The Visual-Paired Comparison Task; limitations of the novelty preference as an index of memory

The Visual Paired Comparison task (VPC) is an established methodology for measuring
infant recognition memory. The standard index ofmemory in this task is the novelty
preference - longer looking at a new stimulus. However, a growing number ofstudies
report a preference for the familiar stimulus. This thesis explores the parameters within
which the VPC task produces a novelty preference, examining the variables of
movement, interaction and emotion at learning.
In Experiment I, infants were habituated to a moving, colourful puppet held by an
experimenter. Six-, 9- and l2-month-olds demonstrated an attenuated novelty
preference; 18 and 24 months demonstrated a familiarity preference. Removing the
human experimenter from view attenuated the novelty preference at 6-, 12- and 18 months
when the habituation was live, and attenuated the novelty preference at 6- and 18 months
when the habituation was on pre-recorded video.
In experiments 2-4, adults exhibited a novelty preference in the traditional VPC
procedure and an attenuated novelty preference when there was social interaction with
the stimulus. A static habituation face displaying emotion attenuated the novelty
preference; a neutral habituation face and emotion displaying test stimulus resulted in a
novelty preference.
Experiment 6 introduced the importance ofaccounting for cortisol levels in infant
memory research. The relationship between cortisol, emotion and memory was
examined, with emphasis on the regulatory role of the amygdala in the developing
memory system.