C Stan1, C Astefanoaei2, E Pretegiani3, L Optican4, D Creanga5, A Rufa6, C P Cristescu7. 1. Department of Physics, Politehnica University of Bucharest, 313 Spl. Independentei, RO 060042, Romania. Electronic address: cstan@physics.pub.ro. 2. Physics Department, University Alexandru Ioan Cuza, 11 Blvd. Carol I., Iasi, Romania. Electronic address: corina_astefanoaei@yahoo.com. 3. Eye-tracking & Visual Application Lab EVALab, Department of Medicine Surgery and Neuroscience, University of Siena, Siena 53100, Italy. Electronic address: elena.pretegiani@nih.gov. 4. Laboratory of Sensorimotor Research, IRP, National Eye Institute, DHHS, Bethesda, MD 20892, USA. Electronic address: lmo@lsr.nei.nih.gov. 5. Physics Department, University Alexandru Ioan Cuza, 11 Blvd. Carol I., Iasi, Romania. Electronic address: dorina.creanga@gmail.com. 6. Eye-tracking & Visual Application Lab EVALab, Department of Medicine Surgery and Neuroscience, University of Siena, Siena 53100, Italy. Electronic address: rufa@unisi.it. 7. Department of Physics, Politehnica University of Bucharest, 313 Spl. Independentei, RO 060042, Romania. Electronic address: cpcris@physics.pub.ro.
Abstract
BACKGROUND: Saccades are rapid eye movements used to gather information about a scene which requires both action and perception. These are usually studied separately, so that how perception influences action is not well understood. In a dual task, where the subject looks at a target and reports a decision, subtle changes in the saccades might be caused by action-perception interactions. Studying saccades might provide insight into how brain pathways for action and for perception interact. NEW METHOD: We applied two complementary methods, multifractal detrended fluctuation analysis and Lempel-Ziv complexity index to eye peak speed recorded in two experiments, a pure action task and a combined action-perception task. RESULTS: Multifractality strength is significantly different in the two experiments, showing smaller values for dual decision task saccades compared to simple-task saccades. The normalized Lempel-Ziv complexity index behaves similarly i.e. is significantly smaller in the decision saccade task than in the simple task. COMPARISON WITH EXISTING METHODS: Compared to the usual statistical and linear approaches, these analyses emphasize the character of the dynamics involved in the fluctuations and offer a sensitive tool for quantitative evaluation of the multifractal features and of the complexity measure in the saccades peak speeds when different brain circuits are involved. CONCLUSION: Our results prove that the peak speed fluctuations have multifractal characteristics with lower magnitude for the multifractality strength and for the complexity index when two neural pathways are simultaneously activated, demonstrating the nonlinear interaction in the brain pathways for action and perception.
BACKGROUND: Saccades are rapid eye movements used to gather information about a scene which requires both action and perception. These are usually studied separately, so that how perception influences action is not well understood. In a dual task, where the subject looks at a target and reports a decision, subtle changes in the saccades might be caused by action-perception interactions. Studying saccades might provide insight into how brain pathways for action and for perception interact. NEW METHOD: We applied two complementary methods, multifractal detrended fluctuation analysis and Lempel-Ziv complexity index to eye peak speed recorded in two experiments, a pure action task and a combined action-perception task. RESULTS: Multifractality strength is significantly different in the two experiments, showing smaller values for dual decision task saccades compared to simple-task saccades. The normalized Lempel-Ziv complexity index behaves similarly i.e. is significantly smaller in the decision saccade task than in the simple task. COMPARISON WITH EXISTING METHODS: Compared to the usual statistical and linear approaches, these analyses emphasize the character of the dynamics involved in the fluctuations and offer a sensitive tool for quantitative evaluation of the multifractal features and of the complexity measure in the saccades peak speeds when different brain circuits are involved. CONCLUSION: Our results prove that the peak speed fluctuations have multifractal characteristics with lower magnitude for the multifractality strength and for the complexity index when two neural pathways are simultaneously activated, demonstrating the nonlinear interaction in the brain pathways for action and perception.
Authors: John Suckling; Alle Meije Wink; Frederic A Bernard; Anna Barnes; Edward Bullmore Journal: J Neurosci Methods Date: 2008-07-23 Impact factor: 2.390
Authors: Abdulla Al Suman; Carlo Russo; Ann Carrigan; Patrick Nalepka; Benoit Liquet-Weiland; Robert Ahadizad Newport; Poonam Kumari; Antonio Di Ieva Journal: PLoS One Date: 2021-12-02 Impact factor: 3.240