Definition: The process of detecting an environmental stimulus and converting it into neural activity.
Steps for the five major senses (sight, hearing, touch, taste, smell):
Reception: Sense organs receive sensory stimulation (e.g., light enters the eye).
Transduction: Specialized sensory receptor cells convert the stimulus into a neural signal (e.g., rods and cones in retina).
Transmission: Neural signals pass through the thalamus, which acts as a relay station for sensory systems.
Processing: Signals are routed to brain areas specialized for processing:
Occipital lobe: Visual signals
Temporal lobe: Auditory signals (sound)
Parietal lobe: Touch and temperature
Gustatory cortex: Taste
Exception: Smell does not pass through the thalamus. Instead, it goes through the amygdala (emotion) and hippocampus (memory).
Perception
Definition: The identification and interpretation of sensory information.
Factors Affecting Perception:
Absolute Threshold: Minimum stimulus intensity needed for a receptor to react (e.g., lowest volume of a tone).
Just Noticeable Difference (JND): Minimum change in stimulus intensity that can be detected (e.g., weight perception).
Sensory Adaptation: Decreased response of sensory receptor cells after continuous stimulation, reducing perceived intensity (e.g., becoming less aware of a foul odor over time).
Perceptual Constancy
Definition: The tendency to perceive familiar objects as unchanging despite slight changes in the stimulus (e.g., constant shape, size, color).
Perceptual Set
Definition: The tendency to perceive certain stimuli over others based on past experiences.
Influences interpretation of ambiguous information and can lead to processing errors.
Both perceptual constancy and perceptual set are top-down processes, utilizing prior knowledge to interpret sensory information.
Bottom-Up Processing
Definition: The process where the brain uses raw sensory data to create a perception.