Tina Weis1, Barbara Estner1, Christoph M Krick2, Wolfgang Reith2, Thomas Lachmann3. 1. Cognitive and Developmental Psychology Unit, Center for Cognitive Science, University of Kaiserslautern, Erwin-Schrödinger-Straße 57, 67663 Kaiserslautern, Germany. 2. Clinic of Diagnostic and Interventional Neuroradiology, Saarland University Hospital, Kirrberger Straße 100, 66424 Homburg, Germany. 3. Cognitive and Developmental Psychology Unit, Center for Cognitive Science, University of Kaiserslautern, Erwin-Schrödinger-Straße 57, 67663 Kaiserslautern, Germany. Electronic address: lachmann@rhrk.uni-kl.de.
Abstract
BACKGROUND: Stimulus-response compatibility (SRC) plays a major role in choice-reaction tasks. In specific cases, SRC leads to phenomena like the Spatial Numerical Association of Response Codes (SNARC) or the Spatial Pitch Association of Response Codes (SPARC) effect: small numbers or low pitches lead to faster responses when answered with the left hand, whereas large numbers or high pitches lead to faster responses when answered with the right hand. The previous study, investigating the combination of SNARC and SPARC with numbers spoken in different pitch heights, points towards an interdependency of both SNARC and SPARC compatibility effects, suggesting an automatic process. METHODS: In the present event-related functional magnetic resonance imaging (fMRI) study, we investigated the underlying neural activity when SNARC and SPARC are combined within the same auditory stimulus (numerical condition). Additionally, we included a categorical condition (the words "small" and "large") as variation of the stimulus type. RESULTS: We found neither an effect for SNARC nor for SPARC Compatibility in the neuronal data, whereas SNARC Compatibility was found in the behavioral data. According to the behavioral as well as the neuronal data, in the bilateral auditory cortex, SNARC and SPARC Compatibility interacts with Stimulus Type, i.e., whether numerical or categorical stimuli were presented. CONCLUSIONS: We concluded that both effects are interdependent and that this interaction strongly depends on the semantic information.
BACKGROUND: Stimulus-response compatibility (SRC) plays a major role in choice-reaction tasks. In specific cases, SRC leads to phenomena like the Spatial Numerical Association of Response Codes (SNARC) or the Spatial Pitch Association of Response Codes (SPARC) effect: small numbers or low pitches lead to faster responses when answered with the left hand, whereas large numbers or high pitches lead to faster responses when answered with the right hand. The previous study, investigating the combination of SNARC and SPARC with numbers spoken in different pitch heights, points towards an interdependency of both SNARC and SPARC compatibility effects, suggesting an automatic process. METHODS: In the present event-related functional magnetic resonance imaging (fMRI) study, we investigated the underlying neural activity when SNARC and SPARC are combined within the same auditory stimulus (numerical condition). Additionally, we included a categorical condition (the words "small" and "large") as variation of the stimulus type. RESULTS: We found neither an effect for SNARC nor for SPARC Compatibility in the neuronal data, whereas SNARC Compatibility was found in the behavioral data. According to the behavioral as well as the neuronal data, in the bilateral auditory cortex, SNARC and SPARC Compatibility interacts with Stimulus Type, i.e., whether numerical or categorical stimuli were presented. CONCLUSIONS: We concluded that both effects are interdependent and that this interaction strongly depends on the semantic information.