Chapter 4 Flashcards
What is sensation?
Stimulation of sense organs
Sensation is the initial stage of processing sensory information better known as bottom-up processing
Define stimulus in the context of sensation.
Physiological energy that serves as ‘raw data’ about the outside world
Stimuli can be light, sound, touch, etc.
What are receptor cells?
Specialized cells that receive stimuli in the eyes, ears, skin, nose, tongue, etc.
These cells convert physical energy into neural signals.
What is perception?
Organization and interpretation of sensation
Perception helps the brain make sense of raw sensory data. Known as Top-bottom processing
How do retinal ganglion cells function?
Respond to and enhance contrast, useful for edge detection
They play a crucial role in visual processing.
What does the dorsal stream in the visual system represent?
The ‘where’ pathway related to action
It helps in locating objects in space.
What does the ventral stream in the visual system represent?
The ‘what’ pathway related to perception
It is involved in object recognition.
List the three laws of Gestalt psychology.
- Law of Closure
- Law of Similarity
- Law of Proximity
These laws describe how we perceive patterns and objects.
What is the law of closure?
Organizes perception into whole rather than parts
It helps us complete incomplete figures.
What is the law of similarity?
Like things get grouped together
This law explains how we perceive similar objects as a group.
What is the law of proximity?
Things that are close together get grouped together
This affects how we perceive spatial relationships.
What is object recognition?
Involves sensing different basic features and integrating them into a perceptual whole
It is critical for identifying objects in our environment.
Define top-down processing.
Processing driven by belief and expectations about how the world is organized
It relies on prior knowledge to interpret sensory information.
Define bottom-up processing.
Processing driven by physical input contacting the sensory receptors
It starts with sensory input and builds up to perception.
What is presbyopia?
Age-related farsightedness
It occurs when the lens loses flexibility, making it hard to focus on close objects.
What role does the pupil play in vision?
Regulates the amount of light passing into the eye
The pupil adjusts its size based on lighting conditions.
What is the function of the lens in the eye?
Focuses light rays to fall on the retina
The curvature of the lens adjusts for distance.
What are rods in the context of vision?
Receptors for night and peripheral vision
They are sensitive to low light levels.
What are cones in the context of vision?
Receptors for daylight, fine detail, and color vision
They are concentrated in the fovea and function best in bright light.
What does the retina do?
Tissue lining the inside back of the eye that contains receptors for seeing
It converts light into neural signals for the brain.
Trichromatic Theory
3 types of receptors with differing sensitivities to different wavelengths
Opponent process Theory
Complimentary pairs of colour where one colour becomes more excited and the other becomes inhibited to display contrast in colour.
- red vs green, yellow vs blue, black vs white
Sublimation perception
Detecting information you already know in a hidden context (below level of conscious awareness)
After image
Sensation experienced after stimulus is removed
- should see after image of opposing colours
- current colours tire out and their complimentary are released from inhibition
Monocular cues
- clues about distanced based on image
Motion Parallax
Objects at different distances move across retina @ diff. Rates
Linear Perspective
Lines converge in distance
Pitch
Subjective perception of frequency
Low frequency
Low pitch
High frequency
High pitch
Outer ear: PINNA
Funnel sound waves to middle ear
Middle ear: eardrum
Vibration amplification by 3 tiny bones
Inner ear: Cochlea
Vibration converted into neural signals sent
Basilar membrane
Lining of cochlea w/ tiny hair protrusions
Frequency Theory
- perception of pitch corresponds to frequency or rate the basilar membrane vibrates
Place Theory
Perception of pitch corresponds to place of vibration along basilar membrane
- high pitch towards opening of cochlea
- low pitch towards end
