Flashcards in Week 5 - Sensation & Perception Deck (45):
What is Sensation?
The process by which the sense organs (eg eyes, ears, skin) gather information about the environment
What is Perception?
The process by which sensory information is selected, organised and interpreted
There is no 1:1 correspondence between what (2) things?
physical and psychological activity
What is the process of transduction?
Turning environmental energy into neural impulses
Sense receptors transduce stimuli into signals
What is the study of Psychophysics?
Study of how we perceive sensory stimuli based on their physical characteristics
What is the Absolute Threshold?
The lowest level of a stimulus (on its own) that we can detect 50% of the time
eg a candle 30km away
What is Just Noticeable Difference?
Smallest change in intensity of a stimulus we can detect
What does JND depend on?
Level of intensity of a new stimulus
Level of stimulation already present
What is Weber's Law?
Regardless of the magnitude of the two stimuli, the second stimulus must differ from the first by a constant proportion for it to be perceived as different
- 1/50 for the average person
What is the Signal Detection Theory?
Sensation occurs when we judge whether a stimulus is present or not
What 2 processes contribute to signal detection?
Initial sensory process (sensitivity to the stimulus)
Decision process (the individuals readiness to report detecting a stimulus when uncertain
What is Attention?
A mental phenomenon of concentration and its shifts in focus
What is attention influenced by?
External and internal events
What is Selective Attention?
Allows us to select some inputs for further processing and ignore others
What does the Cocktail Phenomenon suggest?
That even when we selectively attend to a conversation we are subconsciously monitoring other conversations around us.
What are the 2 errors of attention?
What is Inattentional Blindness?
A failure to see something in plain slight
What is Change Blindness?
The inability to detect changes in scenes when looking at them
What is Divided Attention?
Performing multiple tasks simultaneously
Mixing light produces =
Mixing pigments produces =
What are the 2 processes involved in the eye?
Focussing light on the retina
Transducing the image into nerve signals
What is Myopia?
Nearsighted (light focused in front of the rear of the eye)
What is Hyperopia
Farsighted (light focused behind the rear of the eye)
What are the 2 photoreceptors?
rods and cones
What is the role of photo receptors?
Turn light into electrical signals
Rods are associated with? (3)
Cones are associated with what? (3)
Central Vision (fine detail)
The retina contains what?
Rods and cones
Simple cells respond best to which stimuli?
Light of specific orientation at a particular level
Complex cells respond best to which stimuli?
Specific orientation but less dependent on location
Feature Detectors respond best to which stimuli?
Lines and edges (simplex/complex), lengths of lines, shapes, movement, colour etc
What are the 2 theories of colour vision?
Opponent Process Theory
Explain the Trichromatic Theory of colour vision
Colour vision is based on our sensitivity to three primary colours (red, blue, green)
- Consistent with three types of cones in the eyes
- Explains colour blindness
Explain the Opponent Process Theory of colour vision
Colour vision is a function of complementary opposing colours
- red vs green
- blue vs yellow
- black vs white
What are the 2 treatable causes of blindness?
Cataract and Glaucoma
What are the 3 types of colour blindness?
What is the most usual cause of colour blindness?
Faulty cone development (can be genetical)
- Far more common in males
What can also cause colour blindness?
Physical or chemical damage to the eye, optic nerve or cortical visual processing areas
What is Motion Blindness?
Inability to perceive motion (or stitch together the incoming images)
What is Visual Agnosia?
Inability to recognise objects, despite normal ability to describe the shape and colour etc
What is Prosopagnosia?