Sensation and Perception Flashcards
What 3 things need to happen in order to feel sensations?
1: Detection
2: Transduction (translated to a message for the brain to understand)
3: Transmission (message must be sent to brain for analysis)
What do sensory receptors do?
They respond to stimulation and energy from the world.
What is bottom-up processing?
Our senses collect raw data from the external world. With the sensation, we start from scratch and we build up.
What is psychophysics?
The scientific study of the link between the characteristics of the physical world, and our psychological experiences of them.
Define ‘absolute threshold’.
The minimum amount of energy/stimulation that must be there in order for us to detect it 50% of the time.
Define ‘difference threshold’.
Not enough for us to detect an energy; it’s essential for survival that we can detect changes in stimulation. It is the minimum amount of changes in stimulation that must take place in order for us to detect it 50% of the time.
Signal detection theory is the theory that…
…our ability to detect stimulation/energy does not depend ONLY on how strong the stimulation is but also external factors like motivation, emotion, health, fatigue, etc.
What is the definition of perception?
The meaning of what you’re looking at.
More info: The brain is going to interpret information in a meaningful way. That means the brain is going to use its existing knowledge, past experiences, beliefs, assumptions, expectations, etc, in order to interpret the information
What is prosopagnosia?
People that see properly but can’t remember faces, sometimes even their own.
Prosopagnosia is an example of…
…having a sensation but no perception.
What are two examples of having perception but no sensation?
Hallucinations and being on drugs.
In order for us to see, there must be _____.
Light.
Light is a form of _____________ __________, which travels in the form of a wave.
Electromagnetic radiation.
Humans can only detect ___ to ___ Nanometers (nm).
400 to 700
Which 2 physical characteristics of the light wave that are of interest to us?
Wavelengths and hue.
What is a wavelength?
A wavelength is a physical characteristic that is going to translate into the psychological experience of colour or hue.
example: https://youtu.be/dQw4w9WgXcQ?si=mXN5_Q0xjTArGI_B
In order for us to see, light must enter the eye and it must reach the _______.
Retina.
Where is the retina located?
The back of the eye.
What are the sensory receptors of the eye?
Rods & Cones
Bipolar cells are connected to ________ cells.
Ganglion.
The axons of the ganglion cells are going to bunch up together, and they form ___ _______ ________.
The optic nerve.
What does the optic nerve do?
It leaves the eye to transmit the information to the brain.
What is the blind spot?
This is where the optic nerve leaves the eye.
What does the fovea do?
It allows us to see fine details.
What are photoreceptors?
They are the ones that detect the light, transduce it, and transmit the information to the brain.
Where does the process of visual information begin?
The retina.
Where does the processing of visual information begin?
Bipolar cells.
What does the parietal lobe do?
It let us knows where an object is in space, is it moving or not.
What are temporal lobes?
Temporal lobes are known as the “what” pathway, and they are known as the ventral stream.
What does the limbic system control?
It controls emotional reactions.
According to the trichromatic theory, because we can see 3 light colors (R, G, B), we should have…
…3 cones (light receptors).
Based on the trichromatic theory, the brain will perceive the color we see based on…
…which of the 3 cones activate.
What did Hering find out about the trichromatic theory?
Hering found that the trichromatic theory was valuable. However, trichromatic theory can’t explain complimentary afterimages (seeing an image even after it disappears).
What are complementary afterimages?
Perceiving an object, even though we aren’t looking at it anymore, even though there is no stimulation coming from it.
Stare at blue for 30+ seconds. After looking at a white screen, we will see…
Yellow.
The same applies backwards (look at yellow for 30+ sec then a white screen and you’ll see blue).
Stare at green for 30+ seconds. After looking at a white screen, we will see…
Red.
The same applies backwards (look at red for 30+ sec then a white screen and you’ll see green).
The antagonizing color system (Opponent-Process theory) proposes that we have…
4 primary colors - Red, Green, Blue, Yellow
According to the antagonizing color system, this suggests we have 3 antagonistic color systems:
Red - Green
Blue - Yellow
Black - White
What is a gestalt?
A gestalt is a form; a meaningful whole. When we look at something or someone, we see a gestalt.
The ‘whole’ of a gestalt may exceed the sum of its parts, an example is…
(I know this is confusing and I’m sorry, you’ll grasp the idea and the answer with repetition)
A painting on the surface is just a canvas and paint. However, the whole will understand that the painting has meaning.
What is the perceiving brain?
It does not process information as it is. Rather, the perceiving brain is going to use its knowledge, experiences, beliefs, expectations, assumptions, etc. in order to meaningfully interpret sensory information.
In order for us to hear, there must be __________.
Stimulation.
What is a sound wave?
Stimulation for a person to hear
The sound waves have 3 different physical characteristics that are of interest:
1: Frequency
2: Amplitude
3: Complexity
What is frequency?
The pitch of a sound. (Measured in Hz)
What is amplitude?
The loudness of a sound. (Measured in decibels)
What is complexity?
The uniqueness of a sound.
What does the pinna do?
The pinna captures and funnels the sound waves into the auditory canal.
What does the auditory canal do?
It provides a passage of sound waves to the ear drum.
What do the ossicles do?
The vibration of the ossicles will cause the oval window to vibrate.
What is the oval window?
The oval window is a membrane in the ear.
What does the cochlear fluid do?
The vibration from the oval window is going to cause the fluid in the cochlea to move in waves. These waves make the basilar membrane vibrate.
What does the vibrations of the basilar membrane do?
It allows for hair cells, which are the sensory receptors in our ears, to receive the sound wave and perceive sound.
What does the auditory nerve do?
The auditory nerve will carry the information to the brain.
What 2 theories help us understand how we perceive pitch?
1: Place theory
2: Frequency theory
What is place theory?
Sound waves of different frequencies will activate different areas of the basilar membrane. They activate hair cells located in different parts of the basilar membrane.
HF (high frequency) sound waves: Activate hair cells that are located at the BEGINNING of the basilar membrane.
LF (low frequency) sound waves: Activate hair cells that are located at the END of the basilar membrane.
Based on the location of firing, the brain will determine if the sound wave is high or low pitch.
What is frequency theory?
The soundwave of different frequencies will influence and affect the rate of firing.
Every 1 Hz will cause 1 action potential
What are cutaneous senses?
through our skin we can feel more than just touch. (temperature, weight, dry/wet)
A variety of __________ pick up different sensations.
Receptors.
What does the merkel receptor do?
Feels pressure for as long as there is pressure.
What does the meissner receptor do?
Feels changes in pressure. (When pressure is applied and taken off)
What does the Ruffini cylinder do?
Feels stretching of the skin.
what does the Pacinian corpuscle do?
Feels vibration.
What are nociceptors?
Pain receptors. Send all info about pain.
What is the complexity of pain?
Pain does not depend only on tissue damage. It also affects emotions, motivation, culture.
What is the neurological gate affiliated with?
The state of the gate is linked with the experience of pain.
What does S-fibre do?
Transmits pain information throughout the body.
Neurological gate will be open therefore you’ll likely feel pain.
What does L-fibre do?
Transmits non pain-related information throughout the body.
Neurological gate will be closed therefore you’ll feel little to no pain.
T-cells must be…
…activated for neurological gate to open.
What can affect our perception of pain?
Stimulation of certain areas of the brain.
Our beliefs.
Stress.
Emotions.
Self-confidence.
Culture.
Where does stimulation from smell come from?
Odor molecules.
