Additional flashcards

Purity

The degree where a light source is emitting just one wavelength or a mixture of wavelengths

Cornea

Clear smooth outer tissue which bends the light wave when it first enters the eyes

Pupil

A hole in the coloured part of the eye, where the light from the cornea passes to

Iris

Translucent, doughnut shaped muscle that controls how much light enters the eye and the size of the pupil

Bipolar cells

Collect electric signals from the rods and cones and transmit them to the outermost layer of the retina 

Retinol ganglion cells (RGC)

Neurons that receive the elctric signals from bipolar cells and organize them to send it into the brain

Optic nerve

Leaves the eye through a hole in the retina, this hole creates a blind spot

Lateral geniculate nucleus (LGN)

After RGC leaves the optic nerve to go to different hemispheres, it goes to this part which is located in the thalamus of each hemisphere

Visible spectrum

Rainbow of hues and accompanying wavelengths

Colour vision deficiency/Colour blindness

When one of the three cones are missing and can’t perceive certain colours

Visual streams

Visual processing areas split into two functionally distinct pathways

Ventral stream

A visual stream that travels across the occipital lobe into the temporal lobes and include brain areas on an object’s shape and identity. Called a what pathway.

Dorsal stream

A visual stream that travels up from the occipital lobe and into the parietal lobes (including some middle and upper level temporal lobe) that distinguish where an object is and how it is moving. Called a where pathway.

Machine learning

Computer learning from large data sets to identify patterns

Conceptual knowledge

The facts and meaningful knowledge we have about a familiar object

Gestalt perception grouping rules

How humans are likely to perceptually organize things even though it could be organized in other ways. Dictated by simplicity, closure, continuity, similarity, proximity, and common fate

Reversible figure-ground relationship

Where visual system focus on one interpretation and fluctuates every few seconds. The edge that separates equally defines both figures. When seeing one interpretation, there is more activity on that specific region

Relative size

Perceive distance as a cue to how far away they are

Linear perspective

Linear lines seems to converge as they go on

Texture gradient

Textures look detailed when directly in front but uniform and smooth when away

Interposition

When one object partially blocks another

Relative height in the image

Objects closer are lower in a visual scene and higher when far away

Forced perspective illusion

When one perspective is be viewed by one point

Outer ear

Collect sound wave and funnels them toward the middle layer. Consists of auditory canal, eardrum, and flap of skin that vibrates

Middle ear

Transmits the sound vibrations to the inner ear. Air filled chamber that contains three bones. Transmits and amplifies the vibration to the inner ear

Inner ear

Where the sound is transduced to neural impulses. Contains a cochlea

Conductive hearing loss

Eardrums and ossicles are so damaged they cannot produce sound waves to the cochlea

Sensorineural hearing loss

Damage to the cochlea, the hair cells, or the auditory nerve, happens to everyone as they age

Cochlea implant

Restores hearing when hearing loss is severe

Somatosenses

Body senses are close and personal

Thermoreceptors

Nerve fibres that sense cold and warmth respond to when skin temperature changes

A-delta fibres

Axons that transmit initial sharp pain

C fibres

Axons that transmit longer-lasting, duller persistant pain

Periaqueductal grey (PAG)

Brain’s feedback to the spinal cord comes from a region in the midbrain called:_______. Under extreme conditions, endorphins activate PAG to send inhibitory signals to the neurons in the spinal cord to surpress pain

Odourant molecules

Naturally occuring odours like the smell of bread come from this

Olfactory sensitivity

Ability to detect odours

Olfactor acuity

Ability to distinguish different odours

umami

savoury like miso soup

papillae

bumps that cover the tongue

microvilli

react with tastant molecules and is on the tip of taste receptors

Experience

The ability to feel pain, pleasure, hunger, consciousness, anger, or fear

Agency

The ability for self-control, planning, memory, or thought

Intentionality

One basic property of consciousness, it is directed towards an object and always focused on something

Unity

One basic property of consciousness, the body’s senses turns everything into a unified whole

Selectivity

One basic property of consciousness, the conscious can select some things to tune out

Transience

One basic property of consciousness, there is a stream of consciousness

Locked-in syndrome

Patients have full awareness but cannot demonstrate it

Physical dependence

The pain, convulsions, hallucinations, or other unpleasant symptoms that accompany drug use

Psychological dependence

Tendency to go back to a drug even without physical dependence

Projection neurons

Has cool shapes like pyramidal cells and a long axon that projects to a different brain area like from cortex to amigdala

Tripartite synapse

Describest the spacing between the synapse which includes the axon terminal (pre-synaptic), synapse, and post-synaptic for dendrites

Blood brain barrier

When the blood can’t get into the brain as it could be fatal. Microglia looks for virus and will engulf it if found

Schwann Cell

Produce myelin for a single axon, a type of glial cell. Does this in the peripheral nervous system.

oligodendrocyte

Has branches and myelate several axons. Done at the central of the brain

Astrocytes

Wrapped around blood vessels to handle nutrition. Oxygen and blood goes through this. Wrapped around neurons and synapse, release gliotransmitters to receive signal from neurons

Chemical gradient

Chemicals want to move from a high concentration to a low concentration

Electric force

Negative ions and positive ions want to come together

Chemical force and electric force

The two forces are working against each other because potassium is trying to get out from chemical concentration, but it is trying to stay in because of the negative electrical force

Phospholipid bilayer

Two layers with a phosphate head and two lipid tails. Likes water goes out through the fat and vice versa. This means things can only go in through channels and pumps

Channels

Clear continuous passageway from one side of the cell to the other specific side of an ion. Lets K⁺ move to outside and not Na⁺

Na⁺/K⁺ pump

Let three Na⁺ out and two K⁺ pump in

Depolarization

A stimulus cause the Na⁺ to open and go in due to electrochemical gradients, making inside spike with positive charges for the action potential spike. One segment cause another segment of Na⁺ to open.

Repolarization

The channels for Na⁺ close and K⁺ to open and go back outside until inside is negative again

Hyperpolarization

The Na⁺/K⁺ pump restores ion concentrations, returning the neuron to –70 mV and ready for the next signal

Pre-central gyrus

In front of the central fissure. Contains the motor cortex and the output layers are thick and prominent

Post-central gyrus

Contains the somatosensory cortex. Part of the cortex that registers touch and pain. Layers are small for input

Dura mater

Outermost layer of the brain

Arachnoid mater

Middle layer of the brain

Pia mater

Translucent and see through

Cerebral spinal fluid

Have this all on the outside and the inside. Has nutritional support and acts as airbag of the brain, fluid slows down brain from hitting skull. Waste goes into this.

Sensation

The way in which we represent the energies of the world in our nervous systems where our sensory receptors turn into action potential 

Perception

Organization of sensory information that happens below our consciousness

Senses

Receive sensory stimulation from specialized cells

Transduction

Transform stimulation into neural impulses. Turning photons of light and vibrations to voltage and action potential

Psychophysics

Studying the relationship between physical energies and our psychological experiences, where the amount of light we receive is not what we get

Signal detection theory

how and when we will detect a faint stimulus

Individual absolute threshold

The minimum intensity of a single stimulus a specific person can detect (50% of the time)

Absolute threshold

the minimum intensity of a single stimulus a population can detect (50% of the time)

Subliminal

Stimulus that is below the absolute threshold but nervous system still receive it (we aren’t consciously aware of it)

Priming

Activates our nervous system to have us behave a certain way, can be from subliminal messaging

Difference threshold/just noticeable difference

Minimal difference between stimulus to know they are different

Weber’s Law

The just noticeable difference (JND) between two stimuli is a constant ratio of the original stimulus

Subliminal stimuli

Sensory messages or images presented below the threshold of conscious perception

Subliminal sensation

A sensory input that is processed by the brain but remains below the threshold of conscious perception. Transduced by cells but we aren’t aware of it.

Subliminal perception

The idea that subliminal stimuli could change our behavour, influence us. However, it is short-term and can’t influence us indefinitely

Sensory adaptation

We become less sensitive to constant stimulation such as not seeing blood vessels in front of eyes

Perceptual set

Predisposition to seeing some things and not other things, have an inclination to perceive the world in certain ways. Determined by schemas

Schemas

• a way in which we think of our brain organizes all information

• As we take new information, or organize it towards our existing schemas

• True for information in general

• One way to organize it is through cultural experiences

Retina

The light-sensitive layer of tissue at the back of the eye that converts light into neural signals, which are then sent to the brain via the optic nerve to be interpreted as images

Accomodation

• Muscles can pull on the lens where muscles can stretch it or relax it

• It changes the angle of light as it travels the lens

Young-helmholtz trichromatic theory

• First part of colour processing

• if we can create all perceivable colours through different combinations, the human eyes has three types of colour sensing cells

• we detect colour through these cells

• some sensitive to red, some to green, some to blue

• most mammals only have two types of cones instead of three

• human ancestors had 4 types of cones, but we lost one and other lost two

Hering’s opponent process theory

2nd part of colour processing, where brain compares the red and green signals. Color vision is processed by three opposing pairs of color receptors: red-green, blue-yellow, and black-white. That’s why some combinations aren’t perceived.

Feature detection

neurons in the brain are responding to certain features of the stimulus, some interested in the shape, some in movement, some in depth or space, some in colour

Parallel processing

the same information is being processed for different features in different brain areas

Hubel and Wiesel

• nobel prize winners that realized what these features and neurons are detecting

• the representation of the perfect image of the brain isn’t 1 to 1

• some things gets processed differently, ex central of the information

• include stuff like movement and colour

Visual information processing

Scene → retinal processing → feature detection → parallel processing → recognition

Gestalt

Human tends to see things as a whole. Ex. proximity, closure, continuity

Depth perception

The ability to see objects in three dimensions and judge their distance. It is a result of your brain combining slightly different images from each of your two eyes

The visual cliff experiment

Tests depth perception by using a glass-covered platform with a shallow and a deep side to see if infants and animals will avoid a perceived drop

Binocular cues

Two eyes improve perception of depth