Tuesday, October 31, 2006

Elephants Have Self-Concept

The Proceedings of the National Academy of Sciences will be releasing a study soon that shows elephants can recognize themselves in a mirror.

Among animal psychologists this is taken as evidence that they have a sense of self, a self-concept. Researchers gave three captive elephants the mirror and mark tests that were invented in the 70s by Gordon Gallup, a psychologist. Animals who don't recognize themselves in the mirror either ignore it or attack it. Those who do understand they are looking at themselves often inspect parts of their bodies that they can't normally see.

Chimps check out their behinds, the inside of their mouths, and their eyes. Elephants evidently do the same thing. The mark test is a variation on the mirror test. Visible and invisible paint is placed on either side of the individuals head and then observers watch to see whether the painted animal touches the visible paint spot but not the invisible one.

Members of all great ape species (chimps, bonobos, gorillas, orangutans) have passed these tests, but not all individuals do. Infants and juveniles don't "get it" and neither do infant humans. There is some developmental process that has to happen first, but at some point in time, usually by their first birthday, all normal humans understand the mirror image. Adult dolphins are the only other non-ape to pass these tests — that is up until now.

What's really amazing is that through evolution by natural and/or sexual selection, three very different kinds of critters all wound up with an ability to understand themselves. I wonder if this means they are conscious beings. Do they think about themselves? What do they think?

A while ago when Marc Hauser, a monkey psychologist who has done research on captive marmosets, released his book *** Wild Minds (excellent!!) the NY Times ran an article with a sidebar on testing your dog for self-concept. Max flunked it miserably. As far as I can tell he thinks mirrors are utterly boring. When we got our new pup I was keen to observe her in front of mirrors. We hadn't hung one of ours yet so it was on floor level with her. She was very, very interested in it but didn't do anything that confirmed in my mind that she knew she was looking at herself. I think she may have thought it was one of her litter mates. When we walked her around campus the first few times, she'd spot her reflection in the windows of doors. I think her reactions to them speak more of her outgoing, interested-in-other-dogs personality than her self-concept. Perhaps she does know the image is her, perhaps not. Either way, it's still fun to watch her watch herself. For that matter, it's also fun to watch her watch TV. She really loves dogs and balls. Max never pays attention to TV. Because of these differences I find it hard not to think that Max's new pal is smarter than he is. I think we humans assume that anytime another animal does something human-like that means it's "smart" even if it's a dumb as watching TV.

Some headlines on the elephant self-concept story reflect this assumption.

*** Adult captive cotton-top marmosets have passed these tests according to Hauser's research. He used day-glo neon pink Manic Panic hair dye to color the marmosets' stark white mohawks. This got them to look in the mirrors long enough to realize themselves staring back. Monkeys perceive direct eye contact as a threat (as do dogs) so their instinctual response is to retreat or attack. If they could just get over the eye contact part of it, it's possible that species who respond to eye contact this way would be able to "pass" the tests.

Feral Children

From Romulus & Remus, the mythical founders of Rome, to Mowgli, immortalized by Rudyard Kipling, stories of children raised by animals fascinate students the fictional boyof introductory psychology. The Legend of Tarzan isn't complete fiction. There are plenty of real cases of "feral children" who have grown up to be something other than human, halfway between man and beast. The children seem genuinely wild; having no language, they communicate only in grunts resembling the sounds of whatever animal raised them. Many crawl rather than walk. It takes years to socialize them to live semi-normally among humans and many never learn to talk.

One of my enterprising students showed me this neat website devoted to feral children.

Some wild children have been raised in isolation, as was Genie, who was kept in a closet most of her life with no interaction with anyone. She is probably the best known case of a wild child in this country, but looking at this list it's clear she's got no shortage of company. It seems that many feral children turn up in India. "One explanation is that women with young children or babies would leave their infants at the edge of a field while working, and wolves would emerge from the forest and steal them," says the feral children website.

I think these cases are fascinating because they reveal just how vital early experience with other members of our species is to normal human development. Without contact with others of own kind, particularly adults, humans don't grow up to speak, walk bipedally, or wear clothing. It's not 100% instinctual to do so.

These stories also demonstrate that some animals, dogs and primates, may actually take care of a human infant. One theory is that maternal care is instinctively "released" by cuteness (small body, big head, large eyes, soft wimpers) and that humans are sufficiently cute to some other animals to stimulate the maternal instinct to care for them. It's a little like a vireo feeding the cherry red gaping mouth of the cuckoo who parasitized the nest simply because it's instinctual to drop food into a gaping mouth. Brood parasitism is one of the neatest things that happens in the animal world.

Wednesday, October 25, 2006

Soy & Phytoestrogens

Last week I finished reading an article from Hormones and Behavior about the metabolism of hunger and sex drive. Within it, I learned some more interesting factoids about the consequences of ingesting soy. I think I drink a lot of soy, and I also eat tofu occassionally, so I am interested.

I'm still trying to wrap my head around the wide-ranging article, to fit the pieces together myself, so I'll just report some of the more interesting elements of the story.

1 - Fat cells have estrogen receptors! Mice without working estrogen receptors become obese.

2 - Body fat distribution is more critical to long term cadiovascular health than body fat content or BMI. Gluteofemoral fat deposits are cardioprotective. So, if you have an hourglass figure (narrow waist with wide hips and fleshy butt and hips - an hourglass/pear figure rather than an apple) you're at reduced risk of heart disease. Also, women with a .70 waist to hip ratio (the hourglass figure) have higher fertility.

3 - Insulin levels are associated with visceral (deep belly) fat, whereas leptin levels are associated with subcutaneous gluteofemoral (butt, hips, thigh) fat. Hormones of the HPA axis (hypothalamus - pituitary - adrenal glands), such as cortisol, are also implicated in body fat distribution. Stress may cause you to put on more visceral fat.

4 - Eating disorders (of which the author seems to be primarily interested in obesity) may arise from changes in neural sensitivity to estrogen that occur early in brain development.

5 - These changes might be intitiated by exposure to phytoestrogens in our diet and pollutants.

So, evidently, consuming soy is cardioprotective and reduces the risk of developing obesity only when consumed as an adult. BUT - and this is a big but - consumption of soy during pregnancy or exposure of a fetus to soy and phytoestrogens actually increases the risk of cardiovascular problems and obesity.

Pregnant women and infants should not consume soy or any products containing phytoestrogens because the phytoestrogens bind to the body's estrogen receptors in the brain, various internal organs, and particular body cells like fat cells. This leads to organizational changes in the infant's brain that masculinize a female's body fat distribution after puberty: more visceral fat around the waist, less around the hips and butt. This places her at greater risk of developing heart disease and obesity.

The paper, however, focused on an evolutionary theory that there are brain mechanisms dependent on hormones that serve to signal an animal when it's time to eat vs. mate. The author explored the metabolic control of hunger inhibition, arguing that such a mechanism is adaptive because it would "bring the cessation of hunger and eating long enough to find and court potential mates." She suggests that the hormone leptin, known as a hunger hormone because high levels of it inhibit appetite, should come to be viewed as a sex hormone too. Evidently, leptin enhances sex behavior - in rats and mice. It stimulates the preference of having sex over eating. The author also argues that the hormone neuropeptide Y which is known as an appetite stimulant, should also come to be viewed as a sex hormone that stimulates the preference for food over sex.

Monday, October 23, 2006

Psychology News Roundup

We all have ideosyncratic facial expressions. My guess is that more than once you've realized that you exhibit some of the same facial mannerisms your parents do. I noticed a while ago that I purse my lips the same way my mom does. Not so long ago my husband commented during a conversation that I had just made a facial expression that is typical of my youngest sister. I really didn't believe him. How could I have picked that up from her, or her from me? We have never lived together and haven't spent a ton of time together. Do families share similar facial expressions? If so, why?

A recently released study in the PNAS suggests there is a genetic basis for shared family facial expressions.
Read more.

In other news, Giant Pandas appear to have some capacity to see in color! Read more here.

Charles Dickens had a keen eye for the observation of neurological disorders, so perfectly describing the symptoms of Tourette's, Parkinson's and "restless legs syndrome" that medical reference texts at the time used his character desciptions. Although he had no formal knowledge of psychological conditions, he had tremendous skills of observation. Read more here.

Pulfrich's Pendulum

The teaching of psychology listserve I subscribe to presented an interesting vision demo that I haven't tried yet, but want to.

Here's how it goes:
Slowly swing a golf ball attached to a string from side to side. The string should be about 3.5 feet long. You'll need to stand on a chair or table for this to work well. Students hold a shaded filter over one eye while viewing the moving ball. A 2 inch square of colored transparent material will work just fine. They will perceive the ball moving in a circular fashion. When you have them move the filter to the other eye, the ball will move circularly in the opposite direction.

Why does this happen?

Lower contrast stimuli are perceived by our visual system to more slower than higher contrast stimuli. The filter reduces the contrast in just one eye so the subjective speed of the ball in that eye is slower. It appears to lag behind. To the brain, that difference in speed is perceived as a disparity between the two eyes in the distance of the object. The resulting impression is a ball moving along an elliptical path. The illusion is known as Pulfrich's pendulum

More interesting apparent motion information can be had here.

That website suggests that a similar effect can be achieved by watching a TV set to a vacant channel with one eye covered by sunglasses. The "snow" will appear to swirl. Switch the filter to the other eye and it will swirl in the other direction.

Stereoblind people, who can't fuse random-dot stereograms (i.e. MagicEye pictures), still perceive the apparent motion of the Pulfrich pendulum. The authors conclude that stereoblind people retain some residual binocular mechanism for depth perception.

The apparent motion effects caused by difference in contrast arise from the different speeds that neural impulses have when conducted down the optical nerve. High contrast stimuli travel faster. The symptoms of multiple sclerosis result from slower neural conductivity brought on by the deterioration of the myelin that insulates the axons of neurons. Without insulation, electrical impulses travel slower. It's possible that people with MS, cataracts, or some other neurological condition that affects the speed of neural impulses in just one eye could experience Pulfrich-like effects.

Friday, October 20, 2006

A Natural History of Peace

Robert Sapolsky, neuroscientist and primatologist extraordinaire, wrote A Natural History of Peace a while back for Foreign Affairs. I just discovered it today. It's long so I'm archiving the link here so I'll be able to retrieve it easily later.

Sapolsky is a fantastically funny writer and is razor sharp. I've read his Why Zebras Don't Get Ulcers tome about how stress affects the immune system and brain. He's known for his discovery that the hippocampus (for memory) shrinks over time from chronic stress. If you are at all interested in stress and health, I very much recommend it.

The Trouble With Testosterone, his collection of short essays reprinted from pop science magazines, is also very good. "Curious George's Medicine Cabinet" is my favorite essay from the collection. It's what introduced me to zoopharmacognosy, the study of animal self-medication with plants and other substances. It inspired me to include a unit on that topic in my primate class. Did you know that chimps travel out of their way to eat a particular kind of leaf with spines that removes their intestinal parasites when swallowed whole? How about the habit of clay eating that spider monkeys and other primates indulge in when they need a little natural Kaopectate? Or lemurs that rip open certain millipedes and rub the juices over their fur to repel insects? All are examples of animal self-medication.

For a hilarious read on what it's really like to be a field primatologist, check out A Primate's Memoir. His stories about drinking the local beer are worth the read alone.

Sapolsky is one scientist I would be very, very excited to meet. If you ever get a chance to hear him give a lecture, GO!!

Thursday, October 19, 2006

Newfoundland Photo Collage

Evidently the recent lack of news about The Baroness von Roughenhausen has come to the attention of some loyal readers. Here's an update.

Katy now weighs about 80 pounds at seven months old and is still up to her old ankle shark tricks. She has what we've affectionately started calling 'nonregulation Newfy ears.' They're really long and her adult coat hasn't fully grown in yet, so she's got a bit of a mad bomber hat look about her which is made ever so endearing when she just wakes up and strolls in to say hello, face pointed at the floor, ear flaps flopping.

Besides being the Baroness von Roughenhausen, she's also known around here as the Mad Bomber.

She still likes to pounce on Max, intimidate him into dropping his bone, and run him off the road so to speak. She likes him though and when she lingers around outside longer than I'd like to, all it takes to get her excited about going back inside is a quick "Wanna go find Max?"

She invites him to play constantly but he always turns her down. She has to settle for his snarling versions of play.

She loves to lick the inside of his ears. Ewww gross. At least someone else is cleaning them these days! It's as affectionate as they get... except for the times we come home and find them sleeping on the couch together.

We take her down to campus to let her run off some steam off the leash on Ankeny Field. She loves to play chase and fake-tackle. She still gets really hyper at least once everyday at home. She tears ass around the house, running a circuit from the front to back as fast as she can go, sometimes running a figure eight around some barrier. When she's done I have to go around and straighten out the rugs. We can always tell if she's had one of these hyper fits while we've been gone because the rugs are out of whack.

She is fascinated by the shower. Whenever I get one started she pokes her head in to take a drink. Sometimes I form a little cup with my hands to assist her gulping. She comes in to visit every so often during my showers too. To rewet her head? Check on my progress? See if I need a rescue? Newfoundlands were bred to be water rescue dogs afterall. One time while I was shaving my legs she poked her head in and licked my butt. I had no idea that was coming, but now I know not to turn my back on the curtain! There could be a Newfy tongue waiting to ambush me. I think she just likes to get her head wet. Once her ears dry out she looks like she's just visited the bedroom beauty salon of a thirteen year old girl in the 80s, major crimping action!

I'd love to see her swim with Alasdair. That would be an absolute riot.

This morning she had a decidedly non-Newfy day. She refused to go out in the rain. WTF? It was really bizarre. I expect that from Max but not her. Maybe she's feeling a little off given her bladder infection. We noticed her 'urinary incontinence' problem over the weekend. She got to spend a night at the vet and came home with not one but two bottles of Cephalexin because of her S.I.Z.E. I guess she really is big. She's still very much a puppy though.

She learns quickly and has mastered SIT, LIE DOWN, COME, GIVE and all of the accompanying had signals. We need to work on stay. I suppose she could learn a few more tricks too. She knows shake. We haven't taught her roll over or circling yet. They seem kind of boring because Max does them with such gusto. Any ideas for cool tricks to teach a smart dog? I suppose we could teach her to speak on command. Max doesn't vocalize enough for us to have taught him that, but Katy has a whole range of things she 'says.' Her bark is serious and sounds like something a bloodhound or basset would produce. She also gives a hilarious yowl-moan when she flops down.

She's a wonderful dog. We've had yet another Hug Your Newfy Day today.

And, she is much prettier than the Newfoundlands featured in the calendar that arrived today courtesy of my dad.

Wednesday, October 18, 2006

Hardly A Day Goes By

Yesterday my dear sweet Man With Fins told me a hilarious story about someone who proposed to write a science column for the local newspaper that he edits. The lead for one of the columns read "Hardly a day goes by without thinking about DNA..."

I doubt that's true even for geneticists, so we collectively laughed uproariously.

Ironically, today I realized that I really had been thinking about DNA for the last couple of days because of a short article I read in The Economist about epigenetic imprinting. In short, mice that are licked and groomed by their mothers early in life grow up to handle stress better because that early experience adds a little chemical to a portion of their DNA which then changes the way that gene works. So, you could have identical genes expressed differently in two different people because they have different life experiences. The article paints a much more interesting picture of this. I certainly recommend reading it!

Among other things, epigenetic imprinting has been hypothesized to play a role in cancer and mental illness.

October is Breast Cancer Awareness month. This morning I heard a statistic that 90% of women who get breast cancer have no family history of it. I've also heard that aluminum in anti-perspirant has been linked to breast cancer, BUT did you know that epigentic imprinting may play a role in breast cancer and your weight at birth might be a risk factor?

A paper released this month in the International Journal of Cancer proposes that premenopausal breast cancer may originate in utero. That's right ladies - before you were even born your cells might have been marked. A higher weight at birth increases a girl's chances of getting breast cancer. "Loss of imprinting of growth hormone genes relevant for intrauterine growth, such as insulin-like growth factor 2 (IGF2), leads to abnormally high levels of these hormones evidenced by high birthweight," the study says.

I wonder how gestational diabetes plays into this. Women with gestational diabetes are at risk for having a baby that grows too large. Perhaps too much glucose causes the baby's genes to fail to turn off the growth factor?

I drink a lot of soy milk so I read this other abstract that says agoutis (cute rodents that can be seen in Belize and Guatemala where I saw them) not only change their hair color in response to ingesting phytoestrogen that is present in soy, but also receive protection from developing obesity by, you guessed it, the way the phytoestrogen changes how their DNA gets expressed. What's also interesting is that they say phytoestrogen is linked to "diminished female reproductive performance." Does that mean I harm my fertility by drinking soymilk?

More interesting genomic imprinting information can be found at geneimprint, a site set up by Randy Jirtle, an epigeneticist.

Friday, October 13, 2006

An Island of Colorblindness

I don't spend much time thinking about what life would be like if I couldn't see the difference between cyan, turquoise, indigo, cerulean, and azure or even between red and green, but after watching Oliver Sacks documentary "An Island of Colorblindness" I have a whole new appreciation for being a trichromat. The documentary chronicles the rare condition of achromatopsia that affects many of the residents of Pingelap, an atoll in the South Pacific. People with the condition see entirely in shades of gray.

Achromatopsia is caused by a genetic mutation that results in the complete or partial absence of cones, the retinal cells that translate photons of light into color with a bit of help from the brain. Light doesn't have any color to it all; color is a construction of our visual system. For the people with achromatopsia on Pingelap, vision that is dominated by rods instead of cones presents its own set of challenges. They have poor visual acuity and sunlight is very painful. They look down virtually all of the time during the day, squint, and blink a lot.

Now that sort of photophobia was actually something I could empathize with; I've experienced that fairly often and acutely so after a brush with something called microcystic edema. I had extreme sensitivity to light, couldn't see to read unless I held the pages about 5 inches from my face, and saw huge rainbow halo around lights. It was awful - there was no treatment, no correction for my vision available - but fortunately it cleared up on its own and hasn't appeared since. Phew. I also stopped wearing contact lenses.

That's probably the last time I thought seriously about vision until I took a graduate level class on vision. I've thought about it a lot since then too. As a psychology professor it's an occupational requirement. And as a primatologist I've read a paper or two about the evolution of color vision among primates. Some species of monkeys are dichromats - they have only two kinds of cones and see much like what most people think of when the term colorblind comes up. Scientists believe the ability to distinguish red from green helped newly evolving diurnal monkeys spot edible leaves and fruit better in the daytime. Previously, monkeys had been nocturnal and ate insects and tree sap. Monkeys who could distinguish colors in the daytime could exploit new niches. They thrived. As a dabbler in art, I appreciate matching and mixing colors for the most pleasing aesthetic effect. But, I take for granted the ability to actually see in color.

Los colores son mi vida is the motto of my impressively talented and successful mother-in-law who weaves multi-colored palettes of yarn into beautiful fabrics. My husband weaves too. They have an entire vocabulary of color terms that never fails to impress me when I eavesdrop on their plans for "warping the loom." I might look at a selection of threads and call them purple while they toss around terms like plum, violet, lavender, eggplant and more. While watching the story of the Pingelapese I was struck by how totally unnecessary such an advanced linguistic library would be for them.

Thursday, October 12, 2006

Science of the Mind

I'm always on the lookout for cool stuff to use in intro psych classes, my primates class, or in a new line of research. Here's a random selection of stuff I've found lately.
Be sure to read the five star story!

Neuroscientist Ramachandran on his theory of the evolution of consciousness. I really liked his reference to lemurs.

The BBC is airing a new show "Chimps Are People Too," a documentary with Sue Savage-Rumbaugh and Kanzi, the bonobo famous for his language and Pac-Man playing skills. As far as I can tell, having not yet seen the show, it's about pointing out the similarities between humans and non-human apes that reveal qualities of "personhood." Granting them special status as "people" would of course entail a major change in how laboratory research is done, not to mention keeping them on display in zoos. This is the goal of the Great Ape Project.

My dissertation committee cheerleader has been getting a lot of press for her newly published article on cryptic ovulation. The popular press headline floating around reads: "Fertile women dress to impress, U.S. study finds." It's classic evolutionary psychology stuff. Ethologist Karl Grammer discovered about ten years ago that women who are ovulating show more flesh at singles bars. Haselton found the same thing happened for college students who were asked to show up at her lab two different times to participate in a research project. When the women arrived during the time they were ovulating and most likely to become pregnant if they had sexual intercourse, they wore more revealing clothing, flashier jewelry, and more trendy clothes.

This fits with the idea that although humans don't overtly advertise when they are ovulating (as some primates - chimps, bonobos, baboons - do with giant pink ano-genital skin swellings), they still send cryptic signals that they are fertile. The science reporting in the press releases and interviews is rather dismal. "Another non-winner for science writing skill" says my scientifically astute journalist husband. He's also heard me lecture on this subject before! I'd like to see these articles get into why this is significant and worth talking about on a theoretical level.

See, knowing that a species overtly advertises ovulation tells us about that species' ancestral social organization.

Fewer than 10% of female primates overtly advertise when they are most likely to conceive. This information is very valuable for males because they can use it to avoid wasting time and energy courting a female who is not likely to become pregnant. What's really interesting is that solitary primates (like orangutans) do not have the visible swellings that are so pronounced for chimps and baboons. Monogamous species don't overtly advertise fertility either. You would think that being solitary would raise the stakes for males. Ditto for monogamous males. If they know when their mate is most fertile, they can guard her when she is and prevent other males from inseminating her. Monogamous and solitary species should overtly advertise, but they don't.

When we survey the primate species that have overt advertisements of ovulation, we see they tend to live in multi-male, multi-female social groups in which females mate with multiple males more or less indiscriminately. A female chimp typical mates with nearly every adult male in her group when she sports the equivalent of the human female's short skirt, plunging neckline top and flashy jewelry. In other words, the general rule of thumb is that cryptic ovulation (the subtle changes in appearance that Haselton found) are associated with species that have relatively monogamous females. Species in which females flaunt their fertility tend to be composed of Nelly Furtado-style promiscuous girls.

Thus, based on this evidence for cryptic ovulation among humans, we can infer that our ancestors may have evolved in groups that tended to be composed of one male with a female or group of females who tended to be relatively monogamous with him. Other lines of evidence from comparative anatomy (testicle size and penis length) suggests instead that our ancestors probably lived in groups with a significant amount of male-male competition over females and female promiscuity to drive males to evolve relatively large testicles (more sperm) who could then win paternity at the level of sperm competition.

My own guess, and that is all it is, albeit a professinal one (!) is that human ancestors tended to be monogamous but did cheat opportunistically and regularly. Having totally concealed ovulation means that a male never knows when to guard the female, so he has to be present all of the time, thus we get pairbonding. If ovulation is slightly noticeable, a woman might use her subtle signals to achieve an extra-pair courtship, a secret lover if you will.

Is that so hard to work into a story?

Male and female voices are processed differently by the brain which suggests that perhaps male and female brains have different ways of working out dominance differences based on voice. One reader commented, "It looks like the team stumbled on a key to the mechanism that works out dominance in the male status hierarchy." This is related to a study I reported on back in August about female preference for deeper, more dominant/masculine male voices. It's a great post, definitely worth a read if you want to learn more about evolutionary psychology! In a nutshell, that study provided evidence that male voices have been sexually selected to be deeper. The study I just found provides evidence that these differences might show up at the level if neuroanatomy, an important link between evolutionary theory and actual behavior. Another study "Men Act Like Dogs to Show Dominance" identified that men unconsciously lower their voices when talking to someone they think is less dominant. In essence, whoever has the lower pitched voice signals dominance.

My undergraduate thesis explored dominance displays through eye contact. I should blog about that some time... I think it's better than my MA thesis. Hell, it might be better designed than my dissertation. All of my college friends (who are probably the only ones still reading this lengthy post) remember well my knack for writing dissertations in college. We all thought it was just a joke, but it turns out there was a healthy portion of truth to it.

Anyhow, I have been toying with the idea of launching a new research project once I finish my dissertation. I'd like to explore human female vocal dominance. The authors of these studies imply that it's not worth it to study modulation of female pitch in social contexts because women have not been sexually selected to have higher pitched voices. That may be, but I think these *guys* who published those studies might buy into the old theory that women don't have dominance hierarchies and that status differentials are irrelevant to women. Well, I am here to say that is bull. It may only be my personal experience, but I am intensely aware of female dominance plays. I really want to do the study I have planned out in my head. I should sit down and write it all down. It's so simple. I just need a way to measure pitch changes during a conversation ...

CRIKEY! My laptop has a battery reading that says 0%
Woah, that's a first.
Problem solved.

Coming soon: Island of the Colorblind by neurologist Oliver Sacks. This is easily one of the coolest videos I have seen for use in intro psych! I was totally captivated by it. I base some of my story of cones and color vision and acuity and sensitivity to light on a character from the movie K-Pax, a science fiction story in which Kevin Spacey plays an alien from a low-light planet who has a hard time on earth because the bright light hurts his eyes. The first time I taught intro psych FIVE years ago (!) the movie had just come out. Now, no one recognizes it so I need a new hook. In walks Oliver Sacks and his story of an equatorial island populated by people who are completely colorblind. They are the real life version of the K-Pax character who I thought was completely fictional. The students really enjoyed this video - it had frequent drug references. I highly recommend it. And, I see used copies of the Sacks book are available for less than 2 dollars from Amazon.

Wednesday, October 11, 2006

iPod to TV connection

I can't get videos to play on my TV through my video iPod. I have the dock, the cable (S-video), the TV set to the right "channel" and all the cords hooked up properly. I have even changed the settings on my iPod under "video settings" so the TV setting is ON, yet no picture shows up - only sound.

So, rather than watching a purchased video on the TV like we had hoped, my dear sweet husband and I watched it on his outdated desktop. The video card probably isn't top of the line so the video feed was a little choppy. We reduced the screen size to about 5 by 3 inches and set the background screen image to black. It was okay - small and still a little choppy, plus the seats were less than ideal. Our office chairs - IKEA garden furniture that we bought because we thought we'd actually use our deck in the back to play Scrabble during the long summers here. Instead we used the table as a table in our living room and the chairs became office chairs.

I'd like to figure out how to make the iPod -TV connection work so that next time, if there is one, we'll be able to watch missed TV episodes on the bigger screen from the comfort of the couch cushions. We don't do the whole Tivo thing. The list of television shows we indulge in is short - Grey's Anatomy, Lost, 24, and Desperate Housewives. Recently we happened to stubble on a new one that we both really like - Heroes, "an epic drama that chronicles the lives of ordinary people who discover they possess extraordinary abilities." We missed the second episode. Hopefully we won't miss any others, but if so, watching them on my laptop wouldn't be so bad. We should have downloaded the episode on it instead of the desktop, but we weren't thinking we'd have to actually watch it on that. We figured we could hook my VIDEO iPod up to the TV, but alas, that didn't work out. What is the problem???

I'd sure like to know how to make the iPod images appear on the TV.

Anyhow, NBC offers free downloads of the Heroes episodes after they air but I haven't been able to get them to download on my Mac. Maybe it's the browser? We gave up and bought episode two from iTunes for two bucks. And then it wouldn't play on the TV. Grrrrr.

The episode was great.

There's a cheerleader who kills herself over and over to prove she's indestructible, two brothers who can fly, a guy who has psychic powers, a guy who can paint the future, and another one who can alter the space-time continuum. Heroes is one of the four shows on TV that holds our attention for the full episode. I have to admit to doing other things while watching DH, but Heroes is so captivating I would never want to sneak a quick read of an Economist article.

Lost was always the same way, but I have to say that I was a little disappointed by the first episode of season three. The highlight was Sawyer finally figuring out how to get the treat dispenser in his cage to work. It was easy for the psychologist in me to imagine him inside one of Thorndike's puzzle boxes, tripping levers and pushing pedals randomly and then intelligently to get the reward. The speed of problem solving is often equated with intelligence and Sawyer's mental alacrity has been the subject of a few snippets on the show here and there, so when the Others henchman came by to condescendingly say the bears figured it out far faster, it was a classic Lost moment. There weren't enough of thoe, but I'm sure they'll come. It has been my favorite show on TV for the last two years. Sawyer's probably my favorite character. Charming, sexy smart-ass bad boy with a brain... sounds like someone I know :-)

Heroes is a lot like Lost. There's mystery, interesting characters who find connections, and an element of science that makes it a thinking show. This house's favorite Heroes character right now
is Hiro, the Japanese office worker who can bend the space-time continuum. He's a lovable geek who likes comic books and Star Trek. He's also so exuberantly confident in his abilities and his coworker friend is in such joyful disbelief that the play between the two buddies is a pleasure to watch.

Plus, he's got a great costume, as all super heroes should. In the first two episodes he wore a totally awesome sweater exactly like the one that my dear sweet husband scored at Urban Outfitters on our trip to Seattle over spring break. The sweater cost too much but it was on a serious sale and was like nothing we had ever seen before. (He looks far too cute in it.) We were both surprised to see his sweater on TV.

Tuesday, October 10, 2006

Weight Regulation

One of the things I try to get across to students in my intro psych class during our unit on motivation and hunger is why people have so much trouble losing weight and then keeping it off for good. Millions of people struggle with this problem but wind up choosing a strategy that doesn't work. A typical diet involves restricting calories, which at first blush seems like the right thing to do. Pounds disappear one after another. Some may even reach their target weight but then put almost all of the weight back on despite following the same diet.

Why does this happen?

The answer lies in how our bodies are designed. Humans evolved in an environment that was very different from the one we now enjoy. The easy access Americans have to fatty, salty, and sweet calorie rich food is completely novel. Our ancestors probably had to travel long distances to acquire the nutrients they needed to survive, let alone thrive. What was available may not have been particularly nutritious or filling. Tubers, nuts, and fruit were staple items - meat a rare delicacy. Famines may have been a regular problem. Those who could slow down their metabolism in response to famine could conserve the fat and muscle they had stored and wait out the "lean times." Our bodies aren't prepared to deal with regular indulgences that we have access to now.

When a dieter consistently restricts calories over a period of time, the person loses weight but also winds up signaling the brain (the hypothalamus) that s/he is in the midst of famine conditions. The brain responds adaptively by slowing metabolism down. If the person eats the same amount, s/he will start gain weight again as the body "saves up." Restricting calories even more will exacerbate the problem and create new ones (malnutrition).

In order to keep the unwanted weight off, the body's "set point" has to be changed. The set point is the genetically determined weight the person tends to have when s/he isn't dieting, overeating or engaging in an exercise program. That set weight point depends on the person's metabolism and this is what has to change in order for the person to permanently keep lost weight off. Metabolism depends on how responsive the hypothalamus is to the various signals that it receives from the body and the concentration of 'hunger hormones' such as leptin, neuropeptide Y, ghrelin, and orexin circulating in the bloodstream.

You can think of the hypothalamus as a thermostat for hunger regulation. Reduced food intake = slow down metabolism. Increased food intake = rev up metabolism. Because the human body evolved in an environment that saw recurrent famines, it is far easier for us to slow our metabolism down than to speed it up. When a dieter loses weight but then starts to gain it all back, that's because the body is doing exactly what it's supposed to do.

So, the real question is how to speed up one's metabolism and permanently reset the body's set point.

One way to try to do this is to get more exercise. Unfortunately, doing this while also cutting calories, releases a whole new wave of metabolic changes that are designed to put the weight right back on! For example, research from the NIH suggests that when a person loses weight and exercises more, thereby creating an energy deficit, ghrelin (an appetite stimulant) kicks into high gear.

That raises the question of whether it's even possible to permanently change a person's set point.

Friday, October 06, 2006

Split Brain

Last night's episode of Grey's Anatomy depicted a patient who underwent a "corpus callosotomy" and then was unable to identify his wife, baby, and a simple object in the room (a cup placed in front of him).

This didn't jive with my understanding of the effects of the procedure, also called a "split brain" operation in psychology. It's a topic that gets brought up in intro psych classes because severing the corpus callosum (a bundle of neurons that connexts the two hemispheres of the brain) produces very interesting side effects that stem from the lack of coordination between the two halves of the brain. It provides a neat case study for understanding how the hemispheres work and also showcases the concept of lateralization - the idea that some functions (such as language) are "specialized" and carried out on one side of the brain.

As the show correctly implied, a split brain procedure is done to treat severe seizures. Cutting the nerve bundle limits the spread of the seizure to the whole brain and greatly reduces the severity of the tremors. It can be done in two stages - the first cutting only the front two thirds of the fibers, leaving the rest intact so the the hemispheres can still share some information. If the seizures are still problematic, the rest of the fibers can be cut.

A full corpus callosotomy creates some interesting side effects - but not the severe one depicted on the show of not being able to identify anything.

What actually happens is that the "split brain" person cannot say out loud the name of an object that is ONLY presented to the LEFT visual field (if the person is left hemisphere dominant for language). The patient would have to close the right eye completely for this to happen. In laboratory tests, split brains look at objects through a tachistoscope that presents information to only one hemisphere or look at image that is flashed briefly to one side of the visual field.

A left hemisphere language dominant "split brain" who viewed an object (spoon, as in the diagram) with only the left visual field would not be able to identify it because that visual input is received by the right hemisphere which can't communicate with the left hemisphere where speech is generated. The person would recognize the spoon but be unable to say it. If asked to pick up the object with the left hand (which is controled by the right hemisphere, the one that saw the object) out of a collection of objects out of sight, the person would correctly pick up the spoon.

These kinds of effects don't usually cause problems for the person because information comes in through both eyes!!!

That's where Grey's Anatomy only captured half of the story. They dumbed it down considerably and even played up a seriously dumbed down version of the brain lateralization story. "McDreamy" the brain doctor said, in explanation of the patient's side effects, that it will take a while for emotional messages to travel to the other side of the brain where information is processed.... or something like that. I wanted to gag.

Anyhow, if you'd like to learn more about split brains, the study of which won Roger Sperry the Nobel Prize for medicine, check out this cool site:

A split brain game you can play.

One of the things that helps to understand, on a deeper level, why the split brain person experiences these weird side effects is that the eyes are connected to the hemispheres in a really unsual way.

The right half of each eye's retina projects to the right hemosphere (shown in dark grey in the diagram above) while the left half of each retina (white) projects to the left hemisphere. Also, half of the retinal fibers (the nasal halves, closest to your nose) cross over to the other hemisphere at the optic chiasm. This means that the temporal halves (the right side of your right eye and the left side of your left eye) don't cross over at all. Your nasal retinal halves can be completely blocked and you'll still have a full field of view because the temporal halves cover the whole field. If you don't believe me or the diagram, hold three fingers right in front of your nose.

I could deliver an emancipation proclamation of the the evolutionary reasons for this weird set up, but suffice it to say that this arrangement allows us to have excellent depth perception.

It also means that a split brain person only receives information that can be verbally identified by one fourth of the available retinal area - the quarter that projects to the right visual field which is on the left side of the left eye (shown in white in the diagram). Notice those fibers don't cross to the other hemisphere; they are the ONLY fibers that project straight back to the left hemisphere. So, only information presented to the right visual field can be verbally identified.

All of this makes me wonder - is the optic chiasm cut during the corpus callosotomy and if so, does the person lack depth perception?

I assume it is cut because all of the textbooks on the subject present the fancy little images of the right and left visual fields and the projections to the nasal and temporal halves, but the side effects would be the same if the retinal inputs could cross over because the two retinal halves would see the same thing. In that case, the brain could still compute the difference in distance from the right and left eye's inputs and triangulate the distance.

Anyhow, that's probably more than you wanted to know about why I thought Grey's Anatomy flunked last night in the way they presented the split brain patient. It's great - I'm glad they did. Maybe somewhere out there someone taking intro psych watched it and realized the same thing I did and actually asked their psych prof about it later.

Thursday, October 05, 2006

Lactose Intolerance

Over the weekend a good friend of mine visited for our college reunion. She's lactose intolerant and likes to enjoy ice cream and other dairy products so she brought lactase pills along with her so she could digest the milk sugar lactose. She was also told by her pediatrician the day after she returned home that she's got to fatten her one year old daughter up. I asked her how she's supposed to do that. Cheese! Makes sense, but she's worried her daughter might be lactose intolerant too. Being fully capable of digesting the stuff myself, the concept of lactose intolerance is not something I spend much time thinking about... until recently.

According to Steve Lewis, a professor of Darwinian medicine, mammals lose the ability to digest milk with age. This might "form a biological mechanism whereby the ties between mother and child are broken so that she can go on and have more offspring and the child can go and have offspring of its own." Symptoms of lactose intolerance include gas, bloating, abdominal cramps and diarrhea result. The NIH estimates that in the U.S. about 15% of people of European descent have it. Half of Latinos, 60-100% of Native Americans, 80% of African Americans, and 90% of Asian Americans are lactose intolerant. The ability to digest milk depends on how heavily a culture depended nutritionally on the milk of their herded animals.

What is really interesting to me from an evolutionary perspective is that lactose intolerance is something all humans should experience yet many don't. Relatively new research has discovered a genetic mutation that gave some adult humans the ability to digest lactose. This occurred sometime in the last 5,000-10,000 years and coincides with the origin of pastoralism in Europe.

This finding poses challenges to evolutionary theories about human behavioral adaptations (such as males' preference for mating with nubile women) that are thought to take hundreds of thousands of years longer to develop in a population. EPs can't go back in time to determine what kind of ecological conditions human ancestors lived in at the time we were evolving these adaptations (the so-called "environment of evolutionary adaptedness"), so most EPs infer what kind of behavioral adaptations would have been most adaptive for our ancestors by examining the ecological conditions of extant human hunter-gatherers. They assume the living conditions are essentially the same and that not enough time has passed for new adaptations to take hold, so if it would be adaptive for hunter-gatherers now it was probably adaptive in the past too. Obviously trouble arises when new evidence suggests that humans can evolve faster than expected. If a gene for making lactase well into adulthood can take hold in the last 10,000 years it is also possible that a gene for constructing hypothalamic-visual cortex connections in the brain that fire maximally for men viewing nubile young women could take hold that fast too. I seriously doubt that there was ever a time when the average man was turned on by the sight of a pre-pubescent or wrinkled old woman. It wouldn't make much sense for successful reproduction.

However, there are other adaptations that are more controversial and could conceivably be a product of relatively recent changes. The female orgasm, the desire for men to have more sex partners than women, sexual jealousy, monogamy, etc.

The discovery that lactose is newly digestible does NOT mean evolutionary psychology is a rotten paradigm, as some would have it (David Buller), but it does mean that care needs to be taken when hypothesizing adaptations that assume nothing has changed within the last 10,000 years.

As for my friend's daughter, she should be able to digest cheese just fine. Lactose intolerance doesn't set in until later in life and is a recessive trait, so if her dad can still digest lactose, she should be able to later in life too.

Tuesday, October 03, 2006

Impossible Things

This week's introductory psychology class introduced students to a magician's take on optical illusions. His name is Jerry Andrus and a little googling found that he makes appearances every so often in Corvalis, OR. Besides introducing young people to the wonders of the Monte Hall problem and a rotating spiral illusion, he constructed an impossible box that I think is very neat.

It's very similar to the Penrose triangle illusion. A larger than life one can be seen in Australia (see the photo to the right). There's also one located on the campus of Willamette University in Salem, OR. No Photoshopping tricks are involved. Just arrange the elements the right way and take the photo from the perfect vantage point. If you've got the time, it is possible to create a desk sized impossible triangle out of cardboard.

The Ames room is another neat optical illusion that plays on the way our sensory system processes depth. The two girls are identical twins yet one appears much larger. The diagram below shows how the room is constructed. If you have time, a desk sized one could be made. Two pennies could take the place of the girls.

What's really weird is that a couple of psychologists found that when women view their spouse inside an Ames room, they perceive less size distortion than when viewing a stranger! This effect didn't occur for men viewing their wives though, and the degree of distortion perceived was inversely related to how much love and trust each woman felt for her husband.

This shadow illusion is fun. When looking at the shaded squares it is difficult to believe they are actually the same color as the "darker" unshaded squares in the checkerboard.

Can you believe these two tables are exactly the same size?