BENGALURU: Two new studies from the Centre for Neuroscience at the Indian Institute of Science here explore how attention and eye movements are linked closely and unveil how the brain coordinates the two processes.
Attention is a unique phenomenon that allows us to focus on a specific object in our visual world and ignore distractions.
When we pay attention to an object, we tend to gaze towards it, leading scientists to suspect that attention is tightly coupled to rapid eye movements, called saccades.
In fact, even before our eyes move towards an object, our attention focuses on it, allowing us to perceive it more clearly, which is a well-known phenomenon called pre-saccadic attention.
However, in a new study published in the journal ‘PLOS Biology’, the researchers at CNS show that this perceptual advantage is lost when the object changes suddenly, even a split second before our gaze falls upon it, making it harder for us to process what changed.
“Our study provides an interesting counterpoint to many previous studies which suggested that pre-saccadic attention is always beneficial,” explained Devarajan Sridharan, Associate Professor at CNS and corresponding author of the study.
In the ‘PLOS Biology’ study, Priyanka Gupta, a PhD student in Sridharan’s laboratory, trained human volunteers to covertly monitor gratings (line patterns) presented on a screen without directly looking at them and to report when one tilted slightly, according to a press release issued on Thursday by the Bengaluru-headquartered IISc.
“Importantly, the participants did this task just before their eyes moved, in the pre-saccadic window.
So, we were able to study the relationship between pre-saccadic attention and the detection of changes in the visual environment,” explained Gupta.
A tracker was used to monitor their eye movements before, during, and after their gaze fell on the object, the release said.
“To our surprise, participants found it harder to detect the changes in the pre-saccadic window,” Gupta added.
In a follow-up experiment, they made the participants monitor two gratings presented one after the other quickly, again, just before their eyes moved.
