The neural network sustaining crossmodal integration is impaired in alcohol-dependence: an fMRI study.
BACKGROUND
Crossmodality (i.e., the integration of stimulations coming from different sensory modalities) is a crucial ability in everyday life and has been extensively explored in healthy adults. Still, it has not yet received much attention in psychiatry, and particularly in alcohol-dependence. The present study investigates the cerebral correlates of crossmodal integration deficits in alcohol-dependence to assess whether these deficits are due to the mere accumulation of unimodal impairments or rather to specific alterations in crossmodal areas.


METHODS
Twenty-eight subjects [14 alcohol-dependent subjects (ADS), 14 paired controls] were scanned using fMRI while performing a categorization task on faces (F), voices (V) and face-voice pairs (FV). A subtraction contrast [FV-(F+V)] and a conjunction analysis [(FV-F) ∩ (FV-V)] isolated the brain areas specifically involved in crossmodal face-voice integration. The functional connectivity between unimodal and crossmodal areas was explored using psycho-physiological interactions (PPI).


RESULTS
ADS presented only moderate alterations during unimodal processing. More centrally, in the subtraction contrast and conjunction analysis, they did not show any specific crossmodal brain activation while controls presented activations in specific crossmodal areas (inferior occipital gyrus, middle frontal gyrus, superior parietal lobule). Moreover, PPI analyses showed reduced connectivity between unimodal and crossmodal areas in alcohol-dependence.


CONCLUSIONS
This first fMRI exploration of crossmodal processing in alcohol-dependence showed a specific face-voice integration deficit indexed by reduced activation of crossmodal areas and reduced connectivity in the crossmodal integration network. Using crossmodal paradigms is thus crucial to correctly evaluate the deficits presented by ADS in real-life situations.
Neuroscience, Systems and Cognition (NEUROCS) Research Unit, Institute of Psychology, Catholic University of Louvain, Louvain-la-Neuve, Belgium. pierre.maurage@uclouvain.be
Pierre
P
Maurage
Frédéric
F
Joassin
Mauro
M
Pesenti
Cécile
C
Grandin
Alexandre
A
Heeren
Pierre
P
Philippot
Philippe
P
de Timary
D000161:Acoustic Stimulation; D000328:Adult; D000437:Alcoholism / Q000503:physiopathology* / Q000523:psychology*; D002540:Cerebral Cortex / Q000502:physiology; D004522:Educational Status; D004644:Emotions; D005145:Face; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009434:Neural Pathways / Q000503:physiopathology; D010465:Perception / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012677:Sensation / Q000502:physiology; D012938:Social Perception; D014831:Voice