Please go through the handouts you have received through email. Please find two topics from the handouts that are of interest to you and conduct some online research on those topics. Synthesize are report your findings on this post. Next indicate two topics that you would like further clarification on.
Online Assignment Thursday Week #4
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TrackBack URL: http://www.psychologicalscience.com/cgi-bin/mt/mt-t.cgi/1908
My topics of interest were more about the anatomy of the brain, such as the different lobes, and what each of their functions are. I am also interested in lateralization studies and how each half of the brain has different major functions.
The cerebral cortex is made up of four different lobes. The frontal lobe, located around the forehead and extending to the middle of the top of the head, functions in reasoning, planning, parts of speech, movement, emotions, and problem solving. The parietal lobe, located where the frontal lobe ends and extending to the middle of the back of the head, is involved in movement, orientation, recognition, and the perception of stimuli. The temporal lobe, located above the ear and extending towards the back base of the head, is associated with perception and recognition of auditory stimuli, as well as memory and speech. Finally, the occipital lobe, located at the base of the skull, functions in visual processing.
The corpus callosum is also an important structure of the brain. It divides the brain down the middle, into the right and left hemispheres. It consists of a bunch of axons that serve to connect these two hemispheres. The left portion of the brain is associated with language, math, and logic abilities, whereas the right deals more with creativity, special abilities, face recognition, visual imagery, and music.
The corpus callosum also serves to pass information from one hemisphere to the other. Muscle control is very much dependant on the lateralization of the brain. Movement of the right side of the body is controlled by the left hemisphere and vice versa. The same is true for language. As already stated, the left side of the brain is dominant for language in most individuals. Broca and Wernicke discovered that those who had brain damage to the left side of the brain had troubles with speech, whereas, those who had the same damage on the right side did not experience these problems.
Terms: cerebral cortex; frontal lobe; temporal lobe; parietal lobe; occipital lobe; corpus callosum; right and left hemispheres; Broca; Wernicke
Topics for clarification:
Sperry and Gazzaniga—split brain research
Flouren’s Aggregate Field Theory
(just don’t remember what the research for both of these were exactly)
Sources
http://faculty.washington.edu/chudler/split.html
http://serendip.brynmawr.edu/bb/kinser/Structure1.html
Online Assignment – Week #4
Topic #1: Selective Attention
Attention can be plainly described as the cognitive process of selectively concentrating on one aspect of the environment while you’re ignoring other things. Getting more specific, Selective Attention can be stated as focusing in on one main thing in a certain situation. A good example of this is having a conversation on your cell phone while you are driving your car to school.
Throughout history our “Attention” has been researched thoroughly. One main area of research dealing with Attention was the analysis of the “Cocktail Party Effect”. The Cocktail Party Effect can be explained by a person being at a party (Cocktail Party) and listening into one main conversation while there are several conversations going on. Researchers wanted to understand how people can select the particular conversation they want to listen to while ignoring all the other conversations. This later became known as the “Cocktail Party Problem”. Researchers also referred to this as “focused attention”. In 1953 Collin Cherry became fascinated with this phenomenon and created many experiments to test the theory. His experiments began to test what we now know as Dichotic Listening. His experiments consisted of people using headphones to listen to two conversations in the two different ears and selectively focus on one.
Today, Cognitive Psychologists explain the phenomenon known as Attention to have two models to explain its functioning. It is thought that our visual attention can function as a two stage processing system. In the first stage, attention is focused on the visual area and the process of information is performed in parallel. The second stage consists of a concentration to a specific area of the visual scene and therefore the information processing is done in a “serial fashion”. An example of this is looking at something through a camera. What are we trying to take a picture of? We focus the lens (our focus) into a point of interest in the scene we’re looking at and then take the picture.
Topic #2: Automatic Processing
Automatic processing refers to the thinking that it done unconsciously, unintentionally, involuntarily, and effortlessly. Psychologists believe that our processing is done to guide our behaviors. It is done without us realizing that we’re actually doing and doesn’t interfere with any other activities that we are doing at that time. A good example that explains this is the thought of driving down the street (our automatic processing) while looking for someone’s address (conscious processing).
To test the effectiveness of our automatic processing a test referred to as the Stroop effect has been applied. The Stroop Effect is a demonstration of reaction time during a task. A person is taking part in the test they are given the name of a color. That color is written in another color of ink and they keep track of the amount of time it takes for them to name the color of the work. Researchers have found that it takes longer and the people are more likely to get the color wrong when it is written this way. John Ridley Stroop was the creator of this test in 1935.
Topics that I would like to discuss further are Perceptual Span and the Function of Sensory Stores.
Topic 1: Broadbent Filter
Donald Broadbent first proposed this theory in 1958. His theory claims that people are only able to attend to one message at a time. Also, Broadbent modeled the the the process of attention as a physical channel that could allow only one message, which was identified by its physical characteristics,to pass through into the processes of perception and short-term memory. Another interesting idea of this Theory is the idea of 'attending to a message.' Broadbent believes that we attend to a message by allowing the message into our conciousness. Within my research of this topic, I also learned that the Broadbent Filter has limitations. This theory could not explain why certain words, such as a subject's name, seemed to pierce the selective filter. Also, the Broadbent model could not account for Anne Treisman's discovery of "intrusions" into attention, during which listeners accidentally followed a message from one ear to another.
Topic 2: Dichotic listening tasks
To perform a dichotic listening task, subjects are asked to listen through a set of headphones to two different messages that are being played to each ear and are asked to focus on the information that is being played to one ear. A couple of interesting experiements of dichotic listening have shown that little information is processed from the unattended ear's message. First, an experiment done by Colin Cherry showed that people can never tell very much about the information that was going into their unattended ear aside from base characteristics such as the sex of the speaker and whether or not it was a human voice. The next experiment held by Kotecki, Brehm, and Healey, tested Cherry's findings further by playing the same message into the unattended ear as into the attended ear at a five second delay. The results of this showed that the majority of the subjects recognized no similarity between the two messages when questioned later. Our text provides an example of how dichotic listening works by describing being at a cocktail party or in a noisy restaurant. There are three factors that help us attend to only one message of the source or subject we have interest in. These factors are distinctive sensory characteristics of the target's speech, sound intensity, and location of the sound source.
I would like to further clarrification on perceptual span, specifically how iconic and echoic storage function.
URLS:
http://everything2.com/user/fuzzy+and+blue/writeups/Attention?displaytype=printable
http://www.alma.edu/departments/psychology/st2002/dichotic/dichotic.htm
I decided to do further research in the area of attention. There are many related topics or sub-topics within this one - most of them will be related to Chapter 3’s slides on attention. I will discuss selective attention, dichotic listening, theories of attention, divided attention, and automicity. I have done a little research on these topics but that was fairly broad. This new information with be a little more in depth and with some new points of view about attention.
First, and in general attention is the ability to concentrate and focus on a task(s). Selective attention is when it is difficult to pay attention to more than one stimulus at a time. One must chose what to put their attention towards (whether it is conscious or unconscious will come up later). When we use selective attention we pay attention to one stimulus over another or others. The Stroop test refers to reading and seeing color. When looking at words in different colors our attention will be put towards reading the word before determining the color (again, I will talk about why later).
Further, on having multiple stimuli involves dichotic listening. When two different messages are put into either ear we will select once message to listen to and the other to avoid. We attend or use one ear over the other. With the ear we attend we will know what kind of voice and what the message said - we will be able to repeat it. Repeating the message is called the Shadowing experiment. Whereas, with the unattended ear we may be able to tell if it was human or not. The message however, we will not know what they said or if it was even spoken in English.
Three different theories (and many more I’m sure) were proposed for why we have dichotic listening. First, there is the Bottleneck theory from 1958. This is when there is a limit to the amount of information that can get in - or how much stimuli from our environment we can process. Second, we use physical characteristics about the messages to help us determine which to listen to. Lastly, we can have multiple messages get through to our brain but we can only produce one response or response to one stimulus.
Next we will jump to divided attention. This is when our attention is tending to multiple stimuli from our environment - multitasking. There are two theories for divided attention. One, there are limited resources to react. Second, we have the resources to react but we can only react to a limited amount. So, these theories are again addressing the issue of how much we can take in at one time.
Now, we will move in to automicity. This is unconscious processing - the opposite to controlled processing which is the realm we had been looking before now aside from the Stroop test. Finally, we can address what was mention earlier with the Stroop test. We read before we see color. This is not a controlled response - it is automatic and unconscious. That is why we have no say in what our attention selects in that situation. Another example of automicity is when we are driving and listening to music in the car.
Other terms that can be used to describe attention include the following. Parallel processing, this is when we have divided attention and we are processing multiple things at the same time. Serial processing is when we can only comprehend one item at a time - like selective attention. An example of both of these terms is when a situation demands different amounts of attention depending on the amount of stress that situation is causing us. When there is low stress we can divide our attention and tend to other tasks. Whereas, when the situation is more stressful it will demand more of out attention - sometimes to a point where we cannot focus on any other task. Being in school I am sure we can relate to this. A visual for this type of attention/stress relationship is described as an inverse-U shape. At the top of the U that is when our attention is given at the best rate to accomplish or complete that task. There are many other areas of attention that I could have done research. Such as, selective attention and ADHD. I would also like to know more about the central nervous system (CNS) and our attention. In some of my reading I came across CNS stimulants that help with ADHD. I think that would be an interesting area to do more research. In general I would like to know more about the different types of medications that we use to change our focus (and mental state all together). I would also like know how these medication work with children versus adults.
Terms: attention, selective attention, dichotic listening, shadowing experiment, divided attention, automicity, controlled processing, parallel processing and, serial processing
Proceedings of ICAD 04-Tenth Meeting of the International Conference on Auditory Display,
Sydney, Australia, July 6-9, 2004 (couldn't find the URL for this - it was an online article)
http://www.alleydog.com/cognotes/attention.html
http://www.mindtools.com/stress/UnderstandStress/StressPerformance.htm
Topic #1: Iconic Storage
Iconic storage is referred to as the visual sensory register. Before the idea of iconic storage, a man named Sperling was interested in how much can be seen in a single exposure. In his experiments and experiments before him, after brief flashes of visual information, people reported that they had seen more than they could actually report to the experimentor. Sperling hypothesized that people couldn't say everything about something they saw because their visual record (or iconic storage) faded too rapidly. He suggested they people could obtain a lot of visual information from a brief glance, but they could not report it fast enough before they lost it. He also stated that as icon faded a person would be able to report less and less things as a result.
The information recieved through sensory input is kept in the mind for only a split second, allowing a mental model to be made for further processing. This information can be passed to short term memory, and then along to long term memory if used enough.
Topic #2: Echoic Storage
While iconic storage is the visual system, while echoic storage is refered to as the auditory sensory register. The idea of echoic storage is relatively similar to that of iconic, besides the fact that it lacks visual and instead is based on auditory. The term was first coined by Neisser. While they are both similar though, auditory information is more temporal than spatial, and visual is the opposite... causing some discrepancies. Echoic's main purpose is to preserve temporal patterns.
Auditory sensory contains only raw unidentified echoes. Darwin and Cowder found this, repeating an experiment that was much like the one done by Sperling, but with auditory information. They also estimated that auditory information is stored for about a duration of 2 seconds.
Urls:
http://books.google.com/books?id=CQN5a45npM0C&pg=PA243&lpg=PA243&dq=echoic+storage&source=bl&ots=aNcMoIGowf&sig=Yx4u9vQUvi1jbnFrWPXxa_mEDuU&hl=en&ei=-RedTPqZMoKdnwfC7uCMDQ&sa=X&oi=book_result&ct=result&resnum=4&ved=0CCIQ6AEwAw#v=onepage&q=echoic%20storage&f=false
http://www.evl.uic.edu/sugimoto/psych1.html
Further clarification on perceptual scan and processing capacity
Two topics of which I am vaguely familiar with include iconic and echoic storage. Since I am not completely aware of what iconic and echoic storage are I decided to research them and gain more of an understanding on both topics. Both iconic and echoic storage are related to how the brain converts sensory input into our memory. Iconic memory deals with how the brain processes visual stimuli from the retina into memory. George Sprerling was known for researching iconic memory by testing individuals’ iconic storage abilities. He would use tests in which participants would be flashed short rows of letters and then be asked to read what letters they saw. Each person was able to read around 3-4 letters out loud. He found that eye fixations are what help create visual memories. George reached this conclusion because he began by implementing a tone that was heard by the subjects a quarter of a second after he flashed rows of letters. Subjects thought that they were reading off letters when in fact they were no longer visible and they were only remembering the letters because of iconic storage. In my experience of learning about iconic storage I recall learning that the human brain usually has the capacity to remember around seven items at a time. For example, in some introductory psychology classes I have taken I have completed some short tests that showed how skilled my iconic memory was. The professor would flash letters every few seconds beginning with one letter and adding a letter to the list for every new flash. I was able to remember exactly seven letters in order correctly and at eight or more letters I was unable to correctly identify the letters in order. This is just one type of test that I am familiar with that begins to understand how iconic storage works.
Echoic storage is another form of memory that relies on sensory input. Echoic storage on the other hand deals with auditory input. From the website that I used to research the topic I found it very interesting to learn that echoic storage relies on the fact that the individual realizes a repeating sound is occurring. Two men who were known for testing echoic storage were Guttman and Julesz. They made test participants listen to segments of white noise. White noise is made up of all the different frequencies humans are able to detect but are only detected as a blur of noise that sounds like “shh.” White noise has no basic pattern of sound, but in this testing Guttman and Julesz made subjects listen to a repeated segment of white noise that continuously repeated itself. Participants were unable to distinguish the repeated segment if they listened to the white noise for more than a few seconds. Yet, astonishingly if the participants only listened for less than two seconds they were able to identify a pattern of white noise was occurring. Interestingly enough they were unable to describe what the sound was, but were able to notice a pattern was occurring. This test can show how echoic storage works because it proves that echoic memory lasts for only up to two seconds. I found another example on this website that made it very easy to understand the concept of echoic storage. I’m sure everyone can relate to this specific example. Echoic storage is working when a person asks you a question and you ask them to repeat it because you couldn’t hear them, but then in a few short seconds your brain processes what it is that person asked you. For example, maybe your teacher is asking if you prepared for your upcoming test and you reply by saying, “What? Oh, yes I did.” This has probably happened to everyone and it can be frustrating as a speaker when you have to repeat your question when the person you ask interrupts finally with their reply. Both websites I visited only briefly explained what iconic and echoic storage is, but I feel that I now have a wider knowledge on the topics. What I would like some clarification on is how a person’s attention is related to how they process and store visual and auditory stimuli.
http://www.psywww.com/intropsych/ch06_memory/iconic_memory.html
http://www.psywww.com/intropsych/ch06_memory/echoic_memory.html
One of the topics I would like to focus on is split-brain research. I find this specific topic extremely interesting. Split-brain research refers to the corpus collosum no longer connecting the two hemipsheres of the brain. This causes the two hemispheres to no longer be able to communicate like they use to. This procedure started to be done to help people with epilpsey. Things that are so peculair about this, is that a person who is shown something on the left side of their visual field will not be able to physically say what they saw. This is because the information will be sent to the right side of the brain, and (typically) the left side of the brain is where the "communication center" is. Due to the split of the corpus collosum the left side of the brain cannot communicate to the right side of the brain. Instead the person would be able to draw the object with their left hand or pick out an object that represented what they saw. I find it very interesting that in certain cases the person is almost speechless and has no idea what they saw in their left visual field, but then they close their eyes and draw exactally what they saw. The second video in particular has a man named Joe with a split-brain and gives a better example of what exactally these people go through and experience.
Phantom limbs is another topic that I am very interested in. Someone I know has lost the bottom part of their leg (fromm their knee down) in an accident and he often experiences his toes itching even though they are not there. As many as 60-80 percent of people with an amputation will experience the feeling of having a phantom limb. It is very interesting how our brain can interpret no longer having a limb. The fact that those sensations still seem so real makes it seem as though the brain is just playing tricks on the person again. Phantom limbs can cause people a lot of pain. Stress and anxiety may increase a persons liklihood of experiencing phantom limb and its pain. One of the main therapies for phantom limb right now is simply mirror therapy. This really just is a way of "tricking" the brain that the limb is still there and is moving just like the other limb only in an opposite way. This activity is suppose to calm down the brain and any other thoughts that it may have been generating before about the phantom limb.
Topics I would like futher clarification (or just a review over) would be anatomy of the brain (what the fuctions are and where they are located), Iconic/Echoic Storage, and Models of Selective Attention.
http://www.youtube.com/watch?v=MZnyQewsB_Y&feature=related
http://www.youtube.com/watch?v=2DnS_Yjd51g
http://www.privatehealth.co.uk/news/september-2010/phantom-limb-linked-to-strokes-32937/
http://www.youtube.com/watch?v=YL_6OMPywnQ
Topics: Cocktail party phenomenon, attention deficit
Cocktail party phenomenon is well-known to all of us. Imagine people talking in a noisy place: a restaurant, concert, party. Despite the noise they are still capable to maintain the conversation and do not pay attention to other distraction. Listener focuses his or her attention on a partner and ignores the background noise. But if someone calls his or her name, the person will react immediately. Additional effect of this phenomenon is that the human auditory system seems to ignore most of the reflected sound, because it arrives from other directions than the direct sound. Switching direction of attention from one source of sound to another by auditory system also takes place.
The whole process is binaural. Researches have shown that it is related to the localization of the sound sources. From the findings we know that the auditory system can localize at least two sound sources simultaneously and detect the correct sound source characteristics to these sound sources at the same moment. The new research from the Northwestern University has shown that this process is based on modulation by specific characteristics of the speaker’s voice, and segregation them from other signals in the surroundings. It is seen through the activity in brainstem. But in children with dyslexia this modulation is impaired.
Experiments based on the non-invasive method for recording the electrical activity of the brainstem showed that the response of the auditory brainstem depends on the context in which the stimulus (speech sound) was presented. As a result in normal situation the neural representation of the sound become fine-tuned to the repetitive syllable instead of the variable one. The repetition of the syllable influences plasticity in the brainstem and then the response is automatically sharpened to elements of the signal related to voice pitch.
Voice pitch is so important because this characteristic is used to distinguish between different voices. Such adaptation allows to perceive speech in a noisy environment and to segregate the voice from it.
However in case of dyslexia the neurons in the auditory brainstem do not fine-tune their response to speech cues. This leads to difficulties in excluding background noise from the significant auditory information. Thus dyslexic kids have difficulties in distinguishing between the background noise and speech.
This new research has serious impact on the teaching practice and learning strategies, adjusting class environment for children experiencing difficulties paying attention in a noisy classroom.
http://scienceblogs.com/neurophilosophy/2009/11/dyslexia_cocktail_party_effect.php
http://www.inpp.org.uk/learning_difficulties/index.php
For this blog I decided to look more into a subject within the topic of selective attention: the cocktail party phenomenon and other related phenomenon that goes with it. I chose this topic because it’s something we all do and never even think about it and I find it amazing that we are capable of doing it, without even trying. And how we miss so much are brain automatically finds unimportant (hopefully it is right).
The cocktail party phenomenon is the humans being able to focus on a single noise, a single person in a busy, crowded area that could have multiple conversations taking place, a band playing, and the sound of moving or dancing people. It can also be used to describe sitting in your classroom and being able to focus on a lecture while the air is going, there are other students in the back chatting, and the mechanics are working in the hall.
This phenomenon happens automatically without any need for conscious thought. Our brain has built in filters. Scenery and situational cues help aid the unconscious mind to figure out what is going on with the person/object that is being paid attention to. But even items that are not being paid attention to can often be remembered for a short period. Such as when you are paying attention to something else (like eavesdropping on another nearby conversation) while someone is talking you and you ask “What did you say?” and as they repeat themselves you remember it as they begin to repeat it (named the what did you say phenomenon). Another explanation is included in the communication theory by kind of guessing what is going to come next by probability. For example if you hear the word cook you are more likely to think of stove, oven, kitchen, etc. and not unrelated words like sidewalk, homework, sunset, etc.
Some cues that help use in the cocktail party phenomenon is similarity (such as just explained), proximity (we group things together that are close together in time or space), continuity (we group things that go in the same direction), common fate (we group things that move together), and symmetry and closure (we group things that are enclosed and symmetrical). Other factors (some that are related) are loudness differences, history, schemas, and the visual channel effect which being able to tell where sounds are coming from by what you can see visually. Determining where the sound comes from appears to be primarily a left-brain function.
Terms: Selective attention, cocktail party phenomenon, conscious, what did you say phenomenon, communications theory, similarity, proximity, continuity, common fate, symmetry, closure, visual channel effect, schemas, left-brain
http://xenia.media.mit.edu/~barons/html/cocktail.html
http://www.spring.org.uk/2009/03/the-cocktail-party-effect.php
http://www.hear-it.org/page.dsp?page=5854