Tag Archives: perception

Ouch! My Visual Cortex Hurts.


If you have been on a social media site in the last few days then I’m sure you have probably seen the image above before. The biggest question on the internet has been, which do you seen, black-and-blue or white-and-gold? The picture showed up randomly on Tumblr from a dress maker in India and since then it has taken the internet by storm. This entire issue is all thanks to our top-down processing.

We must first realize that color is a subject perception. Meaning that what I would call red, doesn’t necessarily mean that another would call red (or whatever color). This is the same with all sensory information; for example, I am a super taster, which means that I have more bitter receptors on my tongue than most other individuals and what others may taste as only slightly bitter, I’ll be in the trash can trying to get the remnants off with a fork. The difference with vision is that we take in additional contextual information such as shadows.

Shadows play a huge part in how we perceive many things visually such as motion and color. The video shown above shows a few examples of just how much our visual perception relies on shadows. This is purely top-down processing. We see the shadow and expect that the color is actually lighter than it is. This is referred to as color constancy. Color constancy is a Gestalt principle which basically suggests that the context in which we view an object influences our perception of that object.

With this in mind we must then understand what top-down processing is. To put it simply, top-down processing is how we form expectations of the world around us and how magicians, for example, are able to fool us. Now, look at the picture below, do you see anything? This is a good example of top-down versus bottom-up processing. Bottom-up processing just see’s the image as a bunch of dots whereas once I tell you that there is a Dalmatian in the picture with its nose to the ground that it then becomes a top-down issue. If you look close enough, it’s as though you can actually see the lines which make up the dog, but look again, they’re not there. It’s all your brain connecting the dots and creating the object out of the minimal amount of information given.

So this goes to a larger question of how we perceive our world. How could a simple dress fool the way in which we see? I think the biggest thing we must realize is that color isn’t a physical thing that actually exists. Color is our brains interpretation from data it receives from our eyes which is simply waves of radiation bouncing off of the objects that we are looking at. Simply put, our brain creates color.  A fact that I have found interesting from my very first Psychology class is that since vision is simply light waves bouncing off of an object, when we think of color, the object is every color EXCEPT the color we see. For example, I have a green apple sitting on my stand right now. As light waves hit the apples skin the light is absorbed by the skin of the apple, except the green waves are bouncing off and traveling to my eye which then my brain interprets into “green”. The apple is not actually green; green is the only color it is NOT. With this in mind we can see how easily our brains can be fooled into seeing something that doesn’t actually exist, especially when we through shadows into the mix as well.

So then back to the original dress debate. The answer is that the dress is really blue and black. The reason 3/4ths of those who look at it see white and gold is because of the light behind the dress. It’s tricking your brain into thinking that the dress is in shadow so it then must be lighter than what are eyes are seeing. The question I have now though, is how the other 25% of people (I’m included) didn’t see white and gold. Even after I knew the answer and knew why it was this way, I still fail to see white and gold. Perhaps that is a question for a later post. I leave you with this ASAP Video on the matter.

Inattentional Blindness

As evidenced by my previous post, I have always been fascinated with the concept of blindness – all types, in fact. Since I discovered my love and interest in psychology, I have found myself to be more aware of examples of anything I learn in class or from the textbooks in everyday life, particularly examples of any kind of blindness. A couple of weeks back my friends and I got together for out weekly Tuesday dinners at Seacobeck. While one of my friends – Timmy – got up from the table to get more food, my prankster friend decided to steal his phone and stash it in my coat pocket. As a side note, my coat is black. When he came back, it took him about twenty minutes to realize his phone was gone. Once he reached that realization, he began quizzing us on where it was. I gave him three clues:

1) It’s in a deep, dark place where hidden objects often go.
2) It’s in a place of pitch blackness.
3) You’re looking right at it.
(He sat across the table from me.)

Regardless of these clues, Timmy simply could not figure out where his phone was, looking under the table, in the flag, in my black purse, and in my shoes. I was surprised that he missed the most obvious of places – my coat. I then began to wonder: “Is it simply because it’s so obvious, that he missed it?” This brought me back to our discussion of inattentional blindness, something I think Timmy perfectly demonstrated that night in Seacobeck.

An article in the Psychological Review refers to many incidents where people fail to notice stimuli appearing in front of their eyes when they are preoccupied with an attention-demanding task; the task Timmy in particular was preoccupied with was finding his missing cell phone. In this article, each study refers to incidents when people were so focused on one task, they missed another stimulus that may seem blatantly obvious to others. For example, there was an American naval submarine that slammed into a Japanese fishing vessel, killing nine crew members and students on board. When questioned, the crew in the sub all insisted that while quickly scanning the waters for enemies and other submarines, they had simply missed the fishing trawler. While this is a catastrophic example, one that certainly does not have a very clear correlation to Timmy’s search, it makes me think of how exactly he was searching for his cell phone. Instead of looking carefully and really thinking about the clues I gave him, he was scanning the area around where we were sitting very quickly, not lingering on any object. When thinking about this case of the submarine and traffic accidents where drivers missed seemingly obvious obstacles in their way, I am able to see how Timmy may have missed the obvious choice of my black coat.

Though Timmy admittingly does not have the best common sense in the world, I still don’t want to think that he simply did not even consider the fact that the phone in my pocket – in fact, the reason my friend hid the phone in my pocket was because she thought it would be the first place he would think of. As this article points out, there is a phenomenon within inattentional blindness, called implicit perception, that suggests that when people don’t consciously notice a stimuli, it still is encoded outside of their awareness, also determining their future behaviors. As Timmy did finally decide that I had it hidden somewhere in my coat (nearly half-an-hour later), this suggests that he had registered the existence of my coat in his consciousness, but didn’t access it until we practically gave away the location.

This experience of inattentional blindness in my everyday life was not only hilarious and slightly annoying, it further instilled in me an understanding of this concept, as well as a deeper understanding of the mind of my friend Timmy. I look forward to more times I can experience the concepts of cognitive psychology in real life!