We’ve all heard of amnesia – a loss of memory usually caused by a traumatic event, injury or illness. There are two main types of amnesia: retrograde (the subject can’t remember the information before the injury or disease) and anterograde (inability to create new memories after the event).
But not many people know about visual memory-deficit amnesia – a specific form of amnesia with different symptoms and mechanisms.
How Do Our Memories Work?
Our cerebral cortex plays a vital part in the creation and storage of memories. In it, you can find different association cortices: visual (in charge of our visual memory), olfactory (smell), auditory (sound), and emotion association cortex. When a memory is triggered, they all work together.
For example, if you suddenly smell burgers, that would trigger a reaction in your olfactory cortex. This then leads to a pattern of firing in your visual cortex (you suddenly remember seeing your friend making burgers). This activity then creates a reaction in your auditory cortex (you remember a conversation you had with that friend), and so on.
As some studies show, vision and visual imagery play a pivotal role in our memory. In fact, retrieving a visual image of a memory helps us classify it as an actual event, rather than imagination.
So, if you were to lose access to this stored visual material, how could you remember things?
The Phenomenon of Visual Memory-Deficit Amnesia
In an extensive study, David Rubin of Duke University explains how visual memory-deficit amnesia works. Unlike other forms (which are caused by an inability to encode or retrieve new information), VMDA is caused by damage to the system which stores visual data. This means that VMDA mostly affects our previous memories, while our ability to create new ones stays almost intact.
Research also shows that people with VMDA produce new memories similarly to the totally congenitally blind. They use other sensory data, such as smell and sound to create memories.
That about explains it, doesn’t it?