Chapter 4: Sensation and Perception Flashcards
What is the difference between sensation and perception?
- Sensation: stimulation
- Perception: processing of stimulation to form a mental representation
What is transduction?
- Sense receptors convert physical signals into neural signals.
Give examples of how sensation and perception are measured.
- Through psychophysics such as displaying different circles of varying brightness.
What are the physical properties of light and how do they relate to the psychological dimensions of brightness, colour, and saturation:
- Amplitude: brightness
- Wavelength: colour
- Purity: saturation
How does the eye convert light waves into neural impulses?
- Light enters the eyes through the cornea and is bent through the pupil at the centre of the iris.
- The lens adjust to focus the light on the retina.
- Retina converts light into neural impulses
How do we perceive colour?
- Through the three types of cones: L- (red), M- (green), S- (blue).
- All other colors are combinations of these three wavelengths
What are the functions of the dorsal and ventral visual streams?
- Dorsal: occipital to parietal; location of object and how it is moving
- Ventral: occipital to temporal; recognition of object
What are the factors that allow us to recognize objects by sight?
- Motion
- Shape
- Edge
- Color
Describe the visual cues essential for depth perception:
- Linear perspective: straight lines converging in the distance
- Texture gradient: gradient is more smooth when further way
- Interposition: near objects block distant objects
- Relative height: near objects are lower in the visual field
- Retinal disparity: smaller difference = closer
How do we perceive motion and change?
Through the visual system encoding information about both space and time
What are the physical properties of sound waves?
- Frequency: pitch
- Amplitude: loudness
- Complexity: timbre
How does the ear convert sound waves into neural impulses?
- Sound waves cause basilar membranes to bend, leading to movement of hair cells.
- Bending of hair cells cause neurotransmitters to be released
How do touch receptors transmit messages to the brain?
- Neural impulses are sent to the somatosensory cortex where it is converted into the feeling of touch.
Why is pain a psychological perception?
- Because it indicates damage or potential damage to the body and has survival values.
How are odourant molecules converted into neural impulses?
- Odourant molecules travel through the nose to olfactory epithelium, where they bind to receptors
- ORNs (receptor cells) transduce signals into neural impulses
