Przemyslaw Tomalski

Publications (8) View all

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  Available from: Derek G. Moore

  Article: Socio-economic status and functional brain development – associations in early infancy

  Przemyslaw Tomalski, Derek G. Moore, Helena Ribeiro, Emma L. Axelsson, Elizabeth Murphy, Annette Karmiloff-Smith, Mark H. Johnson, Elena Kushnerenko
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  ABSTRACT: Socio-­‐economic status (SES) impacts on both structural and functional brain development in childhood, but how early its effects can be demonstrated is unknown. In this study we measured resting baseline EEG activity in the gamma frequency range in awake 6-­9 months-­‐olds from areas of East London with high socio-­‐economic deprivation. Between-­‐subject comparisons of infants from low-­‐ and high-­‐income families revealed significantly lower frontal gamma power in infants from low-­‐income homes. Similar power differences were found when comparing infants according to maternal occupation, with lower occupational status groups yielding lower power. Infant sleep, maternal education, length of gestation, and birthweight, as well as smoke exposure and bilingualism, did not explain these differences. Our results show that the effects of socio-­‐economic disparities on brain activity can already be detected in early infancy, potentially pointing to very early risk for language and attention difficulties. This is the first study to reveal region-­‐selective differences in functional brain development associated with early infancy in low-­‐income families.
  Developmental Science 01/2013; · 3.89 Impact Factor
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  Available from: Przemyslaw Tomalski

  Article: Atypical Audiovisual Speech Integration in Infants at Risk for Autism

  Jeanne A Guiraud, Przemyslaw Tomalski, Elena Kushnerenko, Helena Ribeiro, Kim Davies, Tony Charman, Mayada Elsabbagh, Mark H Johnson
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  ABSTRACT: The language difficulties often seen in individuals with autism might stem from an inability to integrate audiovisual information, a skill important for language development. We investigated whether 9-month-old siblings of older children with autism, who are at an increased risk of developing autism, are able to integrate audiovisual speech cues. We used an eye-tracker to record where infants looked when shown a screen displaying two faces of the same model, where one face is articulating/ba/and the other/ga/, with one face congruent with the syllable sound being presented simultaneously, the other face incongruent. This method was successful in showing that infants at low risk can integrate audiovisual speech: they looked for the same amount of time at the mouths in both the fusible visual/ga/2 audio/ba/and the congruent visual/ba/2 audio/ba/ displays, indicating that the auditory and visual streams fuse into a McGurk-type of syllabic percept in the incongruent condition. It also showed that low-risk infants could perceive a mismatch between auditory and visual cues: they looked longer at the mouth in the mismatched, non-fusible visual/ba/2 audio/ga/display compared with the congruent visual/ga/2 audio/ ga/display, demonstrating that they perceive an uncommon, and therefore interesting, speech-like percept when looking at the incongruent mouth (repeated ANOVA: displays x fusion/mismatch conditions interaction: F(1,16) = 17.153, p = 0.001). The looking behaviour of high-risk infants did not differ according to the type of display, suggesting difficulties in matching auditory and visual information (repeated ANOVA, displays x conditions interaction: F(1,25) = 0.09, p = 0.767), in contrast to low-risk infants (repeated ANOVA: displays x conditions x low/high-risk groups interaction: F(1,41) = 4.466, p = 0.041). In some cases this reduced ability might lead to the poor communication skills characteristic of autism. Citation: Guiraud JA, Tomalski P, Kushnerenko E, Ribeiro H, Davies K, et al. (2012) Atypical Audiovisual Speech Integration in Infants at Risk for Autism. PLoS ONE 7(5): e36428. doi:10.1371/journal.pone.0036428 Editor: Copyright: ß 2012 Guiraud et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The British Autism Study of Infant Siblings (BASIS) is supported by a consortium of funders led by Autistica (see www.basisnetwork.org). This project is additionally supported by MRC (Medical Research Council) grant G0701484 to MHJ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist.
  PLoS ONE 05/2012; · 4.09 Impact Factor
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  Available from: Przemyslaw Tomalski

  Article: Cortical sensitivity to contrast polarity and orientation of faces is modulated by temporal-nasal hemifield asymmetry.

  Przemyslaw Tomalski, Mark H Johnson
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  ABSTRACT: Behavioral studies demonstrate that the efficiency of detection of faces is dependent on configural and contrast polarity information characteristic to human faces. Stimulus inversion or contrast polarity reversal can disrupt this process. We investigated whether a face-sensitive event-related potential component, the N170, is modulated by the orientation and contrast polarity of highly degraded schematic face-like patterns (Experiment 1) in the same manner as it is for face photographs (Experiment 2). Inversion and/or contrast reversal delayed and enhanced the N170 for both kinds of stimuli, suggesting that a white oval with three black squares is sufficient to elicit face-sensitive cortical responses. In Experiment 3 we further tested whether the extrageniculate visual pathways modulate early cortical responses to faces. We found that the N170 responses to configural and contrast information are modulated by temporal-nasal visual field asymmetry under monocular viewing conditions, suggesting the involvement of subcortical, extrageniculate visual pathways in face detection. These results are consistent with the idea that an ontogenetically early and primitive bias to orient towards face-like patterns with relevant configural and contrast information influences the early stages of cortical face processing.
  Brain Imaging and Behavior 03/2012; 6(1):88-101. · 1.66 Impact Factor
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  Available from: Przemyslaw Tomalski

  Article: Differential habituation to repeated sounds in infants at high risk for autism.

  Jeanne A Guiraud, Elena Kushnerenko, Przemyslaw Tomalski, Kim Davies, Helena Ribeiro, Mark H Johnson
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  ABSTRACT: It has been suggested that poor habituation to stimuli might explain atypical sensory behaviours in autism. We investigated habituation to repeated sounds using an oddball paradigm in 9-month-old infants with an older sibling with autism and hence at high risk for developing autism. Auditory-evoked responses to repeated sounds in control infants (at low risk of developing autism) decreased over time, demonstrating habituation, and their responses to deviant sounds were larger than responses to standard sounds, indicating discrimination. In contrast, neural responses in infants at high risk showed less habituation and a reduced sensitivity to changes in frequency. Reduced sensory habituation may be present at a younger age than the emergence of autistic behaviour in some individuals, and we propose that this could play a role in the over responsiveness to some stimuli and undersensitivity to others observed in autism.
  Neuroreport 09/2011; 22(16):845-9. · 1.66 Impact Factor
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  Available from: Przemyslaw Tomalski

  Article: The effects of early adversity on the adult and developing brain.

  Przemyslaw Tomalski, Mark H Johnson
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  ABSTRACT: Recent advances in neuroimaging methods have provided new ways of unravelling the complex interplay between genetic and environmental factors that influence functional brain development in the critical first years of life. This has allowed new insights into the effects that early adverse experience can exert on the brain later in life. We review recent progress in the characterization of those effects and underlying mechanisms through which adverse environment influences the neurocognitive development. Socioeconomic background may have a profound effect on structural and functional brain development, especially in the domains of language and prefrontal executive control. These effects are mediated by several factors: diet, quality of parental care, impoverished environment, prenatal exposure to toxic substances and so on. Other circumstances such as perinatal brain injury, early sensory deprivation or limb malformation may result in atypical functional organization of the brain and lasting cognitive impairment of certain functions. Early experience of maltreatment or institutionalized care may alter the development of the social brain, contributing to negative mental health outcomes, which may be partially reversed through early intervention programmes. Subsequent models of psychiatric disorder should take into account early risk factors and embrace developmental models at multiple levels of biological organization. There is a continuing need for the study of optimal environmental input during sensitive periods in brain development.
  Current opinion in psychiatry 03/2010; 23(3):233-8. · 3.57 Impact Factor