Please go through the handouts you have received attached to this email. Please find two topics from the handouts that are of interest to you and discuss what your text has to say on those topics. Next indicate two topics that you would like me to cover in more depth in class.
Class Handouts Week #5 (Due Tuesday)
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The notes from chapter three focus largely on attention and how the brain uses sensory input and perception to selectively attend to or ignore certain auditory stimuli. After reading the attention chapter in my textbook, I must admit I was a bit confused at times. I felt that my textbook made it confusing to separate different attention theories from one another. Since I found the topics of early and late attention patterns to be the most challenging I decided I wanted to fully understand how to compare and contrast the two. One thing I found interesting to read about was how certain spoken words vary in their level of importance, and how words help our brain decipher what it wants to attend to. In my textbook it used the example of two men talking together and paying attention to each other while ignoring outside conversations. Yet, when one of the men hear their name being called from outside of their conversation he will probably focus his attention on whomever spoke his name (Kellogg 2003). No matter the process that our brain takes to attend to auditory stimuli there are some words that immediately focus our attention on that word.
What I found difficult about the attention chapter was in trying to understand the mental processes that occur to attend and respond to auditory stimuli. The first attention pattern described is known as early selection. This pattern is supported by Broadbent after he completed studies on attention. Early selection means that a person’s attentional filter (what they want or don’t want to attend to) operates after sensory processing, and before sensory input is semantically processed (Kellogg 2003). If I were to put this in my own words I would say early selection occurs if a person first senses input then makes the decision to pay attention or not to this input, all before processing what the sensory input means. Broadbent used this attentional process to explain the data he received from testing participant’s attentional abilities.
The opposite of early selection is late selection. The late selection process is supported by Treisman’s attenuation model (Kellogg 2003). Treisman’s attenuation model deals with the strength of sensory input that seems to be ignored. As with the example of the two men talking, a person’s name would have a high strength and would therefore be attended to quicker than a meaningless word being called out. When explaining late selection, it is important to be familiar with early selection also. This is because both are attentional patterns with the same process, but the process occurs in a different order. With late selection the attentional filter follows both sensory input and semantic processing, but is experienced before a response occurs. According to my textbook, the only way to choose which model is better at explaining attention is to figure out if ignored sensory input is semantically processed fully or not. Depending on this factor, either early or late selection may best explain the attentional process being used. In a way, attention is a complex process even though it occurs within less than seconds. After reading about experiments that were used in order to explain attention I would like clarification on how dichotic listening is related and how dichotic listening works.
One of the topics discussed in class relates to the mind-body issue. This issue basically separates the two by stating that the brain is the physical structure (the body) and the mind is what the brain does. The text explained the difference between the two concepts but also how they work together. It gave good examples of each. The mind is the processes carried out by the brain, for example, thinking, perceiving, judging, making jokes (Solso, MacLin & MacLin, 2005). In contrast, the body is made up of physical components and things that are governed by laws. For example, the regions of the brain and the brain as a whole. This issue is important to understand when learning the structure of the brain, specifically the intricate parts of a neuron. The subject of the parts of a neuron is most related to the body portion of the mind-body issue.
The structure of the central nervous system (CNS) can be broken down into many complex parts that work together. The basic structure is the neuron. Its function is to transmit messages to other neurons throughout the body. There are a vast number of neurons throughout the entire body, about 100 billion. The neurons are absolutely crucial in the brain because they are the transportation method needed for many cognitive functions.
Each neuron has basic parts with their own functions: dendrites, cell body, axon and presynaptic terminals. (I will describe each and relate their physical description to a human hand.) The dendrites can be pictured as the fingers of a hand, or similar to the branches of a tree. Their function is to pick up neural impulses from other neurons. The cell body would be representative of the hand itself, inside which is the nucleus of the neuron. The axon would be comparable to the arm. It acts to transport the neural impulse or message on to other cells. The human hand and arm comparison ends here because on the other end of the axon are more branches with terminal buttons or presynaptic terminals on the tips. These are located close to the next neuron’s dendrites in order to pass along a message from one neuron to the next.
Topics for more explanation:
Echoic and iconic storage
Terms: mind-body issue, central nervous system, neuron, dendrites, cell body, axon, presynaptic terminals
One topic from the handouts that I am interested in is selective attention. Basically selective attention is when we process certain bits and pieces of information while disregarding others. We are bombarded with vast amounts of information we must somehow sort through and process what we choose and ignore the rest.
Another topic I find interesting is automatic processing. Automatic processing occurs when actions that we have practiced become automatic or are like second nature; they require minimal thought for us to perform. The text discusses three characteristics of automatic processing: automatic processing occurs unintentionally, they are unconscious, and they take place without effort. However, activities we perform that seem to occur automatically may at one time required our attention and conscious involvement.
If anything I would like further discussion of the areas of the brain and what basic functions they are associated with. For example the what areas are associated with the senses.
Two areas that I looked into were illusions and attention. My book shed some light on the areas but that also makes me ask more questions. My book did not have anything that was directly related to illusions. They referred to out visual fields and how we take in the stimulus from our environment. My book also talked about how our brains will fill in ‘assumed’ information. During a lecture last year you talked about how our brian lies to us. This is also mainly what my book discussed. Things such as an implied line or two figures that are the same size are shown in a context when one looks much larger than the other. However, I would like to know what is going on in our brains when someone hallucinates. For example schizophrenic people versus hallucinatory drugs. Is there a difference between the images? When a schizophrenic person sees something is that because there are poor or extra neurological connections? Are the images in our hallucinations just images from our memory bank? Are images from our memory bank used only when we take hallucinogenic drugs?
I also looked into visual attention. In my text book Kellogg described it as a spot light. Our visual field can be narrowed to see only one focal area. This makes me think of when we are straining to see something far away or trying to bring something into focus. Kellogg goes on to say that our attention can also be in multiple areas at once - divided attention. An example I would use for this is when you are babysitting three kids, by yourself. You cannot just focus on one child at a time! Reading this made me wonder if all of our senses are comparable in their processing? I now know that we can see and focus our attention on more than one things. In a previous blog I looked at divided attention and dichotic listening. With this sense we can not hear more than one message at a time. I understand this because I have experienced it, however, I would like to know the neural functioning or a lack there of for why this is how our senses work.
Two areas of further research include the central nervous system and our brain’s functioning and using the CNS. I would also like to know more about damage and repair to these areas. I am curious because I have a cousin who was diagnosed with MS a few years ago. I have a brother and many other cousins the same age. It is scary to think of what this disease could do to him and to know that it does have some genetic causes. I would like to know more about what has happened and what may happen to him.
Terms: Illusions, attention, divided attention, memory bank, visual attention, dichotic listening, CNS and, brain damage/repair in the context of the CNS.
When looking over my notes the thing I found most interesting was selective attention. I am not going to pick another topic because selective attention is such a multifaceted idea that I have my work cut out for me. My book refers to selective attention in a matter a fact way stating that we usually focus our attention on one or a few tasks or events rather than on many. What occurs if we take in too much information is our brains without noticing shuts out or doesn’t pick up on any other information around us. The book points to the fact that cognitive psychologist struggle with finding out what information we do not pay attention to. Because by telling us not to pay attention we will pay attention. What scientist have done to deal with this issue is develop what our notes mention as dichotic listen task. What occurs is we listen to a pair of headphones where messages are played at the same time. The subject is then asked to repeat aloud one of the statements that was said to them. This process is known as shadowing. This task is rather demanding because the statements that are played on the headphones are given at a rather rapid rate averaging out to about 150 words per minute. The end result in most cases is that the shadowed phrase is remembered because of the large amounts of mental resources that were needed to remember the statement.
This process of leaving one message unattended lead to what is pointed out in our notes as the filter theory. This simply stated means that there are limits to how much information one can process. Thus, when information overload occurs we unconsciously filter out information we find unnecessary. This theory was developed by Broadbent. One thing that should be noted is that this is all early in the processing process, and it is assumed that no information can be processed that does not pass this filter.
Leading to the theory that was developed by several psychologists over time called the late-selection theory. This states that all messages are routinely gathered to derive some since of meaning. Thus a choice of which message to respond to occurs later on.
Further explanation: Iconic and Echoic storage.
One of the topics I have chosen is the prospect if sensory illusions. My text book makes the argument that nothing we see is real, that our mind distorts it all.
We've already seen plenty of evidence for this, especially in the case of the colorblind painter and in the case of Virgil. The colorblind painter could obviously see, he could detect light and isolate objects. However, his sight was limited to wavelength detection. and he did not have the benefit of color labeling. The way I've put it in my mind, he has a pure form of seeing, free of any distortions by color. Lo and behold, his life was miserable for a time.
Virgil, on the other hand, did not know how to interpret what he saw. He had trouble categorizing the impressions on his retina. Honestly, he has a pure form of colored seeing, he sees a mess of colors but does not know what to make of them. His brain is unable to interfere. And his life was miserable because of it.
The authors of my text book ponder in wonder why the brain should do this. They begin their discussion by pointing out that the eye has evolved over thousands of years. In this perspective, it makes absolute sense that the brain should distort what we see. After all, as seen in the previously discussed cases, these distortions are hugely beneficial. The eye was selected for because it aided in survival.Therefore it makes sense that the end result of this evolution, we end up with a product that changes what we see in a way that would help us.
I've also read a little on automatic processing. There was a time when I was really interested in the piano. Unfortunately, I was unable to put certain motor movements into the automatic processing part of my brain and ended up quitting it. I am a little disappointed by how little is written on automatic processing. There seems to be no information on it other than the fact that it does happen and somethings can be made automatic with practice.
I do wish you will mention something more on it. I would also like it if you could clarify what is meant by the "computational brain." Is it just referring to the fact that the brain, as in everything else, functions like a computer in the matter of sensory processing?
I know I am continuing on the pattern, but I chose to do selective attention. In blatant terms seletive attention refers to the ability to perceive a particular stimulus of interest while ignoring numerous other stimuli. The opposite of selective attention would be divided attention, defined as when two or more stimuli share cognitive resources.
An example of these would be like you being in a restaurant... while in the process of selective attention you would be listening to the person you are with and be ignoring those making conversation around you. In divided attention you may be listening to the person you are with, but also those who may be around you.
To study selective attention the most classical way was through dichotic listening, like the example I gave the paragraph above this one. When a person is being tested with dichotic listening, both of their ears recieve stimuli in synchrony and are asked to only attend to one ear or the other. The participant than does something that is referred to as shadowing, or repeating aloud the stimuli that they were presented to attend to. Most people in these series of tests do not remember what they were presented in the other ear, they seem oblivious to it.
The second topic I chose was not something specifically stated in the notes, but it relates to visual attention. I wanted to focus on the neural basis of selection and talk a little bit about that. Neurons in the occipital cortex act as feature detectors turned to respond to visual features like a specific orientation, etc. The thing that we see needs to stimulate a specific area in the retina, further defining the receptive field of that specific neuron. Cells inside the retina map to a neuron in the cortex that looks for the feature it is tuned on.
The size of a receptive field can change size, getting smaller when you only need a small object or small stimulus relevant to what you are doing, and larger when the tasks requires more information from the environment. The change in these receptive fields takes place in the thalamus, as revealed by PET scans. An interesting disorder called spatial neglect is characterized by the failure to attend to all areas in the visual field. These people cannot shirt their attention to a neglected side of their visual system, even though their ability to see is in perfect working order.
terms: selective attention, divided attention, dichotic listening, shadowing, occipital cortex, receptive field, thalamus
(sorry this post was late, I was confused about what I was supposed to do because nothing was attatched to me email)
The first topic I would like to discuss would be the pop-out effect, dealing with our visual attention. The book doesn’t go into much more detail than we did already in class. The pop-out effect is basically when looking at an image that has something distinctive about it and the person looking at it can identify the difference within 50 milliseconds. However, the more similar the items in the image are the longer it takes and the harder the person has to search for the different image within the image. One possible explanation could be preattentive process which quickly scans an object for all its characteristics. Another explanation would be feature maps; which seems to act like a filter.
The second topic I would like to address when it comes to attention would be automatic processing. What pops into my mind when I think of automatic processing is practice makes perfect. It is what takes a novice to expert. It is efficacy. It is what the point of training is. Our first many times driving is full of anxiety, fear, and trying to divide and pay careful attention to many things at once. Today, most of us typically drive without giving much thought to it. We turn on our blinkers without effort, we stop at a red light without consciously thinking that we are doing so. We even become accustom to switching off our brights for oncoming traffic. We use automatic processing numerous times a day. I am now as I type for example, you as you read this. It happens without thought.
As far as a couple of topics I would like to learn more about is automatic processing and how we interpret illusions.