Targeted Memory Reactivation

          December 10, Eitan Stechman-Drayman discussed the technique of targeted memory reactivation. This technique has an influence on memory consolidation and through cues while one’s sleeping, there is an enhanced ability for people to activate certain memories that may not be consciously accessible. Our memories are short term and have to go through memory consolidation in order for them to be stabilized as long-term memories. Memory storage is constantly updated and it needs to be activated and reactivated in order to conserve those memories. When trying to achieve memory reactivation and then consolidation, you would essentially be quizzing yourself over and over in order to remember the material at hand. Sleep is a very specific type of architecture in that it is presently vital in the efforts of memory consolidation. Typically our sleep cycle is anywhere between eight and nine hours long and is divided into two stages: NREM which is early night's sleep and REM which consists of sleep later in the night. Through both stages of sleep or brain is active and still engaging in cognitive activity, so our consciousness is never technically completely lost, but how we preserve experiences that we have had in the past have to be reactivated in some way in order for them to be consolidated and conserved. Through certain cues researchers were able to determine through cueing individuals in their sleep, there was an enhancement in memory consolidation and that was done using the method of targeted memory reactivation.

Through this research, the behavioral effects of TMR were determined according to the cognitive domain that was probed. Throughout the study, declarative memory, procedural memory, emotional memory, creativity, and social cognition were all assessed. Researchers wanted to see the differences in behavioral effects of TMR when specifically targeting one type of memory or behavior. Researchers wanted to test TMR in demographics that most likely would benefit from enhanced memory consolidation. These groups consisted of children up into the elderly and even psychiatric patients, in order to determine the variability in not only the cognitive domain specifically, but also the different effects throughout our growth and evolution. 

         Specifically, declarative memory and procedural memory are the main cognitive domains tested. With regards to declarative memory, TMR has been proven to be a really good technique for humans in memory retrieval. Our declarative memories are malleable and can either be strengthened, weakened, or even transformed depending on the rendering. With each type of rendering, their initiates more resistance to any sort of interference and in turn makes those memories that are intended for preservation less vulnerable to be forgotten. When going into mechanisms of testing TMR on declarative memory, introducing a time delay between cue and auditory feedback was proven to preserve the memory enhancing effect of TMR. Procedural memory is more interactive in how it is tested. Small tasks such as the finger tapping task were utilized, in order to condition a certain behavior and determine the restraints and effects TMR has on the specified cognitive domain. There are conditioned cues for various facets of life, such as the use of sensorimotor interrogation in order to memorize music, and when doing so, it’s been shown that the medial temporal lobe has a high dependency point when it comes to determining the effects of TMR. Through the findings of Draymond’s research, “the neuronal replay induced by auditory cueing is highly specific for the targeted material” in not only procedural domains but also declarative

Through all of the research and subsequent evidence it is suggested that TMR can be a powerful tool to enhance memory consolidation, but it does come with its risk. If TMR were to be popular rise there would need to be certain restrictions when doing self administration so in order not to damage any memory domains. There is a certain modification of knowledge through interrogation re-organization and generalization, that coincides with our cognitive function and TMR aids in all of those processes. There are a number of different reasons as to why humans have memory impairment, but TMR is a useful tool that is non-invasive and has no use for medical drugs to incite some sort of memory recollection.

References:

Rasch , B., & Göldi, M. (n.d.). Effects of targeted memory reactivation during sleep at home depend on sleep disturbances and habituation. NPJ Science of Learning. Retrieved from https://www.nature.com/articles/s41539-019-0044-2

Schouten, D., Pereira, S., Tops , M., & Louzada, F. (2016). State of the art on targeted memory reactivation: Sleep your way to enhanced cognition. Sleep Medicine Review.