Common measures in Cog Sci 7.2 Flashcards
Self report
Examples
•Surveys, questionnaires, interviews
Self report pros
- Direct, fast, easy
* Generally high face validity
Self report cons
- Dishonesty, lack of self awareness, different interpretations of same scales
- Socially-desirable responding
- Demand characteristics
Behavioral measurements
Examples
•Reaction Time, accuracy, signal detection (d’)
•Observed behaviors, e.g., hand gestures, body language, speech disfluencies
•Analysis of verbal or written responses
Behavioral measurements pros
- Generally inexpensive and easy to administer
* Many have a long history of use
Behavioral measurements cons
- Some behaviors can be difficult to elicit
* Coding complex behaviors
Response/reaction time
Ex: mental chronometry
•Assumes longer RT corresponds to
additional information processing
Accuracy & errors
- Advantages
- Simple and intuitive
- Concerns
- Ceiling and floor effects
- Response biases
d’ (sensitivity or discriminability index)
- Considers hit rate & false alarms
- Separates signal from noise
- Controls for response bias
Accuracy and serial position effects in Memory
First and last items you remember more, middle lowest recollection
Accuracy as a Manipulation Check
- Narratives and vignettes
- Are the participants actually reading the stimuli?
- Short, fairly easy comprehension questions
- Did the mother buy some clothing?
- Visual stimuli
- Intermittent attention and memory tests
- Was there a house in that last photo?
- AFC tasks and MC surveys
- Select ”A” as the answer for this response
Observed behaviors
•There are many behaviors that can be measured •Often coded via ratings ex: •Imitation learning of aggression in preschool children
Physiological measurements
- Examples
* single-unit recordings, EEG, ERP, fMRI, eye-tracking…
Physiological measurement pros
•Objective measurements
Physiological measurements cons
- Equipment might be expensive
* Equipment might be disruptive to natural behavior
Single unit recordings
Great spatial resolution
Great temporal resolution
•Invasive
•Can (mostly) only be done with animals
Electroencephalography (EEG)
•Electrical activity at the scalp (brain
waves)
•Summed, synchronous postsynaptic potentials
of cortical neurons
•High temporal resolution
•Poor spatial resolution
•Different brainwaves are associated with
different processes
•Delta (<4Hz) slow wave sleep
•Beta (16-31 Hz) thinking
•Mu (8-12 Hz) suppression – mirror neuron
activity
Event Related Brain Potentials
Averaged EEG, time-locked to stimulus
onset
•Negative voltage typically plotted up
•Different ERP components associated
with different cognitive processes
•Good for examining real-time information
processing in human brains (not locations)
Functional Magnetic Resonance Imaging
fMRI
•Indirect measure of brain activity
•Assumes changes in blood flow index changes in
neural activity
•BOLD (Blood Oxygen Level Dependent contrast)
•High spatial resolution •Poor temporal resolution •Good for addressing questions about wherebrain activity differs but not timing issues •Images reflect contrasts between conditions
Eye-tracking
•Logic – we tend to look at things we are thinking about •High temporal resolution •Different features can be measured (e.g., looking time, number of saccades)
Different measures differ in their reliability
•EEG records brain activity at the scalp, and the brain is doing much more than simply
processing your stimuli
•Response times are a product of multiple processes, each of which contributes to the
variability of an RT
•The mean of many trials is a more reliable indicator than the mean of a few
