FINAL BLOG ENTRY

This class has been very interesting this semester.  Learning about each of the five senses was something that has always intrigued me.  I had often thought about how life would be had they been different.  My favorite sense to learn about was vision.  Specifically, I enjoyed learning about the difference between laterally placed eyes on animals and frontally placed eyes on humans.  It was very interesting to learn about how preys usually have laterally placed eyes because they have to take in more of the environment, where as predators have frontally placed eyes so they have more binocular overlap and better depth perception.  I had never made this connection before, but now it makes perfect sense.  Preys need the lateral vision to see their surroundings better and see if a predator is coming from any angle.  Predators need frontal eye placement to track their prey better.  With the overlap of vision seen between the two eyes, predators have much better depth perception.

Along the same lines, I really enjoyed learning about depth perception, specifically in regards to stereograms.  Ever since I was younger, and I’m sure this is true with every kid, I was obsessed with any image that looked 3D.  Even as a teenager, I was thoroughly excited as soon as I saw the 3D glasses needed for the Shrek 4D ride at Universal Studios.  Knowing now how exactly the glasses work changed my whole perspective about these experiences.  As I have mentioned in past entries, I have also really enjoyed learning about Magic Eye autostereograms.  I remember spending hours doing different ones, like this one.  I would usually be able to see the depth, but never really be able to discern what the object was.  For the example I linked to above, I can tell it is supposed to be a heart, but this is one of the few I can identify.

In general, this class has really openned up my eyes (no pun intended) to the wonders of perception and I have really enjoyed it.  I hope you have a great summer.

 

Depth Perception in Art

Art has always been an important part of our culture, from primative cave drawings to three-dimensional images.  Finding ways to represent a three dimensional world on a two dimensional surface caused many problems for artists before the Renaissance.  They often had troubles showing depth in their paintings.  One example of this can be seen in Giovanni Bellini’s The Madonna and Child.  When looking at the painting, you can tell that something is wrong with the depth.  You know from the context of the picture that the child is sitting on the woman’s lap, but something just does not seem right about it.  The artist solely used occulusion to show depth in this painting, but in everyday life, we use many other techniques to recognize depth.  These include linear perspective, texture gradiant, arial perspective, size, shading, motion parallax, and disparity.  After the Renaissance, artists began to understand how to use these techniques within their paintings.  This can be seen in Madonna of the Harpies by Andrea del Sarto.  This painting shows a good use of shading, size and linear perspective.  Soon enough, artists have learned to use even disparity in their images, as seen in autostereograms like this one.

 

Colorblind

“I am colorblind…
Coffee black and egg white…”

-Counting Crows “Colorblind”

Colorblindness is a fascinating condition.  Most people assume that people afflicted with this condition just cannot see certain colors.  Instead, they see colors but cannot discriminate between two colors, usually either red and green or blue and yellow.  Good examples of how they test this are seen in Ishihara Color Vision Test, seen on this website.  If a patient cannot see the numbers in the top right, second row on the left, or either in the bottom row, then that person suffers from colorblindness.  They would only see dots of one color in the circles as long as all of the dots are of the same lightness. 

What is interesting about this, however, is that they still see some color in in these circles.  Most people assume that people with colorblind vision only see in black and white.  This mistaken belief is far from the truth.  Colorblind people have difficulty discriminating between the two colors, but they can usually see some slight difference and can usually use that to compare the two colors.  This website gives very nice examples of what people with deficient colorblind vision see.  

This leads to the very interesting question of what the world would be like if what one person considers red is what another person considers blue.   There was a book that I read when I was younger, and sadly I cannot remember the name of it, but this question was a large part of the plot.  All people saw the colors of the rainbow in a certain way, but the main character saw them differently and still called them the same names.  It is interesting to think of how we adjust from what society tells us is normal.  Society told him that water was blue, but his version of blue was our version of red and this seemed normal to him because that was what he grew up with.

 

Visual Processing

There are so many different areas of the cortex devoted to processing different types of visual information because there are so many different types of visual information in the world that we need a lot of processing power in order to understand it all.  We need to understand the texture, color, brightness, shape, orientation, etc of the objects surrounding us to know what the object is.  You would require even more space on the cortex in order to understand the combination of these aspects of the visual field.  You need all of these pieces to work together in order to understand things that are similar in some aspects, but not others.  An example of this would be a red ball and a yellow one.  They are both the same shape, texture, and orientation, but without having the capacity to notice the color difference, we would have no idea that the two balls were not identical.

 

Change Blindness

Change blindness occurs when you don’t relize that some aspect of your current situation has changed because you attention was placed elsewhere.  In class, we discussed a situation in which someone is stopped on the street and asked directions somewhere.  As they are talking, some construction workers walk between the two of them with a large board and as they do so, the person asking the question actually changes to another person.  Change blindness occurs when the subject doesn’t realize that the person has changed and this occurs around 75% of the time.  I found a clip on YouTube that is very similar to this situation, except now the subject comes up to a table to complete some forms for a psychological experiment.  After they have finished signing the form, the experiementer ducks behind the table, appearing to put the form away and find a new one, and while he is beneath the table, another experimenter takes his place.  The second experimenter completes the conversation with the subject and sends them on their way.  In most cases, people had not noticed the change.  It is theorized that the only people who do notice the difference are those who paid attention to some small detail on the first experimenter, whereas other subjects were focused on other details of their environment.  In this experiment, the two experimenters were wearing different colored shirts and it is suspected that those who were focusing on their shirts would be the ones who noticed the change.

One of the most common instances of this in real life is seen in movies, when the details of a scene are changed between takes accidentally.  In fact, this happens so often that some movie production companies hire people to watch the details of a scene and make sure they remain constant throughout the movie.  Here and here are some good clips of times when this person was not completing their job to their best ability.

 

Transformers

“Transformers! More than meets the eye!”

Not only is this theme song a catchy lyric, but it is also a very true statement about our vision.  According to the song, the fact that the characters are “robots in disguise” is why they used the first lyric.  Usually the robots disguise themselves as a car or some other type of machine and then turn into their robot-forms once they go into battle. 

In the case of vision, I would say that this statement refers to illusions and for how we interpret images.  In most illusions, we think we see something that is not there.  An example of this is seen in my blog before this, on the Hermann Grid.  The observer thinks that they see black dots in the space between the black boxes, but they are not in fact there.  In this case more is going on than meets the eye because you are perceiving something that is not there.  Another case of this is seen here.  When most people see this image, they see four black circles with a white square on top, when in fact it is only four black circles with pieces cut out of the circles.  The viewer sometimes will go as far as to say that they see very faint lines outlining the square.  This shows that what we are perceiving is definately more than what is actually seen by the eye.  There is more processing going on after the eye registers the image.

 

Hermann’s Grid

     Optical illusions have amazed many people since they were children.  Seeing one face and changing your position to see the other, seeing dots where they aren’t, or seeing a staircase that always descends or ascends are a few examples of these baffling images.  Some may say that these pictures are just children’s games and that there is no point in studying them.  However, these pictures can tell us amazing amounts of information about our brains and how they are used.  An example of this is shown in an illusion seen on this page.

     As I stared at this image, I saw black dots appear in between the figures in the graph, but once I moved my eyes, the dots disappeared and reappeared on other circles. This image is known as Hermann’s Grid.  It was originally discovered by L. Hermann in 1870 while he was looking at a graph in a book by John Tyndall about sound.  Why does this strange phenomenon occur?  Why does the brain tell us things that aren’t there?     To help understand this occurrence fully, the reader must understand the receptive fields of the eyes.  The eyes are made up of two kinds of synapses, excitation and inhibitory.  Excitation synapses increase the neural activity when they are stimulated and are completely surrounded by inhibitory synapses, which decrease neural activity when stimulated.  The eyes see this image as though it was made up of two components.  Component One is the intersection of the vertical and horizontal lines.  Component Two is the white line that separates two black boxes.  When the eye looks at Component One, the excitation synapses focus on the very center of the intersection, while the inhibitory take in the rest of the immediate surroundings in the form of a circle.  When the eye looks at Component Two, the excitation synapses focuses at a center point of the white line, while the inhibitory take in the rest of the surroundings.  The inhibitory synapses in Component One take in much more of the white space than the inhibitory synapses of Component Two do.  This overwhelming amount of white suppresses the excitation synapse, and makes the center of the intersection appear darker than the areas surrounding it.A psychologist may learn some important things about the mind with this illusion.  It shows that we often see things that are not truly in front of us.  For example, our mind tells us that in this image, there are black spots, when in fact there are none.   This process is often referred to as the lateral inhibition network and is closely related to the part of the brain that is not being used, the “unconscious” brain.  This illusion, therefore, tells psychologists more about this “unconscious” brain, and how it can occasionally take over and show us things that are not there.

 

Works Cited:http://serendip.brynmawr.edu/bb/latinhib.htmlhttp://psylux.psych.tu-dresden.de/i1/kaw/diverses%20Material/www.illusionworks.com/html/hermann_grid.html

 

Purse Ep Shun

At the end of class today, we spoke briefly about the importance of context in understanding speech.  One of the examples Professor Boucher used was when listeners misunderstand what a song is actually saying, which is called a mondegreen.  One of the most famous examples of this that I know of is in the song “Bad Moon Rising” by Creedence Clearwater Revival.  One of the last lines of the chorus says “There is a bad moon on the rise.” One would think that the name of the song would make it obvious that that is what he is saying, but still people believe that he is singing “There is a bathroom on the right.”  Another great example of this was in a recent Cingular commerical where two guys debate the lyrics to “Rock the Casbah.”  Unfortunately, I couldn’t find this commercial online, but in the process of looking, I found this interpretation of the entire song with misheard lyrics.  After seeing this one, I began to look at others which were also very funny.  One of these was the song “Numa Numa” by O-Zone.  This song is in Russian and as you listen to it, it’s hard not to try to relate some of the words to English and end up with nonsense as the video shows.  Another example of this is seen seen in the song “Moskau” by Dschinghis Khan, which is a particular favorite of my friends because of the ridiculous dancing and costumes.  (Warning: there is some coarse language written in the subtitles)

 During all of this researching, I was also reminded of a game I had played once when I was younger called Mad Gab.  You would be split into teams and when it was your turn, your team is given cards with a bunch of random phrases on them.  You have to sound the phrase out, saying it faster or slower or emphasize different pieces, in order to find out what the secret phrase is.  For example, a card could say “Sand Tack Laws” and your team would need to figure out that this sounds like Santa Claus.  This game is fun because as you are reading the words, you can’t get past the exact words that you are reading, but if you are listening to the other team try to guess, it’s much easier to tell what the phrase should be.  Here is a link to its description on Amazon.com and a demonstration of people playing the game.

 

Hearing Underwater

When I grew up, I loved being in the water.  Pools, oceans, anything, you name it.  One of my favorite games was to go underwater with my friends and guess the song that the others were singing.  It was always so difficult to understand and you’d have to stand very close to the singer in order to hear the song.  This is why I was so surprised to learn in class that sound travels five times faster in water than it does in air.  I decided to do more research on this topic.  On The Physics of Diving: Sound and Hearing site, I learned this:

“The volume does not depend on the speed of sound; rather, it is dependent on the amplitude of sound waves and on the perceptive capabilities of the audial organs. There are two methods of perceiving sound waves; the first being air conductivity (outer audial opening, eardrum or tympanum, audial bones of the middle ear) and the second being bone conductivity (the vibration of the bones of the skull). Air conductivity is prevalent in the air, whereas bone conductivity is prevalent under water. This peculiarity is due to the fact that the acoustic resistance of water is close to that of human tissues and the loss of energy for the transition of sound waves into skeletal bones is less under water than it is in the air. Air conductivity under water disappears because the outer audial opening is filled with water and there are no conditions for normal vibration of the eardrum.”

After all these games under the water, I also got an occasional ear infection.  I was always surprised to find that the infection would make me lose my balance if I moved too quickly.  After doing some research, I learned that this is because of the workings of the inner ear.  According to WebMd,

“A portion of the inner ear, called the labyrinth, which includes the semicircular canals, contains specialized cells that detect motion and changes in position. Injury to or diseases of the inner ear can send false signals to the brain indicating that the balance mechanism of the inner ear (labyrinth) detects motion. If these false signals conflict with signals from the other balance and positioning centers of the body, vertigo may occur.”

 

Taste

I conducted the Skittles experiment, mainly because of my and my friends’ strong preferences towards the candies.  The results were very much like the ones we had in class.  Most of my friends just guessed on what flavor I had given them.  Also when they stopped plugging their noses, they had a much stronger sense of the taste and immediately knew which flavor they had been tasting, which was very interesting because we all agreed that Skittles had no specific smell.  This shows the very strong connection between the two chemical senses, taste and smell.

 We also discussed the connection between tastes and memory.  This made me think of how the taste of homecooked chocolate chip makes me think of home.  As I grew up, my mom would make chocolate chip cookies whenever there was something special going on, either a birthday or a visiting relative.  Recently, I saw a chocolate chip cookie scented candle and one whiff of the sugary, chocolatey mixture brought me back ten years to my eleventh birthday.