SENSATION AND PERCEPTION

Flashcards covering key vocabulary terms related to sensation and perception, including sensory systems, thresholds, perceptual processing, wave properties, vision, audition, taste, smell, touch, balance, and Gestalt principles.

Sensory Systems

Responsible for providing information about our surroundings, allowing us to successfully navigate and interact with our environments.

Sensation

What occurs when sensory receptors detect sensory stimuli.

Sensory Receptors

Specialized neurons that respond to specific types of stimuli.

Transduction

The process where sensory receptors convert sensory energy into an action potential.

Ten Sensory Systems

Vision, Hearing (audition), Smell (olfaction), Taste (gustation), Touch (somatosensation), Balance (vestibular sense), Body position (proprioception), Movement (kinesthesia), Pain (nociception), Temperature (thermoception).

Absolute Threshold

The minimum amount of stimulus energy needed for the stimulus to be detected at least 50% of the time.

Subliminal Messages

Stimuli for which an action potential is present but below the threshold of conscious awareness.

Just Noticeable Difference (JND)

The minimum difference in stimuli required to detect a change or a difference between stimuli, also known as the difference threshold.

Weber's Law

States that the JND is all about the proportion or percentage of 'change' in a stimulus.

Perception

The way that sensory information is interpreted, organized, and consciously experienced.

Bottom-up Processing

A system in which perceptions are built from sensory input.

Top-down Processing

The interpretation of sensations is influenced by available knowledge, experiences, and thoughts.

Sensory Adaptation

Not perceiving stimuli that remain relatively constant over prolonged periods of time.

Inattentional Blindness

Failure to notice something that is completely visible because of a lack of attention.

Amplitude (of a wave)

The height of a wave, measured from the peak to the trough.

Wavelength (of a wave)

The distance of a wave, measured from peak to peak.

Frequency

The number of waves that pass a given point in a given time period, expressed in hertz (Hz).

Light Wavelength and Color Perception

Longer wavelengths are perceived as reds, intermediate as greens, and shorter as blues and violets.

Light Amplitude and Color Perception

Larger amplitudes of light waves appear brighter (more intense) in color.

Soundwave Frequency

Perceived as pitch; high frequency equals high-pitched sound, low frequency equals low-pitched sound.

Soundwave Amplitude

Perceived as loudness; higher amplitude equals louder sounds, lower amplitude equals quieter sounds, measured in decibels (dB).

Cornea

The transparent outer layer of the eye where light waves are first transmitted.

Pupil

The small opening in the eye through which light enters.

Iris

The colored part of the eye that connects to muscles controlling pupil size.

Lens

Focuses light onto the fovea.

Fovea

Part of the retina that contains photoreceptors and is responsible for sharp central vision.

Photoreceptors

Specialized cells in the retina (rods and cones) that detect light.

Optic Nerve

Formed by axons from retinal ganglion cells, carries visual information from the eye to the brain.

Blind Spot

A point of no receptors where the optic nerve exits the eye, meaning we cannot respond to visual information there.

Cones

Photoreceptors helpful for phototopic (daytime) vision, working best in bright light conditions and providing high-acuity color information; located in the fovea.

Rods

Photoreceptors helpful for scotopic (nighttime) vision, working best in low light conditions, providing high-sensitivity and low-acuity vision; involved in movement perception in peripheral vision; located in the periphery of the retina.

Optic Chiasm

An X-shaped structure just below the cerebral cortex where the optic nerves of each eye merge and visual information crosses to the opposite hemisphere.

Opponent-Process Theory

Theory of color vision stating that color is coded in opponent pairs (black–white, yellow–blue, green–red); applies to cells after the retina.

Trichromatic Theory of Color Vision

Theory of color vision stating that all colors can be produced by combining red, green, and blue; applies to the retina where color vision is controlled by 3 types of cones.

Pinna

The outer, visible part of the ear.

Tympanic Membrane

Also known as the eardrum, separates the outer ear from the middle ear and vibrates in response to sound waves.

Ossicles

The three small bones in the middle ear: malleus (hammer), incus (anvil), and stapes (stirrup).

Cochlea

A fluid-filled, snail-shaped structure in the inner ear that contains hair cells involved in hearing.

Basilar Membrane

A membrane within the cochlea that contains hair cells and is sensitive to sounds of different frequencies.

Temporal Theory (of pitch perception)

Frequency is coded by the activity level of a sensory neuron, but cannot account for the entire range of human hearing.

Place Theory (of pitch perception)

Different places on the basilar membrane are sensitive to sounds of different frequencies (base for high, tip for low).

Gustation

The sense of taste, a chemical sense with about 6 groupings of taste: sweet, salty, sour, bitter, umami, and potentially fatty content.

Taste Buds

Groupings of taste receptor cells with hair-like extensions that protrude into the central pore of the taste bud.

Umami

A taste associated with monosodium glutamate (MSG).

Olfaction

The sense of smell, a chemical sense.

Olfactory Receptor Cells

Cells located in a mucous membrane at the top of the nose, containing hair-like extensions where odor molecules interact with chemical receptors.

Olfactory Bulb

A bulb-like structure at the tip of the frontal lobe where olfactory nerves begin, receiving signals from odor molecules.

Merkel's Disks

Sensory receptors in the skin that respond to light pressure.

Meissner's corpuscles

Sensory receptors in the skin that respond to pressure and lower-frequency vibrations.

Ruffini corpuscles

Sensory receptors in the skin that detect stretch.

Pacinian corpuscles

Sensory receptors in the skin that detect transient pressure and higher-frequency vibrations.

Thermoception

Temperature perception.

Nociception

A sensory signal indicating potential harm and maybe pain.

Vestibular Sense

Contributes to our ability to maintain balance and body posture, with organs located next to the cochlea in the inner ear.

Gestalt Psychology

A field of psychology based on the idea that the whole is different from the sum of its parts, suggesting the brain creates perceptions more than just the sum of sensory inputs.

Figure-Ground Relationship

A Gestalt principle that explains our tendency to segment our visual world into a figure (focus) and ground (background).

Principle of Proximity

A Gestalt principle stating that things that are close to one another tend to be grouped together.

Principle of Similarity

A Gestalt principle stating that things that are alike tend to be grouped together.

Principle of Continuity

A Gestalt principle stating that we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines.

Principle of Closure

A Gestalt principle stating that we organize our perceptions into complete objects rather than as a series of parts.