Less Than Total Recall
Try not think of an elephant.
Recent theories of neuroscience researchers such as Daniel Wegner suggest that it is impossible for people to voluntarily suppress memories. However, in more recently these theories have been brought into question by studies showing that newly learned memories can be temporarily inhibited when participants actively and repeatedly try to suppress them.
Research recently published in the Journal of Neuroscience which was directed by Kepa Paz-Alonso, a scientist Basque Center on Cognition, Brain and Language (BCBL), along with Silvia Bunge of the Helen Wills Neuroscience Institute at the University of California, Berkeley, demonstrates the network of brain regions involved in the ability to suppress memories. In addition, the study shows that differences in the strength of the connections between the regions of this brain network is what differentiates people in their ability to suppress memories.
The strength of this neural network, which connects the hippocampus to the lateral prefrontal area through the cingulate and parietal lobe, appears to be a necessary condition for a person to be able to delete voluntary recall of a recently acquired memory so that it becomes more difficult to recover from the brain.
To test this thesis, Paz-Alonso and colleagues developed behavioral tests and used MRI. Functional magnetic resonance imaging is a technique to examine the brain regions that are activated while a subject is performing a specified task.
During these tests, the participants initially presented word pairs (eg photo or nail-seat train) they had to learn. Once learned, within the fMRI, the first word of the pair was presented to the participants who were asked to either recall the associated word (nail-____) or try not to think of the word pair they had learned (seat-___).
Thus, the networks that are activated and deactivated while successfully recalling a memory or not were observed. Finally, participants were presented with a memory test in which they were asked to try to remember all the words initially studied, and thus the researchers were able to determine those individuals who had been able to suppress the memories.
“The result of the tests,” said Paz-Alonso, “showed that the really crucial thing for a person to be able to delete a specific memory is the functional connection between the hippocampus and the lateral prefrontal area of the brain.” The results of the tests conducted suggest that “this network is more active when intentionally inhibiting memories compared to when they are simply forgotten.”
Although people show ability to inhibit memories, these studies do not necessarily imply that these experiences have been deleted from memory, but rather that they temporarily may be more difficult to recover .
The relevance of this ability of the brain is that the people who are able to manage their minds more effectively and forget certain unpleasant memories can focus your attention on other matters. This may have some relevance for treatment of Post Traumatic Stress Disorder for example.
In addition, this ability to suppress memories can be shown to be subject to improvement by training. It might be possible to develop training programs aimed for example at patients with certain disorders, such as post-traumatic stress disorder. More generally, the development of mnemonic control strategies that enable more efficient regulation of memories and their subsequent influence on behavior and thought will be advantageous to all everyone.
Strength of Coupling Within a Network Control Mnemonic differentiates Those Who Can and Can not Supress Memory Retrieval. Peter M. Paz-Alonso, Silvia A. Bunge, Michael C. Anderson, Simona Ghetti.Journal of Neuroscience
Also of recent and related interest: