Aging affects the impact of light on non-visual congnitive brain responses but not pupillary constriction

Poster (2012, May)

Does pupil constriction under blue and green monochromatic light exposure change with age?

Poster (2012, February)

Le système non-visuel chez l'être humain : lumière, oeil et cerveau

Poster (2011, March)

Non-visual brain sensitivity to light in aging

Poster (2011, March)

Aging affects the impact of light on non-visual cognitive brain functions

in Sleep (2011), 34(Suppl. 1),

Abnormal Hypothalamic Response to Light in Seasonal Affective Disorder

in Biological Psychiatry (2011), 70(10), 954-961

Fast and slow spindle involvement in the consolidation of a new motor sequence

in Behav Brain Res (2011), 217(1), 117-21

This study aimed to determine the distinct contribution of slow (11-13 Hz) and fast (13-15 Hz) spindles in the consolidation process of a motor sequence learning task (MSL). Young subjects (n = 12) were ... [more ▼]

This study aimed to determine the distinct contribution of slow (11-13 Hz) and fast (13-15 Hz) spindles in the consolidation process of a motor sequence learning task (MSL). Young subjects (n = 12) were trained on both a finger MSL task and a control (CTRL) condition, which were administered one week apart in a counterbalanced order. Subjects were asked to practice the MSL or CTRL task in the evening (approximately 9:00 p.m.) and their performance was retested on the same task 12h later (approximately 9:00 a.m.). Polysomnographic (PSG) recordings were performed during the night following training on either task, and an automatic algorithm was used to detect fast and slow spindles and to quantify their characteristics (i.e., density, amplitude, and duration). Statistical analyses revealed higher fast (but not slow) spindle density after training on the MSL than after practice of the CTRL task. The increase in fast spindle density on the MSL task correlated positively with overnight performance gains on the MSL task and with difference in performance gain between the MSL and CTRL tasks. Together, these results suggest that fast sleep spindles help activate the cerebral network involved in overnight MSL consolidation, while slow spindles do not appear to play a role in this mnemonic process. [less ▲]

NREM slow wave oscillation rebound after sleep deprivation : effect of aging

Poster (2010, June)

Sleep spindles and neural activity changes in the cortico-striatal system underlie motor sequence consolidation

in NeuroImage (2010), 51(Suppl. 1),

Brain plasticity related to the consolidation of motor sequence learning and motor adaptation

in Proceedings of the National Academy of Sciences of the United States of America (2010), 107(41), 17839-44

This study aimed to investigate, through functional MRI (fMRI), the neuronal substrates associated with the consolidation process of two motor skills: motor sequence learning (MSL) and motor adaptation ... [more ▼]

This study aimed to investigate, through functional MRI (fMRI), the neuronal substrates associated with the consolidation process of two motor skills: motor sequence learning (MSL) and motor adaptation (MA). Four groups of young healthy individuals were assigned to either (i) a night/sleep condition, in which they were scanned while practicing a finger sequence learning task or an eight-target adaptation pointing task in the evening (test) and were scanned again 12 h later in the morning (retest) or (ii) a day/awake condition, in which they were scanned on the MSL or the MA tasks in the morning and were rescanned 12 h later in the evening. As expected and consistent with the behavioral results, the functional data revealed increased test-retest changes of activity in the striatum for the night/sleep group compared with the day/awake group in the MSL task. By contrast, the results of the MA task did not show any difference in test-retest activity between the night/sleep and day/awake groups. When the two MA task groups were combined, however, increased test-retest activity was found in lobule VI of the cerebellar cortex. Together, these findings highlight the presence of both functional and structural dissociations reflecting the off-line consolidation processes of MSL and MA. They suggest that MSL consolidation is sleep dependent and reflected by a differential increase of neural activity within the corticostriatal system, whereas MA consolidation necessitates either a period of daytime or sleep and is associated with increased neuronal activity within the corticocerebellar system. [less ▲]