Psychology Essay - Bachelor Of Arts
Behavioural Neuroscience: Examination of a Sunset
Date : 07/08/2019
It was a brisk, chilly day that was exacerbated by the openness of the Native Grasslands, a vast field with a few trees, and a solitary hill, which I intended to use to observe the sunset. While it was not a clear day, which had mostly consisted of gloom and dreariness, the weather had improved, with rays of sunlight attempting to burst through the thinning clouds that sped through the sky. I arrived at 6:30 and sat myself down at the top of the hill, and observed the sky, Melbourne s skyline in the horizon, and the accompanying park at the foot of the hill.As soon as I got there, the first thing I noticed was the lack of gradient and a monochromatic hue of yellow that spanned throughout the horizon. The brightness, however, lacked intensity, and this was evident by the minimal filtering of light through the thin layer of clouds that draped over the sky. According to Newton s theory, white light contains all of the visible colours we can see, and the way that we can discriminate one colour from the other is through the subtraction or reflection of this light on the surface. This means that when I observe the yellow tinge that is reflecting off the leaves on trees and the soil that is swept by the wind, I am simply discriminating this white light through absorption and reflection. After around 15-20 minutes, the sun lowered towards the horizon, which greatly altered the spectrum of colours visible to my eyes. Interestingly, the clouds that were supposed to snuff out the hues of colours ranging from yellow to orange to red to magenta, and finally a navy blue instead formed a mosaic of colours in between the clouds, all creating a gradient of colours from the highest point of the sky towards the horizon that was fragmented by the grey clouds that hung over. It was clear that Young and Helmholtz had a certain idea about the retina, albeit without truly understanding photoreceptors. Young claimed that the motion of the retina is a result of vibrations, which allow us to perceive colour, and that each particle in the retina allowed us to interpret three limited primary colours red, yellow and blue . However, using Hering s theory of opponency I experienced the sensation of magenta and orange due to the combination of opponent colours that were set forth, which were blue, red, green and yellow. Magenta is the combination of red and blue, while orange is the combination of red and yellow. It is impossible to create colours out of complementary primaries, according to Hering, which is why I could not observe a combination of green and red/ blue and yellow. Another way I applied his theory of opponency was due to the after images I observed after looking at the sun and the surrounding intensity of light for a short period of time. I observed blotches that ranged from black to purple, that resulted from the overstimulation of photoreceptors so that they become exhausted and produce weaker colours. In addition to the myriad of colours, the intensity of the colours, which varied (a minimal intensity of yellow, while there was a greater intensity towards the hue of red), permeated through the clouds, resulting in rays of light piercing through the edges of the clouds, making them appear more defined, providing a stark contrast to the dull grey clouds that previously seemed to vaporize into the horizon. They now had a solid form and shape, which enabled me to observe the amusing facial features that the clouds adopted, which I personified to human faces in my imagination. This is a testament to the superior object recognition system our brains possess, where we can draw faces out of seemingly inanimate and unrelated objects. Salvador Dali, a surrealist painter in the early 20th century, took advantage of our ability to recognize faces in the most unusual environments, which led to paintings such as Apparition of Face and Fruit Dish on a Beach (1938) . We use several parts of the brain for this object recognition, including the visual cortex, temporal cortex and the prefrontal cortex. The lights not only had an effect on the sky but also the surrounding skyline that previously adopted to the dreary weather with its grey buildings and uninspiring shapes. Glass buildings now reflected the intense oranges and reds that dominated the horizon, painting the buildings in splashes of warm colours. Children who were playing and running around the swing set were now bathed in waves of orange light that highlighted the complementary colours of their clothes which were vibrant and highly saturated. Previously, with the melancholic greyness that drooped around the grasslands, their clothes were muted in colour, and their bright yellow jumpers and green beanies did not pop. In particular, I was observing a dog s eye as it lazed on the hill, and how it glistened at the intensity of the colours as it stared into the horizon. As the lights got brighter, its pupils contracted to adjust the amount of light entering the retina. The sun was now setting rapidly. It had merely been 5-7 minutes since the peak of gradient intensity had occurred. The brightness reduced considerably, which not only reduced the range of hues that dominated the sky but also made the skyline much less visible to the naked eye. Glass buildings which had previously stood out due to its colourful reflections once again remained camouflaged in the horizon. The myriad of colours that dotted the sky now had merged into two main hues, red and blue. The red was highly saturated at the horizon, due to its proximity to the sun. However, what claimed most of the atmosphere was a dark, brooding shade of blue that, to me, represented the mysterious cosmos that we inhabit. This blue blotted out most of the light that had shone over the surface. Furthermore, the clouds had completely dissipated, now exposing the true enormity of the sky, while also providing a more complete picture of the colour gradience visible at that time. It certainly changed the amount of activity in the park as well. The children that were entranced by the beautiful mosaic in the sky were now more subdued as darkness washed over them. The park also became a lot quieter, as the impending twilight meant that it was time to go home. The dog that had previously laid down over the hill, with its incredible reflection of the sunset on its eye, turned over, much to my dismay. Now that darkness was overtaking the light, it was clear that I was switching from my cone-mediated vision to rod-mediated vision to adjust to the darkness. It became slightly harder to define the form and shapes of the buildings over the skyline due to the lack of light illuminating the grey buildings that seemed to camouflage itself into the horizon. Furthermore, it became more difficult to define the human form in this darkness, and the children who remained in the park moulded into the background, joining the trees that were swaying with the breeze. From an auditory perspective, while artificial noises of traffic, human voice and construction in the background reduced, nature seemed to come alive the darker it got. Birds that had been quiet during the sunset chirped a little louder, while cicadas that maintained silence throughout the day, started singing in the night. Due to the recession of artificial sounds, I was more clearly able to hear the leaves rustling against the gentle breeze and scurrying of bats and birds from tree to tree. Finally, the sun had set. The navy blue that had dominated the sky now overtook the horizon as well. The hue of the blue got significantly darker as well due to the lack of yellows and reds to brighten it up. Stars dotted the sky now, and the lack of colour meant that I was primarily using rod-mediated vision. This was when I realized that my observation had come to an end. It is imperative for me to understand that when I stared at a cloud, my perception of it, from the colours to the form to the motion, where it sped through the sky, is all possible due to the photoreceptors on my retina. My cones convert everything that I see, in the form of electromagnetic energy, to electrochemical signals. It creates a two-dimensional image in my retina that gets fragmented and transported through my neurons. It is amazing how our sensations and perceptions are so physical when viewed at a superficial level, but so computational when we dig deeper and analyse our brain processes.
This resource was uploaded by: Akshana