, researchers and psychologists have been searching for the engram, which is the physical trace of memory.
Lashley did not find the engram, but he did suggest that memories are distributed throughout the entire brain rather than stored in one specific area. Now we know that three brain areas do play significant roles in the processing and storage of different types of memories: cerebellum, hippocampus, and amygdala.
Strong emotional experiences can trigger the release of neurotransmitters, as well as hormones, which strengthen memory, so that memory for an emotional event is usually stronger than memory for a non-emotional event. This is shown by what is known as the flashbulb memory phenomenon: our ability to remember significant life events.
However, our memory for life events autobiographical memory is not always accurate. Self Check Questions 1. What might happen to your memory system if you sustained damage to your hippocampus? Personal Application Question 2. Under this theory, intact areas of the cortex could assume responsibility for discrete cognitive functions following injury.
The theory did allow, however, for localization related to sensory and motor processes. Brain mechanisms and intelligence. His complementary principle of "equipotentiality" stated that in the event of damage to one area of the brain, other parts of the brain can sometimes assume the role of the damaged region.
Though his views are now considered too extreme, the principle that memories are not localized to a single spot in the brain is now well accepted. Instead, behavior had to be controlled by a central, hierarchically organized program. Lashley was a pioneer of neuroscience before the term existed, and seeking to understand the connection between the physical structures of the brain and psychological processes of learning, memory, and planning.
However, equipotentiality and the law of mass action don't mean that there is no localization. The principle of equipotentiality is the idea that the rate of learning is independent of the combination of conditioned and unconditioned stimuli that are used in classical conditioning. After performing ablation experiments on birds, and seeing that they could still fly, peck, mate, sleep, and perform a range of other regular behaviors, Flourens concluded that every area of the brain was capable of doing what every other area of the brain could, but only for higher-level functions which he called "perception".
He also argued that elementary sensory input was localized, which is supported by current research. Lashley argued that the brain is sufficiently plastic, such that when one region of the brain is surgically removed or damaged through injury another region takes over the damaged region's function.
This is the principle Lashley referred to as equipotentiality. Extensive regions of the cerebral cortex have the potentiality for mediating specific learning and memory functions. His principle of " mass action " stated that the cerebral cortex acts as one—as a whole—in many types of learning.
In behaviorism[ edit ] In behaviorism , the theory of equipotentiality suggests that any two stimuli can be associated in the brain, regardless of their nature.The main parts of the brain involved with memory are the amygdala, the hippocampus, the cerebellum, and the prefrontal cortex [link]. Equipotentiality theory, however, hypothesized that the severity of cognitive dysfunction was directly related to the total amount of tissue damage. Lashley was a pioneer of neuroscience before the term existed, and seeking to understand the connection between the physical structures of the brain and psychological processes of learning, memory, and planning. Basic neural mechanisms in behavior.
Researchers also expanded the study of working memory, central executive, and further research on memory deficits and learning.
The amygdala seems to facilitate encoding memories at a deeper level when the event is emotionally arousing. The data gathered from these tend to confirm Lashley's theories. However, equipotentiality and the law of mass action don't mean that there is no localization. Participants were then asked which words they had previously seen.
He did this because he was trying to erase the engram, or the original memory trace that the rats had of the maze. The amygdala plays a part in how memories are stored because storage is influenced by stress hormones. People Lashley influenced[ edit ] Karl Lashley worked with Donald Hebb in The Yerkes Laboratories; a lab that worked with monkeys to study various psychological concepts. By showing that lesions that undercut slabs of cortex had far more severe consequences lesions that were perpendicular to the cortex, he helped show that the principal circuits of the cortex ran up and down into the white matter rather than side-to-side across the cortical surface.