Auditory Mismatch Negativity Response in Institutionalized Children

Impact of maternal institutionalization on children's language development: A multidisciplinary study

Research has uncovered extensive negative effects of institutional rearing on development, including language deficits. However, less is known about how these effects may be passed down vertically from mothers to children. The current study examined this pathway with respect to language development using behavioral and neural measures. Participants were mother-child dyads (children aged 8-71 months) where the mothers were either previously institutionalized in orphanages (n = 20) or not (n = 34). Mothers qualified for the study if they were 16 to 35 years of age, had a child aged 8 months to 5 years, and were native Russian speakers. We hypothesized that mothers with a history of institutionalization would provide a linguistically impoverished environment, leading to lower language scores in their children and altered neural responses to language violations. Contrary to our hypotheses, maternal history of institutionalization was not significantly associated with child language abilities (expressive or receptive) or the frequency of conversational turns. However, mothers with a history of institutionalization spoke fewer words around their female offspring relative to mothers raised in biological families. Event-related potential (ERP) analyses revealed topography differences in children's P400 response during phonological processing associated with maternal institutionalization history. We were also able to predict with above-chance accuracy children whose mothers had a history of institutionalization using machine learning on ERP measures. These findings suggest the need for targeted interventions to support language development in children of mothers with a history of institutionalization.

Maturation of the mismatch response in pre-school children: Systematic literature review and meta-analysis

Event-related potentials (ERPs), specifically the Mismatch Response (MMR), holds promise for investigating auditory maturation in children. It has the potential to predict language development and distinguish between language-impaired and typically developing groups. However, summarizing the MMR's developmental trajectory in typically developing children remains challenging despite numerous studies. This pioneering meta-analysis outlines changes in MMR amplitude among typically developing children, while offering methodological best-practices. Our search identified 51 articles for methodology analysis and 21 for meta-analysis, involving 0-8-year-old participants from 2000 to 2022. Risk of Bias assessment and methodology analysis revealed shortcomings in control condition usage and reporting of study confounders. The meta-analysis results were inconsistent, indicating large effect sizes in some conditions and no effect sizes in others. Subgroup analysis revealed the main effects of age and brain region, as well as an interaction of age and time-window of the MMR. Future research requires a specific protocol, larger samples, and replication studies to deepen the understanding of the auditory discrimination maturation process in children.

Effects of childhood institutionalization on semantic processing and its neural correlates persist into adolescence and adulthood

Individuals raised in institutionalized care settings are more likely to demonstrate developmental deficits than those raised in biological families. One domain that is vulnerable to the impoverished environments characteristic of some institutionalized care facilities is language development. We used EEG to assess ERPs and source-localized event-related spectral perturbations (ERSPs) associated with semantic processing at different levels of picture-word conflict and low versus high word frequency. Additionally, we assessed behavioral language ability (a synonyms task) and IQ. Participants (N = 454) were adolescents and adults with a history of institutionalized care (N = 187) or raised in biological families (N = 267), both recruited from secondary educational settings to approximately match the groups on age and education. Results indicate that individuals with a history of institutionalization are less accurate at judging whether semantic information in a spoken word matches an image. Additionally, those with a history of institutionalization show reduced cognitive control of conflict and more reactive N400 ERPs and beta ERSPs when handling picture-word conflict, especially in the left hemisphere. Frontal theta is related to semantic and conflict processing; however, in this study it did not vary with institutionalization.

Early institutionalized care disrupts the development of emotion processing in prosody

Millions of children worldwide are raised in institutionalized settings. Unfortunately, institutionalized rearing is often characterized by psychosocial deprivation, leading to difficulties in numerous social, emotional, physical, and cognitive skills. One such skill is the ability to recognize emotional facial expressions. Children with a history of institutional rearing tend to be worse at recognizing emotions in facial expressions than their peers, and this deficit likely affects social interactions. However, emotional information is also conveyed vocally, and neither prosodic information processing nor the cross-modal integration of facial and prosodic emotional expressions have been investigated in these children to date. We recorded electroencephalograms (EEG) while 47 children under institutionalized care (IC) (n = 24) or biological family care (BFC) (n = 23) viewed angry, happy, or neutral facial expressions while listening to pseudowords with angry, happy, or neutral prosody. The results indicate that 20- to 40-month-olds living in IC have event-related potentials (ERPs) over midfrontal brain regions that are less sensitive to incongruent facial and prosodic emotions relative to children under BFC, and that their brain responses to prosody are less lateralized. Children under IC also showed midfrontal ERP differences in processing of angry prosody, indicating that institutionalized rearing may specifically affect the processing of anger.