Man unable to 'see' numbers after suffering rare brain disease
He can't identify the numbers 2 through 9. But strangely, he can still see ones and zeros.
- When a man who was diagnosed with the neurodegenerative disease corticobasal syndrome looks at the numbers 2 through 9, he sees unintelligible squiggly lines.
- The disability appears to be a peculiar type of metamorphopsia, a visual defect that causes linear objects, like the lines on a grid, to look curvy or rounded.
- The study has some interesting implications on theories of consciousness.
Someone writes the number 8 on a piece of paper. You look at it, see a shape, but you can't identify what number it is, or whether it's a number at all. The markings just look like "spaghetti."
It sounds strange, but that's exactly what happened to a man who suffers from a rare neurodegenerative disease called corticobasal syndrome, and now can't recognize the digits 2 through 9. This disease, caused by damage to the cortex and basal ganglia, often leads to memory problems and difficulty moving, but the inability to identify numbers seems to be a very rare symptom.
In a new study published in Proceedings of the National Academy of Sciences (PNAS), a team of researchers describe how the unique disability sheds light on how the brain processes visual awareness.
The inability to identify numbers posed an immediate puzzle for researchers. If the man (named "RFS" in the paper) can read letters and words, but not numbers, that means his brain must be identifying the numbers — and then selectively discriminating against them.
Johns Hopkins University - Schuberta et al.
The disability appears to be a peculiar type of metamorphopsia, a visual defect that causes linear objects, like the lines on a grid, to look curvy or rounded.
"When he looks at a digit, his brain has to 'see' that it is a digit before he can not see it -- it's a real paradox," said senior author and cognitive scientist, Michael McCloskey, in a news release. "In this paper what we did was to try to investigate what processing went on outside his awareness."
RFS was also unable to see words or drawings placed inside or near the numbers 2 through 9. For example, he wasn't able to see an image of a violin drawn inside the number 3. But when the violin was placed far enough away from the number, he was able to see it.
In an electroencephalography (EEG) experiment, the team found that even though RFS said he didn't see images placed near numbers, his brain was registering that words were there.
"He was completely unaware that a word was there, yet his brain was not only detecting the presence of a word, but identifying which particular word it was, such as 'tuba'," Harvard University cognitive scientist Teresa Schubert said in a press release.
Is it possible that RFS' disability can be explained by a psychological issue?
"Given the rare form of RFS' metamorphopsia, how can we be sure that his deficit is genuine? With any unusual deficit, there is the possibility that the underlying dysfunction is psychiatric, psychogenic, or 'functional', rather than an impairment of basic perceptual/cognitive processes," the team wrote in the paper.
"We believe this unlikely in the present case for multiple reasons … At the time of our study RFS was seeing a psychiatrist for help in adjusting to his condition, and the psychiatrist had no suspicion that any of his perceptual, cognitive, or physical symptoms reflected a functional disorder. In addition, RFS' performance in two-choice discrimination was not below chance, as is often found in cases of malingered deficits."
The research has some interesting implications for theories of consciousness. As the paper states, some theories propose that humans are able to perform "certain types of complex cognitive processes" because our consciousness interacts with deeper-level processes in the brain. But the results suggest consciousness may play less of a role, because RFS seems to be "computing complex, task-sensitive representations in the absence of awareness."
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Whether or not women think beards are sexy has to do with "moral disgust"
- A new study found that women perceive men with facial hair to be more attractive as well as physically and socially dominant.
- Women tend to associate more masculine faces with physical strength, social assertiveness, and formidability.
- Women who display higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, are more likely to prefer hairy faces.
Beards and perceptions of masculinity<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzkxMjM3N30.cH-GqNwP5GVqvstgJWAhBPn1B_lYpVEAI0I7iax7EQw/img.jpg?width=1245&coordinates=0%2C1900%2C0%2C849&height=700" id="caae6" class="rm-shortcode" data-rm-shortcode-id="cb0a355a4e8e1899789bc45f3f7aef56" data-rm-shortcode-name="rebelmouse-image" />
Photo Credit: Wikimedia<p>The study used 919 American (mostly white) women ages 18-70 who rated 30 pictures of men they were shown with various stages of facial hair growth. The photographs depicted men with faces that had been digitally altered to look more feminine or more masculine, with a beard and without a beard. The women rated the men according to perceived attractiveness for long-term and short-term relationships. The study found that the more facial hair the men had, the higher the men were rated on their attractiveness, particularly for their suitability for a long-term relationship.</p><p>Part of this might be attributed to facial masculinity — i.e. protruding brow ridge, wide cheekbones, thick jawline, and deeply set narrow eyes — which conveys information to a woman about a man's underlying health and formidability. Women tend to associate more masculine faces with physical strength and social assertiveness. It can also indicate a man with a superior immune response. The researchers suggested that their findings favoring bearded men could be due to the fact that facial hair enhances the masculine facial features on a man's face, like creating the illusion of a thicker jaw line. This could communicate direct benefits to women like resources and protection that would enhance survival among mothers and their infants. In other words, while a beard doesn't mean superior genetics in and of itself, it might be a primitive, ornamental way of saying, "Hey girl, I'm a testosterone-fueled lean, mean, pathogen fighting machine." <br></p><p>It could also be that a beard becomes its own destiny. The researchers in this study cite prior research that found that by growing a beard, men felt more masculine and had higher levels of serum testosterone, which was linked to a higher level of social dominance. They also tended to subscribe to more old-school beliefs about gender roles in their relationships with women as compared to men with clean-shaven faces.<span></span><br></p>
What does disgust have to do with beard preference?<p>Obviously, not all women dig beards. The researchers were particularly interested in what traits make a women prefer bearded men over clean-shaven faces. They looked into several factors including a woman's disgust levels on various concepts, her desire to become pregnant, and her exposure to facial hair in her personal life. </p><p>According to the study, women who were not into facial hair were turned-off by potential parasites or other critters they imagined could be in the hair or skin. Women ranking high on this "ectoparasite disgust" scale might have viewed beards as a sign of poor grooming habits. However, women who ranked higher in levels of "pathogen" did find the bearded men to be desirable, possibly because they perceived beards as a signal of good health and immune function. An intriguing discovery in the study was links to morality. Women who displayed higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, were more likely to prefer hairy faces. The authors opined that this could reflect a link between beardedness, politically conservative outlooks, and traditional views regarding performances of masculinity in heterosexual relationships.</p>
Additional findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg1My9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTYyNDI1NjUyOX0.P9B8WbmJR0q4nfzYZKbuNSA-2SAigVWJgrQE-_Gxlds/img.gif?width=980" id="49143" class="rm-shortcode" data-rm-shortcode-id="2ed3b1d6f20fc170bf2974646e565e8d" data-rm-shortcode-name="rebelmouse-image" />Giphy<p>The correlations that existed between married and single women's rating on the attractiveness of beards were not particularly clear, although the researchers noted that single and married women who wanted children tended to find beards more attractive than the women who didn't want children. They also found that women with bearded husbands found beards to be more attractive, which might indicate that social exposure to beards influences how desirable they are perceived of as being. Or it could be that men with wives who like beards grow beards.</p><p>It's important to note that culture plays a huge role in how attractive women perceive certain male characteristics as being. This study looked at a small, culturally specific group of American women, so no big, universal claims should be made about masculinity, facial hair, and male desirability to women. However, research like this is important in highlighting how human grooming decisions are driven by much more than fashion trends. Sociobiological, economic, and ecological factors all play a part in the way we choose to present ourselves.</p>
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