Use of eye tracking improves the detection of evoked responses to complex visual stimuli during EEG in infants

Objective To improve the reliability of detecting EEG responses evoked by complex visual stimuli to the level required for clinical use by integrating an eye tracker to the EEG setup and optimizing the analysis protocol. Methods Infants were presented with continuous orientation reversal (OR), global form (GF), and global motion (GM) stimuli. Eye tracking was used to control stimulus presentation and exclude epochs with disoriented gaze. The spectral responses were estimated from 13 postcentral EEG channels using a circular variant of Hotelling’s T2 test statistic. Results Among 39 healthy infants, statistically significant (pPeer reviewe

Phase-based cortical synchrony is affected by prematurity

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Evidence for spared attention to faces in 7-month-old infants after prenatal exposure to antiepileptic drugs

Introduction: Prenatal antiepileptic drug (AED) exposure is associated with an increased risk of cognitive impairment and autism spectrum disorders detected mainly at the age of two to six years. We examined whether the developitiental aberrations associated with prenatal AED exposure-could be-detected already in infancy and whether effects on visual attention can be observed at this early age. Material and methods: We compared a prospective cohort of infants with in utero exposure to AED (n = 56) with infants without drug exposures (n = 62). The assessments performed at the age of seven months included standardized neurodevelopmental scores (Griffiths Mental Developmental Scale and Hammersmith Infant Neurological Examination) as well as a novel eye-tracking-based test for visual attention and orienting to faces. Background information included prospective collection of AED exposure data, pregnancy outcome, neuropsychological evaluation of the mothers, and information on maternal epilepsy type. Results: Carbamazepine, oxcarbazepine, and valproate, but not lamotrigine or levetiracetam, were associated with impaired early language abilities at the age of seven months. The general speed of visuospatial orienting or attentional bias for faces measured by eye-tracker-based tests did not differ between AED-exposed and control infants. Discussion: Our findings support the idea that prenatal AED exposure may impair verbal abilities, and this effect may be detected already in infancy. In contrast, the early development of attention to faces was spared after in utero AED exposure. (C) 2016 Elsevier Inc. All rights reserved.Peer reviewe

Prenatal exposure to antiepileptic drugs and early processing of emotionally relevant sounds

Introduction: Prenatal exposure to antiepileptic drugs (AEDs) is associated with developmental compromises in verbal intelligence and social skills in childhood. Our aim was to evaluate whether a multifeature Mismatch Negativity (MMN) paradigm assessing semantic and emotional components of linguistic and emotional processing would be useful to detect possible alterations in early auditory processing of newborns with prenatal AED exposure. Material and methods: Data on AED exposure. pregnancy outcome, neuropsychological evaluation of the mothers, information on maternal epilepsy type, and a structured neurological examination of the newborn were collected prospectively. Blinded to AED exposure, we compared a cohort of 36 AED-exposed with 46 control newborns at the age of two weeks by measuring MMN with a multifeature paradigm with six linguistically relevant deviant sounds and three emotionally uttered sounds. Results: Frontal responses for the emotionally uttered stimulus Happy differed significantly in the exposed newborns compared with the control newborns. In addition, responses to sounds with or without emotional component differed in newborns exposed to multiple AEDs compared with control newborns or to newborns exposed to only one AED. Conclusions: These preliminary findings suggest that prenatal AED exposure may alter early processing of emotionally and linguistically relevant sound information. (C) 2019 Elsevier Inc. All rights reserved.Peer reviewe

Preterm Birth Changes Networks of Newborn Cortical Activity

CORRIGENDUM: DOI: 10.1093/cercor/bhy100 Published: APR 2019Preterm birth is the greatest risk factor for lifelong neurocognitive deficits, globally. The effect of prematurity on early cortical network function has, however, remained poorly understood. Here, we developed a novel methodology that allows reliable assessment of functional connectivity in neonatal brain activity at millisecond and multisecond scales in terms of cortical phase and amplitude correlations, respectively. We measured scalp electroencephalography at term-equivalent age in infants exposed to very early prematurity as well as in healthy controls. We found that newborn cortical activity organizes into multiplex networks that differ significantly between vigilance states. As compared with healthy control infants, prematurity was found to cause frequency-specific patterns of dysconnectivity in cortical network, changes that were distinct for networks of phase and amplitude correlations. Neuroanatomically, the most prominent markers of prematurity were found in connections involving the frontal regions. Phase synchrony in frontally connected networks was correlated with newborn neurological performance, suggesting the first measure of cortical functional coupling that correlates with neurological performance in human infant.Peer reviewe

Dynamic Eye Tracking Based Metrics for Infant Gaze Patterns in the Face-Distractor Competition Paradigm

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Katseen kuljettaessa : katsekäyttäytymisessä on jatkumoita vastasyntyneisyyskaudelta seitsemän kuukauden ikään

Background and purpose: Newborn visual alertness (NVA) and orientation (NVO) are established clinical markers of brain health and maturation. They are thought to reflect the early form of attentional alerting and orienting networks and form the base for the development of more complex cognitive and executive functions that emerge later in infancy and early childhood. To examine this hypothesis, the present study aimed to find out if NVA and NVO are associated with attention regulation at the age of 7 months. Methods: This study was a part of two larger ongoing research projects. A total of 54 full term low risk infants were included in the study. The infants' NVA and NVO were assessed as part of a regular neurological assessment of a newborn infant. Later, at the age of seven months, the infants participated in an eye-tracking study. Four alternating stimuli (fearful, happy and neutral face and noise stimulus) were presented as the central stimulus and a geometrical shape (black and white balls or checker board) as the overlapping peripheral target. The gaze shift latencies from central stimulus to the peripheral target and the effect of the central stimulus' content on the gaze shift latencies were analyzed and then compared between the different NVA and NVO groups. Results: NVA: Infants with good and intermediate NVA shifted gaze fast and showed the bias towards a fearful face. Infants who looked only briefly at the moving target as newborns (poor NVA) were also fast but had no bias towards fearful faces. NVO: Infants with good NVO were also fast in shifting gaze and fearful faces modified the gaze behavior. Infants who followed moving targets only with gaze without a head turn as newborns (intermediate NVO) were slower than the other infants in gaze shifting at the age of seven months. Additionally, these infants did not show the bias towards fearful faces. Infants with poor NVO were not different from the infants with the best NVO showing fast and flexible gaze behavior. Conclusions: These results suggest a continuum of gaze behavior from the newborn period to the late infancy. Good alertness and orientation were associated with good attentional and perceptual competence at the age of seven months. Weak alertness was associated with fast and less flexible gaze behavior than in the other infants at the age of seven months. Following with eye movements only was associated with slow and less flexible gaze behavior than in the other infants. The differences in the gaze behavior of the infants who followed only with the gaze or had a poor alertness when compared to the other infants can reflect typical but slower maturation of an infant or more persistent difference in the development.Tausta ja tavoitteet: Vastasyntyneen visuaalinen valppaus (VVV, engl. newborn visual alertness, NVA) ja orientaatiokyky (VVO; engl. newborn visual orientation, NVO) ovat tärkeitä aivojen kehitykselle. Näiden kykyjen ajatellaan heijastavan myös tarkkaavuuden säätelyyn liittyvien aivoverkostojen toimintaa, jotka toimivat pohjana myöhemmin lapsuudessa kehittyville monimutkaisemmille kognitiivisille ja eksekutiivisille toiminnoille. Tämän työn tarkoitus oli selvittää, onko vastasyntyneen VVV ja VVO yhteydessä visuaalisen tarkkaavuuden säätelyyn seitsemän kuukauden iässä. Metodit: Tutkimus on osa kahta suurempaa käynnissä olevaa tutkimusprojektia. Tutkimusaineisto koostui yhteensä 54 täysiaikaisena syntyneestä terveestä vauvasta. VVV ja VVO arvioitiin osana vastasyntyneen vauvan neurologista tutkimusta. Lapset osallistuivat 7 kuukauden iässä silmänliiketutkimukseen, jossa heille näytettiin vuorotellen yhtä neljästä erilaisesta ärsykkeestä (iloiset, pelokkaat ja neutraalit kasvot tai häiriöärsyke) ja kuvaruudun laitaan ilmestyvää geometrista kuviota (mustavalkoisia ruutuja tai palloja). Tutkimuksessa mitattiin lasten katseensiirtoja kasvokuvista ruudun laidassa esitettyyn kuvioon silloin, kun molemmat ärsykkeet olivat samanaikaisesti näytöllä. Katseensiirtoaikoja seitsemän kuukauden iässä verrattiin vastasyntyneisyysvaiheen VVA- ja VVO-löydöksiin. Tulokset: Lasten, joilla oli hyvä tai kohtalainen VVV, katseensäätely kyky oli seitsemän kuukauden iässä nopea ja joustava. Lapset, joilla oli heikko VVV vastasyntyneenä, olivat 7 kuukauden iässä nopeita katseensiirroissa, mutta pelokkailla kasvoilla ollut odotettua vaikutusta näiden lasten katsekäyttäytymiseen. Lasten, joilla oli hyvä VVO, katseensäätelykyky 7 kuukauden iässä oli nopeaa ja pelokkaat kasvot vaikuttivat katsekäyttäytymiseen. Lapsilla, jotka seurasivat vastasyntyneenä liikkuvaa kohdetta kääntämättä päätä (kohtalainen VVO) havaittiin 7 kuukauden iässä hidas katsekäyttäytyminen ja pelokkaiden kasvojen vaikutusta ei havaittu. Heikon VVO:n lapsilla katseensäätelykyky oli hyvä. Johtopäätökset: Tulokset tukevat sitä, että vastasyntyneen katsekäyttäytyminen muodostaa jatkumon seitsemän kuukauden ikään. Hyvä VVV ja VVO ovat yhteydessä hyviin tarkkaavuuden säätelyn ja havaitsemisen taitoihin seitsemän kuukauden iässä. Heikko VVV on yhteydessä nopeaan ja joustamattomaan katsekäyttäytymiseen. Orientaatio ilman pään liikettä (kohtalainen VVO) vastasyntyneenä yhdistyi hitaaseen ja joustamattomaan katsekäyttäytymiseen. Nämä erot seitsemän kuukauden iässä voivat ilmentää muihin vauvoihin verrattuna hitaampaa kehitystä tai pysyvämpää eroavaisuutta niillä vauvoilla, joilla oli vastasyntyneenä heikko visuaalinen valppaus tai jotka seurasivat vain katseella kääntämättä päätä

Use of complex visual stimuli allows controlled recruitment of cortical networks in infants

Objective To characterize cortical networks activated by patterned visual stimuli in infants, and to evaluate their potential for assessment of visual processing and their associations with neurocognitive development. Methods Three visual stimuli, orientation reversal (OR), global form (GF), and global motion (GM), were presented to cohort of five-month-old infants (N=26). Eye tracker was used to guide the stimulation and to choose epochs for analysis. Visual responses were recorded with electroencephalography and analysed in source space using weighted phase lag index as the connectivity measure. The networks were quantified using several metrics that were compared between stimuli and correlated to cognitive outcomes. Results Responses to OR/GF/GM stimuli were observed in nearly all (96/100/100%) recordings. All stimuli recruited cortical networks that were significantly different in their properties. The more complex GF and GM conditions recruited wider global networks than OR. Additionally, strength of the GF network showed positive association with later cognitive performance. Conclusions Network analysis suggests that visual stimulation recruits vast cortical networks extending far beyond the conventional visual streams and differ between stimulation conditions. Significance The method allows controlled recruitment of wide cortical networks, which holds promise for the early assessment of visual processing and its related higher-order cognitive processes.Peer reviewe