Sensation and Perception Flashcards
what is sensation?
the act of using using our sensory systems to detect environmental stimuli
what is perception?
recognizing and identifying sensory stimulus
Vision raw sensory data is in the form of…
light waves
hearing raw sensory data is in the form of…
sound waves
smell raw sensory data is in the form of…
airborne chemicals
taste raw sensory data is in the form of…
food chemicals
touch raw sensory data is in the form of…
pressure
What two factors help the transformation of physical stimuli into perception?
sensory receptor cells and sensory transduction
What is the specialized cell that converts a specific form of environmental stimuli into neural impulses?
sensory receptor cell
explain sensory transduction
the process of converting a specific form of sensory data into a neural implies that our brain can read
Different sense have different…
receptor cells
Absolute threshold is the …. amount of a stimulus that one can detect
smallest
Difference in threshold is measured by
JND
What is JND
the minimal difference needed to notice a difference between two stimuli
Different JND depends on the…
strength of the original stimulus
What is sensory adaptation?
contant stimulation decreases the number of sensory messages sent to the brain, which causes decreased sensation
what does sensory adaptation allow?
allows us to focus on important stimuli in our environment
sensation and perception occur together but through different…
processes
What are the two different processes of sensation and perception?
bottom top processing and top down processing
When raw sensory data is transduced, sent to the brain and your brain uses all of the data to build a perception and the neural signals move up to more complex brain regions to start putting together the perception is…..
bottom-up processing
what is top-down processing
it is led by cognitive processes where you use previously learned information to help recognize and interpret the data coming into your brain
What is perceptual set?
the readiness to interpret a certain stimulus in a certain way, expecting to see a specific object, you are more likely to interpret it in that way
perceptual set can affect…
all senses
perception involves both bottom-up process (……) and top-down processes (………)
Neural signals to perception, interpretation based on cognitive processes
When we smell, chemicals are also known as
odorants
Odorants stimulate the 5 million receptor neurons at the top of each
nasal cavity
the …. send a neural impulse (…..) to the smell centre of the brain, also known as the …..
receptor cells, transduction, olfactory bulb
bumps of the tongue are called
papillae
chemical substances in food dissolve in saliva and fall where on the tongue?
between the papillae
papillae holds …
receptor cells
each taste bud contains .. to .. sensory receptor cells for taste
60-100
The taste buds translate the chemical message into a neural impulse, which gets sent to the … and eventually the ….
thalamus - cerebral cortex
what are the 5 different taste receptors?
sweet, sour, bitter, salt, umami
what is umami
the taste of monosodium glutamate (MSG) - such as meat or tomatoes
eating involves multiple senses including
taste and smell, tactile (touch) and olfactory and gustatory receptors
olfactory and gustatory receptors are unique in that they
regenerate if damaged
Explain the two paths of smell
Smell goes to the olfactory bulb which can go to the piriform cortex for experience that effects learning/recognition and memory, or smell can go from the olfactory bulb to the amygdala for emotion, the to hippocampus
Explain the path of taste
taste goes to the thalamus that combines sensory information, it is then integrated with reward circuits
The somatosensory cortex is found where and processes what?
found in the parietal lobe, it processes information about texture, temperature and pain from the tongue
Smell is well developed from
birth
new borns recognize motherly scents such as these 3
amniotic fluid, milk, and mother in general
taste is well formed at birth because…
innate preference for sweet tastes, age 7 develop preference for sour tastes and learning as a whole helps development
Taste changes also occur in the … system because
gustatory system because there are more taste buds as children than as adults. - picky eating?
2 reasons our smell and taste differ
sensitivities change, gender difference as females are more sensitive than males (ovulation, after menopause), types of tasters
What are the 3 types of tasters
non taster, medium taster and super tasters - all respond differently to bitter substances
What makes a super taster?
different concentration in taste buds
after age 50, # of … decline while after age 60, …. decline
tastebuds, sense of smell - decline in interest of foods
What is anosmia?
inability to smell - head trauma
What is ageusia?
the inability to taste - head trauma
What is reflect epilepsy
a seizure occurs only after exposure to a specific odour
what is an aura
false perceptions that precede a seizure or migraine are different than reflect epilepsy
What are migraine headaches
specific odours can trigger migraines
The tactile or somatosensory system is a combination of skin senses:
pressure, touch, temperature, vibration, pain
the tactile senses rely on a variety of receptors located in different parts of the skin. There are different receptors for…
pain/temperature than for fine touch/pressure
Free nerve endings are for
pain and temperature
what receptors are located near the surface fo the skin
free nerve endings
Why are free nerve endings called free?
because the are not specialized like other cells
Which receptor is more simpler in structure?
free nerve endings
free nerve endings convert..
physical stimuli into touch, temperature or pain
What is Meissner’s corpuscles?
located in the fingertips, lips, and palms. They function to trandsduce information
What are Merkel’s Discs?
Located near the surface of the skin and function to transduce information about light to moderate pressure against the skin
What are Ruffini’s end organs
Located deep in the skin and function to register heavy pressure and movement of the joints
What are Pacinian Corpuscles
located deep in the skin and function to respond to vibrations and heavy pressure
What are the 3 steps to perceiving touch
sensory neons register pressure, sends message to spinal cord, then thalamus. Information is then sent to somatosensory cortex that registers the sensation
Tactile information is processed contra laterally, meaning
opposite side of brain
What are the two pathways of pain?
Fast pathway (myelinated) and slow burn (unmyelinated)
Sharp, localized pain is felt quicker because it travels along myelinated neurons to the brain is what kind of pathway?
fast pathway
nagging, burning pain is slower to be felt because it travels along unmyelinated pathways is called what kind of pathway
slow burn
pain systems show
adaptation
Fetuses respond to touch when?
early in prenatal development
response to different tactile stimuli occurs after…
further development and learning in the brain
2 reasons why we feel or not feel pain?
people differ in what tactile stimuli they find painful or pleasurable, and differences in brain activation may cause different responses to pain
What is pain threshold?
at what point we feel pain and how intensely we feel it
Who has lower pain threshold? Men or women?
women - twice as many receptors
What is Gate Control Theory
patterns of neural activity can close a “gate” that prevents messages from reaching parts of the brain where they are perceived as pain - based on neural chemicals
….. pain is the most common abnormality associated with the somatosensory system
chronic
… and … are naturally occurring pain killing chemicals in the brain
endorphins and enkephalins
endorphins and enkephalins can be found in opiates such as
morphine or heroine
endorphins and enkephalins are produced naturally through
intense physical activity, sex or intense stress
What i cingulotomy?
destruction of the cingulate cortex - an extreme form of neurosurgery to relieve chronic pain
What is Familial Dysautonomia
rare genetic condition associated with an inability to detect pain or temperature
What is Phantom Limb?
tactile hallucinations of touch, pressure, vibration and pain in a body part that no longer exists
What are sound waves
vibrations of the molecules in the air
What are the two major qualities of sound waves
frequency and amplitude
What is frequency?
the number of cycles (waves) per second
