Different memory patterns of digits: a functional MRI study

Jingxin Nie,Hong Li,Xin Yang,Jianghua Xu,Lin Ma,Zhibo Wen,Zengqiang Zhang,Sheng Wu,Jinlong Zheng,Sheng Tan,Bin Liu,Bin Wang,Siyun Shu,Yongming Wu,Chunhua Zhu

doi:10.1186/s12929-019-0516-y

Abstract

BackgroundPsychological investigations and functional imaging technology have been used to describe neural correlations of different types of memory with various stimuli. Memory with limited storage capacity and a short retention time can be classified as short-term memory (STM) while long-term memory (LTM) can be life-long without defined capacity.MethodsTo identify brain activation pattern associated with different modes of memory for numerical figures, we detected brain activities from twenty-two healthy subjects when performing three types of memory tasks for numbers, namely STM, LTM and working memory (WM), by using functional magnetic resonance imaging (fMRI) technique.ResultsThe result revealed variable patterns of activation in different brain regions responding to different types of memory tasks. The activation regions with primary processing and transient maintenance of STM for numerical figures are located in the visual cortex and mainly encoded by visual representations, while LTM was encoded by semantics and mainly recruiting left frontal cortex. We also found that subcortical structures, such as the caudate nucleus and the marginal division of the striatum, plays important roles in working memory.ConclusionsActivation of different brain regions in these three kinds of memories, indicating that different kinds of memories rely on different neural correlates and mental processes.

Highlights

Memory is one of the most essential abilities of the human brain
According to the stage model theory [1], the memory system can be divided into three independent sub-systems, including sensory memory, short-term memory (STM) and long-term memory (LTM), while working memory (WM) is not included
During the course of calculation, STM is engaged to store the individual digits and their locations within the number, and WM retrieves arithmetic knowledge from LTM to manipulate the numbers in a specific order [5]

Summary

Introduction

Memory is one of the most essential abilities of the human brain. According to the stage model theory [1], the memory system can be divided into three independent sub-systems, including sensory memory, short-term memory (STM) and long-term memory (LTM), while working memory (WM) is not included. WM refers to the ability of transient storage and manipulation of information held activated for further usage in related cognitive processes or for goaldirected behavioral guidance [2]. These three kinds of memory are highly interconnected so that they cannot work independently in any simple cognition task. WM needs to process novel information from STM and input/retrieve information to/from LTM contiguously. Digits are special and flexible, with various levels of representational properties [6] They are used for counting items, telling the time, calculating prices, identifying telephone numbers, keeping scores of sport games, and so on. Memory with limited storage capacity and a short retention time can be classified as short-term memory (STM) while long-term memory (LTM) can be life-long without defined capacity

Methods

Results

Conclusion