Chapter 5 - Sensation and perception Flashcards
(69 cards)
Stimulus (Plural = stimuli)
Any object or event that triggers a response
- E.g., Light, sound, taste, smell, touch, temperature change
Sensory receptors
Special cells or nerve endings in the body that
detect and respond to sensory stimuli
Sensation
Stimulus detected by sensory receptor
Transduction
The process by which the body’s sensors convert
physical signals from the environment into neural signals
Absolute Threshold
The smallest amount of a stimulus needed for a
person to detect it 50% of the time
- The most sensitive sensory receptors in the back of the eye can detect a candle
flame 30 miles away - The sensory receptors in the ear can detect the tick of a clock 20 feet away
Just noticeable difference (JND)
The minimal difference needed for a
person to notice that a change has occurred
Weber’s Law
Detecting changes becomes harder as the intensity of the
stimulus increases
Perception
The process by which the brain organizes, interprets, and
makes sense of sensory information
- Can be influenced by past experiences, expectations, and context
Bottom-Up Processing
Sensory information from your environment going to your brain
- How sensory information is collected and processed by the sensory organs and then sent to the brain
for interpretation
Top-Down Processing
Using your brain to guide how you interpret and respond to sensory
information from the environment
- Involves psychological factors, such as your previous experiences, knowledge, and expectations,
which influence how you interpret and understand sensory information
Sensory Adaptation
The process by which our sensory receptors become less sensitive to a
constant stimulus over time
- First Experience → Repeated Exposure → Adaptation
Subliminal Messages
Stimuli that are presented below the level of conscious awareness
We CAN process and respond to stimuli outside of our awareness
Inattentional blindness
The phenomenon where people fail to notice an unexpected stimulus in
their visual field because their attention is focused elsewhere
Signal detection theory
The ability to identify a stimulus when it is embedded in a distracting
background
Motivation influences your ability to detect and interpret stimuli by adjusting your sensitivity and decision criteria
based on the importance of the signal
Other factors that affect our perception
Beliefs, values, prejudices, expectation, and life experiences
Müller-Lyer illusion
A visual
illusion where two lines of the same length appear to be different lengths
Trichromatic theory of color vision
Color vision is based on the presence of
three types of color receptors (cones) in the retina, each sensitive to different
wavelengths of light
Cone names and what they detect
- S-cones: Sensitive to short wavelengths (blue/violet)
- M-cones: Sensitive to medium wavelengths (green)
- L-cones: Sensitive to long wavelengths (red)
Opponent-process theory
Color vision is based some cells are activated by
one color of the pair and inhibited by the other, which helps in perceiving
colors and distinguishing between them
- Opponent pairs:
- Black-White
- Yellow-Blue
- Green-Red
Depth perception
Ability to perceive spatial relationships in three-
dimensional (3-D) space
Binocular cues
Depth cues that require the use of both eyes
Monocular cues
Depth cues that can be perceived using only one eye
Binocular disparity
The slight difference in the images seen by each eye
Linear perspective
parallel lines appear to converge or meet at a single
point in the distance, known as the vanishing point, as they extend away
from the observer
