Observe... Silently

Our brain often fools us. It often perceives things differently from the reality. Let us discuss about some of the observations made by Prof. Chris Frith, of the University College London in his book " Making up the Mind."

Our experience of the visual world in rich detail is an experience of what is potentially available to us rather than what is already represented in our brain. Our access to the physical world is direct enough for all practical purposes. But this access depends upon our brain, and even our intact, healthy brain doesn't always tell us everything it knows.

The Hering illusion
Even though we know the two horizontal lines are straight, we still see them as bowed.
The most striking aspect of these illusions is that the brain continues to show false information even when we know that the information is false and even when we know what the object really looks
like.

In the image above the strong (and beautiful) rotation of the "wheels" occurs in relation to eye movements. On steady fixation the effect vanishes.

I cannot see my hand, only the cursor on the screen. I am not aware that, in order to move
the cursor straight across the screen, I am actually moving to the left.

When we move, mental events don't happen at the same time as physical events
The brain activity associated with a movement starts before we are aware of our intention
to move, but the movement starts after we are aware of initiating the movement. The
intention and the initiation are closer together in mental time than in physical time

The Roelofs illusion
If the frame moves to right, the observer thinks the black spot has moved to the left even
though it stayed still. But if the observer reaches out to touch the remembered position of
the spot, he does not make an error.

Our brain automatically prepares action programs for the objects around us
In a series of experiments, Umberto Castiello and his colleagues have demonstrated how
different objects in a visual scene automatically activate the responses needed to reach and grasp them (the action program) without any conscious intention to act. They did this by measuring very precisely the movements of the hand when people grasped objects. When we grasp an object, the distance between fingers and thumb (the grip aperture) is adjusted in advance to match the size of the object. When I reach for an apple, I open my hand more than when I reach for a cherry. But if I reach for a cherry when there is also an apple on the table, then I open my hand more than usual for a cherry. The action needed for grasping the cherry is interfering with my action of grasping the apple. This distraction arising from other objects in the visual world shows that the brain has implemented action programs for all of them in parallel.

A slice through the middle of the brain showing an area that responds to touch: the
secondary somatosensory cortex. Activity in this region of the brain is greater when someone else tickles you than when you tickle yourself even though the touch is the same.

The top domino has five convex spots and one concave spot. The bottom domino has two convex spots. In reality you are looking at a flat sheet of paper. The spots look concave or convex because of the shading. You expect the light to come from above so that shadow will be at the bottom of a convex spot and at the top of a concave spot. If you turn the page upside down, the concave spots become convex, and vice versa.

There are many reasons why prediction is a good thing. If we know what is going to happen, then we can relax. We don't have to keep making new plans about what to do. We need to change our plans only when something unexpected happens. Also if we know what is going to happen, then we feel that we are in control. We all like the feeling of being in control. And the thing we control best is our own body. Yet, paradoxically, because our brain suppresses the bodily sensations it can predict, we feel most in control when we don't feel anything. I reach for my glass and all I experience is the look and taste of the drink as I drink it. I don't experience the various corrections made to the movements as my brain navigates my arm through the various obstacles on the table to reach the glass. I don't experience the change in the angles of my elbow or the feel of the glass on my fingertips as they adjust perfectly to the size of the stem. I feel in control of myself because I know what I want to do (have a drink) and I can achieve this aim without any apparent effort. As long as I stay in control, I don't have to bother with the physical world of actions and sensations. I can stay in the subjective world of desires and pleasures.

Is this a vase or two faces looking at each other?

What I perceive are not the crude and ambiguous cues that impinge from the outside world onto my eyes and my ears and my fingers. I perceive something much richer - a picture that combines all these crude signals with a wealth of past experience.My perception is a prediction of what ought to be out there in the world. And this prediction is constantly tested by action.

Is this the wife or the mother in law? (The young chin becomes the old woman's nose.)

Rubin vase figure and the wife/mother-in-law figure, show the some spontaneous reversals from one percept to another, again because both views are equally plausible. The fact that our brains make this kind of response to ambiguous figures is further evidence that our brain is a machine that discovers what is in the world by making predictions and searching for the causes of sensations.

THE DISCUSSION ABOVE CLEARLY INDICATES THAT OUR BRAIN IS LIKE A SUPER COMPUTER DOING EVERYTHING INDEPENDENTLY AND WITH A GREAT PRECISION.

WE THINK WE ARE DOING EVERYTHING INDEPENDENTLY BUT WE MUST BE VERY CLEAR THAT WHO IS THE REAL BOSS.

LET'S NOT DISTURB THE BRAIN BY THINKING UNNECESSARILY. LET THE BRAIN WORK INDEPENDENTLY.

BRAIN IS LIKE A COMPUTER. WE CAN GIVE INPUT ONLY. WE SHOULD NOT BE BOTHERED ABOUT HOW THE SOFTWARE IS RUNNING INSIDE. WE ARE INTERESTED ABOUT THE OUTPUT ONLY.