sensory/perception exam 3

what is an odorant?

a chemical compound that activates receptors in the nose to make a smell

what qualities must a molecule have to be an odorant and why do they matter?

1. volatile (able to float), if they can’t float, they could never reach the nose

2. small, if its big it can’t float well and wont reach nose

3. hydrophobic, if its not it will get stuck in muscus and wont activate receptors

step by step process of smell

• Air enters the olfactory cleft

• Odor molecules reach the olfactory epithelium

• Odor molecules bind to receptors on the OSNs

• OSNs convert the odor molecules into nerve signals

• OSN axons pass through the cribriform plate

• Signals enter the olfactory bulb

• Granule cells in the olfactory bulb fine-tune and sharpen the smell signals

what is the olfactory cleft

-narrow space at the back of the nose where air flows

-where the main olfactory epithelium is located

-this area tingles when you get water in your nose

what is olfactory epithelium

-a mucous membrane in the olfactory cleft that detects odorants

-the retina of the nose

-has three types of cells: supporting, basal, and OSN

What is Olfactory sensory neurons (OSNs)

-nerve cells the detect smells and sends signals to the brain

-main cell type in the olfactory epithelium

what is a olfactory receptor

-the region on the cilia of OSNs where odorant molecules bind

what is the cribiform plate

a bony structure with tiny holes at the level of the eyebrows that separates the nose from the brain

-axons from OSNs pass through the tiny holes to enter the brain

what is a supporting cell

-cells that help protect and support, and clean the olfactory system and keep it working

what is a granule cell

-cells in the olfactory bulb that help fine-tune smell signals and make it easier to tell smells apart

Approximately, how many smells can humans smell? How many colors can we detect?

smells: 1 trillion

colors: 7.5 million

what is smell tracking? is smell tracking only for dogs?

-using scent trails to figure our where something/someone has moved

-not only for dogs, they are better beacuse they have more OSNs and a larger part of their brain is dedicated to smell

-we can do it pretty well but we dont practice it as much as dogs do

what is anosmia

loss of smell

-two types:

generalized anosmia: no smell at all (more common)

specific anosmia: cant smell a particular smell

what are olfactory bulbs (ipsilateral or contralateral)

small rounded structures in the brain above the nose

-first brain region that processes smell info

-they receive input from OSNs and orginze that info before sending on

-work in an ipispateral way (right nostril has right olfactory bulb)

what is the structural relationship between olfaction and the limbic system? how does it realte to emotionality?

-very direct compared to other scenes

-smell signals travel directly through limbic structures

-which creates a strong connection between smells and emotions

shape-pattern theory

-lock and key system

-odorant moleucules have diff shapes

-oflactory receptors have matching binding sites

-creates a pattern, each smell is unqiue pattern

-best activation is when they are perfect match

-more prominent then vibrational theory

vibrational theory

-smell is based on frequncy of vibrations

-every molecule vibrates at a certain frequncy

-not dominant

analysis, synthesis and analysis and synthesis (mixtures)

-analysis: breaking a mixture into its indivudal parts (hearing diff instruments in a song)

-synthesis: cannot seperate parts (looking at purple you can’t seperate its parts

-analysis and synthesis: can be fused or seperte, depends on conditions

(ex. smell is mostly synthetic but can sometimes seperate sweet or smokey)

what is detection

-is something there?

-just need to know if its there or not

what is discirmmination

-are the two the same or differerent

what is recognition

-have I experinced this? do i remember this

what is idenitification

what exactly is it

SA I

slow adapting I

-fine detail, texture, shape

-ex. feeling braile

FA I

fast adapting I

motion across skin, slip

-ex. thread slipping through fingers

SA II

slow adapting II

finger position, putting glove on and the pressure

-ex. chinese finger trap

FA II

-fast adapting II

-vibration

ex. vibrating phone

what is proprioception? what sense does is continously integrate itself with

-proprioception: a body sense where your body tells you where your body parts are moving without needing to look

-integrated with vision, helps confirm proproception, without it we are less accurate and run into things

What is thermoception? Which modality of thermoception acts faster?

thermoception: sense of temp

-cold receptors act faster

what is nocipcetion? What are A-delta fibers? C fibers? What are the unique perceptual implications associated with each fiber type?

-nociception: detetcs harm or damage, so pain

-A-delta fibers: myelinated fibers, fast responding, sharp localized pain

stepping on something and feeling sharp pain fast

-C fibers: unmyelinated, slow, throbbing pain

throbbing after initial pain

What is interoception? Be ready to provide an example of when you would expect to feel interoceptive feedback

-interoception: sense from internal state

hunger, feeling your stomach growl when you are hungery

What is somatotopical mapping? How is it related to this guy?

-somatotopical mapping: the brain’s way of organizing what part of the body gets more space and sensitivity

-The guy shows the bigger areas have more part of the brain for it so its more sensitive

What is the body schema? What is peripersonal space? In what ways can these entities be flexibly changed?

body schema: where your body is in space and how they are inteacting with the environment

-peripersonal space: near body space, extensions can be added

-Both can be changed by adding a tool to use to grab things

McGurk effect

-when you see lip movments and hear something else your brain creates a third perception that is completely different

ex. hear ba, see ga, perceove da

Cross-modal congruency effect

-reaction time is faster when info from diff senses match

-ex. seeing a ibject on the right then feeling touch on right resond is faster

double flash illusion

-a single flash with two deeps is perceived as two flashes

vection

the illusion of self motion when you are actually still

-sitting in a still train and watching a moving one makes you feel like your moving

ventriloquism

-hear sound and see mouth moving on puppet, brain thinks its coming from it