Attention Modulation of Local and Global Inhibition Mechanisms

Overview

Human behavior is both flexible and adapted to the environmental context through inhibition capabilities; the investigator control the subject's behavior by repressing inappropriate responses and selecting, among several possibilities, those that are appropriate. These mechanisms are not independent of attentional control. Attention acts as a selection filter for the investigator's behavior. This leads us to hypothesize that attention modulates the mechanisms of inhibition. Nevertheless, the different brain structures involved, as well as mechanisms underlying the interaction between inhibition and attention remain largely unknown. Previous research has suggested that inhibition requires selective attention and, conversely, attentional mechanisms would result in the "deselection", or inhibition, of objects in space or irrelevant actions. Reconciling the literature on attention with the one on inhibition appears fundamental for the understanding of the instance to which the mechanisms of inhibition and the cognitive processes interact. Therefore, the goal of this research project will be to investigate how inhibition mechanisms are implemented in the brain and, in more detail, what determines the type of resulting inhibitory control: spatially localized or global. The investigator will test 3 different patient groups (optic ataxia, hemispatial neglect and attention-deficit hyperactivity disorder) compared to control. In conclusion, this research project will aim to develop a theoretical model of the interaction between attentional control and inhibition mechanisms in order to improve diagnostic and rehabilitation tools in the future.

Interventions

• Behavioral experience 1 "The negative priming task"
  The targets are presented to the subject on a computer screen. The subject must make an eye or hand movement toward the target and ignore the distracters.
• Behavioral experience 2 "Stop signal task"
  The targets are presented to the subject on a computer screen. The subject must make an eye movement towards this target. Sometimes a stop signal will appear and the subject will have to avoid to look at the target
• Behavioral experience 3 "Anti-saccades"
  The targets are presented to the subject on a computer screen. The subject must make an eye movement toward this target. Sometimes an instruction will ask the subject to look at the opposite of the target

Primary outcome measures

• error rate [Time frame: at the end of the simulation passage, an average of 3 years]

Secondary outcome measures (1)

• reaction time [Time frame: at the end of the simulation passage, an average of 3 years]

Eligibility criteria

All patients and healthy subjects:

Inclusion criteria

• male and female, age from 18 to 75 years included
• normal vision or corrected vision
• covered by social security
• signed written informed consent

Exclusion criteria

• unable to comply with requirements of the study (neurological, psychiatric, sensory or motor troubles)
• adults under legal protection

Patient with hemispatial neglect:

Inclusion criteria

• After a stroke (> 1 month ago), presence of a neurological impairment documented by brain imaging (standard of care) and by clinical symptoms.
• The diagnosis will be dissociated from hemianopia by perimetry. The hemispatial neglect consists of a lack of perception and responsiveness concerning the controlesional visual hemifield.

Patient with optic ataxia:

• After a stroke (> 1 month ago), presence of neurological injury in parietal cortex only, supported by a standard of care cerebral MRI
• Present optic ataxia symptoms (The OA consists of pointing errors with the hand contralateral to the lesion (hand effect) and / or to visual targets presented in the field contralateral to the lesion (field effect)).

Patient (adult and children) with attention-deficit hyperactivity disorder:

• present a diagnosis of ADHD subtype inattention or impulse / hyperactivity as established by a neuropsychologist.
• Children will be between 8 and 18 years old
• Adults will be between 18 and 75 years old.
• Participants will not report any comorbid learning disabilities to ADHD.

For minors:

\- Having obtained the written consent of the legal representative(s)

Healthy subjects

Inclusion criteria

\- no known neurological injury

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

France · 1 center

• Centre de Recherche en Neuroscience de Lyon — Bron

Identifiers

NCT: NCT04279158 · 69HCL19_0728 · 2019-A03055-52

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗