Unit 4 Sensation + Perception

Sensation

Sensory neurons detecting something in the environment.

Perception

Interpreting sensory information.

Top-down processing

Quick analysis of new information, relies on what we already know or expect.

Bottom-up processing

Slow analysis of new/different information, relying on sensory neurons.

Selective attention

Focusing on important stimuli while ignoring the irrelevant (un/conscious processing).

Cocktail party effect

Ability to detect your own name being spoken in a conversation you are not involved in.

Inattentional blindness

Failing to see visible objects when our attention is directed elsewhere.

Change blindness

Failing to notice "irrelevant" changes in the environment.

Pop-out

Something that immediately gets our attention.

Transduction

Converting sensory energy into neural impulses.

Figure-ground

Organizing the visual field into objects (figures) that stand out from their surroundings (background).

Gestalt

Our tendency to integrate "pieces" of information into meaningful "whole things."

Proximity

Grouping nearby, similar stimuli together.

Continuity

Seeing smooth patterns.

Closure

Fill in the gaps/missing information.

Depth perception (binocular + monocular cues)

Judging distance between two objects.

Binocular cues

Judging depth of nearby objects, requires 2 eyes.

Retinal disparity

By comparing images from the retinas in two eyes, the brain computes distance/depth.

Monocular cues

Judging the depth when objects are far away, or on a flat 2-dimensional surface- requires l eye only.

Relative clarity

Less clear objects seem further away.

Relative size

Smaller objects seem farther away.

Interposition

If one object blocks another, it seems closer.

Linear perspective

Sharper the angle of convergence, the greater the perceived distance.

Texture gradient

Closer objects look coarser and more distinct; they get less distinct with distance.

Rods

Photoreceptors in the retina that detect black, white, and gray; necessary for peripheral vision and seeing in dim lighting.

Cones

Photoreceptors in the retina that detect colors and fine details, function best in bright lighting, concentrated near the center of the retina.

Fovea

Central focusing point on the retina, where cones cluster.

Optic nerve

Bundles of axons that carry neural impulses from the eye to the brain.

Blind spot

Point at which the optic nerve (axons) leaves the eye, creating a "blind" spot.

Ganglion cells

Cells that actually form the optic nerve.

Trichromatic (color) theory

Retina contains 3 different color receptors: red cones (long wavelengths), green cones (medium wavelengths), and blue cones (short wavelengths).

Color blindness

One or more cones are missing or not working.

Opponent-process theory

We have 3 sets of opposing ganglion cells that enable color vision: red-green, blue-yellow, black-white.

Afterimage (explained by opponent-process theory)

Cells responding to 1 color of the pairing, but turning off the other color.

Schema

"Concepts" that we have in our minds (bins of information). Mental structures that allow us to make sense of new/unfamiliar information.

Cornea

Transparent outer layer of the eye that protects it.

Pupil

Adjustable opening in the eye where light passes through.

Iris

Colored muscle in the eye that controls the dilation and constriction of the pupil.

Lens

Changes shape and focuses the image onto the retina.

Accommodation

Changing shape of the lens to focus; if this process is altered, nearsightedness or farsightedness can result.

Retina

Surface of the back of the eye that contains photoreceptors ("sensory neurons" called rods and cones). Converts light waves into neural impulses.

Absolute threshold

Point at which you can detect a stimulus 50% of the time.

Signal detection theory

Ability to detect the presence of faint stimuli amid background stimulation. People will respond differently to the same stimuli.

Subliminal

When we can't detect a stimulus 50% of the time - below the absolute threshold.

Priming

Activation of certain associations that impacts our perceptions.

Difference threshold

Point at which you can tell that a stimulus has changed (AKA just noticeable difference - JND).

Weber's law

Describes how people perceive changes in stimuli - the difference is a constant percentage (but the % varies depending on the stimulus).

Sensory adaptation

Reduced sensitivity to a stimulus because of constant exposure to it. Important stimuli in our environment

Perceptual set

Cognitive bias that affects our perceptions - expectations (top-down processing) - can explain why people "perceive" things differently.

Wavelength

Tells us the hue/color of light.

Amplitude

Wave's amplitude/height - tells us the intensities/brightness of the light (different shades of color).

What is the Phi phenomenon?

An illusion of movement from stationary objects.

What is perceptual constancy?

Perceiving that familiar objects are not changing even though the image cast on our retina changes, maintaining consistent shapes, size, lightness, and color.

What is the critical period for vision?

A period during infancy where visual pathways must be used for normal vision development.

What does wavelength determine in sound waves?

The pitch/quality of sound.

What does amplitude determine in sound waves?

The loudness of sound.

What is the function of the outer ear?

Channels the sound waves into the ear.

Where are olfactory receptors located?

Receptor cells in the nose that detect smells.

What are pheromones?

Odors our bodies produce that trigger social responses.

What is sensory interaction?

When one sense affects another.

What is the McGurk effect?

What we see overrides what we hear.

What is synesthesia?

Experiencing one sense through another sense, such as hearing letters as colors.

Name three ethical guidelines applied in psychological research.

Protect from harm and discomfort, maintain confidentiality, and debriefing

What is kinesthesia?

Sense of how to move your body.

What is proprioception?

Awareness of your body parts and position.

What is the vestibular sense?

Sense of balance and head position; uses fluid in semicircular canals in the ears.

What are the four skin receptors?

Pressure, warmth, cold, and pain.

What are nociceptors?

Receptors that detect harmful stimuli.

What is the gate-control theory of pain?

Spinal cord contains a gate that can close to stop pain signals from getting to the brain.

What is phantom limb syndrome?

Pain in a missing limb.

What are the six basic tastes?

Sweet, sour, salty, bitter, umami (savory) + oleogustus.

What is the function of the middle ear?

Contains 3 tiny bones that amplify the vibration of air and passes the sound onto the cochlea.

What structures are located in the inner ear?

Contains the cochlea and vestibular sacs.

What is the cochlea?

A fluid-filled tube containing a basilar membrane with tiny hair cells that move, triggering neural impulses (transduction).

What is conduction hearing loss?

Damage to the bones that conducts sound waves to the cochlea.

What is sensorineural hearing loss?

Damage to the cochlea's receptor cells; also called nerve deafness, caused by heredity, aging, or listening to very loud sounds.

What does a cochlear implant do?

Converts sounds into electrical signals and conveys them to the brain.

What is the place theory of pitch perception?

Pitch is determined by the place in the cochlea where the hair cells are being stimulated.

What is the frequency theory of pitch perception?

Pitch is determined by the rate of nerve impulses; pitch matches the frequency of a tone.