Sensory Perception and Thresholds: Psychology Key Concepts

Vocabulary flashcards covering sensory perception, thresholds, vision structures, color vision theories, visual conditions, sound properties, pitch perception theories, and hearing impairments.

Sensation

The uninterpreted sensory impression created by the detection of an environmental stimulus; the process of perceiving through the senses.

Transduction

The process by which sensory receptors convert physical energy from the environment into neural impulses.

Absolute Threshold

The minimum amount of stimulation required to trigger a reaction or produce a sensation 50% of the time.

Just-Noticeable Difference

The smallest difference in the amount of stimulation that a specific sense can reliably detect.

Weber's Law

The psychophysical principle that the just-noticeable difference of a stimulus is a constant proportion of the original stimulus intensity.

Sensory Adaptation

Reduced responsiveness in a sensory receptor or sensory system caused by prolonged or repeated stimulation.

Sensory Interaction

The integration of information from different senses to influence a unified perception (e.g., smell influencing the perception of taste).

Synesthesia

A condition in which stimulation of one sensory modality generates a simultaneous sensation in another.

Retina

The light-sensitive inner surface of the eye that contains the photoreceptor cells (rods and cones) and visual neurons.

Blind Spot

The area of the monocular visual field in which stimulation cannot be perceived because the image falls on the optic disk.

Visual Nerve

Formally the optic nerve; the second cranial nerve which carries the axons of retinal ganglion cells, transmitting visual information to the brain.

Lens

The transparent, biconvex structure in the eye that focuses light rays onto the retina.

Accommodation

The adjustment of the eye's lens to focus on objects at varying distances.

Nearsightedness

Formally myopia; a visual defect in which distant objects appear blurred because their images are focused in front of the retina rather than on it.

Farsightedness

Formally hyperopia; a visual defect in which near objects appear blurred because their images are focused behind the retina rather than on it.

Photoreceptors

Cells in the retina (rods and cones) that are sensitive to light and convert light energy into neural signals.

Fovea

A small depression in the central portion of the retina in which cone cells are most concentrated, yielding the highest visual acuity.

Rods

Photoreceptors in the retina that are highly sensitive to low light but do not mediate color vision.

Cones (blue, green, red)

Photoreceptors in the retina that require moderate to bright light to function and mediate color vision and fine visual detail.

Light/Dark Adaptation

The physiological adjustment of the eyes to varying levels of illumination to maximize visual sensitivity.

Trichromatic Theory

The theory that color vision is mediated by three types of cones, each maximally sensitive to a different range of wavelengths (short, medium, long).

Opponent Processing Theory

The theory that color vision relies on opponent neural processes (red-green, yellow-blue, black-white).

Afterimages

A visual sensation that remains after the physical stimulus causing it has been removed.

Ganglion Cells

Neurons in the retina that receive inputs from bipolar cells and whose axons bundle together to form the optic nerve.

Dichromatism

A form of color vision deficiency in which only two of the three fundamental color mechanisms are functioning.

Monochromatism

A rare form of colorblindness resulting in the inability to distinguish any colors, perceiving only shades of gray.

Prosopagnosia

A form of visual agnosia characterized by a severe inability to recognize familiar faces.

Wavelength

The distance between successive peaks of a wave, corresponding to the psychological experience of hue in light and pitch in sound.

Pitch

The psychological property of an auditory sensation that lies on a scale from low to high, determined primarily by sound frequency.

Amplitude

The maximum displacement of a wave from its resting position, corresponding to loudness in sound and brightness in light.

Loudness

The subjective magnitude of an auditory sensation, primarily dependent on the amplitude of the sound wave.

Pitch Perception

The psychological and physiological process of interpreting the frequency of sound waves as specific high or low tones.

Place Theory

The theory that the pitch of a sound is determined by the specific location on the basilar membrane that is stimulated most.

Volley Theory

The theory that groups of auditory nerve fibers fire neural impulses in rapid succession, creating volleys of impulses to match frequencies higher than a single neuron can fire.

Frequency Theory

The theory that the pitch of a sound is determined by the rate of nerve impulses traveling up the auditory nerve.

Sound Localization

The process by which the auditory system determines the spatial origin of a sound based on time and intensity differences between the ears.

Conduction Deafness

Hearing impairment resulting from interference with the mechanical transmission of sound waves to the inner ear.

Sensorineural Deafness

Hearing impairment resulting from damage to the inner ear (cochlea) or the auditory nerve.