perception

1. Unit 2: Perception

2. Introduction to Perception

   1. 1. Sensation vs. Perception:

   2. • Sensation: The process of detecting sensory stimuli from the environment.

   3. • Perception: The interpretation and organization of sensory input into meaningful experiences.

   4. 2. Bottom-Up Processing: Analyzing information starting with sensory input and building toward a perception.

   5. 3. Top-Down Processing: Using prior knowledge, experiences, and expectations to interpret sensory input.

   6. 4. Sensory Adaptation: Reduced sensitivity to a stimulus after prolonged exposure.

   7. 5. Inhibition: The brain’s ability to suppress irrelevant sensory information to focus on relevant stimuli.

3. Depth and Constancy

   1. 6. Monocular Depth Cues: Depth cues that can be perceived using one eye. Examples include:

   2. • Relative Clarity: Objects that are clearer are perceived as closer.

   3. • Relative Size: Smaller objects are perceived as farther away if they are assumed to be the same size.

   4. • Texture Gradient: Objects with more detail are perceived as closer.

   5. • Linear Perspective: Parallel lines appear to converge as they recede into the distance.

   6. • Interposition: Closer objects partially block the view of objects farther away.

   7. 7. Binocular Depth Cues: Depth cues that require both eyes. Examples include:

   8. • Retinal Disparity: The difference in images seen by each eye; greater disparity indicates closer objects.

   9. • Convergence: The degree to which the eyes turn inward to focus on a nearby object.

   10. 8. Visual Cliff Research: Experiments showing that depth perception is present in infants and other animals.

   11. 9. Perceptual Constancy: The ability to perceive objects as unchanging despite changes in sensory input, including:

   12. • Size Constancy: Perceiving an object as having the same size despite changes in distance.

   13. • Shape Constancy: Recognizing an object’s shape regardless of the angle of view.

   14. • Color Constancy: Perceiving consistent color under varying lighting conditions.

4. Organizing Our Perceptions

   1. 10. Gestalt Principles: Psychological rules that describe how we naturally organize sensory information. Examples include:

   2. • Figure-Ground Perception: The ability to distinguish an object (figure) from its background (ground).

   3. • Similarity and Proximity: Grouping objects based on similarity or closeness.

5. Illusions and Other Phenomena

   1. 11. Color Afterimages: A visual illusion where a complementary color is seen after staring at a colored image and then looking away.

   2. 12. Reversible Figures: Images that can be interpreted in multiple ways, such as the Necker cube.

   3. 13. Illusions of Movement: Perceptions of motion where none exists, including:

   4. • Phi Phenomenon: The illusion of movement created by rapidly blinking lights in sequence.

   5. • Stroboscopic Movement: The illusion of continuous motion created by a rapid sequence of slightly varying images (e.g., in movies).

   6. 14. The Müller-Lyer Illusion: A visual illusion in which two lines of equal length appear to be different due to the direction of arrow-like endings.

   7. 15. The Ponzo Illusion: A visual illusion where lines of equal length appear unequal due to converging background lines.

6. Schemas

   1. 16. Schemas: Mental frameworks or concepts that help organize and interpret information, often based on prior knowledge and experiences.

   2. 17. Context: The surrounding information or environment that influences perception.

18.Perceptual Set: A predisposition to perceive things in a certain way based on expectations, context, and prior knowledge.