Perception Data collection (Oct 11/16) Flashcards
What is the definition Discrimination in Speech perception?
-Used to determine if two or more stimuli are perceived as the same or different.
- No need to name or categorize the stimuli
- Examples: AX, ABX, 2AFC
What is the definition of Identification in speech perception?
- Used to label or categorize a given stimulus
- requires naming the perceived stimuli based on predefined categorization.
- Examples: Labeling Tasks, Yes-No tasks
What is the task of the discrimination AX design?
Same different (AX) Design: Identify if the two stimuli are the same or different.
Equal number of same and different pairs: separated by an interstimulus Interval.
What is the task of the discrimination of ABX design?
ABX (AXB,XAB) design
- 3 stimuli present
- listener determines if a or b is similar to x
- each set of stimuli has 2 ISIs.
What is the task of discrimination 2AFC design?
Two alterative forced choice design
- Two stimuli presented on each trial
- Which stimuli came first A or B
Design elements?
- Minimizes bias; ideal for similar stimuli.
- Assumes either order is equally possible.
- Requires discernment of stimulus order.
What is the task of the discrimination 4IAX design?
4-Interval Forced Choice Design
- given 4 sounds with 1 being the same and the comparative.
- the 2 end are “flankers” not the matching one.
What is the task of the identification yes-no design?
Yes- No design
- Only one stimulus is presented per trial
- subjects decide on the nature of the stimulus.
What is the task of the identification Labeling design?
Labeling Design
- single stimulus is presented each trial
- subject apply a label to the stimulus
- aim: access categorical knowledge.
What is the task of the identification oddity design
Oddity Design:
- multiple stimuli presented, one of which is unique.
- Task: identify the odd one out.
- often limited to 3 or 4 stimuli.
What is the nature of judgement of Identification tasks?
Absolute judgement about a single stimulus presented in isolation.
What is the nature of judgement of the discrimination tasks?
Relative judgement comparing 2 or more stimuli presented within the same trial.
What is the goal of an identification task?
Determine if the stimulus matches a pre-established category or criterion)
ex. Is this sound /s/ yes or no?
What is the goal of an discrimination task?
Detect a difference or distinguish between stimuli
ex. which of these 2 tones is higher in pitch?
What is the focus of an identification task?
Identifying whether the stimulus belongs to a category based on memory or knowledge, without comparing to another stimulus.
What is the focus of a discrimination task?
Perceptual comparison between stimuli, not based to matching to internal category.
What is d’ (d-prime)
- a measure of sensitivity in perceptual tasks
- indicates how well an individual can discern between signa (a stimulus) and noise (a distractor or absence of stimulus)
- represents the distance between the means of the signal and the noise distributions, in units of the standard deviation of the noise.
What does hit rate mean?
proportion of times the signal was correctly detected.
What does false alarm rate mean?
Proportion of times the signal was incorrectly detected when it was absent.
What does Z refer to?
Z refers to the inverse of the cumulative distribution function of the Gaussian distribution.
What is d’ calculation?
d’=Z (hit rate) - Z (false alarm rate)
What is the importanct of perception experiments?
-Allows for a bias-free measure of perceptual sensitivity
- commonly used in signal detection theory to quantify the ability to differentiate between information signals in the presence of noise.
- Provides insights into the listener’s/perceiver’s inherent ability, free from decision biases
