Numbsense

[david_myers]

We live wonder-full lives. How blessed I am to be tasked with reporting on those wonders, and, on most days, to learn something new. Last week’s reading brought news—previously unknown to me, and also to you?—of an intriguing phenomenon, numbsense.

But first, some background.

One stunning psychological science revelation concerns how much more we know than we know we know. We operate with two minds—one conscious, the other below the radar of our awareness.

An illustration of this dual processing comes from brain-injured patients who, though consciously blind (unable to perceive their surroundings visually), act as if they see. Walking down a hall, they avoid an unseen chair. Asked to slip an envelope into a mail slot, they—despite being unable to see or describe the slot’s location and angle—can do so. These “blindsighted” individuals suggest that the brain’s “visual perception track” is—surprise!—distinct from its “visual action track.”

Even normally sighted people, when their visual cortex is deactivated with magnetic stimulation, may display blindsight—by correctly guessing the nature of unseen objects.

And now the week’s news: City University of New York researchers Tony Ro and Lua Koenig have also used magnetic stimulation to deactivate people’s sense of touch, leaving them unaware of whether or where someone has touched them. Yet, like some patients who have suffered sensory cortex damage, they can display a blindsight-like “numbsense.” They can guess the location of the unfelt touch.

The big lesson of blindsight and numbsense: The unconscious mind sometimes knows what the conscious mind does not. Moreover, the out-of-sight mind is the bigger workhorse. Much as a cruise ship’s work mostly happens without its captain’s attention, so most of what sustains us is accomplished by our mind’s unseen workers below decks, without engaging our conscious mind’s attention. We are smarter than we know.

(For David Myers’ other essays on psychological science and everyday life, visit TalkPsych.com; follow him on Twitter: @DavidGMyers.)