AP Psychology: Sensation and Perception Notes
Key Terms: Sensation and Perception
Sensory Perceptions and Disorders
- Sensation: The process by which sensory receptors receive information from the environment; includes vision, hearing, smell, taste, touch, and the vestibular and kinesthetic senses.
- Transduction: Conversion of one form of energy into another, as when environmental stimuli are transformed into neural signals.
- Receptors: Specialized structures that detect specific types of environmental stimuli and transduce them into neural signals.
- Absolute threshold: The minimum stimulation required for a particular stimulus to be detected 50% of the time.
- Just-noticeable difference (JND): The smallest change in stimulation that a person can detect 50% of the time.
- Weber’s law: States that the size of the JND is directly proportional to the strength of the original stimulus.
- Signal-detection theory (SDT): A theory that explains how individuals distinguish between meaningful sensory signals and random noise.
- Cornea: The transparent, protective outer layer of the eye that bends light waves to assist in proper focus.
- Iris: A piece of muscle tissue that sits behind the cornea and helps the eye adjust how much light enters. It gives the eye its color.
- Pupil: A small, adjustable opening that is constricted or dilated by the iris. Constriction decreases the amount of light entering while dilation increases the amount of light entering.
- Lens: A transparent structure that sits behind the pupil and can adjust its shape to bend light for proper focus (working with the cornea).
- Accommodation: The process by which the lens changes shape to focus on near or far objects by adjusting how light hits the retina.
- Sclera: The white part of the eye that provides structural support and contains blood vessels.
- Retina: The light-sensitive inner surface of the eye containing a vast network of photoreceptors.
- Photoreceptors: Specialized light-sensitive neurons in the retina that convert light into neural impulses; includes rods and cones.
- Rod: A type of photoreceptor that processes black, white, and gray light; clustered in the retina’s periphery.
- Cone: A type of photoreceptor that distinguishes colors and detects fine details in well-lit conditions; clustered in the fovea.
- Fovea: A small indentation at the center of the retina that contains the highest concentration of cones.
- Visual acuity: The ability to see fine details.