The electrophysiological responses used to study memory are event-related potentials (ERPs), which are a subset of the continuous electroencephalogram (EEG) that reflects transient changes in the brain’s electrical activity in response to a discrete event. The ERP components related to attention and memory in infants and children are the negative central (Nc) and late slow waves, which include the negative slow wave (NSW) and positive slow wave (PSW), all of which are located over frontocentral brain regions (Nelson & McCleery, 2008). The Nc component, in studies of 4.5-, 6- and 7-month-olds, has been

shown to be larger during periods of attention than inattention (Richards, 2003) and larger for novel than familiar stimuli (Reynolds & Richards, 2005). The late slow waves, also in studies of 4.5, 6 and 7-month-olds, were shown during periods of attention to be manifest

as a NSW over frontal regions in response to a novel stimulus and AZD2014 as a PSW over temporal regions in response to a infrequent-familiar stimulus (Reynolds & Richards, selleck 2005). The manifestation of the late slow waves have also been shown to change with development, as another study demonstrated that during periods of attention to a novel stimulus, the PSW was present in 4.5-month-olds, but by 7.5 months of age the NSW appeared and the PSW was no longer present (Richards, 2003). These studies indicate that by 7.5 months Acetophenone of age, the Nc reflects attention and may also play a role in novelty detection, the NSW reflects novelty detection, and the PSW reflects memory updating of partially encoded stimuli (Nelson & McCleery, 2008). A newly emerging field in the study of infant memory is the integration of visual behavioral and electrophysiological measures. (Reynolds & Guy, 2012). A study on 4.5- to 7.5-month-olds showed that overall preference for the novel stimulus on VPC correlated with larger Nc response to the novel stimulus (Reynolds, Courage, & Richards, 2010).

In 6-month-olds, the amplitude of a late slow wave component over the right-central and temporal brain regions during familiarization to a stimulus predicted subsequent performance on the immediately following VPC test (Snyder, 2010). This integration of measures is also beginning to be used to examine the influence of pre- and perinatal experience on infant memory. A study on infants of diabetic mothers (IDM), who are at increased risk of perturbations in hippocampal development due to the adverse effects of metabolic fluctuations during pregnancy, found that even though IDM and control infants performed similarly on the visual paired comparison task, there was a difference in their ERP responses (Nelson et al., 2000). Integrating behavioral and electrophysiological tools may allow for the detection of subtle memory impairments during infancy following potentially adverse pre- or perinatal experience.