Sensation and Perception - Chapter 3

Occiptal lobe

The part our brain responsible for processing the visual information.

Eardrum

The thin membrane at the end of the ear canal that vibrates at a specific frequency when bombarded by sound waves.

Nociceptors

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

Photoreceptor

A type of sensory receptor specifically for vision, which is located on the retina at the back of the eye.

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.

Fovea

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

Attention

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

Somethesis

Bodily sensations.

Polymodal nociceptors

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

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 and lipid soluble chemicals.

Sensory adaption

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 ___ ___ 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.

"where" pathway

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

"what" pathway

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

Cutaneous sensitivity

Also called skin sense. This refers to touch, pressure, temperature, and pain (nociception).

Amplitude

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

Cornea

The surface of the eye.

Sound shadow

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

Dual or 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 of the sharpness of an image.

Olfactory hallucinations

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

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. This is a type of environmental energy, like light, that we are capable of detecting and responding to.

Ocular lubrication

Our visual system is able to make its own surface liquid which 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 motion of solids, liquids, and gases. Mechanical forces are those that tend to deform or accelerate objects possessing mass.

Wavelength

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

Cillary muscles

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

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.

Retina

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

Gustatory hallucinations

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

Interaural time differences

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

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.

Absolute threshold

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

Difference threshold

A method used to study the sensitivity of sensation; the smallest difference between two 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 viewer appears to block another object that is farther away from the viewer.

Pixilation

A physical measure of resolution on a screen.

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.

Top-down processing

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

Bottom-up processing

An information-gathering process starting from each individual stimulus.

Glare

An uncomfortable level of brightness.

Monaural cues

Auditory depth perception that occurs with just one ear.

Binaural cues

Auditory depth perception that occurs with the use of both ears.

Inattentional blindness

Diverted attention resulting in failure of accurate sense detection as if we are blind to that event.

Equal loudness countours

Lines measuring the function of loudness and frequencies of sound waves.

Thermal or mechanical nociceptors

Nociceptors associated with sensations of sharp, stinging pain.

Thermoreceptors

Receptors that are sensitive to changes in temperature.

Photoreceptors

Receptors that are sensitive to radiant electromagnetic energy (light).

Exteroceptors

Receptors that respond to environmental energy or stimuli that are occuring 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.

Doppler shift

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

Perception

The detailed process of interpreting and making sense of a combination of sensations.

Sensation

The detection of physical stimuli in the environment such as light waves, sound waves, pressure, or chemical molecules.

Transduction

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

Decibel

The scientific unit of measurement for loudness.

Taste buds

The sensory receptors for gustation that are located deep within porous structures on the tongue; there are five basic types of taste buds.

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 at 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.

Potential stimuli

These are physical energies that have yet to be detected, but are in fact detectable, like a distant sound. Therefore, if the physical energy from the environment does not cause a change in the organism, it would not be considered as a stimulus. For example, certain animals can detect ultraviolet (UV) light, magnetic energy, or very high-pitch sounds, while humans can't, so such patterns of energy would not be stimuli to humans.

Proprioceptors

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

Nonsensory factors

These can affect the observer's performance in a signal/sensory detection task. 1. Motivation 2. Attention 3. Experience 4. Fatigue 5. Expectation

Interoceptors

These receptors that are able to respond to materials inhaled, ingested, or passed, and to changes in chemical surroundings, chemical pressure or shearing force.

Perceptions

These refer to the psychological processes whereby meaning, past experience or memory, and judgments are used to evaluate the significance of particular stimuli. For example, how is it that we are able to, in a crowded and loud room, attend to our name being said but not to other names? Obviously, our names have greater significance and history than other names. In addition, these are associated with the organization and integration of sensory attributes. For example, flavor is a ______ and is the culmination of taste, smell, and texture.

Hair cells

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

Kinesthetic sensitivity

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

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.