Unit 5

Sensation and Perception

• Sensation: your window to the world. The process by which our sensory receptors and nervous system receive stimulus from the environment.
• Perception: interpreting what comes in your window. The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. Perception is essentially an interpretation and elaboration of sensations.
• Bottom-Up vs. Top-Down Processing
• Bottom-Up Processing: analysis that begins with the sense receptors and works up to the brain's integration of sensory information.
• Top-down Processing: information processing guided by higher-level mental processes. As when we construct perceptions drawing on our experience and expectations.
• Absolute Threshold: the minimum stimulation needed to detect a stimulus 50% of the time.
• Difference Threshold: the minimum difference that a person can detect between two stimuli. Also known as Just Noticeable Difference.
• Weber's Law: the idea that, to perceive a difference between two stimuli, they must differ by a constant percentage, not a constant amount.
• Signal Detection Theory: predicts how we detect a stimulus amid other stimuli. Assumes that we do not have an absolute threshold, we detect stuff based on our experiences, motivation and fatigue level.
• Subliminal Stimulation: below one's absolute threshold for conscious awareness.
• Transduction: transforming signals into neural impulses. Information goes from the senses to the thalamus, then to the various areas in the brain.
• Sensory Adaptation: diminished sensitivity as a result of constant stimulation.
• Selective Attention: the focusing of conscious awareness on a particular stimulus.
• Cocktail Part Effect: ability to listen to one voice among many.