T Minus 18

Cognitive Systems: Memory

The third cognitive system that we are going to measure is memory. Again, a quick glance at a standard information processing model highlights where memory fits into neural processing.

We all know what memory is - it is our ability to store and recall information. What fewer people realize is that there are at least three stages of memory. The first stage is sensory memory (not shown here). Sensory memory is literally the storage of information in neurons that are currently active (i.e., firing) and the reason it is called memory is that this storage lasts briefly after the neuron stops firing. The second stage of memory is called short term or working memory. Working memory is where we hold information that we need to currently use and may attempt to store more permanently. Right now, this definition of working memory is in your working memory! You can hold onto this information for a brief period of time - most estimates are between 30 and 120 seconds - but unless you are actively trying to maintain the "memory" it is forgotten. You may have experienced this shortly after you were just introduced to someone - their name was in working memory - you got distracted, and the name is suddenly gone. However, some of the information in working memory is pushed into long term memory where it is held for a longer duration... days to months to years. The process by which this occurs is called consolidation. Working memory is also where information that we have stored is manipulated.

In any event, memory is crucial in that we need memory to inform us so that we can make decisions. For example, when we decide what to have for lunch we access our memories to ascertain what we like and what we do not like.

As noted at the outset of this post - memory is another important cognitive process and one that we will be monitoring with our brain performance assessment. As with perception and attention, memory is also impacted by cognitive fatigue and thus we will track it as one of our measures of fatigue.