Space, time, and numbers in the right posterior parietal cortex: Differences between response code associations and congruency effects

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2016-04, Vol.129, p.72-79
• Main Authors: Riemer, Martin, Diersch, Nadine, Bublatzky, Florian, Wolbers, Thomas
• Format: Article
• Language: English
• Subjects: Adult; Brain Mapping; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Mathematical Concepts; Mental number line; Mental time line; Numbers; Parietal Lobe - physiology; Perceptions; Posterior parietal cortex; Reaction Time - physiology; Simon effect; SNARC; Space Perception - physiology; Studies; Time Perception - physiology; Transcranial Magnetic Stimulation; Young Adult
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2016.01.030

The mental representations of space, time, and number magnitude are inherently linked. The right posterior parietal cortex (PPC) has been suggested to contain a general magnitude system that underlies the overlap between various perceptual dimensions. However, comparative studies including spatial, temporal, and numerical dimensions are missing. In a unified paradigm, we compared the impact of right PPC inhibition on associations with spatial response codes (i.e., Simon, SNARC, and STARC effects) and on congruency effects between space, time, and numbers. Prolonged cortical inhibition was induced by continuous theta-burst stimulation (cTBS), a protocol for transcranial magnetic stimulation (TMS), at the right intraparietal sulcus (IPS). Our results show that congruency effects, but not response code associations, are affected by right PPC inhibition, indicating different neuronal mechanisms underlying these effects. Furthermore, the results demonstrate that interactions between space and time perception are reflected in congruency effects, but not in an association between time and spatial response codes. Taken together, these results implicate that the congruency between purely perceptual dimensions is processed in PPC areas along the IPS, while the congruency between percepts and behavioral responses is independent of this region. •Congruency effects between space, time, and numbers are mediated by PPC.•Response code associations (Simon, SNARC, and STARC) are independent from PPC.•We assessed time–space interactions via position in time instead of duration magnitude.•We found no association between early/late events and left/right responses.