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❚ perception ❚ sensory ✱ Barbara Tversky

integrating action and sensation

We take the connections between what we see and what we feel for granted, but human babies don’t enter the world with those connections; the connections are learned, slowly over many months. Babies start disconnected, they don’t link what they see with what they do and what they feel and the parts of their body with each other.

Five-month-old might move their hand quite unintentionally and then watch the movement without realizing that they’ve caused it. If you put your finger in their hand, they’ll grasp it; grasping is reflexive. But if the hand disappear from sight, they won’t track them. Gradually, sight and sensation and action get integrated, hands first. Weeks later, they might accidentally catch their foot and bring it to their mouth; putting whatever’s in the hand into the mouth is also quite automatic, and at first they don’t seem to realize that it’s their own.

Ultimately, what unites the senses foremost is action. That is, the output—action—informs and integrates the input—sensation—through a feedback loop. Unifying the senses depends on acting: doing and seeing and feeling, sensing the feedback from the doing at the same time.

We adults do calibrate perception through action too. Seeing in the absence of acting doesn’t change perception. If people are wheeled about in a chair and handed what they need—if they don’t walk or reach for objects— the behavior of passive sitters will become normal.

The general finding is that extensive practice using tools enlarges both our conscious body image and our largely unconscious body schema. That extensive tool use enlarges our body images to include the tools … our cell phones or computers are parts of our bodies. people’s body schemas enlarge to include tools but don’t seem to enlarge to include their backpacks. Ownership depends on simultaneous seeing and sensing … we can’t see our backpacks and whatever sensations we have are pressure or weight on our backs and shoulders, which give no clue to the width of the backpack generating the pressure. Perception serves action and so much more. There are the pure pleasures of seeing and hugging people we love, listening to music we enjoy, viewing art that elevates us. There are the meanings we attach to what we feel and see and hear. Second Law of Cognition: Action molds perception