Vote for our panel at SXSW: Taking Research Out Into the Wild

Like others, we believe that science is a little bit WEIRD — much of research is based on a certain type of person, from a very specific social, cultural, and economic background (WEIRD stands for Western Educated Industrialized Rich Democratic; Henrich, Heine, Norenzayan, 2010).  We want to use the web and the help of citizen scientists to start changing that.  In the next few months, we will be launching an initiative called Making Science Less Weird (stay tuned).

As part of Making Science Less Weird, we have proposed a panel presentation at the SXSW conference next year.  In order to be selected, however, *we need votes*.

To support Making Science Less Weird and help us increase diversity in human research, please go to this link to create an SXSW account:

Then go to this link and click on the thumb’s up (on the left under “Cast Your Vote”) to vote for us:

Thanks for your support!

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Of Mice and Man-sized Unicorns: In Defense of Large Sample Science

Earlier this year, Button et al. published an excellent article highlighting the need for greater statistical power in neuroscience — most neuroscience studies are likely underpowered given the effects sizes one would expect from the literature [1]. Then today, I came across a response to the Button et al. paper called “Misuse of power: In defence of small-scale science” [2], arguing that larger samples are not necessarily better. The argument was something along the lines of: Smaller samples are a way of safe-guarding your findings from small, biologically trivial effect sizes. Larger samples make you vulnerable to detecting these small effects because they are more likely to show up as statistically significant.

Now an argument for smaller (just adequate) sample sizes is fair enough from a resource limitations perspective. But statistically? Scientifically? Oh, no.

Let’s say you are running an animal-finding experiment where you expect a medium effect size… animal. Elephants are big effect size animals, mice are small effect size animals, and you expect a miniature pony of an effect size (say r = 0.5). You have a small sample that is pretty unlikely to find a mouse effect size, which is good (they are pests, after all). However, there are two limitations you might consider in your animal finding experiment:

1. First, because you have a smaller sample, your estimates of how big every effect size animal is will tend to be fairly broad. Smaller samples mean bigger confidence intervals around your effect size estimates. So that means it’ll be hard to say with any certainty how differently sized the animals you find are. An r of 0.5 where N = 30, for example, has a 95% confidence interval of r = 0.15 ish to r = 0.7ish. An r of 0.15 is getting into large rabbit territory! (but still cuddly, right?)

Basically, it might be hard to distinguish between your house cat, gorilla, and giraffe sized effects.

<-- False Positive Unicorn

2. But, what’s that? Even worse! Every so often, you are going to get a false positive — something that looks like an animal of modest effect size, but actually doesn’t exist in real life at all. These are the UNICORNS. They are cute, make good Nature papers, and are totally freaking imaginary.

Now let’s examine the alternative. Here you have a large sample. You still want to find a mini-pony for your kid’s birthday, or whatever, but now you have the statistical power to start doing more. First, you can start drawing some precise confidence intervals around your effect size estimates. The thing you found that’s gorilla size? Probably around the size of a gorilla.

The downside is that you now have the power to detect small effect sizes. These little mouse sized effects can be disconcerting.

<-- Small effect size pests

What is it? What does it mean? Is it a biologically meaningful animal?

Now I personally think mice have their place, and we really don’t know what effect sizes are important and where the cut-off between “biologically important” and “biologically trivial” really is, etc. … but at least with a large sample, you know the mouse you found is approximately mouse-sized. And if you do find something imaginary, it’ll also tend to be approximately mouse-sized.

Your chances of finding a unicorn in a large sample are really, really small.

As a scientist, I prefer mice to unicorns.

1. Button, K. S. et al. Power failure: why small sample size undermines the reliability of neuroscience. Nature Rev. Neurosci. 14, 365–376 (2013).

2. Quinlan, P.T. Misuse of power: in defence of small-scale science. Nature Rev. Neurosci. 14, 585 (2013).

Note: Button et al. have written a splendid reply to this and other comments on their paper:

3. Button, K.S. et al. Confidence and precision increase with high statistical power. Nature Rev. Neurosci. 14 , 585 (2013).

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Hormones and Being Overweight – Research Study at Massachusetts General Hospital

I wanted to pass this along to anyone who is interested.  My colleagues at Massachusetts General Hospital are looking for overweight men and women between the ages of 18-45 who live in the Boston area.  The study is running for the next two months.  The research is focused on understanding the relationship between hormones, appetite, and weight.  We appreciate your help! Details are below.

Overweight women who use hormonal birth control or oral contraceptive pills and overweight men between 18-45 years old may be eligible for a research study investigating the effect of oxytocin on the relationship between hormones and appetite.  The study includes one screening visit to confirm eligibility, and two morning visits which will include a meal, questionnaires, and blood draws. Visits occur at Massachusetts General Hospital in Boston, MA. Eligible participants will receive up to $180 for completing the study. Local transportation and parking costs will be reimbursed. 

For more information or to find out if you’re eligible to participate, please contact Rebecca DeSanti at 617-724-1579 or

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How citizen scientists discovered developmental prosopagnosia

Note: This article also appeared in the Prosopagnosia Research Center  Summer 2012 Face 2 Face newsletter.

Prosopagnosia (also known as face blindness) is a disorder characterized by a profound difficulty or inability to recognize faces.   I have discussed this disorder in a few previous posts.  You can read a list of signs and symptoms of the disorder here.  You can also watch a recent segment about the disorder on 60 minutes.

Prosopagnosia research has made a lot of progress over the last decade. That progress has critically depended on the interest and engagement of people suffering from prosopagnosia and their family members.

In this post, I want to talk briefly about the way citizen science has driven prosopagnosia research, on behalf of all of us at the Prosopagnosia Research Center.

What is Citizen Science?

Citizen science is science done by everyday people rather than professional scientists. Citizen scientists generally have less training and access to resources compared to professional scientists, but they have their own unique set of observations that can contribute to scientific progress in sometimes unexpected and critically important ways. Many of you reading this are citizen scientists. You take part in experiments, share information about yourselves, but most importantly you pay attention to and share your experiences. Our understanding of prosopagnosia took a leap forward at the point that scientists began acknowledging people with face blindness as citizen scientists, who understand their own abilities, experiences, and limitations and are willing to share that knowledge with the community of professional scientists in hospitals and universities.

From my vantage point as a face recognition researcher, I believe the contributions of citizen scientists created the field of prosopagnosia research as we know it today.

The Story of Face Blindness

There are probably many versions of this story, beginning in many homes across the world when people with face blindness began connecting with fellow sufferers through the internet. The version of the story I’d like to tell starts with Bill Choisser.*

A picture of Bill from his website, Face Blind!

Bill Choisser is a self-described “long-haired man in jeans” who lives in the San Francisco Bay Area and has suffered from deficits in face recognition his entire life.  Bill spent many years as an advocate for prosopagnosia awareness. Bill grew up in an Illinois coal-mining town and found that he often recognized other kids by their jeans. He also found when making friends as an adult that he tended to gravitate to other long-haired men in jeans.

Bill didn’t realize he had problems with face recognition until he was in his 40s, sitting in front of the television one day with his partner Larry. They were watching a television program together and Bill expressed frustration that t.v. programs never showed enough of a person’s body and clothes. It was impossible to keep track of characters! Larry looked at Bill and said, “You don’t need all that, you recognize the characters by their faces.” To Bill, this bordered on absurdity.  Faces were impossible to recognize and all tended to look the same.

Bill took it upon himself to start asking around and observing others to see if they relied as heavily on faces to recognize other people as Larry suggested. This made Bill realize that he was relatively unique in his inability to recognize faces. He went to his doctor and asked whether he might have some sort of neurological problem that meant he couldn’t recognize faces. “There’s no such thing” his doctor said.

At the time, the internet was in its preteen years (young, awkward, but with lots of potential) and people were increasingly becoming connected with others in growing online communities. Bill decided to post a message on a forum for neurological disorders. The message said: “I have trouble recognizing faces. Anyone else have this problem?” Then he waited. Soon, he was contacted by someone who reported the same difficulties. Then a second and third person contacted him.  A year later there were about 30 people communicating over the internet who reported lifelong difficulties with face recognition with no clear medical explanation

At around the same time, Glenn Alperin, who also suffered from problems with face recognition was learning about a condition called “prosopagnosia” that he had come across in the medical literature.  In his attempt to learn more about the condition, he too began looking for other potential sufferers on forums and through the internet.

Eventually Glenn and Bill met and, for the first time, a sizable community of people with prosopagnosia existed that could share their experiences with one another and reflect on what it meant to not be able to recognize faces.  But “prosopagnosia” is an unfortunate word: complicated, difficult to remember, and impossible to spell. Bill decided that since people who can’t recognize certain colors are known as “color blind” it made sense that people who couldn’t recognize faces should be called “face blind”.

So, in 1997, the term face blindness was coined and is now an accepted term among scientists and sufferers alike.

At the time, the research community was virtually unaware of developmental prosopagnosia / face blindness (that is, face blindness not caused by brain damage in adulthood). The disorder, if it existed at all, was considered very, very rare. There were a handful of reported cases, and it was unclear to researchers whether their deficits may be explained entirely by some form of early brain damage that was difficult or impossible to see on standard CT or MRI brain scans.  To any researcher studying prosopagnosia or face blindness, Bill Choisser, Glenn Alperin, and their growing face blind community offered a significant opportunity to learn about face blindness, face recognition, and the way the brain develops.

When they approached research scientists who studied face blindness, however, the response was discouraging. Bill Choisser reflects:

“None of the researchers we found had any interest in communicating with us. Some ignored us and some were condescending, while from their responses we could tell…we already knew much more about [face blindness] than they did.”

So Bill and others decided it was up to them to learn about the disorder and create
web resources for fellow sufferers. For example, in 1997 Bill created a website called
“Faceblind!” that described his own experiences with the disorder and his ways of coping.

Time passed, the community grew, but developmental prosopagnosia continued to be
thought of as an extremely rare, virtually unknown phenomenon. In 1999, Dr. Brad
(then a graduate student) came upon Bill Choisser’s website and got in touch with him. “I want to work with you to learn about this disorder,” he said.

Brad Duchaine as a graduate student

Dr. Duchaine saw the opportunity, but, more importantly, recognized the importance of learning about face blindness with the community of sufferers. People with face blindness were collaborators: citizen scientists who could partner with professional scientists to learn (together) how and why face recognition was different for people with face blindness.

Citizen Science –> Scientific Progress

In the intervening years we’ve learned a lot about face recognition and face recognition deficits: that face blindness runs in families, how variations in other abilities seem to be related to face recognition deficits, and how face recognition is just different for people with face blindness. We are also beginning to understand how face blindness might arise from differences in the way the brain develops. Most startling, however, is the realization that developmental prosopagnosia or face blindness is surprisingly common. Based on recent data, Dr. Nakayama and Dr. Duchaine estimated that up to 1 in 50 people have face recognition deficits severe enough to qualify them for a diagnosis of face blindness. It’s not quite as rare as scientists thought! And all of these insights began with the face blind community and people like Bill Choisser and Glenn Alperin: people with a unique set of experiences, a healthy dose of insight, and the willingness to break new ground as citizen scientists.

We believe that scientific research works best when it involves a conversation between professional scientists and citizen scientists, like many of you. In the case of our face recognition work, this is a conversation between researchers and people at the front lines who have first-hand experience of face blindness.  To help us understand this disorder and face recognition more generally, we ask for your continued collaboration: by observing yourself, observing your own experiences, and (when you get the chance) sharing those observations with researchers like us.

For more information, see my previous post on the way web-based cognitive testing has helped many people with face blindness learn more about their face recognition abilities.

You can also look at the recent Harvard Gazette article on TestMyBrain and citizen science.

Finally, check out this clip of Oliver Sacks talking about face recognition and his own face recognition difficulties:

Oliver Sacks on Face Blindness

* Thanks to Bill Choisser for providing information for this blog post.  Bill Choisser would prefer not to be contacted with questions or comments about his story, but please feel free to contact me or leave a comment below.


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Harvard undergraduate anecdata on human uniqueness

Many people believe that their performance on TestMyBrain experiments generally reflects how smart or intelligent they are.  This is not the case.   At TestMyBrain, we tend to focus on experiments that look at different aspects of memory, visual perception, and social cognition.   These abilities can vary tremendously even among very high-performing individuals.

Anecdotes don’t substitute for proper experiments, but I want to give you an example of how much these skills vary in a small group of very successful students that I had the pleasure of working with this last summer.

Four tests that we use a lot are the Cambridge Face Memory Test (face memory), the Abstract Art Memory Test (visual memory), the Verbal Paired Associates Memory Test (verbal episodic memory), and the Reading the Mind in the Eyes Test (complex emotion perception).  You can take the first three tests here and the last test here.

This last summer, we brought in a few undergraduate research assistants from the Harvard Computer Science department to help us on a project looking at culture, cognition, and user interfaces.   There is no question that these Harvard undergrads are smart, sharp, clever, and quick-witted (I could grab a thesaurus and keep going, but you get the idea).

When they started working on the project, we had them complete the set of tests listed above, so they could get a sense of what web-based cognitive tests look like and the type of research that we do.  I’m going to briefly tell you (with their permission) how three of them did.

One student was pretty much good at everything we threw at her.  She could remember faces, words, pictures, and recognize people’s facial emotions well.  As far as we could tell, she was just good at everything.  She was even good at being good at everything.

This woman will remember your socks off

Please note that is not actually her, but just a stock image for “smart and successful young woman”.  

Another student scored low on most of the memory measures (particularly abstract art memory), but then NAILED our test of complex emotion perception.  That is, he only got one item wrong.  Take the test… it’s tough!  Getting only one item wrong is pretty remarkable.  Turns out he is a poker player and studies other people’s facial expressions and body language to help judge who has a good hand and who doesn’t (aka people’s tells).  In poker, it pays to be able to read minds.*

Steely eyed poker player reading your mind

No, he doesn’t look like a thug in real life.  That’s another stock photo.  

Finally, a third student had memory scores (including memory for faces) that put him in the range of impaired performance.  Based on these test scores, we would guess he might have problems in everyday life recognizing other people, especially as he has no strong visual memory abilities that might allow him to compensate for his poor face memory.  In reality (where it actually counts), he is socially adept, recognizes others easily, and will probably rule the world in a few years. Why the discrepancy? I have no idea. But he’s a great example of how little we understand about human individuality and how the brain works.

Future founder of Who-Cares-About-Faces book

Anyway, they and our other undergraduate students did a fantastic job this summer.  Check out to see some of what they worked on. If you go to TestMyBrain and your scores are way above average on everything, that’s fantastic.  If, on the other hand, you do terribly on all of our tests… well, you are in very good company.


*Check out my colleague’s recent paper on the surprising way a person’s face and facial expressions influences how likely they are to successfully bluff in poker:

Psychology of Poker

Schlicht, E.J., Shimojo, S., Camerer, C.F., Battaglia, P., & Nakayama, K. (2011). Human wagering behavior depends on opponents’ faces. Plos ONE, 5(7), e11663.doi:10.1371/journal.pone.0011663. 

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Gut number sense and being a math genius

Don’t count, but are there more yellow or blue dots in the image below?

If you said yellow, you’d be correct…* (see footnote before counting the dots)

As I mentioned in a previous post, many people have come to TestMyBrain over the years to answer questions like “Am I a math genius?”  If you are one of these people, I need to ask you a question.  Are you really, really, really good at math?

If so, it seems quite possible you are a math genius.  You see, we can’t really answer that question based on existing cognitive tests.  But we do think that we’ve developed some ways of understanding the cognitive factors that make some people better with numbers than others.  One of those cognitive factors seems to be a person’s “gut number sense”, or her/his ability to precisely estimate and compare quantities visually, like in the blue and yellow dots image above.

This summer, my colleagues and I published a paper based on data from a group of 10,000 participants who came to TestMyBrain to learn about their ability to visually estimate numbers:

Halberda, J., Ly, R., Wilmer, J., Naiman, D., and Germine, L. (in press) Number sense across the lifespan as revealed by a massive internet-based sample. Proceedings of the National Academy of Sciences.  doi:10.1073/pnas.1200196109 

In a nutshell, we found that people’s ability to visually estimate quantities was related to their performance in school mathematics.  And this relationship held whether the person taking the test was a teenager or recently retired.   We also found that people around age 30 had the best gut number sense, with huge variations in how well people scored at every age group.

Our study got a bit of media attention and you can read more about the experiment and what we found here and here.  Although all 10,000 people who participated in this experiment were tested through, the test is no longer available on our site.  If you want to give it a try though, you can by going to Professor Halberda’s site at

So take the gut number sense test, if you feel like learning a bit about your gut number sense.  Take a math test if you feel like learning a bit about how good you are a math.  And check out the awesome data visualization that colleague and coauthor Ryan Ly made, showing the relationship between gut number sense and school math ability across the lifespan.

* You’d be correct if I was not lying to you.  There are actually more blue dots (14 blue vs. 12 yellow).  Were you fooled?  Guess it depends on how good your gut number sense is.


Posted in Citizen science, Human uniqueness / individual differences, Publications, Visual processing, Why take cognitive tests | Tagged , , , , , , , , , , , | 1 Comment

What being a mother does to your brain

In this post, I want to talk about motherhood.   Not just because I am a mother and feel the need to have a “hear me roar” moment, but also because becoming a parent reshapes who you are — not just the things you care and worry about, but also fundamental aspects of the way your brain works and the way you think.

When I was pregnant with my son, I had this elaborate delusion of what “normal” life as a mother would be like. I had a vision of my home with a baby in it — our usual furniture plus some plastic dealies in the electric outlets for safety and maybe a little stuffed Elmo tucked in the corner.

Someone else's living room.

Instead, this is what happened to my home:

My living room.

I think my living room provides a nice metaphor for parenthood, in general.  Being a parent really takes over your life.  It hijacks every bit of your free space and time, and uses your brain for its own purposes.

For example, I can never seem to remember what day of the week it is or to put money in parking meters.  In fact,  I’ve gotten as many parking tickets in the last year as I had in my entire life before that!  I have, however, become really good at spotting danger.  Harmful threatening things like pen caps and rubber bands that my one year old will put in his mouth faster than you can say the word “No!” (not that it would have made a difference).   I have also developed the very typical mama bear syndrome.  As in the somewhat disconcerting “if you mess with me I will destroy you” feeling that seems to boil up from somewhere in my midsection every time someone does something that threatens my child.

Although research with humans is somewhat limited, studies on the effects of motherhood in other mammal species have pointed to some pretty remarkable brain changes that accompany becoming a mother.

In one study, for example, researchers looked at female rats who either had rat pups or had never been pregnant to see how good they were at acquiring food.  When the rats had to remember the location of food in a maze, the mama rats were able to remember and locate the food much more quickly than the footloose and fancy-free rats that had no pups.   Interestingly, it wasn’t just pregnancy and postpartum hormones that were responsible.  Never-pregnant rats that were given foster pups to care for also showed superior food finding abilities than pupless rats.  So, it seems that something about being exposed to and caring for rat pups also gives a boost to cognition and foraging ability (1).

When researchers looked at the brains of mother rats, they found differences in the structure and functioning of an area called the hippocampus.  The hippocampus does a lot of things, but is most well-known for its role in memory formation and spatial navigation.  For example, mother rats showed massive increases (as much as 10-fold) in the expression of particular genes related to memory, learning, and spatial cognition (2).

The researchers noted:

“Neural activity brought about by pregnancy and the presence of pups may literally reshape the brain, fashioning a more complex organ that can accommodate an increasingly demanding environment.” (1)

But navigating and remembering food location isn’t all rat mothers are good at.

In another study, researchers found that mama rats were also better at capturing prey.  When pupless female rats were let loose to find and kill a cricket hidden in a pile of wood chips, they took an average of about 4 1/2 minutes.  Mama rats, on the other hand, took less than a minute for the same task (3).  The researchers suggested that these differences had little to do with hunger, better cricket smelling abilities, or better hearing, but rather with changes in visual processing that gave an advantage to the mother rats (2).

So, mothers, fathers, and people without pups: what is the take home message?

(1) Motherhood (and parenthood, in general?) may have a profound impact on the brain and on cognition, highlighting how the differences between us that make us unique can be related to major life changes like becoming a parent.


(2) Don’t mess with Mama, because she will hunt you down.*

If you are interested in learning more, I suggest reading the article below from Scientific American, that goes into a lot more detail than I did here:

Scientific American: The Maternal Brain

* Please note this last statement is extrapolating way beyond the data and should not be taken as scientific fact.  It’s just that there are precious few opportunities to feel tough when you have your kid’s breakfast still stuck in your hair, so I couldn’t resist.

1.  Kinsley, C.H., Madonia, L., Gifford, G.W., Tureski, K., Griffin, G.R., Lowry, C., Williams, J., Collins, J., McLearie, H., & Lambert, K.G. (1999).  Motherhood improves learning and memory: Neural activity in rats is enhanced by pregnancy and the demands of rearing offspring. Nature 402(6758), 137-138. doi: 10.1038/459572.
2. Kinsley, C. H., & Amory-Meyer, E. (2011). Why the Maternal Brain? Journal of Neuroendocrinology 23, 974–983. doi: 10.1111/j.1365-2826.2011.02194.x3.
3. Kinsley, C.H., & Lambert, K.G. (2006).  The Maternal Brain. Scientific American 294, 72-79. doi:10.1038/scientificamerican0106-72


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Human uniqueness in visual processing: Bipolar disorder and perceptual switching

As an undergraduate, I confess, I thought studying vision was pretty much as dull as it gets.  As far as I was concerned, vision was mostly about rods and cones and the occasional blob neuron… and at the time I was really interested in WHO WE ARE.  I wasn’t sure what that meant, exactly, but I was pretty sure everyday visual processing had almost nothing to do with it.

In retrospect, my view was somewhat short-sighted (get it? ok, moving on).  I’m not going to be too hard on my younger self though, as the field of vision science hasn’t cared much about human uniqueness and who-we-are-ness* until pretty recently.  Nowadays, vision scientists understand that people differ from one another in many types of visual processing, and that these differences may have important consequences.

So back in time again to me as an undergraduate, ca. 2003. I was sitting in yet another lecture featuring disembodied eyeballs, when the instructor (Dr. David Presti — one of the best instructors I’ve ever had the privilege of learning from) started talking about the way people differ from one another in something called perceptual switching.

Certain types of visual images can be ambiguous or difficult for the brain to interpret.  Take the so-called Necker cube (you can also try this experiment through the BBC):

This cube can be interpreted in one of two ways, depending on which edge of the cube you perceive as being the closest to you.   Your brain tends to switch between these two views as it tries to make sense of the image.

Here is another neat example, Nobuyuki Kayahara’s spinning dancer.

Go ahead and click on the image if you don’t see her spinning.  Most people see the dancer spinning in one direction (e.g. with her right foot on the ground), but if you look for long enough you might see her spontaneously change direction and start spinning the other way.

In the 90s, an Australian scientist named Dr. Jack Pettigrew and his colleagues began to study the relationship between these switches in visual perception and  the switches between extreme positive and negative mood that characterize bipolar disorder.   People with bipolar disorder experience strong mood states that last a long time relative to the mood states of people without bipolar disorder.  Dr. Pettigrew reasoned that people with bipolar disorder might have a sort of “sticky switch” that makes their brain more likely to get stuck in certain mood states.  If this is true, a person with bipolar disorder might also find their brains get stuck in certain perceptual states.  When looking at these ambiguous visual images, someone with bipolar disorder might see the same image for a longer period of time before a perceptual switch occurs, as compared with someone without bipolar disorder.

So Dr. Pettigrew and his colleagues brought people with and without bipolar disorder into the lab.  Each person participating in the experiment was shown a different image in each eye.  The person’s left eye, for example, would be shown this image:

Their right eye, on the other hand, would be shown an image like this:

As a result of their brain’s effort to resolve these two conflicting images, a person would see the image switching between a circle with horizontal lines and circle with vertical lines, through a process known as binocular rivalry.

Each person was asked to say when the image switched from horizontal lines to vertical lines and vice-versa.  Interestingly, each person had a fairly consistent rate of switching.  For one person, their perception of the image seemed to switch every second.  For another person, their perception of the image switched every five seconds.  What was even more interesting though was that people with bipolar disorder seemed to have much slower rates of switching than people without bipolar disorder.  In other words, the same people who tended to get “stuck” in lengthy periods of extreme elation, irritability or depression (i.e. people with bipolar disorder) also had brains and visual systems that got “stuck” perceiving particular images.

This shocked me.  That some basic aspect of visual perception could be related to someone’s risk of mental illness was not something that had ever really occurred to me.    After a decade in the field I now often take this idea for granted — how we see the world is important, how could it not be?  At the time though, for me, it was a completely new way of thinking about the brain and what it means to be an individual.

David Presti’s lecture on bipolar disorder and perceptual switching was a point where my life changed a little.  A few years later I ended up in graduate school studying the development of mental disorders (in one lab) and visual perception (in another lab).  In fact, much of the work on is aimed at understanding the way human uniqueness in visual perception might be related to a person’s broader experiences in the world and their mental health.

So help us out, and participate in an experiment!  (And thank you, if you already have!)

And here is the paper I’ve discussed above, if you are interested:

Pettigrew, J.D., & Miller, S.M. (1998) A ‘sticky’ interhemispheric switch in bipolar disorder? Proceedings of the Royal Society B: Biological Sciences, 265(1411), 2141-2148. DOI: 10.1098/rspb.1998.0551

Also, Dr. Pettigrew’s commentary on the spinning dancer illusion:

*Who-we-are-ness is not a technical term, but is used here to refer to my early ideas about human uniqueness and individual differences.

Posted in Human uniqueness / individual differences, Mental disorders, Visual processing | Tagged , , , , , , , , , , , | 3 Comments

What a science conference and a 5th grade classroom have in common

I just got back from an extended period of traveling that included attending the annual meeting of the Vision Sciences Society in Florida, where I got a chance to meet up with colleagues and present some of my latest work.

I remember in my 5th grade class we had an event called “World Peace Day” (or something similar) where we got into small groups and made posters that illustrated our idea of World Peace.   My group made a poster of stick figures wearing outfits that represented different countries (Disney’s “It’s a Small World” style) and all gathered around a giant symbol that turned out to be the Mercedes logo:

Peace vs. Mercedes

Not the same thing


Once I finished grade school, I assumed that the poster making phase of my life had ended.  Then I entered the world of scientific conferences where posters are a standard way of communicating with other scientists about one’s latest work.  Nowadays, I avoid crayons and try not to include advertisements for luxury car companies.

Here is how the path from research to poster typically works:

  1. Have idea, do experiment, analyze data, hopefully discover something.  (i.e. SCIENCE)
  2. Make a poster showing  your experiment and what you learned from it.
  3. Go to a conference and stand by your poster while other researchers walk by.
  4. Give anyone who stops at your poster a brief presentation about your work and answer their questions.

Here is a picture of someone presenting their poster at the most recent Vision Sciences Society conference.  A colleague of mine solicited the photo, so I’m not 100% sure who this person is, but he does look like he is serious about his work while also conveying a sense of humor:

Guy explaining some sort of hand/face experiment

The VSS conference is a GREAT conference.  It attracts a lot of researchers who are interested in all things visual, PLUS it’s held in a resort hotel right on the beach in Florida.  This means you can spend your day: (1) attending symposia and absorbing science, (2) drinking cocktails by the pool and absorbing sun, (3) looking at posters while you catch up with fellow researchers, and (4) lying on the beach while you catch up with fellow researchers.  So you leave the conference feeling glutted on science, sun, and sand.  Thoroughly awesome.

I’ll spend the next few blog posts talking about human uniqueness from the perspective of vision science.

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Do you suffer from face blindness? Seven signs and symptoms of prosopagnosia

If you read my previous post on the role of cognitive assessment in identifying uniqueness, you’ll know that I’ve worked with a lot of folks who suffer from severe difficulties recognizing faces: a condition known as prosopagnosia or face blindness.

I get a lot of  emails from people who take the face recognition tests on and want to know what sorts of experiences might indicate that someone has face blindness.   If you suspect you have face blindness, you may find you identify with some or many of the experiences below.

7 signs and symptoms of face blindness / prosopagnosia
The list was compiled with the help of the Yahoo Faceblind group.

  1. You have failed to recognize a close friend or family member, especially when you weren’t expecting to see them.
    • Failing to recognize someone in your immediately family, in particular, is something that people with normal face recognition rarely (if ever) experience.  Horror stories include things like picking up the wrong child from daycare or failing to recognize your spouse in your own home.  We tested one family of people with face blindness who wore name tags at family reunions!  Says one woman with face recognition difficulties: “Put my daughter in a crowd, shave her head, and I wouldn’t recognize her unless I knew she was in that crowd.”
  2.  When you meet someone new, you try to remember their hairstyle or a distinctive feature rather than their face.
    • This is a common coping strategy.  One person with face blindness notes that remembering people can be stressful when you are constantly taking this approach: “I must remember that it’s Mary who owns the brightly colored brooch, and John is the one with the limp.”  Another person with face blindness notes, “[I] find it easier to recognize people from a back view than face-to-face.”
  3.  You have trouble following films or television shows that have more than a few distinctive characters.
    • Do you confuse characters in movies or on television more so than other people?  Some people with face blindness avoid movies and television for this reason, although one sufferer notes “I’ve never had problems with cartoon characters!”
  4. You have failed to recognize yourself in the mirror and/or have difficulty identifying yourself in photographs.
    • Failing to recognize yourself can be a disconcerting experience, but is not uncommon among people with face blindness.  Self-recognition can be especially difficult in childhood photographs or when distinguishing oneself from a sibling.
  5. When someone casually waves or says hello in the street, you more often than not don’t know who they are.
    • Explained one person with face blindness: “While friends seem to meet people they know all the time, [I] rarely seem to run into acquaintances.”  Some people use the technique of just smiling at anyone they encounter:  ”You are friendly to everyone, just in case they might be someone you know.”
  6. When someone gets a haircut, you may not recognize them when you see them again.
    • Many people with face blindness use hair as a way to remember people.  When a person’s hair changes, that memory cue is lost.  The mother of a child with face blindness recounted how her son would become very upset if she approached him suddenly with her hair pulled back or after a shower (i.e. when her hair was wet).
  7. You have difficulty recognizing neighbors, friends, coworkers, clients, schoolmates (etc.) out of context.
    • People you know expect you to recognize them.  Failing to recognize someone might make you seem aloof.  Many sufferers report losing friends and offending coworkers because they have failed to recognize them.

Face recognition tests like this one can sometimes help identify a face recognition problem.  However, please note that some people with face blindness still score well on these sorts of tests!   We are only beginning to understand the differences in visual perception and memory that might contribute to face blindness, and there are likely many types of face recognition problems that our tests simply don’t tap into.

I hope this list is helpful to some of you, or at least thought-provoking.  I’ve tried to keep it simple, but if there is anything  you’d like to share please feel free to leave a comment!


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