Sensation and perception Flashcards
1
Q
Sensation
A
- The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
- The brain receives input from the sensory organs
2
Q
Perception
A
- The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events
- The brain ‘makes sense’ out of the input from sensory organs
3
Q
Bottom-up processing
A
- Taking sensory information and then assembling and integrating it
- What am I seeing?
1. Reception: the stimulation of sensory receptor cells by energy
2. Transduction: transforming this cell stimulation into neural impulses
3. Transmission: delivering this neural information to the brain to be processed
4
Q
Top-down processing
A
- Using models, ideas, and expectations to interpret sensory information
- Is that something that I’ve seen before?
5
Q
Signal detection
A
: whether or not we detect a stimulus
- Our detection is influenced by:
physical intensity of the stimulus
psychological factors: experience, expectations, motivations, and alertness
6
Q
Subliminal detection
A
- Below our threshold for being able to consciously detect stimulus
- We cannot consciously learn from subliminal stimuli
- We can be primed by these stimuli (the effect of subliminal stimuli appears in our subsequent choices and behaviour)
7
Q
Perceptual set
A
- What we expect to perceive influences what we do perceive (example of top-down processing)
8
Q
Vision: energy, sensation, and perception
A
- Light is waves of electromagnetic radiation
- Our eyes respond to some of these waves
- Our brains turn our eyes’ responses to these waves into visual information
9
Q
Colour and brightness
A
- The colour or hue of light is related to its wavelength or frequency
- The brightness or intensity of light is related to the height or amplitude of light waves
10
Q
How we perceive visual information:
A
- Light enters through the cornea
- Light makes it way through the pupil
- The pupil is controlled by the iris
- Light is refracted through the lens and focuses the light on
- The retina which contains photoreceptors
- Most photoreceptors are found in small section of the retina called the fovea
- The photoreceptors turn the light energy to neural signals
- The optic nerve carries the signals to the rest of the brain
11
Q
Photoreceptors
A
- Light activates photoreceptor cells in the retina
- Rods: permit black-and-white, low-detail vision
- Dense in periphery of retina, much more common than cones
- Cones: permit high detail colour vison
- Dense in center of retina (‘fovea’)
12
Q
Information processing
A
- The images we ‘see’ are not made of light, they are made of neural signals by stimulating photoreceptors
- Signals are carried through the optic nerve to the thalamus and then to the visual cortex (occipital lobe)
- Neurons in primary visual cortex responds to certain basic features (orientations of lines, edges, direction of movement)
- In association areas of cortex, neurons respond to more complex combinations of features ( permit perception of more complex forms, such as faces
Light waves chemical reactions neural impulses objects
13
Q
Parallel processing
A
Allows for different components of perception to be processed at the same time (instead of serially)
14
Q
Prosopagnosia
A
- inability to recognize faces
- associated with damage to fusiform gyrus of temporal lobe
15
Q
Colour vision
A
- We perceive colour based on the wavelengths of light reflected by objects
- Young-Helmholtz Trichromatic (Three-colour theory)
three types of colour receptors (cones): red, green, and blue
each cone type is sensitive to particular wavelengths of light
everything we perceive are created by light waves stimulating combinations of these cones
