LCT8: Sensation Flashcards
Sensation
the processes by which our sense organs receive information (energy) from the environment
Sensations are…
simple mindless things that happens
Transduction
process through which stimuli reaching the receptors are converted into neural impulses … OR … how physical signals from the environment are changed into the neural signals sent to the brain
Psychophysics
the study of the relationship between physical stimulation and subjective sensations
Absolute threshold
the smallest amount of stimulation that can be detected
Difference threshold
“just noticeable difference” (JND) - the smallest change in a stimulus that can be detected
Signal Detection Theory
theory that focuses on making decisions about stimuli when uncertain - detecting a stimulus is jointly determined by the signal and the subject’s response criterion
Sensory Adaptation
a decrease in sensitivity to a constant level of stimulation
Basic Sensory Processes
- Vision
- Hearing
- Touch
- Taste
- Smell
What kind of neural signals do the eyes transduce light waves into?
electro-chemical neural signals
Where does transduction occur for our vision?
In the rods and cones
Rodes and Cones
photoreceptor cells on the retina
Rods
helps to see in low light, at night, and in peripheral vision - very sensitive, but gray-scale vision
Cones
color vision - less numerous, need high light levels
Where are the rods located?
outer portion of the retina
Where are the cones located?
inner portion of the retina
Ganglion Cells
send signals along their axons, which join to form the Optic Nerve
Blind Spot
where the Optic Nerve leaves the eye (optic disk)
What part of the eye initially captures light?
Photoreceptors
What part of the retina is most sensitive in the dark?
Rods
Optic Nerves
send signals from each eye to the thalamus
Optic Chiasm
where Optic Nerves cross
Visual Cortex
where visual information is transmitted to
Visual Pathway - Stimulas to transduction
Light - cornea - pupil (iris) - lens - retina (rods/cones)
