Dr. Michael Ullman from the Department of
Neuroscience from Georgetown University visited Beijing Normal University last
week. I attended his talk entitled "What Rats can tell us about Language:
Contributions of Declarative and Procedural Memory to Language". He began with
a general overview of the two memory systems, declarative and procedural
memory. Declarative memory is the "what", and can be divided into episodic
(personal experiences) and semantic memory (facts). Procedural memory is the
"how" and is responsible for the learning and control of motor and cognitive
skills. He emphasized some subtle differences between the two memory systems;
speed of learning and retention. Declarative memory involves quick learning with
a moderate retention rate, while Procedural memory relies on a more gradual
learning process but has an excellent retention rate (Maybe that's where the
quote "It's like riding a bike" comes from!).
Both systems involve navigation but in different ways; landmark-based navigation is declarative memory while route-learning navigation is procedural memory. This distinction supports the idea that these memory systems are cooperatively redundant mechanisms. The opposing position is that declarative and procedural memory systems work competitively. Dr. Ullman used the analogy of a see-saw- as one goes up, the other goes down. Estrogen is shown to help declarative memory and to inhibit procedural memory. This finding suggests that the competitive theory is at play. The talk then moved into distinctions among sex, handedness, first and second languages as it relates to the memory systems. In general, females tend to have better declarative memory and males have better procedural memory. Procedural dysfunctions, such as dyslexia and SLI, affect males more than females. Perhaps, this could support the see-saw effect theory. In this case, females would be better able to compensate for the loss in procedural memory because they tend to have a stronger declarative memory than men. He also discussed how frequency effects can show if declarative or procedural memory is being used. Declarative storage assumes that the information is stored as a whole, where you would see frequency effects, while procedural memory assumes composition and shows no such effects. His research looks at the frequency effects for regular and irregular past tense verbs for males vs. females.
I also went on some great trips with Dr. Ullman! One that stands out was the trip to the Great Wall. Dr. Ullman insisted that we try to hike the most difficult and dangerous section of the Wall, called Jiankou. Dr. Guo, Taoran (a graduate student in my lab), and I accepted the challenge. It was the most beautiful and difficult hike I have ever been on. Dr. Guo and I overcame our fear of heights and were able to enjoy the breathtaking views. It was a great time and highly recommend it to any adventurous future PIRE student going to China!