chapter 14 Flashcards
(19 cards)
what is the absolute threshold
is the minimum amount of physical energy needed for an observer to perceive visual stimulus in ideal conditions, 50 percent of the time
absolute threshold for hearing
the ticking of a watch six meters away
AT for smell
one drop of perfume in a large house
AT for taste
one teaspoon of sugar dissolved in 10L of water
AT for touch
the wing of a fly falling on the cheek from a height of one cm
AT for vision
the flame of a candle 50km away on a dark clear night
what are the five tastes
bitter (back of tongue) salty (sides of tongue) sour sweet (top of tongue) unami (middle of tongue)
how many rods are there in the eye
125,000,000
location and responsibility of rods
located at the edges of the retina
they’re responsible for vision in low light situations and for peripheral vision
black and white
requirements of rods
registers only in black and white
cannot register detail
number of cones in the eye
65,00,000
location and responsibility of cones
located in the middle of the retina
responsible for colour vision
requirements of cones
requires high levels of light to be able to respond
Sensation process in vision
Reception, transduction and transmission
Reception
Light enters eye through the cornea and then the pupil. The lens focuses the light on the retina where the rods and cons are
Transduction
Electromagnetic energy is converted by rods and cones into electrochemical nerve impulse
This allows visual info to travel along the fibres of the optic nerve to the brain
Transmission
Rods and cones send nerve impulses along the optic nerve to the primary visual cortex, where receptor cells respond and visual perception continues
Perception process in vision
Selection. Organisation. Interpretation
Selection - image broken up by feature detectors and they respond to lines of a certain length , angle or movement
Organisation -
The brain reorganised info so we can make sense of it using depth cues, Constancies and principles
Image then travels through the temporal and parietal lobes where it is made sense of
Interpretation: visual stimulus is given meaning
Object is identified by comparing incoming info to memory
What are the six stages of the process of sensation through to perception
Reception Transduction Transmission Selection Organisation Interpretation
process of sensation in taste
reception: chemicals are dissolved in saliva through chewing
transduction: chemical energy is converted by the receptor cells on the tastebuds to the electrochemical nerve impulse
transmission: from the tastebuds the nerve impulses travel through the thalamus to the primary gustatory cortex low in the parietal lobe
process of perception in taste
the brain recognises the sensation of a mixture of the five primary tastes and combines this with the smell, colour, and texture of the food to perceive the flavour of what we eat
the visible light spectrum
light entering the eye is an important part of our ability to receive and interpret a visual stimulus
the light energy must be within the visible parts of the electromagnetic spectrum. this is between wavelengths of 360-760 nanometers
