Both Gibson and Gregory theories of perception emphasize the significance of the eye-retina in the process of perception. They both contend that without the eye-retina, sight becomes impossible. This viewpoint is shared by both theories and is substantiated by the case study of SB, a man who was born blind due to cataracts. At the age of 52, SB underwent a restorative surgery that enabled him to regain his vision. Thus, this case exemplifies the crucial role of the eye-retina in facilitating perception.
Both Gibson and Gregory have different theories about perception. Gibson supports the direct theories of perception, using the theory of bottom-up processing to explain visual illusions. On the other hand, Gregory believes in the indirect theories of perception, using the theory of top-down processing to explain visual illusions. According to the direct theories, the eye-retina is essential for perception. Both theories provide explanations for how we visually analyze the world, starting from basic sensory inputs at the bottom level and moving towards the higher cognitive levels of the brain.
Theories of top-down processing propose that our perception of the visual world depends on using stored knowledge and problem-solving skills. As a result, there are different theories about perception. The debate between nature and nurture has emerged from Gregory’s indirect theory of perception and Gibson’s direct theory of perception. In psychology, this is an important debate about whether genetics, as suggested by Gibson’s theory, or upbringing and social environment, as proposed by Gregory’s theory, influence or shape perception.
The Nativists contend that a person’s nature is determined by genetics, whereas the Empiricists argue that nurture and experience have a greater influence. Meanwhile, an Eclectic approach proposes that both nature and nurture intertwine to shape outcomes. It is plausible that genetics establish a predisposition, but environmental factors are also vital for growth.
In addition to the aforementioned points, Gibson and Gregory have different theories of perception. According to Gregory, perception requires additional processing and background knowledge to interpret the environment beyond sensory input. On the other hand, Gibson believes that perception is an inherent adaptive mechanism for survival and does not rely on stored knowledge or past experiences. Additionally, Gregory argues that expectations influence perceptions, whereas Gibson disagrees with this notion.
There is empirical evidence supporting Gregory’s idea, as demonstrated by a study conducted by Simons and Levin. In this study, 50% of the participants failed to notice a change in individuals. This lack of perception can likely be attributed to the participants not anticipating a switch of people. Another study conducted by Selfridge also supports Gregory’s concept. Selfridge’s study illustrates that our perceptions are influenced by our expectations, as individuals were able to interpret the figures as “the cat.”
The reason people have certain expectations about cats is because these words are commonly used. Several studies have shown that people saw what they expected to see, proving that expectations can impact perception. These findings support Gregory’s theory of perception, which contradicts Gibson’s theory. Gregory argues that context plays a role in our perceptions, while Gibson disagrees. Supporting evidence for Gregory’s assumptions is provided by Selfridge’s study, which shows that context influences visual perception. This study suggests that context helps with perception.
Both Boring’s study and Warren’s study support Gregory’s idea about the impact of context on perception. Boring’s study focused on top-down processing and the role of context in visual perception, while Warren’s study examined how context influences auditory perception. In Warren’s study, participants used context to understand complete words within sentences. These research findings emphasize the significance of context in filling in missing information and imply that successful perception relies heavily on contextual cues.
The mentioned studies in the text provide support for Gregory’s theory instead of Gibson’s. Moreover, Gregory’s theory offers an explanation for our occasional perceptual errors. An example of this is when we ignore spelling mistakes in our own writing because we can understand words through context. Additionally, Gregory asserts that we interpret our visual surroundings by relying on our stored knowledge and past experiences, which contradicts Gibson’s perspective. Furthermore, Gregory suggests that understanding our environment requires a certain level of background knowledge acquired through learning, rather than solely relying on sensory input as proposed by Gibson.
According to Gregory, the Muller-Lyer figure shows that the left line appears longer than the right one because of our use of top-down processing. He suggests that we tend to perceive the left figure as resembling a corner in a room we are in, while perceiving the right figure as resembling a corner of an externally viewed building. This inference highlights the importance of context in influencing our perceptions. In addition, Gregory mentions the hollow mask phenomenon, which involves perceiving a hollow mask pointing outwards when viewed from inside. This aligns with our usual perception.
However, Gregory’s outlook has some issues. Firstly, when we replace the arrows with circles in the Muller-Lyer illusion, we can still observe the same effect. This implies that the notion of perceiving corners of rooms or buildings, etc. cannot be the sole explanation. Therefore, Gregory’s assumption about perception theory may be incorrect. Furthermore, Gibson asserts that using visual illusions as information is not valid because it presents a false stimulus that does not occur in reality. This indicates that the theory cannot be applied to real-life situations.
Visual illusions occur in real life, such as trains and car washes. Despite this, Gibson challenges Gregory’s theory and supports the direct theory of perception. Gibson argues that prior knowledge is not necessary for accurate perception of objects. Instead, perception is influenced by biological inheritance, unlike Gregory’s proposal. Warren and Hannon conducted a study where participants made judgments about direction using dots, providing evidence for Gibson’s concept of optic flow patterns.
This indicates that Gibson’s theory may support a more realistic perspective compared to Gregory’s. However, research conducted by Lee and Lishman suggests that adults possess a greater breadth of worldly experiences in comparison to children, which questions Gibson’s theory. Additionally, a study conducted by Hahn, Anderson, and Saidpour has revealed that participants were able to perceive direction and movement regardless of the condition they were in. This finding contradicts Gibson’s concept of optic flow. Consequently, Gregory’s theory may be more accurate than Gibson’s.
