Laterality

Morphological right-left asymmetry appears to be the rule, rather than the exception in nature, all the way from chiral molecules to the Baryon asymmetry in the universe. Asymmetry is the rule for biological systems as well, whereby even single-celled organisms are commonly asymmetric.

Human beings are certainly structurally and functionally asymmetric, from the size of their feet and hands to the placement of visceral organs and facial features. In fact, the two aspects of behavior specific to humans, the use of language and the strong population-level preference for hand use, are both asymmetric, lateralized traits. When it comes to language, the majority of humans are left-hemisphere dominant for language functions, while the right hand is the preferred hand for over 9 out of 10 individuals; a pattern far from negligible.

Laterality is the main focus of our work. We have been studying behavioral laterality (e.g., handedness, footedness, and cradling laterality) as well as brain laterality (also known as brain asymmetry, hemispheric dominance, or hemispheric specialization). We are using meta-analytic methods, as well as behavioral, hormonal, and brain imaging techniques to study questions such as sex differences in handedness and brain lateralization, handedness in populations with special education needs, and cerebral laterality during writing.

This endeavor, apart from its intrinsic interest, gains importance from the fact that the study of handedness and language lateralization contributes to the broader question of individual differences in brain organisation and abilities. Such differences are of key importance to psychiatric, neurological, and neuropsychological research and practice as well as to the study of the genetics of asymmetry.

Relevant publications

Papadatou-Pastou, M., Ntolka, E., Schmitz, J., Martin, M., Munafo, M. R., Ocklenburg, S., & Paracchini, S. Human handedness: A meta-analysis. Psychological Bulletin, in press. Doi: https://doi.org/10.1037/bul0000229

Packheiser, J., Schmitz, J., Berretz, G., Rook, N., Abdelkader Serir, A., Papadatou-Pastou, M., & Ocklenburg, O. (2019). Handedness and sex effects on lateral biases in human cradling: Three meta-analyses. Neuroscience and Biobehavioral Reviews, 104, 30-42. Doi: 10.1016/j.neubiorev.2019.06.035

Mohammadi, H., & Papadatou-Pastou, M. (2019). Cerebral laterality as assessed by hand preference measures and developmental stuttering. Laterality: Asymmetries of Body, Brain and Cognition, 1-23. Doi: 10.1080/1357650X.2019.1621329

Ocklenburg, S., Isparta, S., Peterburs, J., & Papadatou-Pastou, M. (2019). Paw preferences in cats and dogs: Meta-analysis. Laterality: Asymmetries of Body, Brain and Cognition, 1-31. Doi: 10.1080/1357650X.2019.1578228

Ntolka, E., & Papadatou-Pastou, M. (2018). Right-handers have negligibly higher IQ scores than left-handers: Systematic review and meta-analyses. Neuroscience & Biobehavioral Reviews, 84,376-393. Doi: https://doi.org/10.1016/j.neubiorev.2017.08.007

Markou, P., Ahtam, B., & Papadatou-Pastou, M. (2017). Elevated levels of atypical handedness in autism: Meta-analyses. Neuropsychology Review, 1-26. Doi: https://doi.org/10.1007/s11065-017-9354-4

Papadatou-Pastou, M., & Martin, M. (2017). Cerebral laterality for language is related to adult salivary testosterone levels but not digit ratio (2D: 4D) in men: A functional transcranial Doppler ultrasound study. Brain and Language, 166, 52-62. Doi: https://doi.org/10.1016/j.bandl.2016.12.002

Papadatou-Pastou, M., Martin, M., & Mohr, C. (2017). Salivary testosterone levels are unrelated to handedness or cerebral lateralization for language. Laterality: Asymmetries of Body, Brain and Cognition, 22(2), 123-156. Doi: https://doi.org/10.1080/1357650X.2016.1149485

Kondyli, D., Stathopoulou, D., Badcock, N. A., & Papadatou-Pastou, M. (2017). Cerebral laterality for the generation of silent and written language in male and female right- and left-handers: A functional transcranial Doppler ultrasound study. Acta Neuropsychologica, 15(4), 407-432. Doi: https://doi.org/10.5604/01.3001.0010.7480

Papadatou-Pastou, M., & Sáfár, A. (2016). Handedness prevalence in the deaf: Meta-analyses. Neuroscience and Biobehavioral Reviews. 60, 98-114. Doi: https://doi.org/10.1016/j.neubiorev.2015.11.013

Papadatou-Pastou, M., & Tomprou^, D. M. (2015). Intelligence and handedness: Meta-analyses of studies on intellectually disabled, typically developing and gifted individuals. Neuroscience and Biobehavioural Reviews, 56, 151-156, Doi: https://doi.org/10.1016/j.neubiorev.2015.06.017

Papadatou-Pastou*, M. (2015). Functional magnetic resonance imaging: The hemodynamic

Κουφάκη, Α., & Παπαδάτου-Παστού*, Μ. (2014). Δυσλεξία και εγκεφαλική ασυμμετρία. Ανασκόπηση μελετών ανατομικής και λειτουργικής απεικόνισης. Ψυχολογία, 21(4), 379-394

Παπαδάτου-Παστού*, Μ., Κουφάκη, Α., Ράντου, Ν. Μ., & Τόμπρου, Δ. Μ. (2013). Λειτουργικός διακρανιακός υπέρηχος Doppler: αρχές λειτουργίας και εφαρμογές στη μελέτη της ημισφαιρικής επικράτησης της γλώσσας. Hellenic Journal of Psychology, 10, 61-77.

Papadatou-Pastou, M., Martin, M., & Munafò, M.R. (2013). Measuring hand preference: a comparison among different response formats using a selected sample. Laterality: Asymmetries of Body, Brain and Cognition, 18(1), 68-107. Doi: https://doi.org/10.1080/1357650X.2011.628794

Papadatou-Pastou*, M. (2011). Handedness and language lateralization: Why are we right-handed and left- brained? Hellenic Journal of Psychology, 8, 248-265. (English-language paper)

Martin, M., Papadatou-Pastou, M., Jones, G. V., & Munafò, M. (2010) Sex and location as determinants of handedness: reply to Vuoksimaa and Kaprio (2010). Psychological Bulletin, 136(3), 348-350. Doi: http://dx.doi.org/10.1037/a0019215

Bishop, D. V. M., Watt, H., & Papadatou-Pastou, M. (2009). An efficient and reliable method for measuring cerebral lateralisation during speech with functional transcranial Doppler ultrasound, Neuropsychologia, 47, 587-590. Doi: https://doi.org/10.1016/j.neuropsychologia.2008.09.013

Papadatou-Pastou, M., Martin, M., Munafò, M. R., & Jones, G. V. (2008). Sex differences in left-handedness: A meta-analysis of 144 studies, Psychological Bulletin, 134(5), 677-99. Doi: http://dx.doi.org/10.1037/a0012814