THE HUMAN BRAIN AND HOW IT SEES COLOR. Jessica Zhong. Cary Academy ABSTRACT

THE HUMAN BRAIN AND HOW IT SEES COLOR Jessica Zhong Cary Academy ABSTRACT The purpose of this study was to determine how the brain processes colors, words, and other things, and which ones are more dominant. When the eye sees a color (objects absorb all colors except for the ones corresponding to the color humans see), a message is sent to the brain, which then processes what it sees. Each time the brain receives something new, a signal is sent between neurons (strengthening their connection), and the brain slightly changes its physical structure. Colors were written in different colors not corresponding to the word, and test subjects were given a certain amount of time to read the color and then the word, and the number of mistakes made were recorded. It was determined that when the words were being read, the participants made considerably less amounts of mistakes than when color was being read. This was because people read words more frequently than they read color, so the brain becomes better at reading words, causing fewer mistakes as well. INTRODUCTION The eye is a sense organ, stimulated by light. It can detect only certain frequencies of light the spectrum of visible light which ranges from 400-700 nm. White light (sunlight) consists of a combination of all the frequencies, and when certain frequencies are absorbed and then radiated, the eye detects the frequency of the light wave entering the eye; thereby detecting color. Neither light nor objects are colored, but are rather generated by the brain for reasons of biological advantage. Objects absorb all the colored light rays, except for those corresponding to the color seen. It reflects that color instead of absorbing it, and sends a message to the brain. For example, what humans see as a red apple absorbs all colors but red, and instead reflects it. The eye sees it,

and sends a message to the brain. The black dot in the center of the iris (the colored part of the eye) is called the pupil, a hole through which light may enter. The white surrounding the iris is called the cornea. Light entering the eye through the pupil passes through the lens, which inverts the image and focuses it onto the retina, a screen on which the image is produced. It contains light sensitive cells, which transmit impulses to the brain through the optic nerve. These cells are the ones that detect color. Some of the cells are shaped like rods, while others are shaped like cones. The rods see in the grayscale, and are used for viewing objects in dim light, where only the shape of the object and shade of black can be detected. The cones, however, are sensitive to different frequencies of light; i.e. they are sensitive to colors, primarily red, green, and blue. The combination of these colors produces all the countless hues, tints, and shades of the spectrum. It all depends on how much the cones are stimulated by the particular frequency of light. There are 3 types of cones; those sensitive to long wavelengths, those sensitive to medium wavelengths, and those sensitive to short wavelengths. Depending on the intensity of the light falling on these cones, the brain interprets the cones signals in terms of clarity or sharpness of the image and in terms of color. Humans name the colors they see when the brain recognizes them, and that is why the brain is able to identify colors by name. The brain is a very complicated, and very important, part of the human body. The brain stem, which consists of the medulla (an enlarged portion of the upper spinal cord), pons and midbrain, controls the reflexes and automatic functions (heart rate, blood pressure), limb movements, and visceral functions (digestion, urination, etc.). The cerebellum integrates information from the vestibular system that indicates position and movement and uses this data to coordinate limb movements. The hypothalamus and pituitary gland are responsible for visceral functions, body temperature, and behavioral responses such as feeding, drinking, aggression, and pleasure. The cerebrum, which includes the hippocampus and amygdala, is also known as the telencephalon. It is divided into left and right hemispheres, which are linked by a bridge of nerve fibers, the corpus callosum. Each hemisphere controls the opposite side of the body. Together with the parts it wraps around the thalamus, hypothalamus, and associated parts, collectively known as the diencephalon it comprises the major brain division known as the

forebrain (prosencephalon). Speech and language, as well as reasoning and analysis, and certain communicating values are based mainly on the left side of the brain. The right hemisphere is more concerned with sensory inputs, auditory and visual awareness, creative abilities, and spatial-temporal awareness (what happens in one s surroundings every second). The cerebrum consists of 4 lobes: Frontal, Parietal, Temporal, and Occipital. The frontal lobe controls elements including creative thought, problem solving, intellect, judgment, behavior, attention, abstract thinking, physical reactions, muscle movements, smell, and personality. The parietal lobe focuses on comprehension: Visual functions, language, reading, internal stimuli, tactile sensation, and sensory comprehension are monitored here. It consists of 2 parts: the sensory cortex and the motor cortex. The sensory cortex monitors the other body parts (how they are moving), and the sense of touch, such as pain or pressure. The motor cortex helps the brain monitor and control movement throughout the body. The temporal lobe controls visual and auditory memories. It includes areas that help manage some speech and hearing capabilities, behavioral elements, and language. Part of the temporal lobe is called the Wernicke s area. It is formed around the auditory cortex, and it helps the body formulate or understand speech. The occipital lobe is located in the back of the head and it helps to control vision. Part of the occipital lobe, the Broca s area, controls the facial neurons as well as the understanding of speech and language. It is located in the triangular and opercular section of the inferior frontal gyros. The brain, as well as the rest of the nervous system, controls what the human body does, whether it is voluntary or involuntary. Every neuron maintains a voltage gradient across its membrane, due to metabolicallydriven differences in ions of sodium, potassium, chloride, and calcium within the cell, each of which has a different charge. This pulse travels rapidly along the cell s axon, and is transferred across a specialized connection known as a synapse to a neighboring neuron, which receives it through its feathery dendrites. A synapse is a membrane complex, or gap, used to transmit signals between cells, and this transfer is therefore known as a synaptic connection. Each individual neuron can form thousands of links with other neurons in this way, giving a typical brain well over 100 trillion synapses. Functionally related neurons connect to each other to form neural networks. The

connections between neurons are not static, though, they change over time. The more signals sent between two neurons, the stronger the connection grows, and so, with each new experience and each remembered fact or event, the brain slightly rewires its physical structure. Many scientists have previously done tests on color, memory, and other tricks to mess with the human brain. An experiment by Katie Shy was done to test the effects of age on people s memories. Participants filled out a short survey, looked at 40 random pictures for 1 min, then sat for 30 sec and wrote down as many pictures as they could remember. The results were that people at the age of 25 remembered the most and people at the age of 12 remembered the least. This is because the age of 25 is about when people start to stop going to school, or receiving education. Their mind begins to deteriorate and they start to forget the things they learned previously. MATERIALS AND METHODS In these experiments, different amounts of colored words printed on paper, colored shapes printed on paper, a PowerPoint with questions on it, a timer, and various test subjects were used. Different amounts of colors spelled out in words were printed on paper, 10, 20, 30, and 40 words. The words did not correspond to the color they were written in. A test subject was asked to read the colors in each set of words, and they were timed to see how long it took them to finish reading each set. This process was repeated on 4 other volunteers of approximately the same age for an average. In a second experiment, only the paper with 20 color words on it was used. A test subject was given 25 sec to read all the colors. The number of mistakes they made when reading was recorded, and any words that were not read at all were counted as mistakes as well. The same process was repeated for reading words, and then 4 other test subjects performed the same steps for an average.

Time it Takes to Read the Words (sec) In the third experiment, only the paper with 40 color words on it was used. A test subject was told to read out loud the colors of the word as fast as they could, and the number of mistakes they made was recorded. However, the test subjects were not told this. This was repeated 3 times nonstop on each volunteer, and each time the mistakes were recorded. Again, 4 other volunteers repeated all these methods, and an average was taken from the results. For the final experiment, the paper with the color shapes on it, as well as the paper with the colored shape words, was used. A volunteer was given 1 min to observe and study the colored shapes on the paper. Then the paper was taken away and the test subject was showed 5 memory questions based on the shapes. The percentage of correct answers was recorded, and 4 other volunteers repeated the steps for an average. All these methods were repeated with colored words, which spelled out shape names, as well. RESULTS AND DISCUSSION 45 40 35 30 25 20 15 10 5 0 0 10 20 30 40 50 Number of Words Figure 1. Time taken to read when increasing amounts of words When test subjects were asked to read different amounts of words, 40 words were found to take the longest amount of time (41.4886 sec), and 10 words were found to

Number of Times Messed Up take the least amount of time (9.37 sec). In general, the more words, the longer it took to read them. This was because each word took approximately 1 sec to read, and so naturally the amount of words multiplied by the amount of time it takes to read each word would be the amount of time it takes to read all the words. The times increased rather steadily as more words were added on, but the transition from 20 words to 30 words was more dramatic than any other increase. This was perhaps because the brain was starting to become confused by the color and word differences, and so it slowed down slightly when continuing to read and process them. 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 Color What was being Read Word Figure 2. Number of mistakes when reading color and words As shown in Figure 2, test subjects made more mistakes when reading color than when reading words. Humans read more words on a daily basis than they would read color, so they have more practice with words. This would explain why they are more fluent in words and therefore make fewer mistakes when reading words. The more often something is looked at, read, or processed, the more the brain would adapt to that and get used to it. In this case, since words are processed so much more than color on a daily basis (humans think about words but not about color), the brain becomes used to processing words and reads them more fluently. On the other hand, colors are often paid less attention to, so mistakes occurred more frequently when color was read. This could also perhaps explain that in the brain s complicated processing system, words

Number of Mistakes dominate over color. This could be especially true to adults and older people, because color doesn t matter as much in jobs, and again, people would be less exposed to them. 2.5 2 1.5 1 0.5 0 0 0.5 1 1.5 2 2.5 3 3.5 Number of Times Read Figure 3. Number of mistakes made as the number of times read increased It was found that when test subjects were asked to read words written in different colors various numbers of times, the least mistakes were made at 3 times, and the most mistakes were made at 1 time. Overall, the results showed that the more times the words were read, the less mistakes were made. This was because as the brain became more accustomed to the same words and colors being read multiple times sequentially, the brain cells and their synapses received the information, memorized it, and was therefore more successful in future attempts. However, the change from 2 times to 3 times decreased rather dramatically (compared to the change from 1 time to 2 times). This may have been because the brain had already read and memorized the words 2 times, and that made the memorization after 1 time even stronger. By the 3 rd time the words were read, they were already molded into the reader s mind, and the reader had almost no trouble going through the words again. If this experiment had continued, it would be expected that the number of mistakes would have continually decreased, until it reached 0 mistakes. At that point, the mistakes would always hover right on top of or above the zero line.

Percentage of Right Answers 100 90 80 70 60 50 40 30 20 10 0 Shape What is Being Read Word Figure 4. Percentage of right answers after a color/shape memory test As shown in figure 4, test subjects performed better when tested on memory of shapes than when tested on words. This was perhaps because shapes are more visual than words, and past studies show that many people are visual thinkers. Also, the shapes were bigger, seemed brighter, and looked more attractive to the eye. This could have caused the test subjects to focus more on the shapes than on the words, which may have looked dull in comparison. The brain automatically memorized the bright shapes and colors, and caused the participants to do better on their tests. CONCLUSION It was determined that words are more easily read than color. This data was expected due to the fact that most people mainly read words, or language, every day much more often than color. These findings would be valuable to scientists majoring in phycology, or just everyday people, because it could show more clearly what parts of the brain specialize in certain areas, even simple things such as color, words, and shapes. In the future, it would be interesting to determine what age, gender, and other physical qualities of the test subjects lead to the best and worst results.

CITATIONS - Brain and spinal cord. Britannica School. Encyclopædia Britannica, Inc., 2014. Web. 22 Jan. 2014. - Carter, Rita. The human brain book. London: DK, 2009. Print. - Mastin, Luke. Neurons & Synapses. The Human Memory. N.p., 2010. Web. 22 Jan. 2014. - Mobile Color Matters. How the Eye Sees Color. J.L. Morton, n.d. Web. 15 Jan. 2014. - Parts of the Brain and Their Functions. MD-Health.com. MD Health, n.d. Web. 21 Jan. 2014. - Purves, Dale. Brains: how they seem to work. Upper Saddle River, N.J.: FT Press, 2010. Print. - Shy, Katie. A Study of the Effects of Age on People s Memories. Cary Academy. 2008. - The Human Eye, How We Perceive Color: Biology: Science Behind Colors: Colors. ThinkQuest. Oracle Foundation, n.d. Web. 16 Jan. 2014.