Pupil Dilation as an Index of Learning

Abstract

Physiological assessment of cognitive processes has become a topic of increased interest. The value of understanding and measuring brain function at work has the potential to improve performance. The emphasis of this paper is to discuss how pupil diameter can be applied to learning. The link between pupil diameter and task difficulty, or cognitive load, has been repeatedly demonstrated for the past 40 years. However there has been little work to date on measuring cognitive load during training or looking at how real time metrics of cognitive load could be used to adapt training. According to Cognitive Load Theory, cognitive load should be reduced as an individual learns a task and he/she relies more on long term memory than working memory. Ten participants completed a simulated unmanned aerial vehicle task in which they had to identify targets and report their direction of movement. There were three levels of increased difficulty. As expected, pupil diameter significantly dropped within each block as participants learned the task, and then increased again at the start of the next level of difficulty. The results suggest that pupil diameter may be a useful metric for assessing when an individual has transferred information into long term memory. Implications for how pupil diameter can be used to drive an adaptive training system are discussed.

Human place and response learning: navigation strategy selection, pupil size and gaze behavior

“…The approach direction of the subsequent test trial did not affect average pupil size during presentation of the mask, and no interactions were observed (all p > .05). The decrease in pupil size across experimental blocks during test trials and presentation of the mask is consistent with effects attributed to learning (Mueller et al, 2008;Sibley, Coyne & Baldwin, 2011). Furthermore, larger pupil size during different-direction trials as compared to same-direction trials may reflect the additional cognitive effort required by users of the configuration strategy to perform spatial transformations when the approach directions during training and test are not identical.…”

“…First, average pupil size decreased over the course of the experiment, which can be explained by learning effects and/or the transfer of task relevant information from working memory to long-term memory (Mueller et al, 2008;Sibley et al, 2011). Second, average pupil size was larger during different-direction trials compared to same-direction trials, which is thought to reflect the additional cognitive effort required by users of the configuration strategy to transform viewpoints when the approach directions during training and test did not match.…”

Modeling User Behaviors to Enable Context-Aware Proactive Decision Support

“…Physiological sensor data can provide information about a user's state in near-real time. For example, previous research has shown that an individual's mental effort correlates with pupil size [48,49] and heart rate variability [50]. Furthermore, eye gaze analysis can be used to assess where an individual is allocating attention (or failing to attend to), and therefore be employed to provide alerts and prevent errors in real time [51,52].…”

Pupil diameter differentiates expertise in dental radiography visual search

“…Then, the link between 155 attention and capacity was promoted [42]; where higher load on the working memory 156 showed a larger change in pupil dilation. Additionally, pupillary response has been 157 found to be an indicator of learning [34], where pupil diameter decreased with more 158 experience in a task. This understanding of pupil diameter changes has further been 159 employed as a robust cognitive load classifier [39].…”