DEP 3115
Dr. Lorraine Bahrick
Infant Research Techniques
I.
Early attempts at investigating infant learning
A. Adapt methods from animal studies – rewards & reinforcement schedule
B. Infants motivated to pick up new information
II.
Modern methods: Psychophysiological
A. Heart rate (HR)
B. EEG/ERP
III.
Modern methods: Behavioral: (Looking, sucking, head turn, kicking, specialized measures)
A. Looking --Visual preference method (Fantz)
a. Two stimuli side by side - measure visual fixations
b. Assumption--if a group of infants looks consistently more to one object than the other, and
position is counterbalanced, then they can discriminate between the two objects
c. Problem - infant must prefer one stimulus
B.
Looking -- Novelty preference method
a Assumption--infants look more to a novel display than to a very familiar one if they
can tell the difference between them
b. Method--infant is familiarized with one stimulus to create a visual preference
c. Problem--length of familiarization
d. Different infants process information at different rates
C.
Looking -- Habituation/dishabituation (infant control procedure)
a. Gets all subjects at about the same point along the novelty-familiarity preference
curve
b. Uses habituation to create a visual preference for the novel stimulus
c. Assumption--any response to a stimulus will decline with repeated presentations &
increase again to a novel stimulus
d. Infant control procedure
e. Habituation criterion
f. Response recovery indicates discrimination
g. Can test categorization
D. Operant Conditioning: Sucking --Nonnutritive sucking (NNS) variation of the habituation
method
a. Nipple connected to pressure transducer to measure sucking rate and intensity
b. Baseline
c. Stimulus contingent upon high amplitude sucking
d. Habituation occurs
e. Dishabituation/response recovery
E. Operant Conditioning: Head Turn
a. Assesses discrimination
b. Anticipatory head turns
F. Comparisons- 5 behavioral methods (above) primarily assess discrimination – not meaning of
stimulation
G. Methods using specialized measures/responses
a. Better for getting at infant detection of meaning (reaching, cliff avoidance)
b. Kicking method (Operant conditioning) – Rovee-Collier conjugate reinforcement:
assesses memory