L1 Intro to Perception Flashcards
What is the origin of the word ‘Perceive’?
per - means “in front of”
ceive - (capere - latin) means “to capture”
Why is it critical for animals to sense?
Without sensory, we would not be able to react and respond to various forms of energy in the environment.
We would not be able to respond to significant objects and events and therefore could not survive.
What are our 5 input senses?
Sound, Smell, Sight, Temperature, Touch
Why is perception a part of psychology?
Perception is the foundation for everything else:
Memory, learning, motor skills, emotion, motivation, social psychology, personality and pathology.
What are the ‘two different worlds we live in’?
The Perceptual World and Physical World
What we hear, see, smell taste and touch depends on the physical world but that also entirely dependent for us on our sensory apparatus and nervous system (perceptual world).
What are the 5 classifications of the senses?
Sense,
Stimulus,
Sensory Structure,
Receptor,
Cortex
What is sensory information processed by to give us perception?
Our Brain
What is proprioception?
The position of your body in space.
Tells you where your body is.
- What is ‘The Fallacy of our Percepts?’
- What is the psychological answer?
- How can we know anything if our senses are subjective and constantly changing?
- If we can determine how perception changes under various conditions, then we should be able to predict these changes and therefore understand perception.
Describe the physical process of the eye and how it creates vision.
The info comes in through pupil,
then projected upside down and a little blurry on the fovea,
then you have optic nerve fibres which go to the receptor cells (rods and cones).
Where is the ‘blind spot’ in the eye?
Where the optic nerve meets the back of the retina.
(Just to the right of the fovea)
What is the area of vision around the ‘central viewing area’ called?
The periphery.
Why do we not know we have a blind spot in our vision?
Our brain ‘guesses’ and fills it in for us.
Why are there lots of cones at 0 degrees in the centre of the Fovea?
Cones are how we see colour and sharp clarity and is most sensitive to daylight levels of wavelength (560nm).
It is in the fovea because that is where we can actually focus (centre of vision).
What is the difference between Rods and Cones?
Rods are responsible for vision at low light levels (scotopic vision). No colour vision. Low Spatial Acuity.
Cones are active at higher light levels (photopic vision). Capable of colour vision. High Spatial Acuity.
What is the part of the eye that is responsible for our focused vision (point of central focus)?
The Fovea
What does a ‘bi-lateral representation of the cortex’ mean?
We have a similar structure on either side of the brain.
What is Psychophysics?
The branch of psychology that deals with the relations between physical stimuli and mental phenomena.
What is a Threshold in Psychophysics?
A border or boundary
What is an Absolute Threshold in Psychophysics?
The minimum amount of energy needed to detect a stimulus.
There might be light around, but there isn’t enough to detect a person or see things.
What is the current idea of threshold in psychometric function?
That the threshold is a continuous function, gradually increasing in as a sigmoid (S-shaped).
(50 may be where we start to see something (estimate of the absolute threshold for the object))
For measuring perception, what were the 3 psychophysical methods proposed by Fechner (1860)?
Method of Adjustment
Method of Limits
Method of Constant Stimuli
Describe the Method of Adjustment for measuring perception.
Ask the observer to adjust the intensity until they can barely detect the stimulus.
Describe the Method of Limits for measuring perception.
The experimenter adjusts intensity up (or down) until the observer changes their response.
Describe the Method of Constant Stimuli for measuring perception.
Observers view several preset stimulus intensities (in random order) and judge whether each is perceived or not.
(Most popular method)
What is sensitivity in comparison to the psychophysical function?
Sensitivity is the inverse of threshold.
sensitivity = 1/threshold (1 over threshold)
What is the difference threshold?
(JND-just noticeable difference)
The minimum change in a stimulus in order for the change to be perceivable
What are the three different types of absorption spectra for cones?
Short Wavelengths (Blue)
Medium Wavelengths (Green)
Long Wavelengths (Red)
Name and describe the two types of colour vision deficiency.
Deuteranopes: complete lack of green (medium wave) cones
Protanopes: complete lack of red (long wave) cones
Which gender is more likely to have colour vision deficiency?
Men
What is an Ishihara colour plate do?
Tests for colour blindness.
What is the part of the brain responsible for vision called?
Primary Visual Area or Striate Cortex
What is the retina?
A layer at the back of the eyeball that contains cells sensitive to light.
These trigger nerve impulses that pass via the optic nerve to the brain, where the visual image is formed.
What was the classic idea for ‘threshold’?
That there was absolutely no reaction until it hit the threshold then it rocketed straight to 100% perceptible.
