title: From perceptual to lexico-semantic analysis--cortical plasticity enabling new levels of processing.
abstract: Certain kinds of stimuli can be processed on multiple levels. While the neural correlates of different levels of processing (LOPs) have been investigated to some extent, most of the studies involve skills and/or knowledge already present when performing the task. In this study we specifically sought to identify neural correlates of an evolving skill that allows the transition from perceptual to a lexico-semantic stimulus analysis. Eighteen participants were trained to decode 12 letters of Morse code that were presented acoustically inside and outside of the scanner environment. Morse code was presented in trains of three letters while brain activity was assessed with fMRI. Participants either attended to the stimulus length (perceptual analysis), or evaluated its meaning distinguishing words from nonwords (lexico-semantic analysis). Perceptual and lexico-semantic analyses shared a mutual network comprising the left premotor cortex, the supplementary motor area (SMA) and the inferior parietal lobule (IPL). Perceptual analysis was associated with a strong brain activation in the SMA and the superior temporal gyrus bilaterally (STG), which remained unaltered from pre and post training. In the lexico-semantic analysis post learning, study participants showed additional activation in the left inferior frontal cortex (IFC) and in the left occipitotemporal cortex (OTC), regions known to be critically involved in lexical processing. Our data provide evidence for cortical plasticity evolving with a learning process enabling the transition from perceptual to lexico-semantic stimulus analysis. Importantly, the activation pattern remains task-related LOP and is thus the result of a decision process as to which LOP to engage in.
authors: Department of Neurology, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors: Lara
authors: L
authors: Schlaffke
authors: Department of Neuropsychology, Ruhr-University Bochum, Bochum, Germany.
authors: Naima N
authors: NN
authors: Rüther
authors: Department of Neurology, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors: Stefanie
authors: S
authors: Heba
authors: Department of Neurology, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors: Lauren M
authors: LM
authors: Haag
authors: Department of Computer Science, University of Bonn, Germany.
authors: Thomas
authors: T
authors: Schultz
authors: Department of Experimental Psychology, University of Regensburg, Germany.
authors: Katharina
authors: K
authors: Rosengarth
authors: Department of Neurology, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors: Martin
authors: M
authors: Tegenthoff
authors: Department of Neuropsychology, Ruhr-University Bochum, Bochum, Germany.|Department of Psychology, Heinrich-Heine University Düsseldorf, Germany.
authors: Christian
authors: C
authors: Bellebaum
authors: Department of Neurology, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
authors: Tobias
authors: T
authors: Schmidt-Wilcke
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D006801:Humans; D007802:Language; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D012660:Semantics; D055815:Young Adult
keywords: cortical plasticity; fMRI; learning; levels of processing; perception