Infant research is providing accumulating evidence that number-space mappings appear early in development. Here, a Posner cueing paradigm was used to investigate the neural mechanisms underpinning the attentional bias induced by nonsymbolic numerical cues in 9-month-old infants (N = 32). Event-related potentials and saccadic reaction time were…

This experiment tests the age at which left-to-right spatial associations found in infancy shift to culture-specific spatial biases in later childhood, for both numerical and non-numerical information. Children ages 1-5 years (N = 320) were tested within an eye-tracking paradigm which required passive viewing of a video portraying a spatial…

It is surprising that there are inconsistent findings of transitive inference (TI) in young infants given that non-linguistic species succeed on TI tests. To conclusively test for TI in infants, we developed a task within the social domain, with which infants are known to show sophistication. We familiarized 10- to 13-month-olds (M = 11.53 months)…

An ability to perceive tactile and visual stimuli in a common spatial frame of reference is a crucial ingredient in forming a representation of one's own body and the interface between bodily and external space. In this study, the authors investigated young infants' abilities to perceive colocation between tactile and visual stimuli presented on…

Saccade latency is widely used across infant psychology to investigate infants' understanding of events. Interpreting particular latency values requires knowledge of standard saccadic RTs, but there is no consensus as to typical values. This study provides standard estimates of infants' (n = 194, ages 9 to 15 months) saccadic RTs under a range of…

Over the past few decades, there has been extensive debate as to whether humans represent number abstractly and, if so, whether perceptual features of a set such as cumulative surface area or contour length are extracted more readily than number from the external world. Here we show that 7-month-old infants are sensitive to smaller ratio changes…

Although human infants demonstrate early competence to retain visual information, memory capacities during infancy remain largely undocumented. In three experiments, we used a Visual Paired Comparison (VPC) task to examine abilities to encode identity (Experiment 1) and spatial properties (Experiments 2a and 2b) of unfamiliar complex visual…

The present study examined the hypothesis that inhibitory visual selection mechanisms play a vital role in memory by limiting distractor interference during item encoding. In Experiment 1a we used a modified spatial cueing task in which 9-month-old infants encoded multiple category exemplars in the contexts of an attention orienting mechanism…

Two experiments examined infants' ability to form a spatial category when habituated to few (only 2) or many (6) exemplars of a spatial relation. Sixty-four infants of 10 months and 64 infants of 14 months were habituated to dynamic events in which a toy was placed in a consistent spatial relation ("in" or "on") to a referent…

Dynamic spatial indexing is the ability to encode, remember, and track the location of complex events. For example, in a previous study, 6-month-old infants were familiarized to a toy making a particular sound in a particular location, and later they fixated that empty location when they heard the sound presented alone ("Journal of Experimental…

This paper presents two methods that we applied to our research to record infant gaze in the context of goal-oriented actions using different eye-tracking devices: head-mounted and remote eye-tracking. For each type of eye-tracking system, we discuss their advantages and disadvantages, describe the particular experimental setups we used to study…

Infant eye tracking is becoming increasingly popular for its presumed precision relative to traditional looking time paradigms and potential to yield new insights into developmental processes. However, there is strong reason to suspect that the temporal and spatial resolution of popular eye tracking systems is not entirely accurate, potentially…

To examine the development of visual short-term memory (VSTM) for location, we presented 6- to 12-month-old infants (N = 199) with two side-by-side stimulus streams. In each stream, arrays of colored circles continually appeared, disappeared, and reappeared. In the "changing" stream, the location of one or more items changed in each cycle; in the…

Fundamental to amassing a lexicon of relational terms (i.e., verbs, prepositions) is the ability to abstract and categorize spatial relations such as a figure (e.g., "boy") moving along a path (e.g., "around" the barn). Three studies examine how infants learn to categorize path over changes in "manner," or how an action is performed (e.g., running…

A version of the line motion illusion (LMI) occurs when one of two adjacent surfaces changes in luminance; a new surface is perceived sliding in front of the initially presented surface. Previous research has implicated high-level mechanisms that can create or modulate LMI motion via feedback to lower-level motion detectors. It is shown here that…