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A Blind Person Understands The Way A Sighted Friend “Sees” The World

Trendiness in the brain sciences often has an   obscure, esoteric quality that belies the prominence accorded neuro in both academia and popular culture.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Trendiness in the brain sciences often has an obscure, esoteric quality that belies the prominence accorded neuro in both academia and popular culture. Toward the top of the list of arcana resides the ponderously titled "embodied cognition." This is the idea that cognitive processes—thought, emotion—arise from our interactions with the physical world around us. Reduced to its simplest level: holding a warm tea cup might make you feel well disposed toward your lunch guest.

Some of the proponents of embodied cognition take all this much further, postulating that the way we reason about how others think—essential to social interactions—musters the same mental processes brought to bear when we perceive the world around us. So when we imagine a child seeing a clown at the circus, we use the same visual pathways that we would if we were ourselves seeing the big red nose and the oversize floppy shoes. Taken to its logical extreme, this idea would imply that a visually impaired person might somehow be unable to fully develop a mental picture of the child's trip to the circus.

If this strikes you as a little too facile, you're not alone. Some neuroscientists—experimentalists as well as theorists—wonder whether sensory inputs are necessarily as paramount in shaping subjective mental states as the embodiment proponents would have us believe. Jorie Koster-Hale, a graduate student at MIT in the research group of Rebecca Saxe, decided to put to the test the idea of "embodiment" by asking whether you really need to be able to see the world around you to understand what it means for another person to do the same.


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She and her team put nine congenitally blind people and 13 sighted individuals into a functional MRI scanner and asked them to listen to stories about other people immersed in an experience that required either seeing or hearing. "When she gets home from the store, Gladys sees a note on her front door from one of her friends." Or: "When she gets home from the store, Gladys hears a new telephone message from one of her friends."

In a person with normal vision, listening to these stories elicits activity in the brain regions associated with social cognition—reasoning about other people's minds. One of these areas shows a different pattern of activity when reasoning about the way other people are seeing something as opposed to hearing it—seeming support for embodied cognition. But it turns out that the brain region involved—the temporoparietal junction—has a similarly distinctive pattern of activation for the congenitally blind people in the study, according to preliminary research that Koster-Hale reported at the recent Society for Neuroscience meeting.

The blind people in the study had the same contrasting neural responses as the sighted participants. So maybe cognition isn't always so embodied. "What this work suggests," says Koster-Hale, "is that not being able to see doesn't limit your ability to build a mental model about somebody else being able to see."

Source: Mike 384/Wikimedia Commons

Gary Stix, Scientific American's neuroscience and psychology editor, commissions, edits and reports on emerging advances and technologies that have propelled brain science to the forefront of the biological sciences. Developments chronicled in dozens of cover stories, feature articles and news stories, document groundbreaking neuroimaging techniques that reveal what happens in the brain while you are immersed in thought; the arrival of brain implants that alleviate mood disorders like depression; lab-made brains; psychological resilience; meditation; the intricacies of sleep; the new era for psychedelic drugs and artificial intelligence and growing insights leading to an understanding of our conscious selves. Before taking over the neuroscience beat, Stix, as Scientific American's special projects editor, oversaw the magazine's annual single-topic special issues, conceiving of and producing issues on Einstein, Darwin, climate change, nanotechnology and the nature of time. The issue he edited on time won a National Magazine Award. Besides mind and brain coverage, Stix has edited or written cover stories on Wall Street quants, building the world's tallest building, Olympic training methods, molecular electronics, what makes us human and the things you should and should not eat. Stix started a monthly column, Working Knowledge, that gave the reader a peek at the design and function of common technologies, from polygraph machines to Velcro. It eventually became the magazine's Graphic Science column. He also initiated a column on patents and intellectual property and another on the genesis of the ingenious ideas underlying new technologies in fields like electronics and biotechnology. Stix is the author with his wife, Miriam Lacob, of a technology primer called Who Gives a Gigabyte: A Survival Guide to the Technologically Perplexed (John Wiley & Sons, 1999).

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