Sensation and Perception Flashcards
What is the difference between sensation and perception?
Sensation is the unfiltered raw information that PNS receptors receive and perception is the processing of this information in order to understand its significance
Transduction
Conversion of physical, electromagnetic, auditory, and other information from our internal and external environment to electrical signals in the nervous system
Does sensation start in the PNS or CNS?
PNS to CNS
Ganglia
Collections of neuron cell bodies found outside the CNS that receive a stimulus and transmit it to CNS
Projection areas
Parts of the brain that accept electrochemical energy (sensory input) and further analyze it
What do photoreceptors respond to?
Electromagnetic waves in the visible spectrum
What receptors are involved in sight?
Photoreceptors
What do hair cells respond to?
Movement of fluid in the inner ear
What receptors are involved in hearing?
Hair cells
What receptors are involved in rotational and linear acceleration?
Hair cells
What do nociceptors respond to?
Painful or noxious stimuli
What receptors are involved in somatosensation?
Nociceptors
What do thermoreceptors respond to?
Changes in temperature
What receptors are involved in thermosensation?
Thermoreceptors
What do osmoreceptors respond to?
Osmolarity of the blood
What receptors are involved in blood osmolarity?
Osmoreceptors
What do olfactory receptors respond to?
Volatile compounds
What receptors are involved in smell?
Olfactory receptors
What do taste receptors respond to?
Dissolved compounds
What receptors are involved in taste?
Taste receptors
Absolute threshold
Minimum stimulus energy required to activate a sensory system
Is an absolute threshold a threshold in sensation or perception and why?
Sensation - the change will still cause a difference in the receptors but is not enough to create an action potential
Threshold of conscious perception
Stimulus is enough to be transduced by the CNS but still not big enough to be perceived because it is either too short or too subtle
Just-noticeable difference (difference threshold)
Minimum difference in magnitude between two stimuli before one can perceive the difference
Weber’s Law
There is a constant ratio between the change in stimulus magnitude needed to produce a JND and the magnitude of the original stimulus
Signal Detection Theory
Changes in our perception of the same stimuli depending on both internal and external context
Response bias
Tendency of subjects to systematically respond to a stimulus in a particular way due to nonsensory factors
What happens in a catch trial?
Signal is presented
What happens in a noise trial?
Signal is not presented
What are the four outcomes in a signal detection experiment?
Hit: correct detection of a signal
Miss: subject fails to perceive a certain signal
False Alarm: subject seems to perceive a signal when none was given
Correct Negative: correct identification that no signal was given
What is it called when your body and mind try to focus only on relevant stimuli?
Adaptation
Threshold
Minimum amount of stimulus that renders a difference in perception
Duplicity theory of vision
The retina contains two kinds of photoreceptors
What are the two kinds of photoreceptors
Rods: light and dark perception
Cones: color detection
What are cones?
Used for color vision and to detect fine details
Which photoreceptors are used for color vision?
Cones
What are rods:
Used for sensation of light and dark
Which photoreceptors are used for light and dark vision?
Rods
Are there more rods or cones in the retina?
Rods (120mil vs 6mil)
Where are rods and cones found?
Retina, eye
What pigment do rods contain?
Rhodopsin
What are the three types of cones and which colors do they have the highest absorption at?
S: short - blue/purple
M: medium - green
L: long - red
What is the central part of the retina called?
Macula
Macula
Central part of the retina that has a high concentration of cones
Fovea
Centermost point of the macula which contains only cones
Which part of the retina contains only cones?
Fovea
Which photoreceptors does the macula mostly contain?
Cones
Where do rods and cones connect?
Bipolar cells
What are bipolar cells?
Cells where rods and cones connect
What do bipolar cells synapse with?
Ganglion cells
What is the optic nerve comprised of?
Bipolar and ganglion cells
What is the relationship between number of receptors and resolution?
As more receptors converge on an individual ganglion cell, resolution decreases
Do rods or cones have greater sensitivity?
Cones
What are amacrine and horizontal cells?
Receive input from multiple retinal cells in the same area before the information is passed on to ganglion cells - accentuate differences between visual information in each bipolar cell
Which cells are important for perception of contrast?
Amacrine and horizontal cells
Which three areas of the brain receive visual input from the optic chiasm?
Lateral thalamus
Visual cortex of occipital lobe
Superior colliculus
Optic chiasm
Fibers from the nasal half of each retina cross paths - tracts from both left sides of the eye go to left brain meaning that right visual field goes to left brain from both eyes
Parallel processing
Ability to simultaneously analyze and combine information regarding color, shape, and motion
Parvocellular cells
Allow detection of shape
Do parvocellular cells have low or high spatial and temporal resolution and what does this mean?
High spatial and low temporal meaning they can see fine detail but only stationary or slow-moving objects
Which cells allow us to see shapes?
Parvocellular cells
Magnocellular cells
Allow detection of motion
Do magnocellular cells have low or high spatial and temporal resolution and what does this mean?
Low spatial and high temporal meaning they can see moving objects but cannot detect rich detail
Which cells allow us to see motion?
Magnocellular cells
Sclera
White of the eye, covers the majority of the eye
What is the white of the eye called?
Sclera
Choroidal vessels
Vessels between the sclera and retina
Which vessels lie between the sclera and retina?
Choroidal
What are the two types of eye blood vessels?
Choroidal and retinal
Retina
Innermost layer of the eye, contains the photoreceptors