Metaplasticity of Executive Functions
These lines of research aim at identifying the factors modulating the expression of experience-dependent brain plasticity in executive functions to improve rehabilitation interventions.
Our capacity to inhibit unwanted thoughts, emotions or actions is typically referred to as "inhibitory control". This core component of executive functions allows flexible adaptations to ever-changing goals and environmental contingencies. While the fronto-striatal brain network supporting inhibitory control is relatively well described, how this capacity can be improved with training and the supporting neurophysiological mechanisms remain largely unresolved.
We focus mainly on:
- The effects of inhibitory control training on the anatomo-functional organization of the brain
- The factors modulating training-induced plastic changes in inhibitory control
- How our training interventions can be optimally applied in real-world settings
Please see below for details on our subprojects and examples of our publications for each of them.
Inhibitory control in neurological disorders
Parkinson’s disease is a neurodegenerative disorder characterised by progressive loss of dopaminergic neurons in the Basal Ganglia, a collection of brain nuclei involved notably in motor control. The most common symptoms include a diffuse reduction of movement speed (‘bradykinesia’), a peculiar loss of coordination when performing alternating movements (‘dysdiadocokynesia’), rigidity to passive movement, tremor, a stooped posture, and gait disturbances. Amongst other, gait disturbances in PD are characterised by a progressive acceleration when performing repetitive movements (‘festination’) leading to a reduction of stride length, and a tendency to fall frontwards.
Our research projects in this field aim at identifying key features of existing interventions for reducing the motor symptoms of the disease, in order to maximize the benefits for the patients.
Please see below for details on our subprojects.
Effects of Deep Brain Stimulation on impulsive behaviour in Parkinson’s Disease
This project investigates the behavioural and neurophysiological responses to Deep Brain Stimulation in different brain areas (STN and GPi nuclei). Deep Brain Stimulation is used to improve motor symptoms in Parkinson’s Disease. The results of our study could readily impact target selection for DBS depending on single patient profile, and improve our knowledge of neural processes underlying executive control.
Improving Rhythmic Auditory Stimulation for helping gait disturbance in Parkinson’s Disease
Rhythmic Auditory Stimulation has been successfully used to improve gait in patients with Parkinson’s Disease. However, it may have the reverse effect on patients with lower rhythmic abilities, which tend to decrease as the disease evolves. This project aims at identifying parameters of Rhythmic Auditory Stimulation that will maximize the benefits of such treatment, even for patients with reduced rhythmic abilities.
Accolla, E. A., and Pollo, C. (2019) Mood Effects After Deep Brain Stimulation for Parkinson's Disease: An Update, Front Neurol 10
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Modeling training-induced plasticity in inhibitory control
How our traning interventions modify the anatomic and functional organization of the inhibitory control network?
Based on these findings, we identify the key training parameters to improve the efficacity of the interventions and to boost the underlying neurophysiological mechanisms. We have for instance identified which brain areas are modified functionally and structurally by our interventions, which in turn enables us to better identify how to train patients depending on their specific clinical profiles and needs.
Chavan, C. F., Mouthon, M., Draganski, B., van der Zwaag, W., and Spierer, L. (2015) Differential patterns of functional and structural plasticity within and between inferior frontal gyri support training-induced improvements in inhibitory control proficiency, Hum Brain Mapp 36.
State-dependency of inhibitory control plasticity
The effect of aging, GABAergic transmission and post-lesion delays on the expression of brain plasticity
Do older adults exhibit the same plastic mechanisms as young populations? Do acute stroke patients present the same improvements as chronic patients? How does Parkinson neurodegeneration influence the inhibitory control network?
Hartmann, L., Wachtl, L., de Lucia, M., and Spierer, L. (2019). Practice-induced functional plasticity in inhibitory control interacts with aging, Brain Cogn 132.
Promoting a transfer of the effects of inhibitory control training
What are the training parameters promoting a transfer of the effects of training to untrained conditions and daily living?
Depending on how inhibitory control is trained, stimulus-driven forms of inhibitory may develop. While this type of associative learning results in highly specific effects, it can have exploitable neurocognitive consequences. Developping the automatic triggering of inhibition to specific cues in the environement could be helpfull because it may result in a decrease in behaviors toward them, without requiring an effortfull engagement of control process. Some of our interventions capitalize on this mechanism.
Simonet, M., Roten, F. C. V., Spierer, L*., and Barral, J*. (2009). Executive control training does not generalize, even when associated with plastic changes in domain-general prefrontal areas; Neuroimage 197, 2019.
Najberg, H., Rigamonti, M., Mouthon, M., Spierer, L. (2020). Modifying food items valuation and weight with gamified executive control training, Royal Society Open.