Open AccessDetection and characterization of single‐trial fMRI bold responses: Paradigm free mapping
Author(s) -
Gaudes César Caballero,
Petridou Natalia,
Dryden Ian L.,
Bai Li,
Francis Susan T.,
Gowland Penny A.
Publication year - 2011
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.21116
Subject(s) - voxel , computer science , artificial intelligence , finger tapping , psychology , false discovery rate , inference , brain mapping , functional magnetic resonance imaging , cued speech , pattern recognition (psychology) , neuroscience , cognitive psychology , audiology , medicine , biochemistry , chemistry , gene
This work presents a novel method of mapping the brain's response to single stimuli in space and time without prior knowledge of the paradigm timing: paradigm free mapping (PFM). This method is based on deconvolution of the hemodynamic response from the voxel time series assuming a linear response and using a ridge‐regression algorithm. Statistical inference is performed by defining a spatio‐temporal t ‐statistic and by controlling for multiple comparisons using the false discovery rate procedure. The methodology was validated on five subjects who performed self‐paced and visually cued finger tapping at 7 Tesla, with moderate (TR = 2 s) and high (TR = 0.4 s) temporal resolution. The results demonstrate that detection of single‐trial BOLD events is feasible without a priori information on the stimulus paradigm. The proposed method opens up the possibility of designing temporally unconstrained paradigms to study the cortical response to unpredictable mental events. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.