PBSI Chapter 5

Sensory Receptors

Specialized neurons that respond to specific types of environmental stimuli [3].

Sensation

The process that occurs when sensory receptors detect sensory stimuli in the environment [3].

Transduction

The conversion of sensory stimulus energy into an action potential by sensory receptors [4].

Ten Sensory Systems

Sensory systems including vision, audition, olfaction, gustation, somatosensation, vestibular sense, proprioception, kinesthesia, nociception, and thermoception

Proprioception

The sensory system responsible for detecting body position [4].

Kinesthesia

The sensory system responsible for detecting body movement [4].

Vestibular Sense

Sensory system located near the inner ear cochlea contributing to balance and body posture [4

Absolute Threshold

The minimum amount of stimulus energy needed for a stimulus to be detected at least 50 percent of the time [4].

Just Noticeable Difference (JND)

The minimum difference in stimuli required to detect a change or difference between stimuli [6].

Difference Threshold

Another name for the just noticeable difference which depends on the initial stimulus intensity [6

Perception

The way sensory information is organized, interpreted, and consciously experienced by the brain

APA Definition of Sound

Variations in pressure over time in an elastic medium like air or water capable of being heard by an organism [10].

Bottom-Up Processing

Perceptual processing where system perceptions are built purely from incoming sensory input [11].

Top-Down Processing

Interpretation of sensations influenced by available knowledge, experiences, thoughts, and expectations

Sensory Adaptation

The phenomenon of not perceiving stimuli that remain relatively constant over prolonged periods [13].

Inattentional Blindness

The failure to notice something completely visible due to a lack of attention [13].

Motivation in Perception

A factor where a person may perceive a stimulus even when absent because they want to perceive it [13].

Müller-Lyer Illusion

An optical illusion where identical line lengths appear different due to arrow endings and 3D perception expectations [14

Amplitude of Waves

The height of a wave measured from peak to trough, determining brightness in light waves and loudness in sound waves

Wavelength

The distance of a wave measured from peak to peak, which is inversely related to wave frequency

Wave Frequency

The number of waves that pass a given point in a given time period, expressed in hertz

Frequency and Wavelength Relationship

Longer wavelengths have lower frequencies, whereas shorter wavelengths have higher frequencies

Visible Spectrum Range

The portion of the electromagnetic spectrum visible to humans, spanning wavelengths from 380 to 740 nanometers

Wavelength and Color Perception

Long light wavelengths appear as reds, intermediate wavelengths as greens, and short wavelengths as blues and violets

Amplitude and Brightness

Larger light wave amplitudes correspond to brighter or more intense colors [28].

Pitch and Sound Frequency

Sound wave frequency determines pitch, where high frequency creates high pitch and low frequency creates low pitch

Loudness and Decibels

Sound wave amplitude determines loudness measured in decibels, with conversation at 60 dB and rock concerts at 120 dB

Hearing Damage and Pain Thresholds

Potential hearing damage occurs between 80 and 130 decibels, and the threshold for pain is 130 decibels

Human Audible Frequency Range

The range of sound frequencies audible to humans spans between 20 and 20000 hertz [28

Light Path through the Eye

Light crosses the cornea enters through the pupil (controlled by the iris), and is focused by the lens onto the fovea,

Fovea

The central region of the retina containing high-density photoreceptors for detailed vision [31

Optic Nerve and Blind Spot

Axons of retinal ganglion cells form the optic nerve exiting the eye at the blind spot where no photoreceptors exist [31].

Cones

Photoreceptors in the fovea operating in bright light for photopic daytime vision and high-acuity color perception [33].

Rods

Photoreceptors in the retina periphery operating in low light for scotopic nighttime vision

Dog Photoreceptor Differences

Dogs have two types of cones and more rods than humans, giving them limited color vision but strong movement and night vision

Optic Chiasm Function

An X-shaped brain structure where optic nerves merge

Visual Information Brain Pathway

Visual signals travel from the optic chiasm to the thalamus and then to the occipital lobe for processing [41].

The WHAT Visual Pathway

Visual pathway exiting the occipital lobe involved in object recognition and identification [42

The WHERE/HOW Visual Pathway

Visual pathway exiting the occipital lobe processing object location in space and spatial interactions [42

Trichromatic Theory of Color Vision

Theory stating that all perceived colors result from combining red, green, and blue controlled by three cone types in the retina

Opponent-Process Theory

Theory stating color is coded in opponent pairs (black-white, yellow-blue, green-red) in cells after the retina

Negative Afterimage

Continuation of a visual sensation in complementary colors after stimulus removal due to opponent-process pairings [49].

Color Blindness Cause

Deficiencies or absence in specific types of cone photoreceptors in the retina [51].

Depth Perception

The ability to perceive spatial relationships in three-dimensional space [53].

Binocular Disparity

A binocular depth cue based on the slightly different view of the world received by each eye [53].

Linear Perspective

A monocular depth cue where two parallel lines appear to converge as they recede into the distance [53

Interposition

A monocular depth cue where the partial overlap of objects indicates relative distance [54].

Outer Ear Structures

Composed of the pinna (auricle) and the tympanic membrane (eardrum) [58].

Middle Ear Ossicles

Contains three tiny bones named the malleus (hammer)

Inner Ear Anatomy

Composed of the fluid-filled cochlea and the basilar membrane [58].

Temporal Theory of Pitch Perception

Theory stating that sound frequency is coded by sensory neuron firing rates

Place Theory of Pitch Perception

Theory stating that different locations on the basilar membrane respond to different frequencies

Taste Groupings (Gustation)

Six basic taste sensations including sweet, salty, sour, bitter, umami (MSG), and fatty content

Taste Bud Life Cycle

Groupings of taste receptor cells with hair-like extensions that have a life cycle of 10 days to 2 weeks [62].

Olfactory Pathway Special Rule

Olfaction is the only sense whose sensory signals travel directly to the olfactory bulb and limbic system without passing through the thalamus [64].

Merkel's Disks

Touch receptors located in skin tissue that respond directly to light pressure [65].

Ruffini Corpuscles

Touch receptors in the skin that specifically detect stretch [65].

Meissner's Corpuscles

Touch receptors in the skin responding to pressure and lower-frequency vibrations [66].

Pacinian Corpuscles

Touch receptors in the skin detecting transient short-lasting pressure and higher-frequency vibrations [66].

Thermoception and Nociception

Thermoception senses temperature and nociception senses potential harm or pain, sending signals up the spinal cord to the medulla, thalamus, and somatosensory cortex

Gestalt Psychology Core Idea

Psychological field based on the principle that the whole is different from the sum of its parts [69].

Figure-Ground Relationship

Gestalt principle where visual input is segmented into the focal figure and the surrounding background ground [72].

Gestalt Principle of Proximity

Principle stating that objects physically close to one another tend to be grouped together [74].

Gestalt Principle of Similarity

Principle stating that elements that look alike tend to be grouped together in perception [75].

Gestalt Principle of Continuity

Principle stating we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines

Gestalt Principle of Closure

Principle stating that we organize perceptions into complete objects rather than as a series of disconnected parts [79].