Consciousness and the Social Brain

constriction, hormonal content, digestive activity, temperature, and other matters of the inner environment, occur outside of awareness.
    A part of the human cerebral cortex, the posterior parietal lobe, appears to play a special role in hand–eye coordination. Goodale and colleagues proposed that this brain area functions largely outside of consciousness. 16 , 17 They studied a patient who, due to diffuse brain damage, no longer had any awareness of the shapes, sizes, or orientations of objects in front of her. Despite the brain damage, the patient still had intact parietal lobes. If asked to reach out and grasp an object, the patient would confidently do so, with the correct hand orientation and the correct finger shaping, even though she insisted she was not conscious of the shape or location of the object. When asked to post a letter in a slot, the patient could do so easily, despite having no awareness of the shape of the letter or the orientation of the slot. In contrast, people who had damage to the parietal lobe suffered the opposite set of difficulties. They were unable to reach, grasp, or manipulate objects. They reached to the wrong places, grasped the wrong parts of the objects, and opened their fingers to the wrong extent. Yet they reported a perfect awareness of the objects in front of them, including shapes and sizes. Goodale concluded that the parietal lobe was critical for hand–eye coordination but did not contribute to conscious experience. That brain region carried out its computations outside of consciousness. Yet the parietal lobe contains information as intensively integrated as in any other region of the brain. Indeed, the parietal cortex is one of the main integrative hubs in the brain.
    People can be primed to perform complex tasks without even knowing they are doing so. These tasks can include decoding the emotions in a face, recognizing the identity of a face, registering the meaning of words, registering the mathematical meaning ofnumbers, and other astonishing feats of perception and cognition occurring under the surface of consciousness. 18 For example, if the word
frog
is flashed on a screen in front of you—if it is flashed quickly—you will have no awareness of the word. You might report seeing a flash of light, but no letters. Yet if after that you are asked for a word that begins with
f
, any word—just blurt out the first word that comes to mind—you are more likely to say “frog” than would be expected by chance. Something in your bran must have processed the word. These tasks require the integration of information, yet can be done without awareness.
    Brain systems that operate outside of awareness have been called “zombie units.” 19 Proponents of the integrated information theory might suggest that the zombie units are unconscious because the information in them is less integrated. For my own tastes, however, this explanation seems too convenient. It is too easy to look at a system that does not contribute to consciousness and find, with a little effort, a reason to convince oneself that its information is less integrated. It is too easy to look at a system that participates in consciousness and, again with a little effort, convince oneself that its information is more integrated. When you coordinate your hand and eye, blending the visual input and the muscle control, most of that coordination is computed outside of awareness. But I have a hard time believing that the relevant information is in any way lacking integration. My background in neuroscience lies in the control of movement, so I have an appreciation for the incredible amount of information that needs to be integrated to make any kind of coordinated movement possible.
    Computer technology has reached a point where vast, interconnected networks of information are now possible. The Internet, as far as anyone can tell, is not conscious. Deep Blue, the IBM chess machine, shows no signs of consciousness. Neither does Watson, the machine that plays Jeopardy. A giant interlinked tax code is not conscious. (At least I hope not.)
    To save the integrated information hypothesis of consciousness, one could argue that these complex, information-processing entities are actually conscious but simply don’t have the verbal skills to say so. Maybe the computer on your desk is aware of itself but lacks the ability to communicate that state. This type of argument, however, weakens rather than strengthens the integrated