Transmodal comparison of auditory, motor, and visual post-processing with and without intentional short-term memory maintenance.
OBJECTIVE
To elucidate the contributions of modality-dependent post-processing in auditory, motor and visual cortical areas to short-term memory.


METHODS
We compared late negative waves (N700) during the post-processing of single lateralized stimuli which were separated by long intertrial intervals across the auditory, motor and visual modalities. Tasks either required or competed with attention to post-processing of preceding events, i.e. active short-term memory maintenance.


RESULTS
N700 indicated that cortical post-processing exceeded short movements as well as short auditory or visual stimuli for over half a second without intentional short-term memory maintenance. Modality-specific topographies pointed towards sensory (respectively motor) generators with comparable time-courses across the different modalities. Lateralization and amplitude of auditory/motor/visual N700 were enhanced by active short-term memory maintenance compared to attention to current perceptions or passive stimulation. The memory-related N700 increase followed the characteristic time-course and modality-specific topography of the N700 without intentional memory-maintenance.


CONCLUSIONS
Memory-maintenance-related lateralized negative potentials may be related to a less lateralised modality-dependent post-processing N700 component which occurs also without intentional memory maintenance (automatic memory trace or effortless attraction of attention). Encoding to short-term memory may involve controlled attention to modality-dependent post-processing.


CONCLUSIONS
Similar short-term memory processes may exist in the auditory, motor and visual systems.
Bender
Stephan
S
Psychiatric Hospital, University of Heidelberg, Voßstraße 4, D-69115 Heidelberg, Germany. St.Bender@med.uni-frankfurt.de
Behringer
Stephanie
S
Freitag
Christine M
CM
Resch
Franz
F
Weisbrod
Matthias
M
D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology; D019054:Evoked Potentials, Motor / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D033182:Intention; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D012680:Sensitivity and Specificity; D013997:Time Factors; D055815:Young Adult