The neurobiological basis of bias; A mechanism implicated in visual spatial attention.

The neurobiological basis of bias; A mechanism implicated in visual spatial attention. - The pharmacology of attention

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

NL-OMON

Registry ID

NL-OMON35172

Enrollment

Registered

2009-07-06

Start date

2010-03-03

Completion date

Unknown

Last updated

2024-05-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Geen aandoening

Interventions

Clonidine results in less noradrenaline turnover and in effect inhibits the noradrenergic system. Each participants receives all conditions, 1x clonidine, and 1x placebo, spread across two days.

Eligibility

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: Passing the physical/medical evaluation (in which cardiovascular functioning and blood pressure is evaluated) is a prerequisite.

Exclusion criteria

Exclusion criteria: Diagnosis of psychopathology. Current drug use Low blood pressure.

Design outcomes

Primary

Measure	Time frame
Behavioural measures In the VSC paradigm: the validity effect in ms (RT valid cued target - RT invalid cued target). A larger validity effect reflects either more bias, or less disengagement. In the stop task paradigm: the stop signal reaction time (SSRT); SSRT reflects inhibition and related disengagement. Neurophysiological (Event Related Potentials, task related brain activity) endparameters in the VSC: 1) Parietal cue Event Related Potential (ERP) components. These are the Anterior Directing Attention Negativity (ADAN) and the Late Directing Attention Positivity (LDAP). Both are related to bias. 2) P1 ERP (following a validly cued target); associated with bias. 3) Late Positive Deflection (LPD) ERP (following an invalidly cued target); associated with disengagement. Neurophysiological (ERP) endparameters in the stop task: 1) N2 ERP (following the onset of a stopsignal), associated with disengagement. 2) LPD ERP (following the onset of a stopsignal), associated with disengagement.	—

Measure

Time frame

Behavioural measures In the VSC paradigm: the validity effect in ms (RT valid cued target - RT invalid cued target). A larger validity effect reflects either more bias, or less disengagement. In the stop task paradigm: the stop signal reaction time (SSRT); SSRT reflects inhibition and related disengagement. Neurophysiological (Event Related Potentials, task related brain activity) endparameters in the VSC: 1) Parietal cue Event Related Potential (ERP) components. These are the Anterior Directing Attention Negativity (ADAN) and the Late Directing Attention Positivity (LDAP). Both are related to bias. 2) P1 ERP (following a validly cued target); associated with bias. 3) Late Positive Deflection (LPD) ERP (following an invalidly cued target); associated with disengagement. Neurophysiological (ERP) endparameters in the stop task: 1) N2 ERP (following the onset of a stopsignal), associated with disengagement. 2) LPD ERP (following the onset of a stopsignal), associated with disengagement.

—

Countries

Netherlands

Outcome results

None listed

Source: NL-OMON (via WHO ICTRP)