title: Computer-mouse tracking reveals TMS disruptions of prefrontal function during semantic retrieval.
abstract: Converging evidence from neuroimaging and neuropsychological studies is essential for understanding human frontal cortical function. We introduce a new method for studying the effects of transient disruptions of frontal activity during transcranial magnetic stimulation (TMS). Using a novel combination of TMS and computer-mouse tracking, through two experiments we tested process models of semantic competition in left ventrolateral prefrontal cortex (VLPFC). On TMS stimulation of left mid-VLPFC just after presentation of an ambiguous stimulus, participants' mouse-movement trajectories deviated more toward the incorrect target for weak associate trials than for any other trial type. This effect was extinguished when participants were simultaneously shown both target and cue stimuli. Results suggest that left mid-VLPFC is necessary to resolve semantic competition when a response is underdetermined by the stimulus and the interpretive context of the stimulus is ambiguous. Computer-mouse movements reveal the dynamics of competitive interactions as they resolve, making this technique ideally suited for studying cognitive control processes and a more sensitive index of TMS disruption than reaction time and accuracy alone.
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104-6241, USA. hindy@psych.upenn.edu
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Hindy
authors.forename: Roy
authors.initials: R
authors.lastname: Hamilton
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Houghtling
authors.forename: H Branch
authors.initials: HB
authors.lastname: Coslett
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Thompson-Schill
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D011939:Mental Recall / Q000502:physiology*; D051379:Mice; D017397:Prefrontal Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D050781:Transcranial Magnetic Stimulation / Q000009:adverse effects*; D055815:Young Adult