Instructors of Intro Psych are familiar with the Gestalt grouping principles of proximity and similarity. If we look in a room of 15 people, and we see five people standing near each other to our right, five people standing near each other to our left, and five people standing near each other directly in front of us, we are most likely to group those individuals accordingly and perceive three groups of people rather than perceive 15 individuals. Even though the room also contains tables and chairs, we mentally group people together because of their similarity. We do not also include the nearby chairs with those groups of people. While this room full of people is a perfectly fine example of proximity and similarity at work, a 2022 Psychological Science article provides another example. Psychological scientists at the University of Melbourne combined forces with an astronomer to explore the constellations perceived by different cultures (Kemp et al., 2022). While researchers for decades have noted cultural similarities in some constellations, for this research article, they took a more systematic approach. First, using star map software, they removed all of the stars with a brightness magnitude less than 4.5. That left them with a map of the brightest stars in the sky. Next, the researchers identified the constellations recognized by 22 cultures from around the world and mapped those constellations to see the amount of agreement across cultures. The ten constellations with the greatest overlap are Pleiades, Orion, Hyades, Big Dipper, Southern Cross, Corona Borealis, Castor & Pollux, Cassiopeia, Delphinus, and the head of Aries. Of course, each culture has their own stories and their own imagery, but the stars they use to create those images and stories are sometimes the same. As an example, the researchers noted that the Southern Cross is also perceived as a stingray (Yolgnu in northern Australia), an anchor (Tainui in New Zealand), and a curassow bird (Lokono in the Guianas). Interestingly, there is some overlap in the stories cultures tell about the images they see in the stars. The researchers give as an example Orion and the Pleiades. In Greek tradition, the hunter Orion is chasing the seven sisters (the Pleiades). In a number of Australian Aboriginal cultures, the stars of Orion also represent a hunter (or a group of boys) who is (are) chasing the women of the Pleiades. (For more information, see this blog post by Ray Norris, an astronomer at Western Sydney University.) Next, the researchers wondered what constellations a computer would create based on start brightness (similarity) and proximity. Their computer model identified the same ten constellations that have the greatest overlap across cultures as well as several other constellations or parts of several others. The researchers acknowledged that their computer model identified the star clusters, but did not identify how the stars in those star clusters are perceived to be arranged. In other words, while the model grouped the stars of Orion together, the model is unable to explain why we see the stars of Orion’s belt as, well, Orion’s belt. Or why so many cultures created a similar story of a man or boys pursuing a group of women. There are a few things I love about bringing this example of similarity and proximity into Intro Psych. First, every time students look at the stars in the sky, they will think of psychology. Second, it is a great example of what happens when researchers in different fields—psychology and astronomy, in this case—work with each other. And third, even though people of different cultures attach different interpretations to what they see, the perceptual principles are the same.   Reference Kemp, C., Hamacher, D. W., Little, D. R., & Cropper, S. J. (2022). Perceptual grouping explains similarities in constellations across cultures. Psychological Science, 33(3), 354–363. https://doi.org/10.1177/09567976211044157       ... View more

In the June 2022 edition of the APA Monitor on Psychology is an excellent article on the psychology of traffic safety. The article features David Strayer’s “four horsemen of death”: speed, impairment, fatigue, and distraction. Given the number and breadth of psychological concepts covered, this article provides fodder for a good end-of-term assignment. It may also save the lives of your students. Note that the journalist uses the term “crash” rather than “accident.” “Crash” is the preferred term by U.S. government agencies, such as the CDC and the National Highway Traffic Safety Administration (NHTSA). The word “accident” implies an incident that could not be avoided. The word “crash” does not carry that connotation. Giving the causes of traffic fatalities are due to driver decision-making, whether it be the driver of the vehicle or the driver of another vehicle, “crash” is a better descriptor than “accident.”   Ask students to read the article “Improving Traffic Safety” (Pappas, 2022), and then answer the following questions. How many people died on U.S. roadways in 2020? Speed. What percentage of the 2020 traffic fatalities were estimated to be caused by excessive speed? The article describes three ways that our environment can contribute to unsafe driving. Take a photo of a road in your area that illustrates one or more of these environmental hazards. Explain. The article also describes three ways that our environment can contribute to safe driving. Take a photo of a road in your area that illustrates one or more of these environmental benefits. Explain. In a survey of drivers at the beginning of the pandemic, researchers “saw an increase in respondents saying they were more likely to break the law because they knew they were less likely to be caught.” Explain this finding in terms of operant conditioning. With fewer people on the roads during the pandemic shut-down, researchers speculate that street racing may have increased. What Ontario law led to a reduction in street racing? Explain this effect in terms of operant conditioning. If you are primarily a driver, what can you do to reduce your chances of dying in a car crash due to speed? If you primarily a passenger, what can you do to reduce your chances of dying in a car crash due to speed? Impairment. What percentage of the 2020 traffic fatalities were estimated to be caused by impaired driving? Based on your reading of the article, describe the relationship between stress, alcohol, and driving while impaired. What Big Five personality trait is associated with a history of driving while impaired and reckless driving? Given your knowledge of this trait, why might that association exist? Fatigue. What percentage of the 2020 traffic fatalities were estimated to be caused by fatigue? Why might this number be an underestimation? Summarize what you learned in this course about the effects of sleep deprivation. Choose five effects, and for each, briefly explain how it could negatively effect driving.   According to the article, what have Australian highway authorities done to combat boredom on empty stretches of highway? Distraction. What percentage of the 2020 traffic fatalities were estimated to be caused by distracted driving? Explain how stress may contribute to distracted driving. Explain how the design of cars may contribute to distracted driving. Give at least one example. Conclusion. What was the most surprising thing you learned in this article? Explain. Identify at least one concept you learned in this course that could apply to speed, impairment, fatigue, or distraction but was not discussed in the article. Briefly describe the concept, and then explain how it could be a contributor to car crashes.   Reference Pappas, S. (2022, June). Improving traffic safety. Monitor on Psychology, 53(4), 46–55.       ... View more

What a great discussion-starter for Sensation & Perception. What if we had these abilities too? Five Animals That Can Sense Things You Can't ... View more

In Intro Psych, the sense of smell typically takes a distant backseat to vision and hearing. Part of that short shrift is due to the comparatively sparse research into our sense of smell and smell’s close relative, taste. With temporary loss of smell being one of the common symptoms of Covid-19, thousands of people have gained a new appreciation for this often-taken-for-granted sense. (See this blog post for more information--Covid-19 and a loss of smell: Discussion topic.) During your coverage of the memory chapter, ask your students to consider common odors associated with food: freshly baked cookies or bread, curry, fish, kimchi, etc. Or the smell of the cologne or perfume worn by a loved one. Or the smell of cigarette smoke. Do any of these odors invoke strong memories?  In a small-group—synchronous or asynchronous—discussion, ask your students to share the odor and any associated memories they are comfortable sharing. When you bring students back together as a class, ask the following question using your favorite polling tool: How strong was your memory? Very strong Somewhat strong Neither strong nor weak Somewhat weak Very weak I didn’t have a memory This tendency for odors or tastes to act as retrieval cues for strong autobiographical memories is known as the Proust phenomenon or Proust effect, named for Marcel Proust. In the first book of his 7-book tour-de-force, In Search of Lost Time (also sometimes titled, Remembrance of Things Past), Proust writes of how a madeleine—a buttery cookie—dipped in tea evoked a powerful childhood memory. A recent fMRI study (Zhou et al., 2021) found a strong connection between our sense of smell and our hippocampus—a connection that is much stronger than that for touch, hearing, or vision. The researchers posit that while the pathways for touch, hearing, and vision were all rerouted—over the course of our evolution—to the cerebral cortex before heading back to the hippocampus, that did not happen for smell. Our sense of smell has maintained its direct connection to the hippocampus—the brain structure most associated with the creation of new memories.   Reference Zhou, G., Olofsson, J. K., Koubeissi, M. Z., Menelaou, G., Rosenow, J., Schuele, S. U., Xu, P., Voss, J. L., Lane, G., & Zelano, C. (2021). Human hippocampal connectivity is stronger in olfaction than other sensory systems. Progress in Neurobiology, February. https://doi.org/10.1016/j.pneurobio.2021.102027     ... View more

This is a whole new level of walking in someone else's shoes! Virtual Body Swapping With Friend Can Alter Your Sense of Self https://psychcentral.com/news/2020/08/31/virtual-body-swapping-with-friend-can-alter-your-sense-of-self?utm_source=twitter&utm_medium=social&utm_campaign=owned&utm_content=2021-02-24#1 ... View more

“People are able to see and recognize patterns that can help them make decisions or form judgments, and a lot of this recognition is outside of conscious awareness.” The Science Behind Gut Feelings https://elemental.medium.com/the-science-behind-gut-feelings-e4ed0be994e9 ... View more

In a recent New York Times article(Katz, 2020), the author, Suzy Katz (2020), reflects on how the loss of the sense of smell courtesy of Covid-19 has affected her experience of the world. Most people who have a positive test for Covid-19 will lose their sense of smell or experience “smell distortions,” almost 90% of those infected will regain it within four weeks. That means that 10% don’t (Feuer, 2020). The author of the New York Times article is a member of that 10%--it’s been nine months since she tested positive for Covid-19, and her sense of smell is still AWOL (Katz, 2020). Interestingly, Covid-19 appears to not attack the olfactory neurons themselves, but the cells that support those neurons (Feuer, 2020). Although, that’s small consolation to those, like Katz, who miss their sense of smell. I remember the first student I had who reported not having a sense of smell. Her loss was the result of a head injury. Anosmia—lacking a sense of smell—is a not uncommon effect of head injury. In fact, 13% to 25% of people with head injuries have anosmia. The greater the injury, the greater the likelihood of anosmia. Additionally, 25% to 33% of those with head injuries experience “abnormal odor sensations”—parosmia (Howell et al., 2018). People with parosmia “no longer wake up and can’t smell the coffee; because of parosmia, their coffee smells like burning rubber or sewage. Parosmia is most often an unpleasant smell, a distortion of an actual odor, making many foods smell and taste revolting.” (Feuer, 2020). “Olfactory loss is often discounted as an annoyance, rather than a major health concern by both patients and many healthcare providers. Patients with olfactory impairment have diminished quality of life, decreased satisfaction with life, and increased risk for personal injury” (Howell et al., 2018). For my student, her loss of the sense of smell did not seem to greatly affect her quality of life or her satisfaction with life. My student reported not being particularly bothered by not being able to smell. The biggest change she noted was that she does more laundry than she used to since she can’t sniff her clothes to see if they can make it one more day.  The “increased risk for personal injury,” though, is an interesting point. Katz writes that “I accidentally left a burner on in my apartment and nearly started a fire” (Katz, 2020). How many of us take our sense of smell for granted? Suggested discussion topic Writing prompt for initial post Take an hour and make a note of everything that you smell, e.g., baking cookies, a partner’s perfume/cologne, a pet’s flatulence. If you lack the sense of smell, ask a friend or family member to send you a list of odors that they detected over the course of an hour. Read this article: “Covid stole my sense of smell. The city’s not the same.” [Instructors: provide a library database link to this New York Times article. Your librarians can help you with that.] Quote something from the article that you found particularly interesting. In 150+ words of reflection, explain why. Be sure to use quotation marks for your quote. The quotation is not part of the 150+ word count. Of the odors on your list, which one would you miss the most? Why? If you asked a friend or family member to provide a list for you, which odor would you most like to smell? Why? Writing prompt for responses Please respond to the initial posts of two of your classmates. with at least two of the following types of comments. A compliment, e.g., "I like how... because...," I like that... because..." A comment, e.g., "I agree that... because...," "I disagree that... because..." A connection, e.g., "I have also read that...," "I have also thought that...," "That reminds me of..." A question, e.g., "I wonder why...," "I wonder how..."    References Feuer, S. (2020, September 21). How does Covid-19 affect smell? Smithsonian Magazine. https://www.smithsonianmag.com/science-nature/why-covid-19-patients-are-suffering-distorted-and-phantom-smells-180975826/ Howell, J., Costanzo, R. M., & Reiter, E. R. (2018). Head trauma and olfactory function. World Journal of Otorhinolaryngology - Head and Neck Surgery, 4(1), 39–45. https://doi.org/10.1016/j.wjorl.2018.02.001 Katz, S. (2020, December 15). Covid stole my sense of smell. The city’s not the same. New York Times. https://www.nytimes.com/2020/12/15/well/live/covid-sense-of-smell.html ... View more

"Together, the results from these studies suggest that individuals with social anxiety show an irregular attentional pattern when they are viewing emotional faces." Eye Tracking Evidence Shows that Social Anxiety Changes the Picture http://ow.ly/CfaM30r1XvU #psychstudentrss  ... View more

In the Intro Psych sensation and perception chapter, we often cover monocular cues. While it’s fine to think about how monocular cues help us perceive depth, I had never given much thought to what we would perceive if we lacked several monocular cues. In Your Inner Fish, the author, paleontologist and anatomy professor Neil Shubin, writes There is no field manual for Arctic paleontology. We received gear recommendations from friends and colleagues, and we read books-only to realize that nothing could prepare us for the experience itself. At no time is this more sharply felt than when the helicopter drops one off for the first time in some godforsaken part of the Arctic totally alone. The first thought is of polar bears. I can't tell you how many times I've scanned the landscape looking for white specks that move. This anxiety can make you see things. In our first week in the Arctic, one of the crew saw a moving white speck. It looked like a polar bear about a quarter mile away. We scrambled like Keystone Kops for our guns, flares, and whistles until we discovered that our bear was a white Arctic hare two hundred feet away. With no trees or houses by which to judge distance, you lose perspective in the Arctic (pg. 17).  This photo of Arctic Alaska can help you picture what Shubin and his colleagues were seeing—or not seeing. The caption says that those dark dots are caribou. Looking at this tundra is not unlike looking at the sky, and the sky also frequently lacks monocular cues. When I see a speck with the sky as the background, if I perceive that speck as really close, then it’s a gnat. If I perceive it a little farther away, it’s a bird. If I perceive it really far away, it’s a plane. If I perceive the speck as being someplace between the bird and the plane, it’s Superman. In Shubin’s case, the Arctic tundra didn’t give him many monocular cues to work with. Without a solid sense of distance, it’s difficult to determine the size of the object or critter. After covering monocular cues, share with students the Arctic Alaska photo. Drag your browser so the description of the caribou is off the screen. Ask students to identify the dots in the photo. After all of the guesses are in, tell students that the dots are caribou. Ask students which of the monocular cues you covered can be seen in the photo, such as relative height. Ask students which ones are missing, such as linear perspective. The fewer distance cues we have, the harder it is to determine distance. To close the activity, read students Shubin’s hare/bear paragraph. That will give you a leaping off point to talk about the ways in which our expectations can affect our perceptions. Shubin and his colleagues could have perceived the critter as a hare from the very beginning, but because polar bears were very much on their minds, a polar bear is what they all perceived. That is, until further evidence proved them wrong. ... View more

One of the many things I love about teaching psychology is that I can learn something new about the field—about our humanness—just about anywhere. I am currently reading Skeleton Keys by Brian Switek (2019), a science writer and bone geek. Exploring the origins of our bones, this book is a fascinating history. Any history that starts a few hundred million years ago—as this one does—reminds me how improbable our existence is. It is improbable that mammals exist, that primates in particular exist, that humans exist, and, lastly, that I, specifically, exist. With an incomprehensible timeline that is measured in millions of years, I can’t help but think—in the greater scheme of things—how small I am. While that millions-of-years perspective didn’t stop me from being irritated with some of my fellow drivers on my morning commute, I did think about that dinosaur who one day felt irritated with their fellow dinosaurs when travelling to wherever dinosaurs travelled. You have my empathy, dinosaur. In a brilliant example of burying the lede, I’m actually writing about where the three little bones in the middle ear come from, as I just learned from Skeleton Keys. Stick with me. Protomammals—a group of animals who were precursors to mammals—had jaws comprised of a number bones. Visit the Wikipedia page for Dimetrodon, a protomammal that lived almost 300 million years ago. On that Wikipedia page, scroll down to the drawings of the skull. In the lateral view, notice the quadrate bone at the back of the upper jaw and the articular bone in the back of the lower jaw. Over time—and by “time” I mean millions of years—those bones shrunk in creatures that followed Dimetrodon, but did not disappear. The quadrate evolved into the incus (anvil), and the articular evolved into the malleus (hammer). The stapes (stirrup) had a different origin, but same idea. It was a small bone on top of the hyoid bone in the neck of protomammals (Maier & Ruf, 2016). Press your fingers into the skin right in front of your ear. Open and close your jaw. This is where your upper and lower jaws meet. Those tiny bones of the middle ear are right behind that joint.   References Maier, W., & Ruf, I. (2016). Evolution of the mammalian middle ear: A historical review. Journal of Anatomy, 228(2), 270–283. https://doi.org/10.1111/joa.12379 Switek, B. (2019). Skeleton Keys. New York City: Riverhead Books. ... View more

Because the perception of color is inherent to our experience, it’s difficult to know what someone else’s perception of color is like. People with total color blindness (either monochromacy or achromatopsia) (National Eye Institute, 2015) or color deficiency – can’t know what someone with complete color vision sees. And people with complete color vision can’t know what someone with total color blindness or color deficiency sees. In an article about what it is like to be a woman who is red/green color blind*, Zoe Dubno (2019) tells us about a free app that manipulates color to show us what everyone else is seeing: Color Blind Pal (Android/iOS/Mac). If your students have one of these three types of color blindness, the app will shift the hue of colors to make those colors easier to see. Protanopia/protanomaly (cannot see any red/reduced sensitivity to red) Deuteranopia/deuteranomaly (cannot see any green/reduced sensitivity to green) Tritanopia/trianomaly (cannot see blue/reduced sensitivity to blue) For your non-color blind students who are, say, future software builders, website designers, graphic designers, interior designers or who will ever have a need to create a graph or do a presentation, they should know what almost 10% of their audience (National Eye Institute, 2015) will see. You can give your students this information from the National Eye Institute (2015): Red/green color blindness Protanopia: “Red appears as black. Certain shades of orange, yellow, and green all appear as yellow.” Protanomaly: “Red, orange, and yellow appear greener and colors are not as bright.” Deuteranopia: Red looks brownish-yellow; green look beige. Deuteranomaly (most common): “Yellow and green appear redder and it is difficult to tell violet from blue.” Blue/yellow color blindness Tritanopia (very rare): “Blue appears green and yellow appears violet or light grey.” Trianomaly: “Blue appears greener and it can be difficult to tell yellow and red from pink.” Or your non-color blind students can see the effects of color blindness for themselves in the Color Blind Pal app.  Or your color blind students who are, say, future software builders, website designers, graphic designers, interior designers or who will ever have a need to create a graph or do a presentation, can use the Color Blind Pal app to shift colors into a range they can better see.  Instructions on how to use the Color Blind Pal app are at the end of this blog post. Why is it that a red deficiency results in an inability to distinguish red from green and vice versa, and why is it that a green deficiency results in an inability to distinguish green from red? Follow the link to this image that shows the light wavelengths and how many photons (packets of lightwaves) each cone captures. Notice how much the red and green cones overlap in terms of their sensitivity to the wavelengths of light. For someone who is lacking green sensitivity, for example, their spectrum shifts toward red, making telling the difference between red and green more difficult. Conversely, for someone who is lacking red sensitivity, their spectrum shifts toward green, also making telling the difference between red and green more difficult. Why so much overlap between red and green cones? It looks like red and green cones used to be different alleles of the same gene. And this is still true among New World primates. The continents split 50 million years ago separating what would become New World primates from Old World primates. Around 40 million years ago, in Old World primates what was the green/red gene duplicated, allowing one gene to specialize in creating red cones and the other to specialize in creating green cones. New World primates haven’t had this gene duplication and all remain dichromats (essentially, they’re red/green color blind), except for some females. Since the gene with red/green alleles resides on the X chromosome (and gene for blue cones on chromosome 7), a male New World primate has blue (chromosome 7) and either green or red (he only has one X). A female New World primate has blue (chromosome 7), and, with two Xs, she can have two greens, two reds, or a green and red. In the latter case, she is a trichromat (White, Smith, & Heideman, n.d.). The Ishihara Test After your students have had a chance to explore the Color Blind Pal mobile app, visit a website that displays examples from the Ishihara Test for color blindness, such as this one at colormax.org. Zoom in so that only one test item is displayed at a time. Your students who are not color blind can simulate the different forms of color blindness to see how the number disappears. They can then change the settings in the app so that the app thinks they have, say, deuteranopia, to see how the app changes the colors to make the number more distinctive. Your students who are color blind, using the app set to their form of color blindness may see the number where they hadn’t before.   ******<Start instructions>****** Instructions on how to use the Color Blind Pal mobile app Install the app by downloading it from Google Play (Android) or the App Store (iOS). When it asks, give the app permission to access your camera. If you are not color blind or color deficient: Click on the “i” icon, then click on “Color blindness type.” Choose one of the five “Simulate” options. Start with “Simulate deuteranomaly” (reduced sensitivity to green and the most common form of color blindness), then tap the back arrow. At the top of the screen, you can toggle between “Inspecting Color” which names the color in the middle of the screen and “Filtering Colors.” (Play around with “Inspecting Color” first, if you’d like.) Switch to “Filtering Colors.” Make sure “Shift” is selected at the bottom of the screen. You are now seeing what someone with deuteranomaly sees. Use the app to look at a range of colors, especially green and orange. Compare violet and blue. In the settings, change the “color blindness type” to “Simulate deuteranopia” (green blindness), and tap the back arrow. Look at those same colors again. How does lacking the ability to see any green (deuteranopia) compare to being green-deficient (deuteranomaly)? Change the “color blindness type” again to simulate the other forms of color blindness: protanopia (cannot see red), protanomaly (red-deficiency), tritanopia (cannot see blue). How do colors look different when simulating deuternopia compared to protanopia? If you are color blind or color deficient: Click on the “i” icon, then click on “Color blindness type.” Choose the type of color blindness that is closest to yours: protanopia (red), deuteranopia (green), or tritanopia (blue), then tap the back arrow. If you're not sure which form you have, start with deuteranopia (also covers deuteranomaly, the most common type of color blindness). At the top of the screen, you can toggle between “Inspecting Color” which names the color in the middle of the screen and “Filtering Colors.” (Play around with “Inspecting Color” first, if you’d like.) Switch to “Filtering Colors.” Make sure “Shift” is selected at the bottom of the screen. The app will “shift" hues away from colors that are hard to distinguish toward colors that are easier to distinguish.”   At the bottom of the screen, select “Filter.” Everything will appear gray except for the color you chose on the slider. How do the colors change for you? What looks different now? ******<End instructions>****** *Color blindness vs color deficiency. Technically, the only people who are color blind are those with no color vision at all. Everyone else has different degrees of color deficiency. However, color blindness is in common use to mean any degree of color deficiency, I will use color blindness in this post in that way.   References Dubno, Z. (2019, February 5). Letter of recommendation: Color blind pal. The New York Times Magazine. Retrieved from https://www.nytimes.com/2019/02/05/magazine/letter-of-recommendation-color-blind-pal.html?partner=rss&emc=rss National Eye Institute. (2015). Facts about color blindness. Retrieved February 13, 2019, from https://nei.nih.gov/health/color_blindness/facts_about White, P. J. T., Smith, J., & Heideman, M. (n.d.). The evolution of trichromatic vision in monkeys. Retrieved February 17, 2019, from https://lbc.msu.edu/evo-ed/pages/primates/index.html ... View more

You can buy a good pair of bone conduction headphones for under $150. Some of your students may have seen them or own a set. Here’s a little information to add to your next Intro Psych hearing lecture, or at least some information to hold onto in case a student asks. If you teach Biopsych, you can dig even deeper into this topic – or have your students do the digging. Bone conduction headphones, such as Aftershokz Trekz Air, send vibrations through, well, bone. The headphones speakers are generally positioned against the cheek bone or upper jaw bone right in front of each ear. The cheek bones carry the vibrations through to the temporal bone – the bone that surrounds the cochlea. While the specifics are still under investigation, we know that these vibrations cause the cochlear fluid to move, triggering the cilia that send their messages to the auditory cortex where we hear sound. It could be that the bone vibrations cause the fluid in the cochlea to move due to a change in pressure, the vibrations in the bone put pressure on the walls of the cochlea causing them to compress, or the vibrations in the bone could cause waves in the cerebrospinal fluid in the skull thereby causing waves in the cochlea (Dauman, 2013). Or all three. All of those routes explain how someone with middle ear damage can hear through bone conduction. The vibrations bypass the bones of the middle ear and affect the cochlea directly. Bone conduction hearing devices (previously called bone anchored hearing aids) are for people with issues with their outer or middle ears. These devices can either be surgically implanted with a speaker attached by magnet or just temporarily attached with adhesive (Hearing Link, 2017). The vibrations produced by bone conduction headphones also cause vibrations in the skin and cartilage of the outer ear as well as vibrations in the temporal bone of the skull. Those vibrations cause air to move in the outer ear, triggering the bones of the middle ear to move, and so on, resulting in sound. This may not contribute much to what we hear through bone conduction, but it contributes more if we wear ear plugs with our bone conduction headphones. That brings us to the occlusion effect (Dauman, 2013). While you may not be familiar with the occlusion effect (I wasn’t), everyone with some amount of hearing has experienced it. While talking, plug your ears with your fingers. Your voice will sound up to 20 decibels louder (Ross, 2004).   We hear our own voices through bone conduction. With our outer ears open, the vibrations that come through the bone can vibrate on out through the outer ear. With our outer ears plugged, the vibrations cannot escape and so reverberate back through the middle ear, amplifying our voices. This is one of the reasons some people don’t like (unvented) earmold hearing aids; they completely block the ear canal making our voice sound funny (Ross, 2004). Most earmold hearing aids now come with a vent – an opening that allows the vibrations caused by our voices to escape. Why use bone conduction headphones? There are several advantages to using bone conduction headphones (Banks, 2019). If you are walking, running, or biking on the open road, bone conduction headphones allow you to listen to your tunes without blocking your ear canal. You’ll have a greater chance of hearing that car coming up behind you, but, of course, all of the research on attention tells us that you still may not attend to the sound of the car. Or you may not hear the car at all if the sound of it is masked by whatever you’re listening to through your headphones (May & Walker, 2017). In terms of this sort of safety, bone conduction headphones are likely not worse than any other kind of headphone or speaker (Granados, Hopper, & He, 2018). If you use earmold hearing aids, you can use bone conduction headphones with them. If you are a scuba diver, you can use a bone conduction microphone and headphones to both speak and listen underwater (see for example Logosease). If you have tinnitus, bone conduction headphones can provide auditory stimulation to the cochlea that may reduce tinnitus while allowing you to still have a conversation in, say, a work environment (British Tinnitus Association, n.d.; Schweitzer, 2018), although the research here is scant (Manning, Mermagen, & Scharine, 2017). Can bone conduction headphones produce hearing loss when listening at loud volumes just like regular headphones can? After scouring journals and reading opinions from all corners of the internet, my conclusion, pending further evidence, is a tentative and cautious affirmative; bone conduction headphones can cause hearing loss. Anything that can produce loud sounds, including regular headphones cranked up to a high volume, causes hearing loss by producing tsunamis that damage the cilia in the cochlea. Since bone conduction headphones are also causing waves in the cochlea, it stands to reason that waves caused by bone conduction could also reach tsunami strength. But, then again, maybe bone conduction cannot produce those kind of waves. Some research here would be nice. If you know of any, please let me know!   References Banks, L. (2019). Best bone conduction headphones of 2019: A complete guide. Retrieved February 11, 2019, from https://www.everydayhearing.com/hearing-technology/articles/bone-conduction-headphones/ British Tinnitus Association. (n.d.). Sound therapy (sound enrichment). Retrieved February 11, 2019, from https://www.tinnitus.org.uk/sound-therapy Dauman, R. (2013). Bone conduction : An explanation for this phenomenon comprising complex mechanisms. European Annals of Otorhinolaryngology, Head and Neck Diseases, 130(4), 209–213. https://doi.org/10.1016/j.anorl.2012.11.002 Granados, J., Hopper, M., & He, J. (2018). A usability and safety study of bone-conduction headphones during driving while listening to audiobooks. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 62(1). Hearing Link. (2017). Bone conduction hearing devices. Retrieved February 11, 2019, from https://www.hearinglink.org/your-hearing/implants/bone-conduction-hearing-devices/ Manning, C., Mermagen, T., & Scharine, A. (2017). The effect of sensorineural hearing loss and tinnitus on speech recognition over air and bone conduction military communications headsets. Hearing Research, 349, 67–75. May, K., & Walker, B. N. (2017). The effects of distractor sounds presented through bone conduction headphones on the localization of critical environmental sounds. Applied Ergonomics, 61, 144–158. Ross, M. (2004). Dr. Ross on hearing loss. Retrieved February 11, 2019, from http://www.hearingresearch.org/ross/hearing_loss/the_occlusion_effect.php Schweitzer, G. (2018). Bone conduction headphones for hearing loss and tinnitus. Retrieved February 11, 2019, from https://rewiringtinnitus.com/trekz-titanium-bone-conduction-headphones/ ... View more

Earlier this week, the Internet blew up when an ambiguous audio clip from Roland Szabo of Lawrenceville, GA was posted to Reddit (Salam & Victor, 2018). Video Link : 2251 Some people hear yanny, others hear laurel, and others hear something a little in between, like geary. And a lot of people sometimes hear one and sometimes hear the other. If it feels like The Dress all over again, you are on the mark. (Side note. I have an image of the The Dress in my course materials that students can access before class. A student who had never seen the image scrolled through these materials and saw a gold/white dress. A few hours later when he came back into those materials he saw it as blue/black. He said, “It completely freaked me out!”) Just as the colors in The Dress are ambiguous – the blue/white band is neither blue nor white, but in between – the pitches in the Yanny/Laurel clip are ambiguous; more accurately, both high and low pitches are present. The colors you see in the dress depend on the assumptions your brain is making about the color. The word you hear in the Yanny/Laurel clip depends on what your brain does with those pitches. If you’re more tuned into the higher pitch, you hear yanny. If you’re more tuned into the lower pitch, you hear laurel. The New York Times has created a tool that will let you hear both (Katz, Corum, & Huang, 2018). If you find the sweet spot, the words may alternate for you. When your students ask about this next term, that’s the simple answer. But your more astute students will ask, “But what makes one more tuned into a higher or a lower pitch?” That’s a harder question to answer.  While we’re not entirely sure what those factors are just yet, here are some possibilities (Morris, 2018). Degree and type of hearing loss – if you’ve lost hearing for high-pitched sounds, you’ll be more likely to hear laurel. Perceptual set – what word you’re expecting can influence what word you hear. Using the New York Times tool, start in the middle, and slide in the direction of the word you are not hearing. (I hear yanny at the middle, so I slide toward laurel.) Note where the word changes. Now start the slider on the far end for that word (the laurel end) and slide back toward the middle and note where the word changes. You’ll probably need to go beyond where the word changed for you the first time to get it to change back again. Speaker quality – if your speakers or headphones emit more treble than bass, you are more likely to hear yanny. I know that the sensation and perception researchers are on this and will have some more information for us before fall term starts. #TeamYanny   References Katz, J., Corum, J., & Huang, J. (2018). We made a tool so you can hear both yanny and laurel. Retrieved May 17, 2018, from https://www.nytimes.com/interactive/2018/05/16/upshot/audio-clip-yanny-laurel-debate.html    Morris, A. (2018). Hearing both yanny and laurel? Retrieved May 17, 2018, from https://www.forbes.com/sites/andreamorris/2018/05/16/hearing-both-yanny-and-laurel/#4d3c524d1635  Salam, M., & Victor, D. (2018). Laurel or yanny? What we heard from the experts. Retrieved May 17, 2018, from https://www.nytimes.com/2018/05/15/science/yanny-laurel.html  ... View more

Perceptual illusions are not only great fun, they also remind us of a basic truth: Our perceptions are more than projections of the world into our brain. As our brains assemble sensory inputs they construct our perceptions, based partly on our assumptions. When our brain uses rules that normally give us accurate impressions of the world it can, in some circumstances, fool us. And understanding how we get fooled can teach us how our perceptual system works.   A case in point is the famed Müller-Lyer illusion, for which the Italian visual artist Gianni Sarcone gives us two wonderful new examples. https://www.giannisarcone.com/3-MEDIA_Images/Muller_lyer_star_OR2.gif  https://www.giannisarcone.com/wp/wp-content/uploads/2017/10/Muller_Lyer_waves_S.gif   Many more informative examples can be found amid the 644 pages of the new Oxford Compendium of Visual Illusions. There I discovered a fascinating phenomenon reported by Gettysburg College psychologist Richard Russell.   First (with Professor Russell’s kind permission from his earlier article in Perception) a question: In the pair of Caucasian faces, below, which looks to be the male, and which the female? Do you (as did I) perceive the left face as male, the right face as female?   Many people do, but in actuality, they are the same androgynous face (created by averaging Caucasian male and female faces), but with one subtle difference: the researchers slightly darkened the skin (but not the lips or the eyes) in the left face and lightened the skin in the right face. Why? Because worldwide and across ethnic groups, Russell and others report, women’s skin around the lips and eyes tends to be lighter than men’s. And that means more contrast between their skin and their lips and eyes.   That natural, subtle facial sex difference enabled Russell to recreate what he calls “the illusion of sex” with a second demonstration. This time, he left the skin constant but lightened the lips and eyes of the left face, making it appear male, and he darkened the lips and eyes of the right face, increasing the contrast, making it appear female. Russell suggests that this helps explain why, in some cultures, women use facial cosmetics. Lipstick and eye shadow amplify the perceived sex difference, he notes, “by exaggerating a sexually dimorphic attribute—facial contrast.”   ... View more

Apophenia is seeing patterns in randomness, which may be the mechanism behind conspiracy theory generation. If it feels to me like a set of random events are connected and no one is talking about the connection, then conspiracy must be afoot (Poulsen, 2012). Psychiatrist Klaus Conrad is credited with coining this term in 1958 to describe the descent into psychosis, “Borrowing from ancient Greek, the artificial term ‘apophany’ describes this process of repetitively and monotonously experiencing abnormal meanings in the entire surrounding experiential field, eg, being observed, spoken about, the object of eavesdropping, followed by strangers” (as cited in Mishara, 2010). But this isn’t a post about conspiracy theories or psychosis. While conspiracy theories and psychosis take our ability to see patterns to whole other level, seeing patterns in randomness is just how our brains work. The visual version of apophenia is pareidolia. Have you ever seen a rabbit in a cloud formation? That’s pareidolia. Have you seen a face in a piece of toast? Also pareidolia. After covering the cerebral cortex, tell students that there is an area in the temporal lobe that is especially good at detecting faces: the fusiform face area (FFA). Show students these 20 objects where faces appear. Ask students to guess whether they think that seeing these objects would cause the FFA to be activated. How could that hypothesis be tested? Give students a minute to think about it, a minute to share with a partner, and then ask for volunteers for their suggestions. This would be a nice time to review independent variables and dependent variables. When you’re ready, tell students that researchers compared such face objects with everyday no-face objects, and found that face-objects activated the FFA (Hadjikhani, Kveraga, Naik, & Ahlfors, 2009). If time allows, describe prosopagnosia (pro-soap-ag-nose-ee-ya; face-blindness). Do students think that the FFA would be activated when people with congenital prosopagnosia look at faces? Why or why not? The FFA is activated, but it doesn’t show habituation. When people without prosopagnosia are shown faces a second time, the FFA shows decreased activation; “Not interesting; I’ve seen this before.” For those with prosopagnosia, the activation is just as great the second time around; “Hey, this is new!” (Avidan, Hasson, Malach, & Behrmann, 2005). Again if time allows, do students think the FFA would be activated in people with autism. Why or why not? For the participants in the study, the severity of their autism varied. For those who had impaired face recognition (about half of their sample, 14 out of 27) , the activation of their FFA was weaker.   For 30 years, researchers have debated whether the FFA is face-specific or whether it is for detecting any complex pattern we’re expert in (Kanwisher & Yovel, 2006). Some recent research has found that the FFA is active when expert chess players look at positions of chess pieces, positions taken from actual gameplay, but not a specific chess piece (Bilalic, 2016). And researchers have also compared expert radiologists with beginner medical students. When the experts looked at X-rays, their FFAs were active (Bilalic, Grottenthaler, Nagele, & Lindig, 2016). While the jury is still out on whether the FFA is face-specific or not, this is a wonderful example of science in action. Researchers describe a finding. All researchers start thinking about what might be the cause of that finding, and they start devising experiments to test their hypothesized causes.   References  Avidan, G., Hasson, U., Malach, R., & Behrmann, M. (2005). Detailed exploration of face-related processing in congenital prosopagnosia: 2. Functional neuroimaging findings. Journal of Cognitive Neuroscience, 17(7), 1130–1149. https://doi.org/10.1162/0898929054475154 Bilalic, M. (2016). Revisiting the role of the fusiform face area in expertise. Journal of Cognitive Neuroscience, 28(9), 1345–1357. https://doi.org/10.1162/jocn  Bilalic, M., Grottenthaler, T., Nagele, T., & Lindig, T. (2016). The faces in radiological images: Fusiform face area supports radiological expertise. Cerebral Cortex, 26(3), 1004–1014. https://doi.org/10.1093/cercor/bhu272 Hadjikhani, N., Kveraga, K., Naik, P., & Ahlfors, S. P. (2009). Early (N170) activation of face-specific cortex by face-like objects. Neuroreport, 20(4), 403–407. https://doi.org/10.1097/WNR.0b013e328325a8e1 Kanwisher, N., & Yovel, G. (2006). The fusiform face area: a cortical region specialized for the perception of faces. Philosophical Transactions of the Royal Society B: Biological Sciences, 361(1476), 2109–2128. https://doi.org/10.1098/rstb.2006.1934 Mishara, A. L. (2010). Klaus Conrad (1905-1961): Delusional mood, psychosis, and beginning schizophrenia. Schizophrenia Bulletin, 36(1), 9–13. https://doi.org/10.1093/schbul/sbp144 Poulsen, B. (2012). Being amused by apophenia. Retrieved from https://www.psychologytoday.com/blog/reality-play/201207/being-amused-apophenia ... View more