title: Differential effects of left parietal theta-burst stimulation on order and quantity processing.
abstract: Numbers can be used to represent different meanings, including order information ('Steve lives at house number 24') and quantity ('Steve is paid 24 pounds'). The few previous neuroimaging studies that investigated order and quantity processing reported conflicting evidence as to whether same or partially overlapping brain systems are engaged in these processes. Such inconsistencies may be related to the use of neuroimaging techniques which do not allow causal inference regarding brain-behaviour relationships. To overcome this problem, the present study employed continuous theta-burst stimulation (TBS) to investigate whether interference to either the left or right parietal regions affected order and quantity in similar or different ways. Results revealed that following TBS to the left intraparietal sulcus, quantity processing was impaired and order facilitated; TBS to the contralateral brain region led to no specific effects in either order or quantity processing. These findings suggest that there are at least partially different neuronal populations involved in order and quantity processing, and that the left parietal cortex is critical for both processes.
authors.affiliation: Department of Psychology, Knowles Building, University of Hong Kong, Hong Kong. glfcheng@hku.hk
authors.forename: Gordon L F
authors.initials: GL
authors.lastname: Cheng
authors.forename: Joey
authors.initials: J
authors.lastname: Tang
authors.forename: Vincent
authors.initials: V
authors.lastname: Walsh
authors.forename: Brian
authors.initials: B
authors.lastname: Butterworth
authors.forename: Marinella
authors.initials: M
authors.lastname: Cappelletti
mesh_terms: D000328:Adult; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D059907:Functional Neuroimaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000502:physiology*; D011340:Problem Solving / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013826:Theta Rhythm / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation