The science behind eye tracking

The science

• Eye-tracking games increase beta-band activity in the right dorsolateral prefrontal cortex, while reducing alpha activity in the frontal eye fields for more efficient visual and cognitive control. 
• The retina is as a direct extension of the brain, linking not only to visual areas responsible for perception but also to regions involved in higher cognitive functions such as attention, memory, and decision-making. Notably, it connects to brainstem nuclei such as the locus coeruleus, which, through its extensive neural networks, modulates activity in the frontal and parietal regions critical for attention control. For example, visual-movement neurons in the frontal and lateral prefrontal cortex play a pivotal role in maintaining task-focused attention by suppressing the impact of distracting stimuli. These brain regions, in turn, regulate eye movements. 

Enhancing Attention Through Training Eye Movements 

Eye movements are fundamental to activating these cognitive networks. They are highly organised and encompass various types, including saccades, fixational saccades, tremor, smooth pursuit, drift, and vergence. Each type is linked to distinct neural pathways and serves specific roles in vision and cognition. For instance, saccades—rapid eye movements that occur approximately every 300 milliseconds (or about 150,000 times per day)—provide a constant stream of new visual information and act as primary drivers of brain activity. Even during fixation, micro-movements like tremors and drifts occur, underscoring the continuous engagement of eye movements in cognitive processing. Because each eye is controlled by partially independent neural circuits, the precise and timely coordination of binocular movements is essential for effective vision and cognition. Disruptions or errors in eye movements can have significant consequences for brain responses and cognitive functions. 

Interestingly, ADHD medications not only alleviate behavioral symptoms but also improve certain types of eye movements, including vergence. Similarly, vision therapy targeting vergence movements has been shown to reduce ADHD symptoms. Gaze-adaptive exercises, in particular, have demonstrated effectiveness in improving cognitive challenges and emotional well-being. 

How can games help?

• At a neural level, eye-tracking games significantly impact brain activity, with evidence of increased beta-band activity in the right dorsolateral prefrontal cortex (DLPFC). This indicates heightened engagement of cognitive control mechanisms following training. Additionally, training was associated with reduced alpha activity in the frontal eye fields (FEF) and decreased beta activity in the DLPFC, suggesting enhanced efficiency in processing visual information and exercising cognitive control. 
• Gaze-contingent training also modulates both tonic arousal (sustained attention) and phasic arousal (rapid response to stimuli), as reflected in changes to pupil size and heart rate. This type of training improves arousal regulation, leading to better attentional focus (tonic arousal) and faster, more accurate responses (phasic arousal). These improvements may enhance performance on tasks requiring strong inhibitory control. 
• Gaze-controlled gaming has been shown to enhance attention, memory, reading skills, and overall learning capabilities. 

• These games have proven effective for children with learning difficulties, including ADHD, autism, dyslexia, and other learning disabilities. 

• They improve inhibitory control, reduce impulsivity, improve efficiency in switching between task demands, and support better emotional regulation.  
• Gaze-contingent training improves arousal regulation, enhancing sustained attention (tonic arousal) and rapid responsiveness to stimuli (phasic arousal), which boosts inhibitory control. 
• The games are specifically designed to train different types of attention. For example, tasks targeting focus and inhibition of impulsivity often require players to separate their gaze position (the physical point they are looking at) from their attentional focus (the area they are mentally attending to). In such games, stimuli appear in the peripheral vision and must be attended to without directly gazing at them. These stimuli need first to be processed to a perceptual level to enable decision-making processes. Once processed, the player must decide whether to shift their gaze to the peripheral stimulus or maintain their focus on the already targeted object. 
• This separation of attention from gaze, and of action from perception, is key to improving cognitive flexibility. Feedback from the eye tracker guides the brain in refining this separation, essentially training the brain to take over these processes. 
• Other games are designed to strengthen specific aspects of attention. For instance, some focus on maintaining prolonged attention on a single object, tracking moving objects, or resisting distractions by avoiding gaze shifts to irrelevant objects. In some cases, players are required to use surrounding stimuli to guide the positioning of their gaze without directly looking at those stimuli. 
• The games are gamified to include adaptive difficulty levels, ensuring that the challenges are appropriately tailored to each player's abilities and progress.