Chapter 4 Quiz-sensation And Perception Flashcards
What is an illusion
Perception in which the way we perceive a stimulus doesn’t match its physical reality
What is sensation?
Detection of physical energy by sense organs(including eyes,ears,skin,nose and tongue), which then send information to the brain
-the process by which your sensory receptors(ex. photoreceptors) and nervous system receive stimulus energies from our environment
Describe the perceptual process called filling-in
Occurs without our awareness. The brain’s capacity for dealing with inexplicable gaps in a visual image.
-Our brains have the tendency to fill in gaps to perceive an incomplete pattern or object as complete or whole.
What is transduction
The process by which the nervous system converts an external stimulus/energy, like light or sound, into electrical energy/activity within neutrons
What is a sense receptor
Specialized cell responsible for converting external stimuli into neural activity for a specific sensory system.
Ex. Specialized cells in the backs of the eye transduce light
What is sensory adaptation
Process in which activation is greatest when a stimulus is first detected. After that, our response declines in strength
Ex. After we sit in a chair we no longer notice it(unless it an extremely hard seat)
What is psychophysics?
The study of how we perceive sensory stimuli based on their physical characteristics
What is absolute threshold
Lowest level of a stimulus needed for the nervous system to detect a change 50% of the time
Explain the just noticeable difference (JND)
The smallest change in the intensity of a stimulus that we can detect. The JND is relevant to our ability to distinguish a stronger from a weaker stimulus, like a soft noise from a slightly louder noise
What is the Webers law?
Principle saying that there is a constant proportional relationship between the JND and original stimulus intensity.
-the stronger the stimulus, the bigger the change needed for a change in stimulus intensity to be noticeable.
Ex. Imagine how much light we’d need to add to a brightly lit kitchen to notice an increase in illumination compared to the amount of light we’d need to add to a dark bedroom to notice a change in illumination
What is the signal detection theory developed by David Green and John Swets?
Theory regarding how much stimuli are detected under different conditions.
Ex-trying to figure out what a friend is saying on a cell phone when there’s a lot of static in the connection-that is when there’s a high background noise
What is the signal-to-noise-ratio?
Ratio where It becomes harder to detect a signal as background noise increases
What are response biases?
tendencies to make one type of guess over another when we’re in doubt about whether a weak signal is present or absent under noisy conditions
In signal detection theory, what are the 4 possible responses a subject may have when asked “was there a stimulus”?
True positive(Hit)- report that they heard a sound when it was present False negative(Miss)-deny hearing a sound when it was present False positive(false alarm)-report hearing a sound when there wasn't one True negative(Correct rejection)-deny hearing a sound when there wasn't one
What helps us measure how biased people are to respond “yes” or “no” to the question “was there a stimuli” in general?
The frequency of false negatives and false positives that the subjects respond
State the doctrine of specific nerve energies proposed by Johannes Müller
States that even though there are many distinct stimulus energies-like light, sound, or touch-the sensation we experience is determined by the nature of the sense receptors, not the stimulus
-ex. it doesn’t mater to our brain whether light or touch activated the sense receptor:our brains react the same way in either case
Give an example of a cross-modal process
Ex. The McGurk effect
- we integrate visual and auditory information when processing spoken language and our brains automatically calculate the most probable sound given the info from the two sources
- hearing the audio syllable “ba” while seeing a video track of a different syllable “ga” produces the perceptual experience of a third sound such as “da”
What is synesthesia
A rare condition in which people experience cross-modal sensations, like hearing sounds when they see colours
What is the filter theory of attention and how was it tested?
This mental theory enables us to pay attention to important stimuli and ignore others. This theory is tested using a task called dichotic listening(people hear 2 diff messages, one in left ear another in right, and are asked to ignore messages in one)
-however, the info we’ve supposedly filtered out of our attention is still being processed at some level(even when we’re unaware of it)
What is the cocktail party effect?
Refers to our ability to pick out an important message, like our name, in a conversation that doesn’t involve us
What is inattentional blindness
Failure to detect stimuli that are in plain sight when our attention is focused elsewhere
What is change blindness
The failure to detect obvious changes in ones environment
What does hue mean?
Colour if light
What are the primary colours
Blue, red, green