Matt Murdock, the lawyer-cum-masked vigilante of Marvel’s gritty new Netflix series, suffers from an unusual problem for a superhero: As a result of an unfortunate childhood encounter with some unnamed chemicals, he can’t see a damn thing. There’s an upside, though: Murdock soon discovers that his remaining senses had been heightened to superhuman levels. For example, his “radar sense” allows him to navigate the darkened rooftops of Hell’s Kitchen despite a nonfunctioning visual system.
While Daredevil may seem like just another high-flying superhero epic, there’s at least a sliver of truth to the notion that blind people develop heightened adeptness with their other senses as compared to those who can see. According to research into blindness and the senses, Marvel’s superhero isn’t quite plucked from the real world, but he can teach us a thing or two about how blind people adapt to a world without sight.
Yes, humans can echolocate.
While Murdock displays acrobatic prowess beyond conventional gymnasts or stuntmen, his uncanny ability to navigate with his “radar sense” isn’t necessarily out of the ordinary. While echolocation is more often associated with animals like bats and dolphins, humans often exercise a form of “passive” echolocation by unconsciously relying on echoes to navigate tight spaces. Psychologist Lawrence Rosenbaum uses the example of rushing to leave for work in the morning. “Your eyes and conscious attention are being largely occupied by other matters, [but] some of your navigation is being directed by sounds,” he explained in his 2010 book See What I’m Saying: The Extraordinary Powers of Our Five Senses. “And because many of the obstacles you are avoiding make little if any sounds, it is likely that you are detecting these things from hearing them reflect sounds.”
There have also been several documented instances of blind people developing a habit of conscious or “active” echolocation to navigate their surroundings. The most well-known case is Daniel Kish, the president of World Access for the Blind and “blind man who taught himself to see.” Kish, blind since he was 1 year old, developed a heightened sense of sonar by clicking his tongue and using the sound waves that bounced back at him to navigate his surroundings. By 2011, he and his organization said they had trained some 500 blind children to echolocate. And a 2013 study in Proceedings of the Royal Society B suggests that even sighted children can learn Kish’s method.
But echolocation abilities don’t come from a superior sense of hearing.
The common misconception about remarkable echolocators like Kish is their sense of hearing is enhanced to compensate for their lack of vision. That’s not entirely accurate, according to brain imaging research conducted by University of Western Ontario’s Lore Thaler, Stephen Arnott, and Melvyn Goodale in 2011 on Kish and another blind man, Brian Bushway.
In their study, blind individuals who echolocated scored the same as sighted subjects on conventional hearing tests. But MRI imaging did reveal that the visual cortices of blind subjects became extremely active when they were exposed to recordings of click echoes. (Bushway, blind since he was 14, showed more substantial activity than Kish, who was older than Bushway and blind his entire life.)
So, it likely isn’t superior hearing that allowed echolocators to use their ability to navigate — they’re just simply better at extracting “visual” information from the echoes that sighted people would simply dismiss as background noise. “The fact that the [visual] cortex only lit up when Kish and Bushway heard click echoes suggests that it’s specifically tied to sonar, rather than a more generally acute sense of hearing,” explained science writer Ed Yong. “Neither of the two sighted volunteers reacted in the same way [to the echoes] — to them, the recordings were just noises.”
And blindness doesn’t mean a better sense of smell, either.
Decades of Daredevil comics portray Matt Murdock as a master in olfactory combat; in the Netflix series, he manages to identify a goon in another part of an apartment building based solely on his awful cologne. But reports of heightened smell or taste have been greatly exaggerated by comic-book writers. In a 2000 study in Perception, Hebrew University researchers Ruth Rosenbluth, Ephraim Grossman, and Marsha Kaitz found no significant difference in blind and sighted children’s ability to compare and identify different scents. Similarly, a 2002 study published in the German ophthalmology journal Klin Monbl Augenheilkd used both subjective and objective tests to measure olfactory sensitivity. While blind subjects certainly thought their sense of smell was more acute, the researchers observed no empirical difference.
The same logic applies here as with echolocation and hearing. It’s not that blind people have enhanced olfactory abilities that allow them to collect more smell-information than their sighted peers; rather, they’re able to process the same amount of information more adeptly. Research confirms as much: In the 2000 Perception study, blind children did give a wider range of labels to the smells, suggesting they simply “paid more attention” to different odors. And a 2010 study of blind students conducted by the University of Montreal concluded that blind people possess “no keener sense of smell than the sighted … Vision loss simply makes blind people pay more attention to how they perceive smell.”
Blind people do have a bit of a tactile advantage, but it doesn’t happen automatically.
Throughout Daredevil, Matt Murdock’s remarkable sense of balance allows him to perform incredible acrobatic maneuvers — an ability attributed to his heightened sense of touch. But unless it’s sensing vibrations a millisecond faster than sighted foes, enhanced touch doesn’t afford the blind much of an advantage in the real world.
According to a 2011 study published in the Journal of Neuroscience by a group of researchers from McMaster University, blind people are measurably more sensitive and detect and process tactile information faster than their sighted counterparts. In an effort to determine if relying on a particular sense makes you process it faster than others, the McMaster team tested the tactile skills of 57 people with various histories of blindness and 89 sighted people by asking them to monitor taps from a small probe. Of the subjects, the 22 people who had been blind since birth performed better than both those who could see and those who had become blind later in life.
“Our findings reveal that one way the brain adapts to the absence of vision is to accelerate the sense of touch,” team leader Daniel Goldreich told Science Daily. “The ability to quickly process non-visual information probably enhances the quality of life of blind individuals who rely to an extraordinary degree on the non-visual senses.” Follow-up research by the same group of researchers suggested it’s not the other senses compensating for the lack of sight in any direct way, but simply daily reliance on touch that drives this marginal increase in awareness observed in blind people. It’s the same principle that governs any muscle in the human body: The more you use it, the better.