Ch. 5 Sensation & Perception

Sensation

The essence of sensation is detection

Perception

The essence of perception is interpretaiton

The process that brings them together

Transduction

What does the Necker cube illustrate

your perception of an object can change even when none of the actual features of the figure change

Top-Down processing

You have knowledge based on past experiences, based on that knowledge you can make correct assumptions about the word

Bottom-Up processing

Building a complete picture from scratch using only raw sensory data, rather than prior knowledge or expectations.

Form Perception: Figure-ground

You assume that the white background holds the object and the black thing is the object, vice versa

Form Perception: Proximity

The principle that objects that are physically close to one another tend to be grouped together by the brain.

Form Perception: Similarity

If there are objects that share a similar feature, our brains interpret that they mean something

Form Perception: Continuity

The brain can perceive things that are blocked as one thing but really its two, but we can’t see because its blocked

Form Perception: Closure

brain's tendency to fill in missing visual gaps to perceive a complete, whole object.

Form Perception: Face perception

Seeing faces in objects or landscapes that aren’t really faces, Our brain superimpose a sort of face object because are brains are sensitive to faces

Form Perception: Common fate

Your brain assumes objects that are similar and move in one direction are one group. Like geese flying or schools of fish

What range of light do we see

400-700 nm

Info getting to the Retina

The eye funnels light to the retina. The light travels through the cornea, then the iris/pupil , through the lens and the vitreous humor, and finally lands on the retina.

Retina to Occipital Lobe

From the retina, the information travels down the optic nerve to the lateral geniculate nucleus (LGN). From the LGN, it is sent to the visual striate cortex in the occipital lobe, where it's processed in a way known as retinotopic organization.

Purpose of the eye

It acts as a protective house for the retina, which is actually made of brain tissue and It funnels and focuses light directly onto the retina so your brain can process the image.

What are cones responsible for

for colour vision and detail (5 million)

What are rods responsible for

Rods are active in low light, focus more on movement. (120 million)

What is the dominant sense in humans

Vision

Parts of the ear

Outer eat-pinna, Middle ear, Inner ear, auditory nerve

Place theory

we perceive different pitches based on the specific location (or place) where hair cells are activated on the basilar membrane in the inner ear.

Frequency theory

Cell firing rate produces our perception of pitch. Lower firing rate and pitch, Wide waves. Higher firing rate and pitch, Tight waves

How does the brain make sense of localizing sounds.

It uses two types of differences, interaural time differences and interaural level differences

If a tree falls in a forest and no one is around to hear it, does it make a sound

No it does not, it needs to be perceived for it to be sound.

What are papillae

The little bumps on the surface of the tongue where taste buds are

Four primary tastes (5 technically)

Sweet, sour, salty, bitter and umami

Involuntary musical imagery or ear worm

A song stuck in your head

The McGurk effect

Listeners typically lip read while listening to speech

Pain receptors: Fast

Responsible for immediate pain because the nerve axons have a lot of myelin

Pain receptors: Slow

Axons have no myelin, so conductivity is much slower

Gustav Fechner: the concept of threshold

Absolute threshold: Minimum intensity of stimuli that must occur before you experience a sensations. Detected 50% of the time

Conductive Deafness…

Caused by damage to the middle ear (which accounts for most age-related deafness) and can often be helped by hearing aids.

Sensorineural Deafness…

Caused by damage to the inner ear or the auditory nerve; cochlear implants can help with inner ear damage, but they cannot fix auditory nerve damage.

Noise-Induced Hearing Loss…

Permanent, irreparable damage to the hair cells caused by exposure to sounds that are too loud or last too long.

Just Noticeable Difference (JND)

is the smallest difference detectable between two stimuli.

Weber's Law

States that the size of the JND is proportional to the size of the initial stimuli, meaning a stronger starting stimulus requires a larger change for you to actually notice a difference.

Super tasters

An individual who experiences the sense of taste with far greater intensity than average. This heightened sensitivity is usually due to having a naturally higher density of taste buds (picky eaters)