ABSTRACT
Like attention, memory takes many forms. Possibly the most obvious difference was pointed out by James (1890) on the basis of his own introspection. He distinguished between primary memory, PM, which he described as ‘the rearward portion of the present space of time’, and secondary memory, SM, which was the ‘genuine past’. James appreciated the intricate relationship between memory and attention and realised that unless the unstable memories in PM were captured by attention they would rapidly fade away. He also pointed out the difference between the small amount of fleeting information that could be consciously kept ‘in mind’ in PM, and the vast amount of stable knowledge that could be kept in SM. Today we refer to PM and SM as short-term memory (STM) and long-term memory (LTM).
