Have you ever wondered whether you see the same world as other people see? Or maybe you have noticed that how you see and experience the world around you changes depending on the context.
Gibson argued that sensory input is sufficient for perceiving reality with no need for making interpretations. However, Gregory had a different theory of how perception works. Gregory proposed that our perception is more of an interpretation of what we see, influenced by our past experiences or even our mood. So let's see what evidence can support Gregory's view of perception.
Gregory's constructivist theory of perception used a top-down approach, freepik.com/storyset
How to describe Gregory's Constructivist Theory Of Perception?
Richard Gregory's Constructivist Theory of Perception argues that sensory information alone is not enough to account for perception. According to Gregory, perception is an active process involving making inferences and interpretations based on previous knowledge, experience, and context.
Gregory proposed a constructivist approach to perception. Perception doesn't objectively reflect sensory stimuli; perception constructs a model of reality based on both sensations and inferences.
Top-down processing
Gregory's Indirect Theory of perception is an example of a top-down approach. The top-down approach stresses the role of what we already know and expect on perception. What we perceive is not always the objective truth but rather an interpretation.
The role of interpretation in perception explains why people can perceive the same sensory information differently or why we perceive the same thing differently depending on our motivation or emotions.
If you are scared of spiders and see a spider in your room, you are likely to perceive it to be bigger than it is. Your emotion in that context (fear) makes you exaggerate the size of the spider.
If you're angry and your goal is to throw something, and you see an orange, you are likely to perceive it as a potential missile rather than a snack.
Inferences in Gregory's Indirect Theory of Perception
An inference is our best guess of what we see. Making inferences is a crucial aspect of the constructivist theory of perception. We can make inferences to construct a complete model of an object based on incomplete sensory information. Inferences are based on past knowledge. past experiences and visual cues like depth cues or motion cues, and perspective.
We can make an inference to create an image of an object even if only part of the object is visible. If we can only see half of a table behind other objects, we assume that there is another half to it but something is blocking our view, or we can't see it from our perspective, rather than assume that only half of this object exists.
We use incomplete sensory information like seeing half of a desk or chair to construct a complete model of an object, pixabay.com
The hollow mask illusion: when seeing the concave side of a 3D mask of a face, we experience an illusion that it looks convex. One explanation of this illusion is that we are so used to seeing convex faces that our brain infers that the mask is convex rather than concave.
The model of reality in Gregory's Indirect Theory of Perception
The model of reality constructed from perception is biased by our perceptual set, rather than being objective. Perceptual set refers to the tendency to select certain information that is deemed important, focus on it and ignore less "relevant" aspects of what we see.
The perceptual set is influenced by culture, motivation, emotion and expectation. For example, there is evidence that different cultures tend to make different inferences and perceive the same stimuli differently.
Hudson (1960) found cross-cultural differences in interpreting depth cues in pictures.
Researchers showed participants pictures of a hunter attacking an antelope standing close to him, with an elephant standing on a hill far behind the hunter.
Even though the elephant was far, it appeared between the hunter and the antelope.
Results- It was found that Bantu workers from South Africa interpreted the picture as a depiction of a hunter attacking the elephant instead of the antelope, suggesting that there is a cultural difference in perceiving depth cues in images.
Illustration of example Hundson (1960) stimulus, depth cues (size of an elephant and hills) tell us the elephant is not what the man is aiming for, Vaia Originals, Alicja Blaszkiewicz
We make inferences about what we see based on our past experiences with similar stimuli and visual cues. An example of a visual cue is linear perspective. In the case of the Müller-Lyer illusion, the appearance of linear perspective and our familiarity with buildings affects how we see the two lines, which are the same length.
Segall et al. (1963) found that cultures that are not used to seeing right angles in the corners of rooms in buildings are less susceptible to the Muller-Lyer illusion. Hunter-gatherers were not "fooled" by the illusion like Europeans and Americans were.
One explanation of the Müller-Lyer illusion proposed by Gregory is that people who are used to seeing corners of buildings see the smaller lines as linear perspective cues.
The first line, which looks like an outer corner of a room that is closer to us appears shorter and the second one, which looks like an inner corner that is further away from us appears longer.
Based on the linear perspective, it is inferred that the first figure is close and the second is further away. Due to size constancy, our understanding of how the size of an object changes depending on the distance; if objects appear the same size, but one is further away, it must mean the further away object is larger in reality.
The Müller-Lyer illusion, both lines are the same length, but the second one appears longer, Vaia Originals, Alicja Blaszkiewicz
Nurture or nature?
Constructivist Theory of Perception supports a strong influence of nurture on the process of perception. It claims that perception depends on our previously learned knowledge, experience, and frameworks about the world.
Because making context-dependent inferences and interpretations is a key aspect of the constructivist model, nature is not enough to account for all aspects of the perceptual process.
Evaluation of Gregory's Constructivist Theory of Perception
Let's consider the evidence for Gregory's Constructivist Theory of Perception and the contrasting theories.
Supporting evidence
We tend to perceive certain aspects of sensory information and ignore others selectively. Our perception depends on the context and stored knowledge, specifically culture, motivation, emotion and expectations.
When competing with others, our motivation to win can make us perceive our competitors negatively, only because they are our rivals in that context. For example, if you support one sports team, you are likely to view supporters of competing teams negatively.
This explains some visual illusions - when our brain is "fooled" or confused by visual illusions it is due to our assumptions of how objects look in the real world. Our pre-existing expectations of what visual cues (like depth cues) mean in real-life 3D stimuli distorts our perception of 2D illusions.
- Example: The Müller-Lyer illusion
Contrasting Theories
Gibson proposed a direct theory of perception. According to Gibson, perception is innate and doesn't require top-down processes like creating interpretations.
Gibson claimed that we receive complex information from sensory input, which is enough to make sense of what we see without interpreting it or making inferences. We automatically know what we see and what we can do with it based on only sensory information.
Gregory's Constructivist Theory of Perception - Key takeaways
Gregory proposed a constructivist theory of perception. Perception doesn't objectively reflect sensory stimuli; perception is an active process that constructs a model of reality based on both sensations and inferences.
Gregory's Constructivist Theory of perception is an example of a top-down approach to perception. Constructivist Theory of perception highlight the role of nurture in the perceptual process.
Inferences allow us to construct a model of reality from incomplete sensory information based on our stored knowledge and context.
The model of reality constructed from perception is biased by our perceptual set rather than being objective.
The perceptual set is influenced by culture, motivation, emotion and expectation.
Gregory's constructivist theory of perception, contrary to Gibson's direct theory of perception, accounts for the perceptual set and visual illusions.
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