This study proposes a new method to quantify mental workload (MWL) automatically, without interfering with the operator's primary task performance. An unobtrusive Tobii eye tracker recorded eye movements while participants were engaged in a cognitively demanding N-back task. Original algorithms automatically analyzed the eye data, detected specific eye deviation movements called saccadic intrusions (SIs), and automatically quantified the eye deviation accounted for SIs. This SI measure was strongly correlated with the task difficulty levels in the N-back tasks and with pupil diameter. This indicates that the SI measure appeared to reflect MWL and may be used as a measure of MWL.
Get full access to this article
View all access options for this article.
References
1.
AbadiR.V.GowenE. (2004). Characteristics of saccadic intrusions. Vision research, 44(23), 2675–2690.
2.
EngbertR. (2006). Microsaccades: A microcosm for research on oculomotor control, attention, and visual perception. Progress in Brain Research, 154. 177–192.
3.
EngbertR.KlieglR. (2003). Microsaccades uncover the orientation of covert attention. Vision Research, 43, 1035–1045.
GowenE.AbadiR.VPoliakoffE.HansenP.MiallR.C. (2007). Modulation of saccadic intrusions by exogenous and endogenous attention. Brain Research, 1141:154–167.
6.
JustM.A.CarpenterP.A.MiyakeA. (2003). Neuroindices of cognitive workload: Neuroimaging, pupillometric and event-related potential studies of brain work. Theoretical Issues in Ergonomics, 4(1–2), 56–88.
7.
LaubrockJ.EngbertR.RolfsM.KlieglR. (2007). Microsaccades are an index of covert attention. Psychological Science, 18(4). 364–366.
8.
LeighR.J.ZeeD.S. (2006). The Neurology of Eye Movements. Oxford University Press, New York.
9.
Martinez-CondeS. (2006). Fixational eye movements in normal and pathological vision. Progress in Brain Research, 154. 151–176.
10.
ObinataG.TokudaS.ShibataN. (2008). Mental workloads can be objectively quantified in real-time using VOR (vestibulo-ocular reflex). Proceedings of the 17th World Congress. The International Federation of Automatic Control, Seoul, Korea, July 6–11, 2008. 15094–15099.
11.
RolfsM.EngbertR.KlieglR. (2005) Crossmodal coupling of oculomotor control and spatial attention in vision and audition. ExperimentalBrain Research, 166. 427–439.
12.
SayerJ.DevonshireJ.FlannaganC. (2006). Naturalistic driving performance during secondary tasks. Proceedings of the Fourth International Driving Symposium on Human factors in Driver Assessment, Training, and Vehicle Design. 224–230.
