State Dependence in Memory and Dissociative Amnesia

 

    While studying the brain within Neuroscience and Psychology, studying memory and its consolidation is heavily discussed. Within the overarching subject of memory is more specifically how our senses such as touch, taste, feeling, and more importantly smell, can evoke specific memories, and allow for faster recall. A common and understandable example of this is for example if someone is baking cookies in your household, and then randomly a memory of when you and your grandmother used to bake for the holidays is brought to the forefront of your mind. This is a simple example of how your senses like smell can evoke a memory that you may have otherwise forgotten. Within Odor modulates the temporal dynamics of fear memory consolidation by Stephanie L. Grella, Amanda H. Fortin, Olivia McKissick, Heloise Leblanc, and Steve Ramirez, the researchers aim to further discuss how the hippocampus is helped by specifically smell for remote memory recall and contextualization of memory.

            Dr. Stephanie L. Grella of Boston University whose research interest most importantly includes how in the flexibility of memory how neuro-modulators dopamine and norepinephrine sculpt contextual representations in the hippocampus. Within the paper the researchers explain how remembering personal experiences also known as episodic memories directly relies on the health and normal function of our hippocampus. The hippocampus is plastic and vulnerable and is located within the deep temporal love and plays a major role in learning and more importantly for this paper, memory. Memory is plastic and its encoding, modulation, and recall can be impacted in many ways. According to this research, odor is seen to be very evocative as a cue for intense remote recall. Therefore, they hypothesized that odor may shift the organization of fearful memories when paired with an odor, like PTSD when a certain stimulus like the trauma from the past such as a loud noise can evoke the memory. At the end of the study, it was found that odor influenced the temporal dynamic which biased the memory to the PL to the dCAI when cued by an odor. While behaviorally inhibiting the dCAI had no impact on recall. Overall, it was found that odor can in fact shift the organization of fear memories. I found this extremely interesting, though not too shocking because memories are often studied as plastic at their many different stages. Though it is new to me that the organization of memories can be changed as well even though said memories may be experiences that are years behind, showing that truly all parts of memory are plastic and more specifically, how vulnerable the hippocampus really is.

            Similarly, yet on a slightly different topic, the research done by Dr. Stephanie L. Grella reminded me more broadly of state dependent memory. In the article State-Dependent Memory: Neurobiological Advances and Prospects for Translation to Dissociative Amnesia, speaks on the relationship between state dependence and dissociative amnesia. The reason these two are like me is that they both in a sense involve memories that are evoked from state dependence, whether it be smell or just a situation that evokes a traumatic memory. Though in this article, the evoke memories lead to dissociative amnesia. Dissociative amnesia is when traumatic or stressful events elicit memories which then cause issues in memory processes due to the massive flashbacks or the inability to remember events. Much like in the previous study memories is elicited by stimuli from the environment, though within this article; the stimuli lead to memories that cause maladaptive coping mechanisms or (DA) which leads to the loss of memory, rather than improved remembrance or consolidation.

            These two articles combined can be used to pose many questions about memory, such as why do coping mechanisms lead to maladaptive behavior such as DA, and is there a way to prevent this? Then is there a way to use stimuli like smell to evoke positive responses that could perhaps help people who suffer from DA. If the two could be combined to perhaps further research how to lessen the effects of maladaptive coping mechanisms, it could massively help those who struggle with memories brought back to them solely due to state-dependence.

 

 

 

 

 

References

Grella, Stephanie L., et al. “Odor Modulates the Temporal Dynamics of Fear Memory Consolidation.” 2019, https://doi.org/10.1101/2019.12.19.881615.

Radulovic, Jelena, et al. “State-Dependent Memory: Neurobiological Advances and Prospects for Translation to Dissociative Amnesia.” Frontiers in Behavioral Neuroscience, vol. 12, 2018, https://doi.org/10.3389/fnbeh.2018.00259.