perception

• Perception is the process of understanding and making sense of the sensory information we receive.
• There are various explanations and theories for how perception actually works including how culture can affect perception.
• Perception can be a bottom-up process where our perception is based solely on the information received by our eyes, or a top-down process where our mind generates expectations of what we are looking at, and it is these expectations that then help us make sense of the information our eyes receive.
• Gibson’s direct theory of perception (and the influence of nature) and Gregory’s constructivist theory of perception (the role of nurture) are two main theories that attempt to explain how perception works.
• Sensation is the information we receive through the senses, which is detected by special sensory organs and converted into electrical signals in a process known as transduction.
• The body is bombarded with lots of information, far more than we can actually cope with if we were to give it all attention.
• Perception is the process of understanding and making sense of all the information our body receives.
• Perceptual set is a state of readiness developed by humans to anticipate what is coming so they can act effectively.
• All cognitive processes such as memory, decision-making, learning and perception can be affected by the perceptual set.
• Memory can be affected by the perceptual set as different things are remembered dependent on the mood of the individual.
• Decision-making is also believed to be affected by the perceptual set as dependent on what has just been seen or expected, the decision making is affected.
• Learning is also affected by the perceptual set as we are more prepared to learn some things than others.
• Perception is also affected as when we expect something, we are more likely to notice it and Bruner and Minturn’s study on expectation provides research support for this.
• The culture we are brought up in can influence perception as children in western societies are used to line drawings and cartoons which become a part of their perception.
• Emotions can influence how we perceive things as they contribute to our perceptual set and make us more likely to perceive things in a particular way that is in line with how we feel.
• Children that are excited about Christmas approaching have been shown to draw bigger pictures of Santa which include lots of presents compared to after once Christmas has passed due to less excitement.
• Motivation can influence perception as demonstrated in Gilchrist and Nesberg’s need and perceptual change study (1952) where 26 university students who volunteered to go 20 hours without any food and consume only water were recruited as participants.
• Our eyes, for example, receive information about how much light or darkness there is as well as colour which is picked up as tiny dots however we do not see a mass of tiny dots even though this is actually what our visual receptors see.
• The Necker Cube is an example of ambiguity where the brain cannot decide where the front is as the image is perfectly balanced.
• The Necker Cube can be seen in different ways as there is more than one possible viewpoint for it.
• Fiction is creating something that isn't really there in order to complete the image.
• The Kanizsa Triangle is an example of fiction where a triangle is seen in the middle but it is not there and a form of fiction our perception has created which has been influenced by the shapes around it.
• Our perceptual system generates an image that fills the gap to create something plausible for us.
• The Ames Room illusion uses size constancy to produce a visual illusion.
• Size constancy is keeping the original perception of the size of an object even when information received by the eyes changes.
• Perceptual constancy is about how we perceive objects as being the same (constant) even when the visual image we receive is different.
• Shape constancy is a similar process that occurs when we see people who are in the distance.
• Gregory’s constructivist theory of perception argues that past knowledge and experience is the most important factor when making sense of the world around us.
• Gregory proposed that perception involved cognitive processes and that we do not simply perceive information that we receive.
• Gregory’s theory of perception was evaluated using studies that showed how motivation can affect our perception.
• The Muller-Lyer illusion works because the arrowheads on the lines make them look like the near edge of a building or the far corner of a room which makes us think the line is nearer to us than the other.
• A strength of Gregory’s theory of perception is that the Muller-Lyer illusion still works when the arrowheads are replaced with circles.
• Perceptual set is a state of readiness for the information we receive from the environment around us.
• We instead see patterns such as shapes, people and objects and even if we see some things faintly, our past experience allows us to make out and infer what we think it is because of this process known as perception.
• Monocular depth cues include height in plane, relative size, occlusion and linear perspective.
• Binocular depth cues include retinal disparity and convergence.
• Gilchrist and Nesberg's 1952 Motivation Study investigated how motivation can affect perception.
• The study showed that hunger can affect the way people perceive images of food, suggesting motivation can affect perception.
• The study was realistic and had ecological validity as the participants were tested while hungry.
• The experiment was conducted in a laboratory setting, allowing for easy replication by other researchers.