Posts Tagged ‘legal issues’

False Memories

September 19, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

False memories often stem from memory for the general theme of previous events, called gist. The Deese-Roediger-McDermott (DRM) paradigm is commonly used to study false memory. In the DRM paradigm, lists of associated words are presented during the study phase (e.g.,”web’, ‘insect’, ‘fly’,) and then during the test phase old words, new related words (e.g., ‘spider’), and new unrelated words are presented and participants make “old” — “new” recognition judgments. Not surprisingly, participants have very high levels of false memories for new related words in these paradigms (they usually respond “old” to “spider” in the example above). It is thought that when the associated words are presented during the study phase in such paradigms, participants learn the gist of the list, and this leads to a false memory for the related item. Schacter and others have argued that remembering gist is an important feature of our memory system. Memory for gist is useful as it allows us to remember general information without getting bogged down by useless details. For example, when a person sees a friend (or an enemy) it makes more sense for them to remember the gist of that person rather than retrieve all of their previous interactions. The brain regions associated with true memory and gist-based false memories are very similar.

There are differences in brain activity between true memory and false memory. There was greater activity for true memory than false memory in more posterior early visual processing regions, including V1. These findings indicate that activity in early sensory regions can distinguish between true memory and false memory. The same pattern of visual area activity was reported in a subsequent study that used words as stimuli. So the question is if early visual regions can distinguish between true memory and false memory, why don’t participants use this information to respond “new” to related items? Slotnick and Schacter reasoned that if participants had conscious access to this information they would have used it to correctly reject new related items and, therefore, activity in early visual processing regions may reflect non consciousness. So our conscious mind remains ignorant of what our brain could tell us.

This research is important for neuroscience. However, the research on false memories in the cognitive literature is highly relevant to the law and legal issues. False memories have lead to the wrongful conviction and imprisonment of too many individuals. And there is ample research showing how false memories can be implanted into our brains. The leading researcher in this area is Elizabeth Loftus. Entering “Loftus” into the search box of the healthy memory blog will locate ten posts describing her research.
This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

False memories often stem from memory for the general theme of previous events, called gist. The Deese-Roediger-McDermott (DRM) paradigm is commonly used to study false memory. In the DRM paradigm, lists of associated words are presented during the study phase (e.g.,”web’, ‘insect’, ‘fly’,) and then during the test phase old words, new related words (e.g., ‘spider’), and new unrelated words are presented and participants make “old” — “new” recognition judgments. Not surprisingly, participants have very high levels of false memories for new related words in these paradigms (they usually respond “old” to “spider” in the example above). It is thought that when the associated words are presented during the study phase in such paradigms, participants learn the gist of the list, and this leads to a false memory for the related item. Schacter and others have argued that remembering gist is an important feature of our memory system. Memory for gist is useful as it allows us to remember general information without getting bogged down by useless details. For example, when a person sees a friend (or an enemy) it makes more sense for them to remember the gist of that person rather than retrieve all of their previous interactions. The brain regions associated with true memory and gist-based false memories are very similar.

There are differences in brain activity between true memory and false memory. There was greater activity for true memory than false memory in more posterior early visual processing regions, including V1. These findings indicate that activity in early sensory regions can distinguish between true memory and false memory. The same pattern of visual area activity was reported in a subsequent study that used words as stimuli. So the question is if early visual regions can distinguish between true memory and false memory, why don’t participants use this information to respond “new” to related items? Slotnick and Schacter reasoned that if participants had conscious access to this information they would have used it to correctly reject new related items and, therefore, activity in early visual processing regions may reflect non consciousness. So our conscious mind remains ignorant of what our brain could tell us.

This research is important for neuroscience. However, the research on false memories in the cognitive literature is highly relevant to the law and legal issues. False memories have lead to the wrongful conviction and imprisonment of too many individuals. And there is ample research showing how false memories can be implanted into our brains. The leading researcher in this area is Elizabeth Loftus. Entering “Loftus” into the search box of the healthy memory blog will locate ten posts describing her research.