Forgotten something important that you wanted to remember? You probably didn’t remember it ‘right’! Researchers at the University of California, Irvine, say that the recall of an event depends on how a certain part of the brain ‘packages’ that memory. In the current issue of Neuron, they describe how they used functional magnetic resonance imaging (fMRI) to study the brains of volunteers who experienced an event made up of multiple contextual details. Participants who later recalled the experience vividly had activated the intra-parietal sulcus, a part of the brain’s parietal cortex, to store the details as a ‘package’. See, you can’t get out of memory what you didn’t put into it!
Scientists acknowledge five types of memory: sensory, short-term, semantic (for facts and figures), procedural (for practical skills), and prospective (for things to be done in the future). Sensory memory is the information from our senses that is stored just long enough for our brains to, well, make sense of it. For instance, the momentary retention of images allows you to see a rapidly-changing series of still photographs as a motion picture.
Short-term memory retains information that’s not needed permanently — as when you remember a phone number that you look up in the book long enough to dial it. The next day you probably won’t remember it, perhaps not even making the call! But you will, if that information is put in your long-term memory. Of course, you’ll remember making that call for the rest of your life if the person at the other end tells you that you have won the lottery!
Memories start declining in your mid-20s, although younger people rarely notice they are beginning to forget names and numbers. This is particularly true today when mental stimulation is waning, as people depend more and more on computers for everyday tasks. Rather than tackle the daunting complexity of the human brain to find out how it remembers — or forgets — however, neuroscientists study simpler brains like those of nematodes. These tiny worms, made up of 1,000 cells (of which just 300 are brain cells), can still learn and remember.
It is indeed a long way from the 300-cell brain of a worm to the lingering memories you have of your first solo flight. But scientists are beginning to take strides that may some day lead us to a full understanding of how, and why, we sometimes forget to