title: Inferring common cognitive mechanisms from brain blood-flow lateralization data: a new methodology for fTCD analysis.
abstract: Current neuroimaging techniques with high spatial resolution constrain participant motion so that many natural tasks cannot be carried out. The aim of this paper is to show how a time-locked correlation-analysis of cerebral blood flow velocity (CBFV) lateralization data, obtained with functional TransCranial Doppler (fTCD) ultrasound, can be used to infer cerebral activation patterns across tasks. In a first experiment we demonstrate that the proposed analysis method results in data that are comparable with the standard Lateralization Index (LI) for within-task comparisons of CBFV patterns, recorded during cued word generation (CWG) at two difficulty levels. In the main experiment we demonstrate that the proposed analysis method shows correlated blood-flow patterns for two different cognitive tasks that are known to draw on common brain areas, CWG, and Music Synthesis. We show that CBFV patterns for Music and CWG are correlated only for participants with prior musical training. CBFV patterns for tasks that draw on distinct brain areas, the Tower of London and CWG, are not correlated. The proposed methodology extends conventional fTCD analysis by including temporal information in the analysis of cerebral blood-flow patterns to provide a robust, non-invasive method to infer whether common brain areas are used in different cognitive tasks. It complements conventional high resolution imaging techniques.
authors: Department of Psychological Sciences, University of Liverpool Liverpool, UK.
authors: Georg F
authors: GF
authors: Meyer
authors: School of Psychology, University of Liverpool Liverpool, UK.
authors: Amy
authors: A
authors: Spray
authors: Department of Archaeology, Classics and Egyptology, University of Liverpool Liverpool, UK.
authors: Jo E
authors: JE
authors: Fairlie
authors: Department of Archaeology, Classics and Egyptology, University of Liverpool Liverpool, UK.
authors: Natalie T
authors: NT
authors: Uomini
keywords: Tower of London; cued word generation; hemodynamics; language; lateralization; middle cerebral artery; music; temporal patterns