A Closer Look at Snails and Human Memory

Our memories of past experiences can shape our perceptions of who we are, of the world, and of the future. We learn by experiences because our memories of past experiences shape our perceptions. Per the journal article, Memory and the Sense of Personal Identity: “If I had no memory of past experiences, the sense that I existed in the past would be dramatically compromised.” To complement this phenomenon, scientists researched snails to explain how our brains work.  

Snail Memory

Dr. Michael Crossley, the Senior Research Fellow in Neuroscience at the University of Sussex, discovered that pond snails can only store and recall the first memory when tasked with learning two similar things. On the other hand, when introduced to learning two unrelated tasks, the creatures can retain all the information and store both memories.

Proactive Interference

Brain recording optimized the reality that the same neuron was used when the snail tried to learn two similar things. This is attributed to an overlapping mechanism causing only one memory to survive, which results in proactive interference. This interception prohibits acquiring a new task. Whatever was previously learned interfered with learning and remembering information.

Retroactive interference

In contrast, retroactive interference happens when an individual is unable to recall old information because new information prevents it from retrieval. However, when the experimental snails are introduced to learning something new during a memory lapse, they forget old memories. Usually, during a memory lapse, information is temporarily forgotten while it’s transferred from short to long-term memory.

Great Pond Snails Research

How so? Research conducted on Lymnaea stagnails, also known as great pond snails. These snails can be operantly conditioned depending on the training procedure used, such as intermediate (ITM) or long-term memory (LTM) is created. 

What was the objective? The goal was to study the freshwater pond snail and better understand our abilities for learning and memory. The Lymnaea creates a memory trace encoded by classical conditioning. Firstly, the snails received either a paired or unpaired presentation of the conditioned stimulus (CS) of the neutral amyl acetate flavor (fruity and banana-like flavor) and feeding-eliciting sucrose, the unconditioned sucrose (US). Those creatures that received the paired CS-US would generate a feeding response to the amyl acetate alone. They had learned the association. 

Curiously, the memory for this single trial lasted two weeks after training. Researchers compared the brains of the paired and unpaired snails and concluded that associative training produced a bilaterally paired single serotonergic neuron. This is located outside of the feeding network that modulates its responses to food stimuli.

Snails and Humans

As a result, the snail’s perception is altered, which causes them to favor and consume more water. Therefore, they associated the fruit-flavored water with sugar. In contrast, the snails stopped forming long-term memories after a long period. But they also stopped making new memories. 

Similarly, humans and snails have that in common. Humans constantly absorb new information, and our brains identify what needs to stay and forget. It’s as simple as forgetting what outfit you wore yesterday but capable at the same time of remembering details from a memory from a decade ago.

Final Thoughts

Our memory bank can reach its storage limit. So, a change in perception can help “link past and future memory storage.” We can learn and stimulate our brains to focus on long-term memories.


Leave a Reply