title: Multidisciplinary investigation links backward-speech trait and working memory through genetic mutation.
abstract: Case studies of unusual traits can provide unique snapshots of the effects of modified systems. In this study, we report on an individual from a Serbian family with the ability to rapidly, accurately and voluntarily speak backwards. We consider psychological, neural and genetic correlates of this trait to identify specific relevant neural mechanisms and new molecular pathways for working memory and speech-related tasks. EEG data suggest that the effect of word reversal precedes semantic integration of visually presented backward-words, and that event-related potentials above the frontal lobe are affected by both word reversal and the maintenance of backward-words in working memory. fMRI revealed that the left fusiform gyrus may facilitate the production of backward-speech. Exome sequencing identified three novel coding variants of potential significance in the RIC3, RIPK1 and ZBED5 genes. Taken together, our data suggest that, in this individual, the ability to speak backwards is afforded by an extraordinary working memory capacity. We hypothesise that this is served by cholinergic projections from the basal forebrain to the frontal cortex and supported by visual semantic loops within the left fusiform gyrus and that these neural processes may be mediated by a genetic mutation in RIC3; a chaperone for nicotinic acetylcholine receptors.
authors.affiliation: Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium.
authors.forename: Stefan
authors.initials: S
authors.lastname: Prekovic
authors.affiliation: Department of Psychology, Faculty of Philosophy, University of Novi Sad, Novi Sad, Serbia.|Laboratory for Experimental Psychology, Faculty of Philosophy, University of Belgrade, Belgrade, Serbia.
authors.forename: Dušica Filipović
authors.initials: DF
authors.lastname: Đurđević
authors.affiliation: Institute of Psychology, Faculty of Arts, University of Szeged, Szeged, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Csifcsák
authors.affiliation: Diagnostic Imaging Center, Oncology Institute of Vojvodina, Sremska Kamenica, Serbia.|Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Olivera
authors.initials: O
authors.lastname: Šveljo
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Oliver
authors.initials: O
authors.lastname: Stojković
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Milica
authors.initials: M
authors.lastname: Janković
authors.affiliation: Diagnostic Imaging Center, Oncology Institute of Vojvodina, Sremska Kamenica, Serbia.|Medical Faculty, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Katarina
authors.initials: K
authors.lastname: Koprivšek
authors.affiliation: Wellcome Trust Center for Human Genetics, University of Oxford, Oxford, UK. OX3 7BN.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Covill
authors.affiliation: Diagnostic Imaging Center, Oncology Institute of Vojvodina, Sremska Kamenica, Serbia.|Medical Faculty, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Milos
authors.initials: M
authors.lastname: Lučić
authors.affiliation: Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Van den Broeck
authors.affiliation: Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium.
authors.forename: Christine
authors.initials: C
authors.lastname: Helsen
authors.affiliation: Wellcome Trust Center for Human Genetics, University of Oxford, Oxford, UK. OX3 7BN.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Ceroni
authors.affiliation: Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Claessens
authors.affiliation: Wellcome Trust Center for Human Genetics, University of Oxford, Oxford, UK. OX3 7BN.
authors.forename: Dianne F
authors.initials: DF
authors.lastname: Newbury
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009154:Mutation; D040641:Quantitative Trait Loci; D011932:Reading; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000235:genetics; D012660:Semantics; D055771:Serbia
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C496701:RIC3 protein, human; C506249:RIPK1 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases
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