Description
The idea behind selective adaptation is that when we view a stimulus with a specific property, neurons tuned to that property fire, and if viewing continues for long enough, these neurons adapt. Discuss how the psychophysical procedure of selective adaptation has been used to demonstrate the link between feature detectors and (a) the perception of orientation, and (b) the perception of size. Be sure to include a discussion of your understanding of the rationale behind selective adaptation experiments and how we can draw conclusions about physiology from the results of such a psychophysical procedure. Provide two examples for the class that support your conclusions. For this week’s discussion, it is expected students will use this reading and outside scholarly web sources to answer this question completely.
Minimum 300 words answer
Classmate #1:
Hello fellow classmates and professor! I hope you are all having a stupendous week so far!
There were a few examples in this week’s lesson about how our perception can be fooled, with lines and other tricks. But selective adaptation refers to the brain’s ability to adapt to changing levels of sensory input. In the dark, our eyes adjust to allow more light in and in bring light, they adjust to keep from harming the retina. Our ears adjust to changing levels of sound in an attempt to protect our hearing from loud noises. When we smell something for a few breaths, good or bad, the sensors for these specific smells stop firing, making us unaware of the smell. With visual perception, our brains can adjust to changes in stimuli, for instance, allowing us correctly perceive something such as a room that appears to be upside down. Given time, our brains are capable of learning to invert images, such as in the instance of virtual reality, that makes everything appear to be upside down.Size is another perception that can trick the mind. In the examples, in the lesson, all of the visual misinterpretations can be attributed to our brain not just viewing the lines in question, but also taking in visual cues from other parts of the image. In the one that looks like railroad tracks disappearing into the distance, we are asked if the two yellow lines are the same length or not. In reality, they are the same length, but because of the illusion of distance, our brains initially think they are two entirely different sizes. Our brains take visual cues not just from the object we are observing, but also from our surroundings, and as such, if a picture is drawn just so, it can trick the mind into thinking that those two yellow lines are wildly different sizes. Much the same, the series of arrows pointing in and out gives the illusion that the center lines are different lengths because our brain recognizes the whole arrow and not just the center line. With scientists having studied these phenomena in-depth, we have a greater understanding of how perception works, how the brain processes images, and what it can and cannot overcome. This brings to mind the discovery that phantom limb pain can be eased if not entirely negated by tricking the brain into thinking that the limb is fully functional and intact. Once the brain recognizes that the limb is there with the use of a mirror, it no longer recognizes pain messages from that area.
Classmate #2:
Classmates and Professor,
In this week’s readings and the lesson, we learned about selective adaption and how exactly it pertains to our different senses, as well as the interactions it has with our sensory receptors. Selective adaption is a psychophysical procedure in which repeated exposure to a stimulus produces a sensory adaption that influences the perception of a subsequent stimulus. A good example of this is going into a dark room and not being able to see anything in front of you, after a minute, your eyes will adjust to let more light in, and you will be able to see in the room. In this case, our eyes will adapt to the feature in the room which is the low lighting. Our eyes pupils will open up becoming more full to let more light in. Once more light is let into the eye, our retinas will then send the signals to the visual cortex, from there determining where we are in the room and the objects within the room.
Feature detectors are specialized cells within the brain that detect certain aspects of stimuli that are specific to movement, shape, and angles. Without these types of specialized cells, it would be impossible to detect a baseball thrown by a picture, especially a certain type of pitch thrown. As a batter stands in the box, they realize where they are and where they like to stand in the spatial world. A baseball player is specific where he stands, if they are off a little bit, they will be able to tell. This is known as perceptual constancy. In size constancy, the baseball player can view the ball as the same size from when it leaves the pictures hand until it crosses home plate. The baseball, being the stimulus, travels towards the batter and depending on where the ball is, the batter will or not. The ability for the batter to know where the orientation of the ball is in space and where it will end up is due to their feature detectors.
The batters feature detectors to sum it up, can determine where the ball is in space, determine the spin on the ball, speed, and location to determine where the ball is going to end up and when/if to swing the bat. In perspective to show how amazing these features, adaptions, and our visual system is, a fastball traveling 90 mph reaches Homeplate in 400 milliseconds. The batters themselves only have 250 milliseconds to decide whether to swing or not. Pitchers in the MLB in today’s age pitch must fast than 90. Many of them consistent at 95 and a few who can throw 105-110mph.
Classmate #3:
Sensory adaptation essentially involves the senses becoming used to a stimulus. This adaptation may change the way in which the stimulus is perceived after prolonged exposure. In terms of visual perception, an individual could be presented with a stimulus that may appear to be askew. For example, an individual could notice that a photo on a wall is not sitting straight. For several days, this askew photo would trigger their perceptual process and they would be well aware of the discrepancy. However, over time the individual would develop a sort of adaptation and would no longer pay an extreme amount of attention to the crooked picture frame. In terms of size, an individual may purchase a tv that ends up being much larger than they expected it to be. However, over many days and weeks, the individual will gradually adapt to seeing the large tv within the space and eventually feel as though it fits the space well instead of overwhelming it. With these examples in mind, it is important to note that scientists are very interested in this process of sensory adaptation. There are many ways in which sensory adaptation is studied. One of these experiment types is through the use of color after images and gratings which test visual adaptation. While it is still not completely clear why we develop this type of adaptation, it can be noted that this phenomena helps us pay attention to the more important stimuli within an environment, while ignoring the less relevant and more constant stimuli. An example of this would be an individual noticing a hum coming from an air conditioning unit within their classroom. When they first notice the sound, they may feel quite distracted by it. However, over time the student will become used to the hum and therefore, be able to concentrate despite the actual presence of the sound. Another example of this could be demonstrated through an employee who is annoyed by the smell of their coworker’s lunch. The smell may be so pungent that the employee feels as though they cannot complete their work. However, over time the employee will begin to adapt and experience “nose blindness” that will allow them to ignore the smell and concentrate on their job.
Minimum 200 words answer to each
