Modified Attentional Network Task (ANT)

Background

The Attentional Network Task (ANT), originally introduced by Jin Fan and colleagues in 2002, is a cognitive behavioral assessment tool of different attentional components referred to as 'attentional networks': Alerting ('vigilance'), Orienting ('selective attention'), and Executive Attention (in the form of conflict resolution).

In 2014/2015 Yi-Feng Wang and colleagues introduced a further modified design of the ANT as well as new computing methods of the networking effects. Specifically, Wang et al argue that rather than treating the three networks as mostly independent, parallel systems for the purpose of network score calculations ('orthogonal systems'), the systems should be explicitly treated as interactive and overlapping ('non-orthogonal systems'), which are more efficiently studied using a blocked design in which some attentional influences are systematically varied while others are kept constant. This in return should lead to more accurate network scores and directional interaction effects due to the reduction of within-subject variability caused by inter-network interferences. For example, by running a block of only 'no-cues' and 'center-cue' trials with only congruent arrow configurations, a more 'pure' Alerting Effect can be calculated as the Orienting Attention System as well as the Executive Attention System (aka Conflict Resolution) can (predictively) stay disengaged during this time period.

Task Procedure

The participant sees a configuration of 5 arrows above, below or in the screen center and is asked to press as fast as possible the left response button if the central arrow points to the left or the right response button if the central arrow points to the right (irrespective of where the flanking arrows point). The arrow configuration may be preceded by a brief visual cue. In the example below, the participant works on the 'Alerting Effect Block' and sees one center star that signals that the arrows will come along shortly ('alerting trials'). Trials in this block will all predictably present the arrow configurations in the center and the arrows will all point in the same direction, thus reducing the need for the engagement of the Orienting and Executive attention networks.

What it Measures

The Attentional Network Task (ANT) is a cognitive behavioral test to measure the effects of three attentional networks on accuracy and response times.

Psychological domains

• Attention: Assessment of Attentional Networks
• Vigilance: Measures the ability to achieve and maintain a state of high sensitivity to incoming stimuli
• Selective Attention: Measures the ability to select information from sensory input by directing attention to a specific location in space
• Executive Control: Measures the ability to resolve conflict among competing stimuli, involving response inhibition and decision-making

Main Performance Metrics

• alertingEffect: The effect of alerting signals on response speed and performance
• orientingEffect: The effect of orientation signals on response speed and performance
• conflictEffect: The cost effect of flanker incongruence on response speed and performance

Psychiatric Conditions

ANT performance tends to be impaired in patients with the following psychiatric conditions.

• Attention Deficit Hyperactivity Disorder (ADHD)
• Autism Spectrum Disorder (ASD)
• Schizophrenia
• Major Depressive Disorder
• Anxiety Disorders
• Traumatic Brain Injury (TBI)