Unit 1 part 2 sensation

sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Bottom up processing

"Details to Big Picture" is a way our brain makes sense of information by starting with the small details and then building up to a complete perception.

Top down processing

"Big Picture to Details" involves interpreting sensory information based on the larger context, prior knowledge, and expectations.

Selective attention

the process of focusing on a specific aspect of information while ignoring others. 

Intentional blindness

an individual fails to notice an unexpected stimulus in their visual field when their attention is focused on something else. 

Cocktail party effect

our ability to focus on a single conversation in a noisy environment, like a crowded party, while tuning out other stimuli.

change blindness

the failure to notice large changes in one's environment when the change occurs simultaneously with a visual disruption.

transduction

The conversion of sensory stimuli into neural impulses that can be understood by the brain.

Absolute threshold

The minimum amount of stimulation required for a stimulus to be detected by a sensory system. It represents the point at which a stimulus becomes noticeable to an individual at least 50% of the time.

Just notable difference

 The smallest change in a stimulus that can be detected by an individual. It's the minimal difference needed for a person to perceive that a change has occurred. 

Webers law

The perceived difference in a stimulus must be proportional to the original intensity of the stimulus

Signal detection theory

A theory predicting how and when we detect the presence of a faint stimulus amid background noise. 

Assumes there is no single absolute threshold and that detection depends partly on a person’s experiences, expectations, motivation and alertness.

Sensory adaptation

The process by which sensory receptors become less responsive to constant stimuli over time.

transduction occuring process

in the eye occurs in the retina, convert light into electrical signals that can be processed by the brain.

retina

The light-sensitive inner surface of the eye containing photoreceptor cells that convert light into neural signals. 

lens

Transparent structure in the eye that focuses light onto the retina. It adjusts its shape to help the eye properly refract light, enabling clear vision at different distances.

Accomodation

The process by which the lens of the eye changes its shape to focus on objects at different distances. It allows for clear vision of both nearby and distant objects by adjusting the curvature of the lens.

Rods

Photoreceptor cells in the retina responsible for vision in low light conditions and detecting motion. They provide black-and-white vision and are highly sensitive to light, allowing us to see in dim environments.

cones

Photoreceptor cells in the retina responsible for color vision and detail in bright light. They enable us to perceive colors and fine visual details, such as reading text or distinguishing between different hues.

fovea

Central area of the retina responsible for sharp central vision. It contains a high concentration of cone cells (no rods), enabling detailed and color vision. 

Blind spot

Area on the retina where the optic nerve exits the eye, lacking photoreceptor cells. It's a spot where vision is absent, as there are no light-sensitive cells to detect visual stimuli.

Ganglion cells

Neurons in the retina that receive visual information from bipolar cells and transmit it to the brain via the optic nerve. They play a crucial role in processing visual signals and relaying them to the brain for further interpretation.

nearsightedness

A common vision condition where close objects appear clear, but distant objects appear blurry. It occurs when the eyeball is too long or the cornea is too curved, causing light to focus in front of the retina instead of on it.

farsightedness

A vision condition where distant objects are seen more clearly than close ones. It happens when the eyeball is too short or the cornea is too flat, causing light to focus behind the retina rather than directly on it.

trichromatic theory

A theory proposing that color vision is based on three types of cone receptors, each sensitive to different wavelengths of light (red, green, and blue). The brain combines signals from these cones to create the perception of a wide range of colors.

opponent-process theory

A theory proposing that color vision is based on pairs of opposing color processes (red-green, blue-yellow, and black-white). 

afterimages

Visual sensations that persist after a stimulus is removed. They occur due to temporary overstimulation of cone cells in the retina, resulting in a brief perception of an inverted or complementary image.

dichromatism

A type of color vision deficiency where an individual has only two types of functioning cone cells instead of the normal three. This condition typically results in difficulty distinguishing between certain colors, especially reds and greens. 

monochromization

A rare form of color blindness where an individual has only one type of functioning cone cell, or none at all. This results in the inability to perceive colors, seeing the world in shades of gray.

blindsight

A phenomenon where individuals with damage to their visual cortex can respond to visual stimuli without consciously perceiving them. It suggests that some visual processing can occur unconsciously, bypassing traditional pathways in the brain.

Prosopagosia

A neurological condition characterized by the inability to recognize familiar faces, including one's own face, despite intact vision and intellect. It's often referred to as face blindness.

Viewing the World through different eyes

create simple art pieces that represent the world through the eyes of someone with prosopagnosia or blindsight.

wavelength

The distance between sound wave peaks. Shorter wavelengths mean higher-pitched sounds, while longer wavelengths mean lower-pitched sounds.

amplitude

The measure of the intensity or loudness of a sound wave, represented by the height of its peaks. Greater amplitude corresponds to louder sounds, while lower amplitude indicates softer sounds.

Pitch perception

The brain's interpretation of the frequency of sound waves, determining whether a sound is high or low in tone. Higher frequencies are perceived as higher pitches, while lower frequencies are perceived as lower pitches.

place theory

Idea that different parts of the inner ear detect different sound frequencies. High pitches are sensed near the entrance, low pitches near the end.

synesthesia

neurological phenomenon where stimulating one sensory or cognitive pathway causes involuntary, automatic experiences in a completely separate pathway

wavelength

the distance between sound waves peaks. Shorter mean higher pitched sounds, while longer mean lower pitched sounds

amplitude

The measure of the intensity or loudness of a sound wave, represented by the height of its peaks.

pinna

outer ear

pitch perception

The brain's interpretation of the frequency of sound waves, determining whether a sound is high or low in tone.

place theory

 Idea that different parts of the inner ear detect different sound frequencies.

ear canal

A short tube lined with hairs and wax glands that carries sound waves from the auricle to the eardrum.

eardrum

A thin, dime-sized membrane that vibrates when sound waves hit it, separating the outer ear from the middle ear

cochela

A snail-shaped, fluid-filled chamber containing microscopic hair cells that convert mechanical sound vibrations into electrical nerve impulses.

frequency theory

A theory of pitch perception proposing that the frequency of a sound wave directly corresponds to the rate at which auditory nerve fibers fire.

volley theory

a theory of pitch perception proposing that groups of auditory neurons fire in rapid succession to encode the frequency of sounds above 1000Hz (allows brain to perceive pitches that exceed firing rate)

Sound localization

Brains ability to determine the location of a sound source in space.

conduction deafness

hearing impairment caused by problems with the outer or middle ear (ear canal, ear drum, middle ear bones). Results in difficulty hearing soft sounds

sensorineural deafness

Damage to the inner ear or auditory nerve; results in difficulty hearing soft sounds and understanding speech (often permanent)

sensory interaction

principle that one sense can influence another

McGurk effect

when visual and auditory information clash, we end up perceiving a totally different sound from what we actually hear

thalamus

smell is the only sense that bypasses the

olfactory nerve

Responsible for smell. Special receptors in the nose detect smells and send signals to the brain via the olfactory nerve. The thalamus helps process this information, allowing us to identify different odors.

pheromones

Chemical substances released by animals, including humans, that trigger social or behavioral responses in others of the same species.

gustation

The sense of taste, involving receptors on the tongue that detect different flavors.

warm/cold receptors

 Specialized sensory neurons in the skin that detect changes in temperature.

nociceptors

pain receptors; they detect harmful levels of pressure, temperatures, or substances

Gate control theory

a neural "gate" in the spinal cord's dorsal horn regulates whether pain signals are allowed to reach the brain or are blocked

phantom limb

Sensation of pain or other feelings in a missing limb. It occurs due to the brain's continued perception of the limb, even though it's no longer there.

vestibular sense

your body's balance and spatial orientation system, originating in the inner ear to detect head movement, gravity, and acceleration

circular canals

Fluid-filled structures in the inner ear that detect rotational movements of the head. Helps with rotational movements of the head; helps vestibular sense

kinesthesis

The sense of body movement and position, including the awareness of muscle and joint sensations. When your foot falls asleep that represents a disruption in this sense

Synesthesia

A condition in which stimulation of one sensory pathway leads to automatic involuntary experiences in another sensory pathway

perceptual set

a tendency to perceive or notice some aspects of the available sensory data and ignore others

• influence by expectations, experiences, and context

gestalt psychology

we perceive whole objects or figures, rather than just a collection of parts

figure-ground

refers to the ability to distinguish an object from its surroundings

• involves brains organization of sensory information, highlighting important stimuli while filtering others

The visual cliff

famous psychological apparatus developed in 1960 by psychologists Eleanor Gibson and Richard Walk at Cornell University to study depth perception and fear of heights in human infants and animals

monocular depth cues

visual indicators of distance and space that can be perceived using just one eye

relative clarity

a depth cue where objects that are clearer and more detailed are perceived as closer, while objects that are hazier or less clear seem further away

• helps use gauge distance and depth

relative size

visual cue where objects closer to use appear larger, while objects further appear smaller

texture gradient

the way we perceive texture to become denser and finer as it recedes into the distance

linear perspective

a depth cue where parallel lines appear to converge as they recede into the distance

interposition

when one object overlaps another, leading us to perceive the overlapping object as closer

binocular depth cues

visual information that requires both eyes to percive depth and distance

retinal disparity

when each eye sees a slightly difference picture because of their separate position on our face

convergence

when our eyes move inwards toward each other to focus on a close object

Perceptual Constancies

our brain ability to see object as unchanging even when the image on our retina (ike size shape color) changes

Shape constancy

our ability to perceive an object as having the same shape, even when our angle of view or the distance from which we see the object changes.

size constancy

our perception that an object remains the same size, even when its distance from us changes, causing the image on our retina to grow or shrink

color constancy

ability to perceive colors of objects as stable under varying lighting conditions

apparent movement

the perception of motion when there isn’t any actual movement

perceptual adaptation

refers to our ability to adjust when we are constantly exposed to altered sensory information