By How do we selectively listen as in the cocktail party effect? When hearing the sounds that are all around us, we don’t hear a single complex sound, but a combination of sounds. Hearing a combination of all the sounds occurring around us would be extremely overwhelming and overstimulating if we actually took it all in and heard it in its pure form. Being able to pick out particular sounds is an example of selectively listening. The book gives the example as the cocktail party effect. What this means, is that while at a cocktail party, people are exposed to a variety of sounds like music, and several different conversations.
A person would not be listening to all of the conversations and music going on around them, they would be focused in on whatever they were engaged in. This does not mean that someone would be unaware of the multitude of sounds surrounding them, but that they would be selective to listening to the conversation that they are in. Otherwise we would be distracted and overwhelmed by different noises. Another example of selectively listening would be the ability to pick up on other things that may be of interest to someone.
A person has the ability to listen to the music playing at a cocktail party, but is also able to pick up the sound of someone calling their name, or even talking about them. They would be aware of the conversation pertaining to them and have the ability to listen to the music and also hear someone vocalizing to them or about them. Describe the different types of agnosias. Are there any tasks which would be impossible if someone had each of them? Agnosia, meaning “lack of knowledge” (Garrett, pg. 326), is something that hinders one’s ability to accurately interpret their senses.
There are several different types of agnosia, and each one affects people’s senses differently. Agnosia is often times a result of brain injury. The damage to certain parts of the brain changes the way a person is able to interpret things. As the meaning of the word describes, people lose their knowledge of the particular sensation. “Object agnosia is the impaired ability to recognize objects. ” (Garrett, pg. 326) This is something that will occur when a person suffers trauma to their inferior temporal cortex. Object agnosia hinders a person’s ability to process objects correctly that are right in front of them.
People who experience object agnosia are able to correctly identify objects when they are able to feel the objects, but there is an impairment that occurs when processing the object visually and having the brain interpret what the person is looking at. The book describes a case where a man suffering from object agnosia saw parking meters and his brain interpreted them as children. To this man, his brain was telling him that he was looking a children instead of a parking meter. Having object agnosia would make it impossible for anyone to correctly identify their surroundings.
A person would have to rely on physically touching an object to be completely sure of what they had in front of them. In certain situations, having object agnosia may become dangerous to the person suffering from it. A person may incorrectly identify a sharp knife as a spoon and use it while eating a bowl of cereal. Object agnosia can also present in another form known as prosopagnosia. Prosopagnosia makes it so the person suffering from the condition is unable to recognize faces, even those of family and friends. It is also difficult for the person to recognize emotion. Prosopagnosia is often times seen in patients with Alzheimer’s disease.
As Alzheimer’s disease progresses, often times people forget who even their closest relatives are, like a spouse or children. Their brain is affected from the disease and they are no longer able to recognize the people around them. Prosopagnosia would make having close relationships with people considerably challenging. It would be a challenge if you could not recognize loved ones, for obvious reasons, but also if you were unable to recognize emotions. If you were unable to recognize a person getting irritated, you would not get the social cue to stop whatever behavior it is that is annoying the person.
People rely heavily on social cues and the ability to read faces to know how to respond to others in different situations. Another form of agnosia is color agnosia. “Color agnosia is the loss of the ability to perceive colors due to brain damage. ” (Garrett, pg. 329) A common example of this would be color blindness. Color blindness makes it difficult for a person to correctly interpret colors. The book explains that it is not just incorrectly identifying colors, but it would also make it difficult for your brain to adjust and process the array of colors and shades we see.
Our brains are able to adjust to light and colors due to color constancy. “If not for color constancy, objects would seem to change colors as the sun shifted its position through the day or as we went indoors into artificial light. ” (Garrett, pg. 329) If a person were suffering from color agnosia it would make it difficult for them in situations like driving because it would be impossible for them to interpret the colors of a traffic light signaling to them what to do. The third type of agnosia mentioned in the book is movement agnosia.
“Movement agnosia, an impaired ability to detect movement (Vaina, 1998; Zihl, Cramon, & Mai, 1983). (Garrett, pg. 330) Detection of movement is extremely important for one’s ability to get around. The book describes a patient suffering from movement agnosia who was unable to recognize the hot coffee rising in the cup as she poured, or even more dangerously cars moving closer to her as she crossed the street. It would be impossible for a person with movement agnosia to be able to drive. They would have no spatial perception of where their car was in relation to other cars and objects as they drove closer or further away which would result in serious motor vehicle accidents.
Describe the disorders of movement and provide examples. Movement is a delicate function that we rely on every day to get ourselves around. Although the ability to move seems simple, it actually involves an intricate network of neurons in our brain in spinal cord communicating with the muscles in our body to coordinate smooth, regulated movements. Examples of how our body functions work together to produce smooth movement can be described in something as simple as signing your name on a piece of paper. A person is able to lift up a pen and sign their name in a seemingly effortless manner, without jerking or having odd spasms.
We see this as something normal, and expected, but it is actually the product of our brain and body working together to allow us to create movements with such ease. Unfortunately, for some people, things can go wrong within the body and cause disorders of movement. Some of these disorders include Parkinson’s disease, Huntington’s disease, and autoimmune disorders like Myasthenia gravis and Multiple Sclerosis. “Parkinson’s disease is characterized by motor tremors, rigidity, loss of balance and coordination, and difficulty moving, especially in initiating movements (Olanow & Tatton, 1999; Youdim & Riederer, 1997).
The symptoms are caused by deterioration of the substantia nigra, whose neurons send dopamine-releasing axons to the striatum, which is composed of the basal ganglia’s caudate nucleus and putamen and the nucleus accumbens. ” (Garrett, pg. 362) Parkinson’s disease is a result of a defect in the brain that causes a loss of motor control and uncontrolled movements in the body, or tremors. It is said to be caused my a decrease in dopamine in the brain and is often times treated with medication to increase dopamine timulation, access dopamine, however has also been proven to cause involuntary movement in people with the disease, which is why it is important to find the appropriate dosage.
“Huntington’s disease is a degenerative disorder of the motor system involving cell loss in the striatum and cortex. ” (Garrett, pg. 364) Huntington’s disease is a genetic disease that results from a mutation occurring on the huntingtin gene. It affects movement similar to the way parkinson’s disease does. It begins with small involuntary jerking movements and as it progresses, it causes uncontrolled movement of limbs.
Huntington’s not only affects a person’s movement, but also causes severe emotional disturbances. An autoimmune disease is when a disease causes the body’s immune system to attack itself. “Myasthenia gravis is a disorder of muscular weakness caused by reduced numbers or sensitivity of acetylcholine receptors. The muscle weakness can be so extreme that the patient has to be maintained on a respirator. ” (Garrett, pg. 365) Muscle weakness such as drooping of the eyelids occurs in people with myasthenia gravis. People who have the disease have a good prognosis and respond well to acetylcholinesterase inhibitors.
It is also recommended that patients have their thymus, a lymphatic gland found behind the sternum, removed to completely remove the symptoms of the disease. Multiple sclerosis is another autoimmune disease that causes disordered movement. “Multiple sclerosis is a motor disorder with many varied symptoms, caused by deterioration of myelin (demyelination) and neuron loss in the central nervous system. ” (Garrett, pg. 366) Due to the decreased myelin, patients with MS suffer from symptoms of tremors, muscle weakness, and impaired coordination.
