What makes synesthesia such a powerful lecture topic in the Intro Psych sensation and perception chapter is that it’s a beautiful illustration of how our experience is merely a representation, and just one representation, of the world around us. The neuroscientist David Eagleman provides a nice introduction to synesthesia in this two and a half minute video. Video Link : 1751 Years ago in class, after I concluded my lecture on synesthesia, a young woman in the back of the room raised her hand. She said she didn’t know her experience of the world was different from everyone else’s until a friend of hers took my class a year earlier. She said a group of them were standing around when he started talking about this cool thing called synesthesia that he learned about that day in his Intro Psych course. He explained that the most common form is seeing sounds where sounds produce color, like a filter has been applied to vision. My current student said to her friends, “Doesn’t everybody experience that?” They all stopped and looked at her. At the age of 18, she learned that she was a synesthete. I made the same error once in class. After talking about synesthesia, I said it’s like when you’re drifting off to sleep and a sudden noise causes a black and white pattern to flash in your vision – sound produces a visual sensation. My students looked at me blankly. Apparently I was the only one with such an experience. My visual experience used to happen pretty regularly, probably a few times a week, but now it’s a rare occurrence, probably once every few months. In any case, I learned that it’s non-existent in many, at least amongst my students that term. I suppose this assumption is a kind of extension of the false consensus effect. We not only assume that others share our beliefs and attitudes, but that others share our sensory experiences. There is research evidence that suggests we are all born synesthetes (see for example Wagner and Dobkins, 2011), and as we mature through infancy and childhood our senses begin to specialize, much like how infants can produce sounds used in all languages only to become specialists in their native language or languages as they develop.   Exploring vision in non-human animals helps students appreciate that their own sensory experiences may be very different from others. For example, dogs have two kinds of cones in their retinas; they detect yellow and blue. That may make them roughly equivalent to humans who have red-green color blindness (Wolchover, 2012). And birds? They have four kinds of cones, the fourth allows them to see ultraviolet light. It’s been posited that the ability to see UV light allows some songbirds to better see each other as their plumage glows with UV light and that raptors can better track prey that leave a urine trail that also glows with UV light. There’s reason to believe that the jury is still out on both of those hypotheses (see for example, Lind, et.al., 2013). Both are given though in this rapid-fire 4-minute SciShow on what birds see. Video Link : 1752 And what about infrared light? While the human eye can’t see it, our digital cameras can. Turn on your cellphone camera and direct it at the end of your TV remote, the end you point toward your TV. Press and hold the "on" button on your remote. You’ll see the light through your phone’s camera even though your naked eye can't see it. This is also the easiest way to determine whether you need to change the batteries in your remote or whether it's just your dog standing in front of the TV’s receiver. For a short in-class next-day assignment – or same-day assignment, if your students have in-class internet access – or for an online discussion board assignment, invite students to research other individual differences in human sensation or differences in sensory experiences between humans and other animals. In class, students can share in small groups, and then invite volunteers to share the most interesting things they found. Ask students to identify the site where they found the information and why they believe the site is a reputable source.   References Lind, O., Mitkus, M., Olsson, P., & Kelber, A. (2013). Ultraviolet sensitivity and colour vision in raptor foraging. Journal of Experimental Biology, 216(19), 3764-3764. doi:10.1242/jeb.096123 Wagner, K., & Dobkins, K. R. (2011). Synaesthetic associations decrease during infancy. Psychological Science, 22(8), 1067-1072. doi:10.1177/0956797611416250 Wolchover, N. (2012, June 26). How do dogs see the world? Retrieved from http://www.livescience.com/34029-dog-color-vision.html ... View more

Originally posted on April 25, 2014. We’ve all experienced it. You’re some place where screaming isn’t tolerated, some kids starts wailing, and the parents rush to quiet them down. What happens next is the twist: “They’re the best behaved kids we know,” the parents say, as their child continues to bellow. We nod our heads, feign a smile, and go back to what we’re doing. Before you pounce on me for being impatient and inexperienced, I’m here to share some good news. The more positively we view our close relationship partners, the stronger relationship we have. The best part is that the positivity doesn’t have to exist. If you ask many people, they’ll tell you their close friends are above average on nearly every positive trait. They’re funnier, smarter, and kinder than their peers. We might have positive illusions, but that doesn’t hurt anything. Or does it? Let’s return to how we see our kids. Seeing them as above average might have certain benefits. It might boost your parenting commitment and satisfaction. Who wants to devote the time and energy it takes to parent if you see your kid as a dud? A recent study suggests a potential drawback: many parents perceive their children as healthier than they actually are. The study, which drew on several investigations involving over 15,000 children, found that half of parents who have overweight or obese children rate their child as slimmer than their weight suggests. Just as people villainize parents of screaming children, it’s easy to attack parents who don’t know their children are overweight or obese. But let’s show parents some empathy. Parenting is hard. I don’t have kids, but I can’t tell you how much respect I have for people who do. Parents might not want to hurt their children’s feelings by calling them overweight or obese. They also might not know what it means to be overweight or obese. Is it simply if your son fits into his clothes? If your daughter comes home crying because a school bully called her fat? But there’s a third possibility: when we love someone, we see them in the best possible light. Instead of seeing an obese child, we see our daughter who jumps down the stairs to welcome us home from work. We see our son who loves to get dirty in the mud. When I read about the study, I tucked it away in my files. The next morning my wife and I took our two golden retrievers, Finnegan and Atticus, to the veterinarian. They’re both of our dogs, but Finnegan is mine and Atticus is my wife’s. They weighed Finnegan, who came in at a beefy 85 pounds. Then it was Atticus’s turn. “He’s much skinnier than Finnegan,” my wife, Alice, said. “Just look at him.” I looked and realized we weren’t seeing the same dog. “He looks the same to me. We feed him the same amount and give him the same amount of exercise.” “Nah, I bet he’s 70 pounds,” she said. They took Atticus away, weighed him, and returned with the results. He was exactly the same as Finnegan: 85 pounds. So, this finding might apply to dog owners, too. ... View more

Originally posted on February 5, 2015. Even though the smartphone has only been around for the past seven or eight years, it’s sometimes difficult to remember what life was like before we had so much information at our fingertips. You could argue with a friend about what year “Back to the Future, Part 2” came out, or in what year the “future” was set. (It was released in 1989. The future, filled with flying cars and floating skateboards, was set in 2015.) Back then, you couldn’t resolve discussions by swiping a screen and touching a button. Siri wasn’t even a twinkle in Steve Jobs’s eye. If you got lost, you had to consult a map or stop and ask for directions, and if you got bored while waiting in line, you couldn’t pass the time by playing Candy Crush or perusing Instagram. Luddites argue that life was better before the smart phone, whereas others tout the benefits of instant communication and information. But one thing is certain: The smartphone has changed our lives. And our thumbs. Yes, when we spend time on smartphones using a touchscreen, it changes the way our thumbs and brains work together, according to a new study by researchers from the University of Zurich and ETH Zurich in Switzerland. Our obsession with smartphones presented the perfect opportunity to explore the everyday plasticity of our brains. With smartphones, we are using our fingertips—especially our thumbs—in a new way, and we do it a lot. And because our phones keep track of how we use them, they carry a wealth of information that can be studied. In the study, the research team used electroencephalography (EEG) to record brain response to the touch of the thumb, index finger, and middle fingerprints of touchscreen phone users compared to people who still use flip phones or other old-school devices. They found that the electrical activity in the brains of smartphone users was enhanced when all three fingertips were touched. The amount of activity in the brain’s cortex associated with the thumb and index fingertips was directly proportional to the amount of phone use. Repetitive movements over the touchscreen surface might reshape sensory processing from the hand. Cortical sensory processing in our brains is constantly shaped by personal digital technology. So, the next time you use your thumbs to tweet, answer email, or jot yourself a note, remember that you’re training your brain. Keep in mind, too, that excessive phone usage is linked with motor dysfunction and pain. Remember the so-called “BlackBerry thumb”? ... View more

Originally posted on April 24, 2014. “39-Year-Old Deaf Woman Hears for First Time” headlined Yahoo, in one of the many gone-viral Deaf-can-now-hear videos.  Each depicts the compelling emotions of someone who, thanks to the activation of a new cochlear implant (CI), is said to be hearing sound for the first time—and (in this case) conversing in English!  Was this woman (Joanne) completely congenitally deaf as a result of Ushers Syndrome?  And did she immediately gain, as some media implied, the ability to understand speech on first hearing it? As my brother said in forwarding this, it’s “an amazing story.” The power of CIs to restore hearing is, indeed, amazing, as I can attest from meeting many people with CIs at hearing loss meetings.  As one who is tracking toward the complete deafness that marked the last dozen years of my mother’s life, I anticipate someday benefitting from CIs. Moreover, I appreciate the power of a compelling example, such as the video example I offer (here) of a child’s first experience of a home TV room hearing loop.  And who can suppress a smile when watching this boy’s first experience of a CI? Without disrespecting the Deaf culture (which regards deafness and Sign language as not defects needing fixing), and without diminishing Joanne’s powerful experience, what shall we make of her ability to understand and to speak? Does this video overturn what psychological science has taught us about the critical period for language development during life’s early years?  Is it not important that children receive CIs before language develops?  Haven’t experiments that removed cataracts and “restored vision” to natively blind people taught us that, for normal perceptual experience, the brain must be sculpted by sensory input in life’s early years? I posed these questions to Dr. Debara Tucci, a Duke Medical Center cochlear implant surgeon with whom I serve on the advisory council of the National Institute on Deafness and Other Communication Disorders.  Our shared questions:      1. Was Joanne completely deaf from birth?  Has she heard no sound until the moment of this recording?  As I will explain in a future entry, in popular use “deaf” often conflates true and complete deafness with substantial hearing loss.  Some Usher’s Syndrome patients sometimes are born completely deaf, but others experience progressive hearing loss.  With hearing aids, they acquire language early in life.  Joanne’s use of spoken language suggests that she is not hearing speech for the first time in her life.      2. A person who has been completely deaf from birth could potentially lip read.  When testing such patients with newly activated CIs, it would be interesting to know if they can “hear” speech when the speaker’s face is obscured. As a CI provider, Dr. Tucci nevertheless welcomes such videos:  “Even though the history accompanying the video may not be entirely correct, and a little misleading, it is basically a positive thing.  I would rather have 10 people come in and be told they are not a candidate than miss one person who is.  Also, we are implanting long deafened people who don't have speech/language ability not with the thought that they will develop or understand speech, but to increase connectedness and for safety concerns.” ... View more

Originally posted on April 28, 2014. Reports of restored vision in children in India have been confirmed in a new Psychology Science article, summarized here, on “Improvement in spatial imagery following sight onset late in childhood.” The research, led by Tapan Kumar Gandhi of MIT’s Brain and Cognitive Sciences department, in collaboration with Suma Ganesh and Pawan Sinha, studied children who were blinded from birth by dense cataracts. After surgery removed the cataracts at about 12 to 14 years, the children were no longer completely blind. Their abilities to discern light and dark, enabled some spatial imagery. Practically, I wondered, what does this mean? Doesn’t the brain need to experience normal sensory input early in life in order to produce normal perceptual experience later in life? I asked Dr. Gandhi to explain the children’s post-surgery abilities. Could they potentially ride a bicycle or drive a car? His answer (quoted with permission): The onset of sight is not immediately accompanied by much joy or pleasure, contrary to what is depicted in movies. The child has to get used to the new inputs. Over the first few weeks, the child begins to feel more comfortable with the visual world, even though they might not recognize much of it. Their visual acuity is sub-par, most likely permanently so. But, despite a blurry percept, the brain is able to achieve significant proficiency over the course of the first half year on many visual skills such as face detection, and visually guided navigation. Although driving is well-beyond their economic means, some of the Prakash children have indeed learned to ride a bicycle. We typically find that the children and their parents are in high spirits when they visit us for a clinical follow-up a few weeks after the surgery. ... View more

Originally posted on April 30, 2014. Those of us with hearing loss cheered one of our own, Seattle Seahawks football player Derrick Coleman, as he became a national exemplar in the U.S. for living with hearing loss. We reveled in the Super Bowl Duracell ad chronicling his life story.  And we felt a warm glow when he gifted twin New Jersey 9-year-old sisters with Super Bowl tickets and handwritten encouraging words:  “Even though we have hearing aids, we can still accomplish our goals and dreams!” As 500,000+ Google links to “Deaf Seahawks fullback” testify, Coleman’s story inspires us.  The reports of Coleman’s “deafness” also raise an interesting question:  Who is deaf? By using a combination of hearing aids and the natural lip reading that we all do, Coleman, despite his profound hearing loss, reportedly hears his quarterback call plays amid the din of the Seahawks stadium.  And he converses, as when amiably answering questions at a Super Bowl press session. In doing so, he is akin to millions of others who live well with hearing loss. Without our hearing aids or cochlear implants, some of us among the world’s 360 million people with hearing loss become truly deaf—unable to hear normal conversation.  When I remove my hearing aids before showering in my college gym, the locker room banter goes nearly silent.  In bed at night without my aids, my wife’s voice from the adjacent pillow becomes indecipherable, unless she turns to speak into my ear. So, in his everyday functioning, is Derrick Coleman “deaf”? Am I deaf?  Are my friends in the hearing loss community deaf? Partly out of respect for my nonhearing, signing cousins in the Deaf Culture, my answer is no:  I am not Deaf.  Like Deaf people who fluently communicate with Sign, a genuine language, I am also not disabled or “hearing impaired” (which labels a person).  Rather I am a person with hearing loss.  The Hearing Loss Association of America—“the nation’s voice for people with hearing loss”—offers resources that assist “people with hearing loss and their families to learn how to adjust to living with hearing loss [and] to eradicate the stigma associated with hearing loss”—and thus to live as not-deaf. I asked the Association’s recently retired director, Brenda Battat, whose hearing was partially restored with a cochlear implant, if she considers herself deaf.  “No. From a life experience, functioning, and self-identity perspective I do not consider myself deaf.” Ditto my friend, musician Richard Einhorn, who has a substantial hearing loss and was recently featured in a news story that was headlined: "Hearing Loops Give Music Back to Composer Who Went Deaf in a Day." “The ‘deaf’ label is not accurate,” notes Einhorn, who uses various technologies to hear.  “With a good hearing aid and additional listening technology such as hearing loops, I can hear well enough in most situations to participate fully in conversations and enjoy live music, theater, and films.” Thanks to new hearing technologies, most of us with hearing loss can effectively function as not-deaf.  My state-of-the-art hearing aids amplify sound selectively, depending on my loss at different frequencies.  They offer directionality.  They compress sound (raising soft sound and lowering extremely loud sound).  Via a neck-worn Bluetooth streamer, they wirelessly transmit phone conversation and music from my smart phone to both my hearing aids. And thanks to my favorite hearing technology—the hearing loops that broadcast PA sound wirelessly to my in-the-ear speakers (aka hearing aids)—I hear! Ergo, while most natively Deaf people are served by Sign, the rest of us—the invisible majority with hearing loss—need hearing assistance.  We respect, but live outside of, the Deaf Culture.  We benefit from new hearing technologies.  Lumping all people with hearing loss together as “deaf” respects neither Deaf people nor those with hearing loss.  Here ye, hear ye! ... View more

Originally posted on September 9, 2014. How do we know ourselves?  It’s partly by observing our own actions, proposed Daryl Bem’s self-perception theory.  Hearing ourselves talk can give us clues to our own attitudes.  Witnessing our actions gives us insight into the strength of our convictions (much as we observe others’ behavior and make inferences). Our behavior is often self-revealing. The limits of such self-revelation have recently been explored by one of psychology’s most creative research teams at Sweden’s Lund University. The researchers, including Andreas Lind, were curious: “What would it be like if we said one thing and heard ourselves saying something else?” Would we experience an alien voice?  An hallucination? Would we believe our ears? Through a noise-cancelling headset, the participants heard themselves name various font colors, such as the word green presented in a gray font color. But sometimes, the wily researchers substituted a participant’s own voice saying a previously recorded word, such as “green” instead of the correctly spoken “gray.” Surprisingly, two-thirds of these word switches went undetected, with people typically experiencing the inserted word as self-produced! (For more from the creative Lund University "choice blindness" research group, see here.) A second new demonstration of the self-revealing power of our own behavior comes from research on the effects of feedback from our face and body muscles. As we have known for some time, subtly inducing people to make smiling rather than frowning expressions—or to stand, sit, or walk in an expansive rather than contracted posture—affects people’s self-perceptions.  Motions affect emotions. At the University of Cologne, Sascha Topolinski and his colleagues report that even subtle word articulation movements come tinged with emotion.  In nine experiments they observed that both German- and English-speaking people preferred nonsense words and names spoken with inward (swallowing-like) mouth movements—for example, “BENOKA”—rather than outward (spitting-like) motions, such as KENOBA.  Ostensible chat partners given names (e.g., Manero) that activated ingestion muscles were preferred over chat partners whose names activated muscles associated with expectoration (e.g., Gasepa). Self-perception theory lives on.  Sometimes we observe ourselves and infer our thoughts and feelings. ... View more

Originally posted on February 4, 2015. Friday my focus was hearing research and care—at the National Institute on Deafness and Other Communication Disorders, where I sit on the Advisory Council (assessing federal support for hearing research and hearing health).  Days later, I was cheering on my ill-fated hometown Seattle Seahawks in the Super Bowl. Alas, there is some dissonance between those two worlds, especially for fans of the team that prides itself on having the loudest outdoor sports stadium, thanks to its “12th Man” crowd noise—which has hit a record 137.6 decibels . . . much louder than a jackhammer, notes hearing blogger, Katherine Bouton. With three hours of game sound rising near that intensity, many fans surely experience temporary tinnitus—ringing in the ears—afterwards...which is nature’s warning us that we have been baaad to our ears.  Hair cells have been likened to carpet fibers. Leave furniture on them for a long time and they may never rebound. A rule of thumb: if we cannot talk over a prolonged noise, it is potentially harmful. With repeated exposure to toxic sound, people are at increased risk for cochlear hair cell damage and hearing loss, and for constant tinnitus and hyperacusis (extreme sensitivity to loud noise). Men are especially vulnerable to hearing loss, perhaps partly due to greater noise exposure from power tools, loud music, gunfire, and sporting events (some researchers have implicated noise is men’s greater hearing loss).  But some men know the risks, as 2010 Super Bowl-winning quarterback Drew Brees illustrated, when lifting his son Baylen, with ear muffs during the post-game celebration. For more on sports and noise, visit here. ... View more

Originally posted on March 25, 2015. During a recent visit to Stanford University, psychologist Jeremy Bailenson (pictured) invited our small group of conferees to his Virtual Human Interaction Lab, where he explained his studies and invited us each to experience a virtual world, complete with surround sound and vibrating floor. His expressed aim is to “give you an experience that changes how you think about yourself,” and then to assess the aftereffects. In our group, brain scientist Antonio Damasio found his left and right legs and arms switched, as he popped virtual balloons.  Anthropologist Mel Konner found his identity shifted into a mirrored person.  I found myself in a beautiful forest, cutting down trees, and then underwater in a beautiful lagoon, with fish flying by. Bailenson reports that men who become female avatars later are more nurturing.  Heroes who gain the ability to fly around a city (navigating by arm movements, as below) later become more helpful.  Those who age in front of their eyes become more future oriented. In such ways, Bailenson explores “how virtual reality can change the way people think about education, environmental behavior, empathy, and health.” ... View more

Originally posted on March 27, 2015. At a recent foundation consultation at Stanford, I enjoyed meeting Andrew Meltzoff, the amiable and articulate co-director of the University of Washington’s Institute for Learning and Brain Sciences in my home city (where he lives but a short walk from my former high school). Meltzoff is known to psychology teachers and students for his many studies of infant imitation, including his classic 1977 Science​ report on 2- to 3-week old infants imitating his facial gestures. It was, he reported, a powerful experience to stick out his tongue and have newborns do the same. “This demonstrates to me the essential socialness of human beings.” I’ve always wondered what newborns really are capable of visually perceiving, and he reminded me that it’s not much—but that they have their best acuity for the distance between their mother’s breast and eyes, which also was the distance between his face and the infants’ eyes. His lab is now reading infants brains using the world’s only infant brain imaging MEG (magnetoencephalography) machine, which reads brain magnetic activity more finely than possible with EEG. He reports that “When a brain sees, feels, touches, or hears, its neuronal activity generates weak magnetic fields that can be pinpointed and tracked millisecond-by-millisecond by a MEG machine.” That is allowing Meltzoff and his colleagues to visualize an infant’s working brain as the infant listens to language, experiences a simple touch on the hand, or (in future studies) engages in social imitation and cognitive problem solving. On the horizon, he envisions future studies of how children develop empathy, executive self-control, and identity. He also anticipates exploring how children’s brains process information from two-dimensional digital media versus their three-dimensional everyday world, and how technology can best contribute to children’s development. In such ways, they hope to “help children maximize their learning capabilities.” ... View more

Originally posted on October 27, 2015. Phantom limb sensations are one of psychology’s curiosities. Were you to suffer the amputation of a limb, your brain might then misinterpret spontaneous activity in brain areas that once received the limb’s sensory input. Thus, amputees often feel pain in a nonexistent limb, and even try to step out of bed onto a phantom leg, or to lift a cup with a phantom hand. Phantoms also haunt other senses as the brain misinterprets irrelevant brain activity. Therefore, those of us with hearing loss may experience the sound of silence—tinnitus (ringing in the ears in the absence of sound). Those with vision loss may experience phantom sights (hallucinations). Those with damaged taste or smell systems may experience phantom tastes or smells. And now comes word from the Turkish Journal of Psychiatry that 54 percent of 41 patients who had undergone a mastectomy afterwards experienced a continued perception of breast tissue, with 80 percent of those also experiencing “phantom breast pain.” As I shared this result (gleaned from the Turkish journal’s contents in the weekly Current Contents: Social and Behavioral Sciences) with my wife, I wondered: Is there any part of the body that we could lose without the possibility of phantom sensations? If an ear were sliced off, should we not be surprised at experiencing phantom ear syndrome? The larger lesson here: There’s more to perception than meets our sense receptors. We feel, see, hear, taste, and smell with our brain, which can experience perceptions with or without functioning senses. ... View more

Originally posted on June 22, 2016. As every psychology student knows well, human perception is both a “bottom-up” and “top-down” process. Our perceptions are formed, bottom-up (from sensory input)...but also top-down (constructed by our experience and expectations). Top-down perception is usually illustrated visually. Reading from left to right, our expectations cause us to perceive the middle figure differently than when reading from above. And when first reading the phrase below, people often misperceive it: ...by seeing what they expect (and failing to detect the repeated word). The same constructive process influences what we hear. Told about a young couple that has been plagued by their experience with some bad sects, people may—depending on what is on their mind—hear something quite different (bad sex). The context of a sentence will determine whether you hear “the stuffy nose” or “the stuff he knows.” Likewise, the weather-forecasting “meteorologist” may become, in a discussion of a muscular kidney specialist, the “meaty urologist.” The reality of top-down hearing helps explain why theater instructors and directors, who are training their actors to project their voices, may not appreciate the hearing difficulty faced by those of us with hearing loss—and why we appreciate mic’d actors and the hearing assistive technology described here. The problem has two sources: Most theater directors hear normally, and thus may naturally assume that others hear what they hear. The directors already know what the words are. When my TV captioning is on, I can—thanks to top-down perception—hear the spoken words clearly. My expectations, formed by the captions, drive my perception. If I turn the captions off, I no longer understand the words. Play directors who know their scripts are like those of us who watch captioned TV. But their patrons are in the no-captions mode. Happily, here at my place called Hope (Hope College), hearing accessibility is being addressed. My theater colleagues are working to support their patrons with hearing loss—by seeking to understand their needs, by equipping their facilities with hearing assistance, and by welcoming feedback after plays. ... View more

In this 3 minute and 30 second video (posted June 30, 2016), Mary Roach, author of some of my favorite books, like Grunt, Bonk, and Stiff, reports that the Veterans Administration spends one billion dollars annually on hearing loss treatment. After covering hearing in the Intro Psych sensation chapter, but before showing this video, ask students to consider why there is so much hearing loss in the military (for example, there are lots of things that go boom). Now ask students for some possible solutions. Students may say better ear protection. Better ear protection would block out the sudden loud sounds, but ask students if someone out on patrol might want to also hear softer sounds, like what their fellow patrol-mates are saying. Now, show students this short video. Video Link : 1633 Roach notes that it’s likely that this technology will be available to civilians. Ask students who else might benefit from this technology. ... View more

White light is the presence of all of the visible light waves. White noise is the presence of all of the sound waves within the range of human hearing. Because our sensory systems are optimized to detect change, noises at night are likely to jar us awake. White noise machines or smartphone apps (or fans) mask other noises. The frequencies from those other noises blend into the white noise as long as the loudness of the other noises is the same or lower than the white noise. If they blend in well enough, our brains won’t detect them, and we sleep right through the sound. (Mileage varies. Some people are more sensitive to other noises when presented inside of white noise.) Side note: Pink noise is like white noise in that all of the frequencies are there, but with pink noise, the higher frequencies have decreased loudness. LiveScience has a nice explanation of the difference. Why is it called pink noise? In light, the higher frequencies are on the blue end of the spectrum. If those higher frequencies in white light are reduced, the light would appear more pink. Some people prefer pink noise over white because white noise sounds too high-pitched. World War II (source: 99 Percent Invisible, Episode 208: Vox Ex Machina) The 1939 World’s Fair in New York debuted the first voice synthesizer, created by sound engineer Homer Dudley of Bell Labs. After the 1941 attack on Pearl Harbor, the US called on Dudley to solve a serious communication problem. For allied military leaders to talk with each other, they had to use shortwave radio – that anyone could listen in on. They had been using a scrambling technique that would switch the frequencies of the voices, so that high frequency sounds would transmit as low frequency and vice versa. Decoding those transmissions was as easy as it appears – for anyone listening in. Homer Dudley created a 2,000 square foot, 50-ton computer that compressed and digitized voices then masked them in white noise, on the fly. The trick? Two identical vinyl records of recorded white noise – for each conversation. At least 3,000 pairs of these records were made – each with a different white noise pattern. One set stayed in Washington, DC; the other set was sent to London. Each pair had a codename, such as wild dog. Before a call, the communication officers would decide which record to use. At the Pentagon in Washington, DC, the communication officers would open a short wave radio connection to London. At the designated time, each side would start their records. The voice from, say Truman, would be sent from his microphone, through the machine that digitized his voice, then mixed his digitized voice with the white noise from the record, and finally sent it out over the shortwave radio frequency. To anyone listening in on that radio frequency, they would hear only white noise since Truman’s voice would blend into the white noise. Across the pond in London, the signal would be intercepted, run through the machine where the white noise playing on the vinyl record would be subtracted, and Churchill would hear Truman’s digitized voice. After the call, the records were destroyed. For the next call, a new pair was used. This device “was involved in virtually every major military operation after 1942. It was even critical in the planning of the Manhattan Project and the dropping of the atomic bombs over Japan.” Another side note: When this technology was declassified in the 1970s, researchers put it to good use. It’s digital compression that smooshes our voices enough to be sent through cell phone towers. Our MP3 audio files and streaming video files use this same compression technology. Conclusion This Memorial Day weekend, when you turn on your white noise generator, give a special nod to those fought in World War II. ... View more

Last week I wrote about how it is I came to wear psychology-related t-shirts to my Intro Psych classes. That post included nine t-shirts. [Read that post.] This week I have ten to share. Vision – Childish Side of the Moon This is a pretty straight-forward illustration of how white is the presence of all wavelengths of light. And the Pink Floyd fans in your class will enjoy the reference. Sleep – Big Fan I hammer pretty hard the importance of sleep. Too many students think that staying up all night studying is a good idea, and I present the landslide of evidence that says it’s not. In case they miss my message, perhaps due to sleep deprivation, this t-shirt drives home the point. Sleep – Counting Sheep If I’m feeling more whimsical, I will go with this shirt depicting counting sheep – on a calculator, on “fingers,” on an abacus. Psychoanalysis – Devil and angel bunnies If you talk about the id, ego, and superego, this shirt is a must. Wear a shirt over top, like a denim shirt or a light fleece. As you describe the conflict between the id and the superego, if you’re lucky, a student will say something like, “Oh! Like the devil and angel on your shoulders!” That’s your cue to remove your outer layer, revealing the devil and angel bunnies on your shoulders. Research methods – Science of the Lambs When introducing research methods in Intro, I sometimes talk about how people think that what determines what is a science and what is not are the apparatuses that are used. “If there are flasks and Bunsen burners, then it is science.” If class time allows, I ask students to consider that question: What makes a science a science? This makes for a nice think (on your own for a minute or two), pair (talk with the person next to you for a minute or two), share (ask for volunteers to share their responses) activity. Personality – Introverting When covering the Big Five personality traits, I use this shirt to come out as an introvert. The best metaphor I have heard for introversion and extraversion says that which way you lean is determined by what recharges your batteries most of the time. If your batteries recharge when you are with people, you are more extraverted. If your batteries recharge when you are alone, you are more introverted (see this blog post for example). The message in this shirt is “back off; I’m recharging.” Sensation — Hello? Can anybody hear me? I use this shirt to introduce the idea that sound and color only exist in our brains. Sound waves and light waves exist outside of us, but what we describe as sound and what we describe as color don’t. They are sensations created by our brains, a conversion of those waves into something we can experience. Development – Donkey Kong and Mario  This shirt’s a nod to the gamers in your class. If you’d like to use this shirt for discussion, ask students questions like: Given that Mario is walking, how old would you guess he is? [2-ish] What reflex is Donkey Kong exhibiting with the baby bottle? [grasping] Years later, do you expect them to remember this event? Why? [nope, infantile amnesia] You can also reprise this shirt for the social psych chapter. What are some ways in which Donkey Kong and Mario could work to resolve their conflict? [e.g., superordinate goals].            Optimism/pessimism – Which glass are you? When covering optimists and pessimists, this shirt provides an opportunity to introduce students to some other -ists, such as utopists and surrealists. Be prepared to explain some of these; students will ask. Final exam day – Pencils Since students are required to bring a Number 2 pencil to take the final exam, this handy shirt depicts pencil numbers 1 through 12. ... View more