

Playing video-games is a widely distributed leisure activity in our society. In order to estimate the consequences of video-game play, we study the details of eye movements and pupil light responses as well as perceptual performance affected by shifts of attention. Our results clearly show that video-game players (VGPs) have shorter saccadic reaction times in general compared to non-players (NVGPs). In addition, VGPs seem to have a more efficient control of attention. The precision of gaze movements is not different between VGPs and NVGPs. Therefore, we are able to rule out the explanation that VGPs show shorter latencies because of reduced precision of their gaze movements.
Another peculiarity of our society is the demographic changes. The amount of older individuals is increasing substantially. Therefore, the issue of healthy aging becomes more important. We decided to examine the effects of aging with respect of two types of goal-directed eye movements: saccades and smooth pursuit eye movements.
Effects of video-game play
More than 46% of the 12 to 19 year old Germans consume video-games every day. Despite this wide distribution, the consequences of video-game play are heavily and controversially discussed. We decided to examine the consequences of video-game play by means of multiple studies of eye movement paradigms as well as perceptual tasks.
Please do not look at the target!
We asked our subjects to perform a very simple eye movement task. They were instructed to generate an eye movement response opposite to the presentation of a visual target. If the target was presented on the left hand side, they should move their eyes to the right. These eye movements are called anti-saccades. However, in some trials, the subjects were not able to suppress the visual-grasp reflex to look at the target. These directional errors are quite similar to eye movements directed voluntarily towards the target (pro-saccades). The directional errors are generated by the superior colliculus in the midbrain. The cognitively driven anti-saccades result from neuronal activity of the frontal cortex, i.e. the frontal eye field (FEF). The frequency of directional errors can be used as error rate. The error rate gives a measure of the executive control function of the frontal lobe.
Our sample consists in the gaze movements of 55 subjects aged 15 to 31 years. Subjects were classified as VGPs (35) or NVGPs (20), respectively, based on the amount of their daily video-game play. VGPs played at least one hour per day.
First, we analyzed saccadic reaction times (SRT) of our subjects. In general, directional errors had approximately 100 ms shorter SRTs as anti-saccades. The saccadic latencies of VGPs were significantly shorter than latencies of NVGPs. In addition, saccadic peak velocity of directional errors was significantly higher compared to the peak velocity of anti-saccades. Finally, peak velocity of both types of saccades was higher in VGPs compared to NVGPs.
The shorter saccadic reaction times do not result from an increased error rate in VGPs. We did not find different error rates for VGPs and NVGPs. Therefore, we conclude that the executive control function of the frontal lobe is not affected by the daily consumption of video-games.
Speed of attention shifts?
(Thesis of Helene Wiesmann)
We hypothesized that shorter saccadic reaction times may be caused by faster information processing in VGPs. To test this hypothesis, we performed a perception study. We asked our subject to report the property of a visual target. The subjects were informed about the location of the target by a visual cue. The cue onset asynchrony was varied between 0 and 600 ms. Our sample consisted in 63 VGPs and 53 NVGPs.
VGPs showed a clear advantage in perception expressed as the amount of correct responses. However, our results do not reveal any differences in the temporal pattern of attention shift of VGPs and NVGPs.
Countermanding tasks
(Thesis of Carolin Töpfer and Verena Lohmüller)
In certain conditions, it might be beneficial to suppress an already intended action. In a first study, we asked our 80 subjects to press as fast as possible a key when a green rectangle appeared. As expected, VGPs showed shorted reactions times as NVGPs. Secondly, we changed the paradigm to a Go/No-Go task. In 50% of the trials, the green rectangle changed its color to red indicating to suppress the key press. We used stimulus onset asynchrony (SOA) from 16 to 320 ms. The latency of the Go trials was clearly increased compared to the first experiment. We calculated the stop signal reaction time (SSRT) from the amount of correct responses in the No-Go trials. SSRT gives the minimal SOA for successful suppression of the key press. Across all subjects, we found a mean SSRT of 250 ms. There was no significant difference between the SSRT of VGPs and NVGPs, respectively.
In a second study, we analyzed the suppression of already intended eye movements. Compared to the key press study, the SSRTs in the saccade task were approximately 100 ms shorter. We did not find any significant differences between VGPs and NVGPs either.

2019
Ilg UJ (2019) Neuroscience for the next generation: Was Schülerlabore für die Neurowissenschaft leisten. Neuroforum 25(2):139-142.
2016
Mack DJ, Wiesmann H, Ilg UJ (2016) Video game players show higher performance but no difference in speed of attention shifts. Acta Psychologia 169:11-19.
2014
Ilg UJ.; Multimodal representation of target trajectory in space. Spring School “Multisensory Perception for Action, Wildbad Kreuth. 2014.
Mack DJ, Ilg UJ.; The effects of video game play on the characteristics of saccadic eye movements. Vision Research. 2014; 102: 26-32
2013
Himmelbach M, Linzenbold W, Ilg UJ (2013) Dissociation of reach-related and visual signals in the human superior colliculus. Neuroimage 82:61-67.
2012
Ilg U, Thier P (2012) Neuronale Grundlagen visueller Wahrnehmung. In: Kognitive Neurowissenschaften. Karnath H-O, Thier P (eds). Springer Verlag Berlin-Heidelberg, 35-43
Ilg U, Thier P (2012) Zielgerichtete Augenbewegungen. In: Kognitive Neurowissenschaften. Karnath H-O, Thier P (eds). Springer Verlag Berlin-Heidelberg, 377-388
2010
Ilg UJ, Churan J (2010) Second-order motion stimuli: a new handle to visual motion processing. In: Masson GS, Ilg UJ (eds). Dynamics of Visual Motion Processing: Neuronal, Behavioral and Computational Approaches. Springer, Berlin-Heidelberg, 117-140
Masson GS, Ilg UJ (eds). Dynamics of Visual Motion Processing: Neuronal, Behavioral and Computational Approaches. Springer, Berlin-Heidelberg, 2010
Masson GS, Montagnini A, Ilg UJ (2010). When the brain meets the eye: tracking object motion. In: Masson GS, Ilg UJ (eds). Dynamics of Visual Motion Processing: Neuronal, Behavioral and Computational Approaches. Springer, Berlin-Heidelberg, 161-188
2009
Ilg UJ (2009) Pursuit eye movements. In: New Encyclopedia of Neuroscience, Vol. 7. Larry Squire et al (eds). Academic Press, Oxford, 1263-1269
2008
Biber U, Ilg UJ. Initiation of smooth-pursuit eye movements by real and illusory contours. Vision Research 2008;48:1002-1013
Freyberg S, Ilg UJ. Anticipatory smooth-pursuit eye movements in man and monkey. Experimental Brain Research 2008;186 (2):203-214
Ilg UJ. The role of areas MT and MST in coding of visual motion underlying the execution of smooth pursuit. Vision Research 2008;48:2062-2069
Ilg UJ, Thier P. The neural basis of smooth pursuit eye movements in the rhesus monkey brain. Brain and Cognition 2008;68:229-240
2007
Ilg UJ, Schumann S. Primate area MST-l is involved in the generation of goal-directed eye and hand movements. Journal of Neurophysiology 2007;97:761-771
2006
Ilg UJ, Jin Y, Schumann S Schwarz U. .Preparation and execution of saccades: facing the problem of limited ca-pacity of computational resources. Exp Brain Res 2006;171: 7-15
Lindner A, Ilg UJ. Suppression of optokinesis during smooth pursuit eye movements revisited: The role of extra-retinal information. Vision Res 2006;46: 761-767
2005
Ilg UJ, Churan J, Schumann S. The physiological basis for visual perception and visually guided action. In: Kremers J (ed). The primate visual system. Wiley, West Sussex, 2005;95-100
Thier P, Ilg UJ. The neural basis of smooth-pursuit eye movements. Curr Op in Neurobiol 2005;15:645-652
2004
Aghili J, Ilg UJ. Perception of biological motion in humans and monkeys. In: Ilg UJ, Bülthoff H, Mallot H (eds). Dynamic Perception. AKA Akad. Verlag, Berlin, 2004;169-174
Dicke PW, Barash S, Ilg UJ, Thier P. Single-neuron evidence for a contribution of the dorsal nuclei to both types of goal-directed eye movements, saccades and smooth-pursuit. Eur J Neurosci 2004;19:609-624
Freyberg S, Ilg UJ. Anticipatory smooth pursuit eye movements. In: Ilg UJ, Bülthoff H, Mallot H (eds). Dynamic Perception. AKA Akad. Verlag, Berlin, 2004;113-118
Ilg UJ, Bülthoff H, Mallot H (eds). Dynamic Perception. AKA Akad. Verlag, Berlin, 2004.
Ilg UJ, Churan J. Motion perception without explicit activity in areas MT and MST. J Neurophysiol 2004;92:1512-1523
Ilg UJ, Schumann S, Thier P. Posterior parietal cortex neurons encode target motion in world-centered coordinates. Neuron 2004;43:145-151
Lindner A, Ilg UJ. Cancellation of gaze stabilizing mechanisms during human smooth pursuit: indications for the involvement of an extra-retinal reference signal. In: Ilg UJ, Bülthoff H, Mallot H (eds). Dynamic Perception. AKA Akad. Verlag, Berlin, 2004;107-112
Schumann S, Ilg UJ. Vestibular signals in the neuronal activity of the posterior parietal cortex. In: Ilg UJ, Bülthoff H, Mallot H (eds) Dynamic Perception. AKA Akad. Verlag, Berlin, 2004;45-50
2003
Ilg UJ. Visual tracking neurons in primate area MST are activated during anticipatory smooth pursuit eye movements. NeuroReport 2003;14:2219-2223
Ilg UJ, Thier P. Visual tracking neurons in primate area MST are activated during smooth pursuit eye movements towards an "imaginary" target. J Neurophysiol 2003;90:1489-1502
Ilg U, Thier P. Zielgerichtete Augenbewegungen. In: Karnath H-O, Thier P (eds.). Neuropsychologie. Springer-Verlag, Heidelberg, 2003;311-324
2002
Churan J, Ilg UJ. Neuronal requirements for execution of smooth pursuit and motion perception. In: Lappe, Würtz (eds). Dynamische Perzeption. AKA Akad. Verl. Ges., Berlin, 2002, pp 159-164
Churan J, Ilg UJ (2002) Flicker in the visual background impairs the ability to process a moving visual stimulus. European Journal of Neuroscience 16: 1151-1162.
Ilg UJ. Smooth pursuit eye movements: from low-level to high-level vision. In: Hyönä, Munoz, Heide, Radach (eds). The Brain’s Eyes: Neurobiological clinical aspects of oculomotor research. Elsevier Science, Oxford, 2002, pp 279-298
Ilg UJ, Schumann S. Effects of intracortical microstimulation in area MST on smooth pursuit. In: Lappe, Würtz (eds). Dynamische Perzeption. AKA Akad. Verl. Ges., Berlin, 2002, pp 153-158
2001
Churan J, Ilg UJ (2001) Processing of second-order motion stimuli in primate middle temporal area and medial superior temporal area. JOSA A 18(9): 2297-2306
2000
Ilg UJ, Schwarz U. Dynamische Modulation der visuellen Bewegungssensoren durch Augenbewegungen. In: Baratoff, Neumann (eds). Dynamische Perzeption. AKA Akad. Verl. Ges., Berlin, 2000, pp 63-69
Lindner A, Ilg UJ (2000) Initiation of smooth-pursuit eye movements to first-order and second-order motion stimuli. Exp Brain Res. 133: 450-456
Treue S, Ilg UJ. Image segmentation: a tug-of-war for the eyeball. Current Biology 2000; 10:R746-R749
Completed Dissertations
David Mack (2015)
Consequences of Video Games on Oculomotor Behavior and Attention and Additional Implications for Healthy Aging
Prof. Dr. U. Ilg
Ulrich Biber (2011)
Visuelle Illusionen oder die Illusion des Sehens: Einflüsse von Augenbewegungen auf die visuelle Wahrnehmung
Prof. Dr. U. Ilg
Ines Trigo-Damas (2010)
Speed illusions of human subjects and rhesus monkeys
Prof. Dr. U. Ilg
Stefan Schumann (2004)
Fakultät für Angewandte Wissenschaften, Universität Freiburg
Blickfolgeaktivität in Area MST von wachen Affen
Prof. Dr. U. Ilg
Jan Churan (2003)
Philosophische Fakultät, Universität Köln
Verarbeitung von Bewegungsreizen im Parietalkortex von Makaken
Prof. Dr. U. Ilg
Completed Master / Approval Work
Anna-Lena Kämpf
Flash-lag Effekt bei echter und scheinbarer Bewegung
Prof. Dr. U. Ilg
Lilli Fritz
Antizipatorische Folgebewegungen
Prof. Dr. U. Ilg
Sabrina Fleissner
Details des RepMo-Effekts
Prof. Dr. U. Ilg
Matthias AngeleBeeinflussen Computerspiele unsere Fähigkeit, Mengen abzuschätzenMathematisch-Naturwissenschaftliche Fakultät Prof. Dr. U. Ilg
Michael Eb
Augenfolgebewegungen auf isoluminante Ziele
Mathematisch-Naturwissenschaftliche Fakultät
Prof. Dr. U. Ilg
Jessica Ziemann
Antisakkaden auf isoluminante Reize
Mathematisch-Naturwissenschaftliche Fakultät
Prof. Dr. U. Ilg
Verena Lohmüller (2014)
Blickbewegung oder nicht – eine Frage des Konsums von Videospielen?
Prof. Dr. U. Ilg
Helene Wiesmann (2012)
Aufmerksamkeitsverlagerung bei wöchentlicher Computer- und Konsolenspielzeit
Prof. Dr. U. Ilg
Seda Cavdaroglu (2011)
Neural Correlates of Self-Other Distinctions in Action Perception
Dr. A. Linder, Prof. Dr. U. Ilg
Judith Neuhaus (2011)
Video games change eye movements
Prof. Dr. U. Ilg
Katharina Negele (2011)
Gender differences in the N170 during facial recognition
Prof. Dr. U. Ilg
Thorsten Thiede (2011)
Adaptation exemplified for the motion after effect
Prof. Dr. U. Ilg
Henrike Stutzki (2011)
Adaptation of goal-directed hand movements during the use of a computer mouse pad
Prof. Dr. U. Ilg
Claudia Schneider (2010)
The agony of choice – investigating the mechanisms and fMRI correlates of human decision making under varying choice difficulty
Dr. A. Lindner, Prof. Dr. U. Ilg
Melanie Knupfer (2010)
Einfluss von Computerspiele auf Antisakkaden
Prof. Dr. U. Ilg
D. Merz (2009)
Modulation von Reflexen durch externe Stimuli
Prof. Dr. U. Ilg
Walter Linzenbold (2008)
Untersuchung der Augenbewegung beim Lesen von bewegten und statischen Texten
Prof. Dr. U. J. Ilg
M. Härtel (2007)
Studien zu Latenz, Dauer und Genauigkeit zielgerichteter Handbewegungen
Prof. Dr. U. J. Ilg
Ines Trigo-Damas
Subjektive und objektive Bewegungsanalyse: Details und neuronale Grundlagen
Prof. Dr. U. Ilg
André Mandler
Augenbewegungen beim Lesen bewegter Texte
Prof. Dr. U. Ilg
Ulrich Biber
Initiierung von Augenfolgebewegungen
Prof. Dr. U. Ilg
S. Gulan (2005)
Modellierung sensorischer Verarbeitung für zielgerichtetes Verhalten
Prof. Dr. U. Ilg
Janine Aghili (2004)
Wahrnehmung von biologischer Bewegung
Prof. Dr. U. Ilg
Natalie Rüb (2001)
Antizipatorische Augenfolgebewegungen als Nachweis für die Existenz von extra-retinalen Signalen im posterioren Parietalkortex
Prof. Dr. U. Ilg
Completed Bachelor Theses
Galina Henz (2014)
Aufmerksamkeitsverlagerung bei Computer-Spielern und Nicht-Spielern
Prof. Dr. U. Ilg
Charlotte Mezö (2014)
Blickbewegung oder nicht – eine Frage des Konsums von Videospielen?
Prof. Dr. U. Ilg
Dennis Fritsch (2013)
Vergleich der sakkadischen Reaktionszeit mit den VEP-Latenzen im EEG
Prof. Dr. Uwe Ilg

Center of Neurology
Hertie Institute for Clinical Brain Research
Department Cognitive Neurology
Otfried-Müller-Straße 27
72076 Tübingen
Phone: +49 (0)7071 29-87602