You might have heard Brad Pitt talk about how he has difficulty differentiating and remembering faces. He probably suffers from something termed ‘prosopagnosia‘ (don’t sweat trying to read it, it’s proso-pag-nosia), essentially ‘face blindness’. When Brad Pitt sees 2 different people, he might be able to recognize them by their voice, body language, gestures etc, but not by their facial features.
Imagine functioning in the world like that! :O
If you’re finding it hard to imagine, I’ll give you something that might help you understand what prosopagnosia patients go through.
Look at these puppy faces.
They all look the same, don’t they?
Do you think dogs aren’t able to differentiate each other’s faces? -of course they can! This is how prosopagnosia patients live their lives- navigating social interactions with one less tool at their disposal.
Now the diseases exists as a spectrum- from complete inability to identify faces, to mild deficiency. While most patients inherit the disease when they’re born, some acquire it at a later age due to conditions like stroke, traumatic brain injury or neurodegenerative diseases.
Interestingly, there is another mechanism to develop this condition, and in fact, it is applicable to a lot of more senses, like speech, music, and even sign language perception- Perceptual Narrowing.
What’s more, EVERY SINGLE ONE OF US UNDERGOES THIS PROCESS during our early years of life!!
So what exactly is perceptual narrowing (and, why should you care)?
As a newborn, we have the ability to discriminate a very, very wide array of stimuli, such as a large number of speech sounds (from multiple languages), and faces across multiple races and even species (think dogs!), but, as we age, neural pathways for stimuli that we consistently receive get strengthened, while others, stimuli that we aren’t exposed to in early childhood, get less and less efficient.
So, in a sense, an infant’s brain learns to focus on certain common stimuli in their environment, creating better ability to distinguish even tiny differences in sound and structure, at the cost of a myriad of other stimuli that the brain feels are not very necessary. An infant likely has the ability to discriminate between different puppy faces too!
So again, how does knowing this affect your life?
- It’s just plain fascinating, isn’t it? 😛
The fact that our brain has the capacity to sense a whole lot more stuff that we just don’t use it anymore, and that our perception of the world is greatly determined by what we did, and equally importantly, did not experience in our early childhood.
With the internet, I do believe that kids these days have exposure to a larger variety of stimuli than we, and our parents ever did, and that it certainly reflects in their perception of the world, and simultaneously, their learning and motor abilities as well.
- It is, in my opinion, really important to understand the fact that our perception of the world is very different from those around us, even our own family. Acknowledging this allow us to appreciate that REALITY, and our experience of reality, are two different things. Perceptual narrowing is just one such brain phenomenon, there are many others that collectively create a unique experience of the world for every individual.
Something I’ve always wondered is that why a lot of the Western world is unable to differentiate the ‘t’ sound in ‘table’ from the ‘t’ sound in ‘tabla’. If you’d notice, the English language doesn’t contain the ‘t’ sound of ‘tabla’ and ‘d’ sound of ‘diwaar’ at all. Alternately, languages like French have both these sounds, but lack the ‘t’ sound of ‘table’ and ‘d’ sound of ‘dance’. Children born and raised in English and French-speaking households respectively are never exposed to these phonemes, so they can not appreciate. Hindi, on the other hand, uses all these different phonemes, and thus, we’re able to easily perceive the difference between them!
- I believe perceptual narrowing is much more universal than just face and speech recognition, these areas just tend to be more extensively studied currently. But there is no reason to believe that similar differential reinforcement and attenuation does not occur for other perceptions, such as danger signs, emotions etc. We do know that the emotional environment of a baby determines their ability to sense and reciprocate certain emotions. A baby that has not experienced safety as a child, won’t feel safe no matter how safe they really are. A baby that was never loved, would not know how to love another human. And so again, acknowledging this fact helps us be more accepting of other people and their differing perspectives, because all of us look at the same reality with very different filters.
A lot of our conflicts would just dissolve is we realised that both the individuals involved might want the exact same thing, but due to our very individual perception of reality, we look at situations differently. I feel it is always important in these situations, to take a step (or many) back, and first establish how each of us perceived the situation in the first place. It is okay for both individuals to have different experience/memory of the same instance, because our brains are trained in very specific ways, and are unique to our childhood.
An interesting question that then pops up is, can perceptual narrowing be reversed? There’s lot of research around this, and I’ll explore it in another blog post. 😀
2 Comments
Syed zen · May 3, 2023 at 6:19 pm
Much understandable
Eagerly waiting for your another blog.
Hope to read a good researched same topic like this by you Dr.
Mridula · May 3, 2023 at 6:44 pm
Thankss 😀