Chapter #3: Sensation and Perception

Amplitude

The amount of vibration or pressure in a sound wabe often referred to as loudness

Ciliary Muscles

The muscles within the eye that stretch or compress the lens for the purpose of focusing the visual image

Cornea

The transparent coatign that covers the eyeball

Nocioceptors

A type of receptor that responds to painful stimuli or stimuli that are capable of causing tissue damage

Parvocellular Pathway

A visual pathway for central vision and high spatial resolution images

Magnocellular Pathway

A visual pathway for peripheral vision and low spatial resolution images from the retina.

Bottom-Up Processing

An information-gathering process starting from each individual stimulus

Absolute Threshold

A method used to study the limits of sensation; the smallest amount of a physical stimulus that can be correctly detected 50% of the time

Weber's Law

A principle in sensation that suggests that the size of the difference threshold is relative to the strength of the original stimulus

Location

2 Important measurements of a person's ability to detect spatial aspects of a sensory experience: - The ability to locate the source/site of stimulation - The ability to distinguish between 2 closely spaced stimuli

Modality

5 Major sensory modalities have been recognized: - Vision - Hearing - Taste - Touch - Smell

Lens

A biconvex crystalline structure that helps focus the visual image onto the retina in the back of the eye

Chemoreceptors

A class of receptors that detect water-soluble, lipid-solube chemicals

Attention

A concentrated mental effort that functions as a filter to ignore unimportant evetns and focus on important events

Sensory Adaptation

A decline in a sensation's sensitivity resulting from the presence of a constant stimulus

Blind Spot

A gap in the retina due to the exit of the optic nerve where no photoreceptors are located; this causes a blind spot in the visual field during sensation

Cones

A specific group of photoreceptors that are specialized to process color and are useful for daylight vision and high visual acuity

Rods

A specific group of photoreceptors that are specialized to process dim light and are useful for night vision and peripheral vision

"What" Pathway

A visual pathway projected into the temporal lobe that responds to and integrates information about the size, color, and/or the identity of an object.

Fovea

An area at the center of the retina that contains the highest density of cones; visual acuity is highest in this region

Red

Angry / Aroused / Energy / Love / Adventure

Proprioceptors

Are sensory receptors that are activated by muscular movement or passive displacement of body parts

Doppler Shift

The change in pitch emitted by an object moving horizontally in space, in relation to a stationary observe

Eardrum

The thin membrane at the end of the ear canal that virbrates at a specific frequency when bombared by sound waves

Sound Shadow

The difference in sound intensity due to head blocking/deflecting some of the sound waves

Dual / Two-Process Theory

The idea that we localize low-frequency sounds by using time or phase differences, or both

Acuity

The level of detail in a picture or the sharpness of an image

Occipital Lobe

The part of our brain responsible for processing the visual information

Transduction

The process of converting a physical stimulus into a meaningful and useful neural signal capable of being interpreted by the brain

Cutaneous Sensitivity

Cutaneous senses (skin sense) refers to touch, pressure, temperature, and pain (nociceptors)

Purple

Mystery / Fantasy / Imagination / Royalty / Spirituality / Justice / Art

Ocular Lubrication

Our visual system is able to make its own surface liquid that serves to keep the eye moist; natural tears are the mechanism for this process

Hallucinations

Perceptions of experiences without corresponding external stimuli together with a compelling feeling that these are real

Mechanoreceptors

Receptors that sense deformations and motions of solids, liquids, and gases, Mechanical forces are those that tend to deform or accelerate objects prossessing mass

Blue

Sad / Depressed / Melancholy / Success / Loyalty / Trust / Confidence

Yellow

Sick / Cautious / Fun / Joy / Warmth / Positivity / Happiness / Clarity / Curiosity

Wavelengths

The linear distance between two successive compressions or peaks in light waves

Pinna

The outer funnel-shaped structure of the ear; normally, this is what people refer to as their ear

Auditory Cortex

The part of our brain that is primarily responsible for processing the auditory information

Optic Chiasm

The point in the brain at which the optic nerves from each eye meet and partly cross over to the other side of the brain

Cochlea

The spiral structure in the inner ear that contains both fluid and the basilar membrane. the latter houses sensory receptors for audition

Pixilation

A physical measure of resolution on a screen

Pink

Feminity / Creativity / Respect / Calm / Intuition / Softness

Green

Jealous / Sick / Beginner / Nature / Luck / Harmony / Loyalty / Health

Decibel

The scientific unit of measurement for loudness

Process of Visual Perception:

- Detection - Discrimination - Identification

Major Functions of the Skin

- Maintenance of body temperature - Protection - Excretion - Synthesis of Vitamin D - Immunity - Blood Reservoir - Detection of Stimuli

Grey

Mature

White

Sacarred / Angelic

Stimulus

A quantifiable pattern of physical energy, which is able to interact with an organism and produce a change in the condition of the organism. That is, a stimulus is a type of environmental energy, like light, that we are capable of detecting and responding to

Optic Nerve

A large bundle of axons that leave the back of the eye and carries visual information to the visual cortex of the brain

Retina

A light-sensitive membrane at the back of the eye that contains the sensory receptors for vision

Difference Threshold

A method used to study the sensitivity of sensation; the smallest difference between 2 stimuli that can be correctly detected 50% of the time; this is also called the just-noticeable difference

Occlusion

A phenomenon in which an object closer to a viewer appears to block another object that is farther away from the viewer

"Where" Pathway

A visual pathway projected into the parietal lobe that integrates information about the location of an object

Intensity

Amount of a sensation dependent upon the strength of the stimulus which is influenced by 2 factors: - Total number of receptors activated - Output generated by a single receptor or a group of receptors

Top-Down Processing

An information gathering process starting from an individual's knowledge, expectations, and prior experiences.

Glare

An uncomfortable level of brightness

Monaural Cues

Auditory depth perception that occurs with just one ear.

Binaural Cues

Auditroy depth perception that occurs with the use of both ears

Somesthesis

Body sensations

Sensation

Certain, immediate, and directly qualitative experiences or produced by simple isolated physical stimuli. Sensations always travel in an ascending fashion, starting from a particular sensory receptor and terminating in the brain

Inattentional Blindness

Diverted attention resulting in failure of accurate scene detection as it we are blind to that event

Kinesthetic Sensitivity

Kinesthetic sense refers to knowledge about spatial position and movement information occurring from mechanical stimulation of mobile joints, muscles, and tendons.

Equal Loudness Contours

Lines measuring the function of loudness and frequencies of sound waves

Polymodal Nociceptors

Nociceptors activated by a variety of high-intensity mechanical, chemical, and very hot or very cold stimuli

Thermal / Mechanical Nociceptors

Nociceptors associated with sensations of sharp, stinging pain

Potential Stimuli

Physical energies that have yet to be detected, but are in fact detectable, like a distant sound.

Black

Powerful / Morbid

Perception

Psychological processes whereby meaning, past experience or memory, and judgments are used to evaluate the significance of particular stimuli

Thermoreceptors

Receptors that are sensitive to changes in temperature

Photoreceptor

Receptors that are sensitive to radiant electromagnetic energy (light)

Exteroceptors

Receptors that respond to environmental energy or stimuli that are occurring from the outside of one's body, such elements include light, sound, touch, and chemical agents

Converge

The ability of the two eyes to move, rotate inward toward the nose; this is often referred to as being cross-eyed

Interoceptors

The recpetors that are able to respond to materials inhaled, ingested, or passed, and to changes in chemical surroundings, mechanical pressure, or shearing force

Duration

The relationship between the stimulus intensity and the perceived intensity

Taste Buds

The sensory receptors for gustation that are located deep within porous structures on the tongue; there are five basis types (i.e. sweet, sour, salty, bitter, umami)

Pacinian Corpuscles

The sensory receptors for touch located under the skin; these sensory receptors respond to pressure applied to the surface of the skin

Interaural Intensity Difference

The slight difference in sound volume as it reaches one ear compared to the other

Phase Difference

The slight difference in the degree the sound wave is moving through its wave when it reaches one ear compared to the other

Interaural Time Differences

The slight difference in time sound arrives at one ear before the other

Hair Cells

Thin, hair-like structures that are the sensory receptors for audition; these are located on the basilar membrane inside the cochlea

Tactile Hallucinations

When someone feels like something or someone touched them, like being grabbed or pulled

Somatic Hallucinations

When someone feels something within their body, such as that of bugs crawling under the skin or like an object trapped in their abdomen

Auditory Hallucinations

When someone hears something that is not there, such as a voice or TV

Visual Hallucinations

When someone sees something that is not real, such as a person or creature

Olfactory Hallucinations

When someone smells something that is not there, such as smoke or coffee

Gustatory Hallucinations

When someone tastes something they did not eat, like metal or spoiled milk