Unit 6 - Sensation and Perception

Sensation

The process through which sensory receptors in the body receive information from the environment.

Absolute Threshold

The minimum stimulation needed for us to acknowledge that we have detected a stimulus in the environment.

Difference Threshold (JND)

The minimum difference between two stimuli required for us to be able to tell the difference between the two.

Weber’s Law

The idea that to perceive the difference between two stimuli, they must differ by a constant percentage, not a constant amount.

Transduction

The process of changing external sensations into electrical messages that can travel via neurons.

Sensory Adaptation

The idea that constant stimulation in the environment fails to be sensed after an extended period of time.

Selective Attention

When focus is directed towards one particular thing, tuning out other stimuli.

Cocktail Party Effect

The phenomenon when an individual focuses on a conversation in a noisy environment, tuning out other conversations.

Inattentional Blindness

Failure to see visible objects when our attention is directed elsewhere.

Perception

The way in which the brain interprets sensations presented by sensory receptors.

Bottom-Up Processing

When sensory information is taken and processed by the brain without the influence of prior knowledge.

Top-Down Processing

When prior knowledge and expectations influence how sensory information is processed.

Hue

The actual color of an object, determined by the wavelength of light.

Accommodation

The process by which the lens of the eye expands and shrinks to focus light on the retina.

Rods

Photoreceptors in the retina that detect black and white; located throughout the retina for peripheral vision.

Cones

Photoreceptors in the center of the retina that detect fine detail and color.

Fovea

The area where cones cluster in the center of the retina and start the process of color processing.

Optic Nerve

The nerve that carries visual information from the retina to the brain.

Place Theory

Pitch is detected based on the specific location in the cochlea where hair cells are stimulated.

Frequency Theory

Pitch is detected based on the rate at which the sound wave messages are sent to the brain.

Conduction Hearing Loss

Hearing loss caused by damage to the outer or middle ear's mechanical parts.

Sensorineural Hearing Loss

Hearing loss caused by damage to the cochlea's hair cells, requiring a cochlear implant for transduction.

Kinesthesis

The body's sense of its position in space and movement.

Olfaction

The processing of odors by the brain.

Gestalt Grouping Principles

Principles such as Proximity, Similarity, Continuity, and Connectedness used to organize visual information.

Binocular Cues

Depth perception cues that require the use of both eyes, such as retinal disparity and convergence.

Monocular Cues

Depth perception cues that require the use of one eye, like interposition and linear perspective.

Extrasensory Perception (ESP)

Awareness that occurs beyond the use of the five senses, including telepathy, clairvoyance, and precognition.