Monday, 2 May 2016

Making a memory

Nothing fixes a thing so intensely in the memory as the wish to forget it. - Michel de Montaigne

As soon as I read this, I was like Oh my God, this person is brilliant. Because even though I can't remember where I kept my keys (everyday), I can't seem to forget the bitter memories of my life. 

Makes me wonder how does my memory actually work, how does it store those moments of embarrassment just to torment me at odd times. Well I started on a research spree for this and found amazing and interesting stuff about how our memory works. 

From the time we understood we remember things we have wondered how it happens. It has been compared to filing cabinet, post its and even a book. I just wish it was that simple. But it has been found that memory is not stored in any one place in our brain. It is a brain wide process to remember something. 

For example, the most simple act of riding a bicycle comes from different parts of the brain. The memory of how to operate the bike comes from one area, while the memory of how to get from one point to another comes from another, safety rules is remembered from another part and fear we feel in traffic is yet another. 

Your "memory" is really made up of a group of systems that each play a different role in creating, storing and recalling your memories. All the different systems work together perfectly to provide cohesive thought. In fact, experts tell us there is no firm distinction between how you remember and how you think.

But this doesn't mean that scientists have figured out exactly how the system works. The search for how the brain organizes memories and where those memories are acquired and stored has been a never ending quest among brain researchers for decades.  But right now this is what they have figured out.

Encoding is the first step of creating a memory. The brain receives information from all the senses and these sensations move to a part of the brain called hippocampus (and no it is not a hippo dancing in the campus :P). After receiving this information hippocampus with another part of the brain called frontal cortex analyses this and decides whether this is worth remembering. If so then this memory becomes a part of your long term memory. 

Consider, for example, the memory of the first person you ever fell in love with. When you met that person, your visual system likely registered physical features, such as the colour of eyes and hair. Your auditory system may have picked up the sound of their laugh. You probably noticed the scent of their perfume. You may even have felt the touch of their hand. All this information collected by different senses will be stored as a single memory.

To properly encode or store a memory, you must first be paying attention. Since you cannot pay attention to everything all the time, most of what you encounter every day is simply filtered out. This is the reason you might remember birthday of a long lost friend but forget what you had for breakfast in the morning. If you stored every single thing that you noticed, your memory would be full before you even left the house in the morning. 

But I wondered does our brain store memories from our birth. But if so then how is it that I can't remember most of my early childhood. This is called infantile amnesia  and  Researchers have attributed it to the child's lack of self perception, language or other mental equipment required to encode memories. Also hippocampus and pre-frontal cortex which are essential to store memories are underdeveloped. It is also argued that rapid growth of new neurons in young brain blocks access to old memories and in particular as new neurons integrate they remodel hippocampus circuits, and the remodeling may lead to degradation of information stored in these circuits. So even though sensations are stored it is blocked from access by new neural pathways.

Once a memory is created, it must be stored (no matter how briefly). Brain stores first in sensory stage, then in short term memory and ultimately for some memories in long term memory. The more the information is repeated or used, the more it will be stored in long term memory. People tend to more easily store material on subjects that they already know something about, since the information that is already stored in their long term memory. 

Which takes us to next question as to why we forget certain things very easily, like names. It is found that our brain is hardwired to recognize facial details like eye colour, smile, length of the nose etc., But names are random and hold no particular information to them, the brains struggles to retain them. When you meet people for the first time, you have little to no context about them outside that brief introduction, so their names typically go in one ear and out the other. 

It is found that we can remember emotionally charged memories more easily than anything. Because when our senses are over firing the brain attaches it to that particular information and stores it. As the same part of the brain which processes our senses is also responsible, at least in part, in storing emotional memories. 

Our senses and memories have a very strong connection. In all our senses smell is known as memory sense, we are less likely to forget something which is related to a strong smell. If I say garbage, you nose crinkles remembering the god awful smell and am sure a image of over flowing garbage pops up in your mind.

But how do we lose memories? 

There are several factors that contribute to bad memory, including age, chronic stress and mental health conditions. As we age deterioration is evident which can be attributed to the brain shrinkage as the hippocampus loses five percent of its neurons every decade. 

Just like muscle strength, we need to use our brain or risk losing it. Many suggests physical activity (to get blood flow to the brain), eating well (provides the brain with nutrients), and challenges (like learning a new language) are the best ways to preserve your memory and keep your brain healthy.

Some of the most interesting facts about our memory are: 
1. There is virtually no limit to the amount of information you can remember
2. But we can only remember a handful of things in our 'short term' memory
3. Learning new things produces physical changes in your brain structure. New neural pathways are formed which strengthens your ability to recall
4. Being able to access information quickly (i.e., on internet) makes you less likely to remember it. Therefore we can not remember phone numbers more than few people after we started using mobile phones.
5. Almost forgetting something makes you more likely to remember it. The feeling of you know the thing but just can't tell it will make you remember it sooner and more efficiently.
6. Emotional intensity prioritizes how memories are stored

There is unending information about how memory works, but researchers are still finding new information everyday. And even with so much knowledge we are still not sure how neurons fire up and make us remember some things so vividly. 

P.S. The more your work your brain, the more you can remember things. So learn a new language, count backwards from 100 to 1, remember the mathematical tables and try to see something new in your everyday routine. Happy remembering :) :)