Posner Task Lab

For this lab we will be exploring the Posner Task and what it tells us about visual attention. To begin click here and read the instructions on the page. Once you have read the instructions click on the link that says "Click here to run a demo of the Posner task." Once you've completed the demo, return to this page.

Now that you've completed the Posner Task demo ask yourself:

When is it harder to respond, after a valid (the x is followed by the go) or an invalid (the x is NOT followed by the go) cue?

When you have to shift attention from an invalid cue to where the target is, what steps are you taking?

Most participants find it harder to respond after an invalid cue than after a valid cue. This is because the "x" cue draws our attention to an invalid location and we must shift our visual attention to respond to the "go" in the correct location.

From researching tasks like these, Posner developed his theory of visual attention. According to Posner's theory there are three steps involved in shifting attention:

1. Disengage: Stop attending to what is currently being attended

2. Move: Refocus “spotlight” on new location

3. Engage: Begin attending new stimulus

Posner's theory of attention can help us to understand certain attentional disorders like Hemispatial Neglect. Hemispatial Neglect is a condition where damage to the parietal lobe of one hemisphere results in an inability to attend to stimuli on the side of the body opposite of the damage. (For example, if you damaged your right parietal lobe, you would stop paying attention to the left side of your body and field of vision). Watch the following video on patients with hemispatial neglect to get a better understanding of what it's like living with the condition: https://youtu.be/d4FhZs-m7hA

Out of the 3 processes in Posner's theory of visual attention what process seems to be failing in patients with hemispatial neglect? Disengage, move, or engage?

Think about it for a second before looking at the answer below...

The answer is disengage! Once engaged in attention in the right visual field, they cannot disengage attention to be able to move or engage with the left side.