The aim is to expand evidence about the importance of the mediodorsal nucleus of the thalamus as a key node in human higher-order cognitive functions such as learning, decision-making, and adaptive behavior. Thus, the project proposes to assess global cognition along with higher-order cognition integrity via sensitive behavior tasks in patients with well localized lesions (mediodorsal thalamic infarcts) compared with healthy participants.

The recruitment of patients with isolated thalamic lesion after stroke is known to be a challenge that the investigators overcame through the expertise of neurologists within their stroke unit.

First, they will describe the cognitive profile consecutive to a lesion of the thalamus, assessed with standardized neuropsychological tests.

Second, and more specifically, they will study performances at experimental tasks focusing on higher-order cognition (decision-making, updating, interference managing, multitasking).

They will use the automatic localization method already performed : the lesions will be manually segmented from T1 morphologic sequences, and then normalized in a template. Finally a numerical atlas of thalamus will be applied on the lesions, determining the injured substructure and the lesion volume.

Besides, this method will be compared with new high resolution thalamus-centered anatomical sequences allowing direct and individual identification of the involved thalamic nucleus.

Inclusion criteria for patients:

• French as their mother tongue
• Absence of cognitive deterioration before the stroke.
• Visual, auditory (equipment authorized) and oral or written skills sufficient for the proper assessment using neuropsychological tests.
• First infarct affecting the thalamus.
• At least seven years' schooling from primary school
• Signed informed consent
• Chronic lesion (> 3 months)

Inclusion criteria for controls:

• French as their mother tongue
• Absence of cognitive complain
• Visual, auditory (equipment authorized) and oral or written skills sufficient for the proper assessment using neuropsychological tests.
• At least seven years of school from primary school
• Signed informed consent

Exclusion criteria for patients:

• Neurological deficit or significant residual disability at inclusion.
• Aphasia, agnosia, apraxia or severe neglect, as demonstrated by clinical examination and neuropsychological tests.
• Subjects with a contraindication to MRI.
• General, neurological or psychiatric progressive disease.

Exclusion criteria for controls:

• Subjects with a contraindication to MRI.
• General, neurological or psychiatric progressive disease.