Sensation and Perception
Optic nerve Occiptal lobe
Ganglion cells form a bundle, called _______, which takes information from the eye to the ________
Absolute threshold
What type of threshold is this? - The minimum amount of stimulus energy that is needed to activate a sensory system - Only sensation - NOT perception
- linear acceleration - balance - spatial orientation
What is the vestibule responsible for?
1. Cochlea 2. Vestibule 3. Semicircular canals
What makes up the inner ear?
OSSICLES: 1. Malleus (the Hammer) 2. Incus (the Anvil) 3. Stapes (the Stirrup)
What makes up the middle ear?
superior olive
What part of the ear is responsible for sound localization (where sound comes from)?
Vestibule
What portion of the ear senses linear acceleration and is responsible for balance / orientation in space?
Eustachian tube
What region of the ear helps equalize pressure between the ear and environment?
1. Pinna 2. Auditory canal 3. Tympanic membrane (aka: eardrum)
What structures of the ear make up the outer ear?
Response bias
tendency of subjects to habitually respond to a stimulus in a certain way because of non-sensory factors
Dilator pupillae
- Opens the pupil when stimulated sympathetically
Malleus
- "The Hammer" - connected to the tympanic membrane - sends vibrations to the incus
Stapes
- "The Stirrup" - Connection between the middle and inner ear - Its base connects to the cochlea on the oval window
Constrictor pupillae
- Constricts the pupil when stimulated parasympathetically
Cochlea
- Crucial for hearing - Contains Basilar membrane and Organ of Corti - Sound waves cause perilymph to vibrate - Tonotopic organization
Auditory canal
- Funnel for sound - Channels sound ways to the tympanic membrane
Adaption
- How a person detects a stimulus can change over time - Affects sensation and perception - Allows our brain to focus attention on relevant stimuli, which are typically changes in the environment
Cones
- Photoreceptor in the retina - 3 types: Blue, Green, Red - Perceive color and fine detail - Highest concentration in Fovea - Not present in optic disk
Accomodation
- Process by which the shape of the lens is changed - Facilitated by the ciliary muscles
Sensory receptors
- Neurons that respond to stimuli and trigger electrical signals - Can encode different parts of a stimulus Process: 1. Receive info from stimulus 2. Send to CNS via ganglia (outside the CNS) 3. Information is sent via neural pathways to projection areas of the brain 4. Brain further processes this information
Hair cells
- Respond to movement of fluid in the inner ear structures - Located on the organ of corti - Have stereocilia - Vibrations cause stereocilia to sway back and forth and open ion channels to create a receptor potential - Send this information down to the vestiulocochlear nerve
Semicircular canals
- Sense rotational acceleration - The ampulla contain hair cells and resist motion when our head rotates
Eardrum aka: tympanic membrane
- Sounds comes from the auditory canal to this location of the ear - Vibrates based on the frequency of sound waves
Difference threshold ("Just-noticeable difference")
- The minimum difference in magnitude between two different stimuli before the difference can be perceived - Related to Weber's law
Two-point threshold
- The minimum distance between two points being stimulated at the same time where those 2 points will be felt distinctly from each other
Sensation
- The process by which auditory, electromagnetic, physical and other information from the environment are converted into ELECTRICAL signals - Uses the process called, TRANSDUCTION - Process: A stimulus is detected in the environment, information is relayed through receptors, and sent to the CNS via action potentials and neurotransmitters
Perception
- The processing of the raw information coming from sensory stimuli
Organ of Corti
- The sensory organ on the basilar membrane that contains the auditory hair cells - When the perilymph of the cochlea vibrates, the hair cells convert physical stimuli to electrical information - This goes to the auditory (vestiulocochlear) nerve
Rods
- Type of photoreceptor - Contain rhodopsin - Allows for the perception of light and dark - Not sensitive to details - No color vision - Allow reduced illumination - increased concentration away from fovea/macula
Scerla
- most outer layer of the eye - "white of the eye" - doesnt cover the front most part of the eye
Choroid
- responsible for absorbing excess light darkly-pigmented cells - layer underneath the scerla
Retina
- the layer underneath the choroid - the region that focuses light - contains photoreceptors
Feature Detection Theory
Explains why different areas of the brain are activated when a person is looking at different things. Which theory is this?
A: Outer Ear B. Middle Ear C. Inner Ear D. Semi circular canals E. Vestibular/Auditory nerve F. Cochlea G. Eustachian tube H. Incus I. Stapes J. Tympanic membrane (Eardrum) K. Malleus L. Auditory canal M. Pinna * Note: K, I and H form the ossicles
Define each region of the ear (see image)
A) Exteroceptors B) Interoceptors
Define the following receptors: A) Receptors that respond to stimuli from the outside world B) Receptors that respond to internal sitmuli
Signal Detection Theory
Define the following: How one perceives a stimulus is influenced by characteristics of the stimulus itself AND nonsensory factors (I.e: experiences)
Photoreceptors Horizontal / Amacrine cells Bipolar cells Ganglion cells (bundles form Optic nerve) Optic chiasm Optic tract Lateral geniculate nucleus (LGN) of thalamus Visual cortex (Occipital lobe)
Describe the visual pathway once stimuli reach the photoreceptors
Right
Each eye's left visual field is projected onto _______ (right/left) half of eye's retina
Left
Each eye's right visual field is projected onto _______ (right/left) half of eye's retina
inner ear
Endolymph and perilympth are fluids seen in which parts of the ear?
Right
Fibers corresponding to the left visual field from both eyes are projected onto the ______ side of the brain.
Left
Fibers corresponding to the right visual field from both eyes are projected onto the ______ side of the brain.
base; close apex; away
High frequency vibrations are at the _____ of basilar membrane which is ______ from oval window.. Low frequency vibrations are at the ______ of basilar membrane which is ______ from oval window.
discrimination
How is just noticeable difference or threshold difference measured?
adaptation
It has been a while since Karen has eaten pizza. When she walks in her best friend's house, you smell pizza cooking in the oven. However, after spending a month at her friend's house, she notices the pizza smell less. What is this an example of: signal detection theory or adaptation?
Answer: B
Low frequency sounds cause hair cells in your ear to vibrate but you do not respond when the sound is present. What type of threshold is present? A) Difference threshold B) Absolute threhold C) Threshold of conscious perception
Threshold of conscious perception
Minimum amount of stimulus energy that is needed for a signal to be send to the CNS and perceived
Lens
Part of the eye that helps control further refraction of the incoming light
Taste receptors
Respond to dissolved compounds taste
How do perception and sensation work together?
Sensation gives us the information from the world Perception allows us to make sense of this information
Posterior chamber
Space between the iris and the lens
False Only sensed but not perceived
T/F - Any stimulus energy that is below threshold of conscious perception is sensed and perceived
False The sclera is continuous with the cornea. Underneath the sclera is the choroid
T/F - The layers of the eye are choroid and then the scerla
False There are NO rods in the fovea / macula region of the eye
T/F: There is a slight concentration of rods in the fovea, but it is mainly cones
semicircular canals rotational
The ampullae is a part of the ________ which is specifically for _______ acceleration
Iris
The colored part of the eye that contains the pupil
higher
The louder a sound is, the _______ the amplitude of the vibration of the eardrum
Threshold
The minimum amount of stimulus required to deliver a difference in perception
do temple
The optic fibers ______ (do / do not) cross paths and carry vision that is closer to the ______ (temple / nose) from each eye
pinna auricle
The outer ear is called the ______ which is also known as the _____
frequency of sound waves
The rate of vibration of the tympanic membrane depends on _________
cochlea
The scalae is part of which region in the ear?
Anterior chamber Posterior chamber
The space in front of the Iris is called _________. The space in between the iris and lens is called ________
do not nose
The temporal fibers _____ (do / do not) cross paths and carry vision that is closer to the ______ (nose / temple) from each eye
Vitreous humor
This is a transparent gel that supports the retina
Scerla
This portion of the eye is continuous with the cornea
Difference threshold
Weber's law is associated with which type of threshold?
hammer anvil stirrup
What are nicknames for the malleus, incus and stapes respectively?
Modality --- type of stimulus Location --- where stimulus comes from Intensity --- frequency of action potentials from stimulus Duration --- how long stimulus lasts
What are the four properties of sensory receptors?
- Help connect input from multiple photoreceptors for bipolar cells before they pass their information to ganglion cells - help eyes adjust between bright and dim conditions - Subtle differences - Increase our perception of visual contrasts (i.e: edge detection)
What are the roles of amacrine / horizontal cells?
rotational acceleration of head and body
What are the semicircular canals responsible for?
Bipolar cells
What cells do rods and cones synapse onto?
change in magnitude of a stimulus that will make it noticeable is a CONSTANT RATIO of the magnitude of the original stimulus
What does Weber's law state?
- Can analyze and combine information regarding color, motion and shape at once to create a cohesive image - The new information can be compared with memories
What is parallel processing?
- Normal temperature of the skin (86-97 degrees Fahrenheit)
What is physiological zero?
perceive where our bodies are in space
What is proprioception?
- Above absolute threshold but below threshold of conscious perception - Will activate sensory system to send signal to CNS but will not reach brain areas that are responsible for attention and consciousness
What is subliminal perception?
The former deals with magnitude differences of two stimuli the latter deals with required stimulus energy
What is the difference between difference threshold and absolute threshold / threshold of conscious perception?
Sensation gives us the information from our surroundings Perception is the processing of this information
What is the difference between sensation and perception?
- Explains that our bodies have the ability to "gate" pain signals turning them on and off via the spinal chord - explains why people have different pain thresholds
What is the gate theory of pain?
- helps keeps the eyes fixed on a single point in space while the head rotates - startle reflex
What is the inferior colliculus responsible for?
1. Hair cells convert vibrations to electrical info 2. Auditory nerve 3. Superior olive 4. Inferior colliculus 5. Medial Geniculate Nucleus (MGN) of thalamus 6. Auditory cortex of temporal lobe
What is the pathway for the auditory system?
Cornea
What is the pathway for visual stimuli that enter the eye? (list all the regions of the eye that a stimulus passes)
130-140 dB
What is the threshold of pain?
sensations of an extremely high or low magnitude
When are instances in which Weber's law does not work?
visual cortex
Where are feature detection neurons located?
photoreceptors
Which receptors are these? - respond to electromagnetic waves in the visible spectrum - Sight
Osmoreceptors
Which receptors do the follwing? - Respond to osmolarity of the blood - Water homeostasis
Thermoreceptors
Which receptors respond to changes in temperature and somatosensation?
Nociceptors
Which receptors respond to painful or noxious stimuli; somatosensation?
Vestibulo-ocular reflex
Which reflex involves the inferior colliculus and helps keep eyes fixed on a single point in space while head rotates?
Optic disk because it is the blindspot
Which region does not contain rods or cones, why?
Cornea
Which region of the eye does the following: Light first hits this region of the eye and refracts light
Fovea
Which region of the eye has the most clear vision?
smell
Which sense is processed in the same brain region as emotion?
Magnocellular cells
Which type of cells can: - Detect motion - Low spatial resolution - less detail of an image - High temporal resolution - work fast with moving objects
Parvocellular cells
Which type of cells can: - Detect shape - High spatial resolution - Fixed objects - Low temporal resolution - movement of objects - Can differentiate the object from its background (i.e: boundaries)
true positive
concluding there is a relationship and there is a relationship
false positive
concluding there is a relationship when in fact there is not
true negative
concluding there is no relationship and there is no relationship
false negative
concluding there is no relationship when in fact there is
Pacinian corpuscles
respond to deep pressure and vibration
Meisser cirpuscles
respond to light touch
Free nerve endings
respond to pain and temperature
Ruffini ending
respond to stretch
Olfactory receptors
respond to volatile compounds smell
Merkle discs
touch (somatosensation) respond to deep pressure and texture
