Using Habituation of Looking Time to Assess Mental Processes in Infancy

Abstract

Habituation of looking time has become the standard method for studying cognitive processes in infancy. This method has a long history and derives from the study of memory and habituation itself. Often, however, it is not clear how researchers make decisions about how to implement habituation as a tool to study processes such as categorization, object representation, and memory. This article describes the challenges for implementing this tool, and describes a set of best practices for its use to study perception and cognition in infancy.

Behavioral and Neural Foundations of Multisensory Face-Voice Perception in Infancy

“…For example, behavioral looking measures can indicate whether an infant notices a difference between two types of stimuli or prefers to look at or remembers one type of stimulus over another, allowing inferences regarding face and voice perception, learning, attentional bias, and memory (see Intersensory Perception 29 Aslin, 2007or Oakes, 2010 for reviews). However, brain measures provide the potential to break down the behavioral outcome into component parts such as sensory processing, attention, and memory.…”

Developmental changes in infants’ categorization of anger and disgust facial expressions.

“…During habituation, infants saw either anger or disgust facial expressions modeled by four different actors. Habituation trials continued until infants' looking time across the last three trials decreased 50% or more from their looking time during the first three consecutive habituation trials or until all 20 habituation trials were presented (Oakes, 2010). Infants were then presented with four test trials.…”

“…To ensure that infants' looking times sufficiently decreased from habituation to test, we conducted a 2 (Gender: male vs. female) x 2 (Age: 10-months vs. 18-months) x 2 (Habituation (Oakes, 2010). No other significant main effects or interactions emerged, all ps > .10.…”

“…All infants were healthy, full-term, and of normal birth weight. Twenty-nine additional infants (10 10-montholds, 19 18-month-olds) were excluded from final analyses for the following reasons: failure to meet the habituation criteria, described below (n=11; 2 10-month-olds, 9 18-month-olds), extreme looking times (±2 SD) during the test trials, indicating a failure to meet the habituation criteria (n=6; 3 10-month-olds, 3 18-month-olds, see Oakes, 2010), failure to complete the experiment due to fussiness (n=10; 4 10-month-olds, 6 18-month-olds), and experimenter error (n=2; 1 of each age). All infants were given a t-shirt and a certificate for their participation.…”

“…Interestingly, children, aged two and older, have shown difficulties in emotion categorization tasks with the within-valence facial expressions of anger and disgust (Widen & Russell, 2008;2010). For instance, Widen and Russell (2003;2008) asked 2-to 7-year-olds to verbally identify facial expressions (e.g., "how do you think she feels?")…”