Assessment of alerting, orienting, and executive control in persons with aphasia using the Attention Network Test

Attention deficits frequently accompany language impairments in aphasia. Most research on attention in aphasia focuses on selective attention measured by executive control tasks such as the color-word Stroop or Erickson flanker. This is despite ample evidence in neurotypical adults indicating the existence of multiple, distinct attention subtypes. Thus, there is a disconnect between the documented attention impairments in persons with aphasia (PWA) and the literature in neurotypical adults indicating that multiple attention components independently modulate an individual's interactions with the world.

This study aimed to use the well-studied Attention Network Test (ANT) to quantify three subtypes of attention (alerting, orienting, and executive control) in PWA and matched controls. It was hypothesized that significant effects of alerting, orienting, and executive control would be observed in both groups, however, the effects would be reduced in PWA compared to the neurotypical controls. It was additionally expected that alerting, orienting, and executive control would not be correlated with one another in either group.

Twenty-two PWA along with 20 age, gender, and education matched controls completed the ANT. Briefly, the ANT consists of a cued-flanker task where the cues provide information about when and where the flanker executive control task will be presented. The combination of cues and flanker targets embedded within the ANT provides measures of alerting, orienting, and executive control. Participants are expected to respond faster and more accurately to the flanker task when cued as to when and where the task will be presented.

In line with previous work, the control group demonstrated significant effects of alerting, orienting, and executive control. However, we only find significant orienting and executive control effects in the aphasia group. Between-group differences were only identified within orienting attention: the control group benefitted more from the orienting cue than the aphasia group. Additionally, alerting, orienting, and executive control were not correlated in the control group, yet, a relationship between orienting and executive control was observed in the aphasia group.

Overall, our findings demonstrate that attention differs between PWA and controls, and that the ANT may provide a more complete picture of attention in aphasia; this may be particularly important when characterizing the relationship between attention and language in aphasia.