Influence of gap and overlap paradigms on saccade latencies and vergence eye movements in seven-year-old children.
The latency of eye movements is influenced by the fixation task; when the fixation stimulus is switched off before the target presentation (gap paradigm) the latency becomes short and express movements occur. In contrast, when the fixation stimulus remains on when the target appears (overlap paradigm), eye movement latency is longer. Several previous studies have shown increased rates of express saccades in children; however the presence of an express type of latency for vergence and combined movements in children has never been explored. The present study examines the effects of the gap and the overlap paradigms on horizontal saccades at far (150 cm) and at close (20 cm) viewing distances, on vergence along the median plane, and on saccades combined with convergence or divergence in 15 normal seven-year-old children. The results show that the gap paradigm produced shorter latency for all eye movements than the overlap paradigm, but the difference was only significant for saccades at close viewing distances, for divergence (pure and combined), and for saccades combined with vergence. The gap paradigm produced significantly higher rates of express latencies for saccades at close viewing distances, for divergence, and for saccades combined with divergence; in contrast, the frequencies of express latencies for saccades at far viewing distances and for convergence (pure or combined) were similar in the gap and the overlap paradigms. Interestingly, the rate of anticipatory latencies (<80 ms) was particularly high for divergence in the gap paradigm. Our collective findings suggest that the initiation of saccades at close viewing distances and of divergence is more reflexive, particularly in the gap paradigm. The finding of frequent anticipatory divergence that occurs at similar rates for seven-year-old children (this study) and for adults (Coubard et al., 2004, Exp Brain Res 154:368-381) indicates that predictive initiation of divergence is dominant.
Bucci
Maria Pia
MP
Laboratoire de Physiologie de la Perception et de 1'Action, UMR 7125, CNRS-College de France 11, Place Marcelin Berthelot, 75005, Paris, France. maria-pia.bucci@college-de-france.fr
Pouvreau
Nathalie
N
Yang
Qing
Q
Kapoula
Zoï
Z
D000375:Aging / Q000502:physiology; D001921:Brain / Q000254:growth & development; D002648:Child; D003290:Convergence, Ocular / Q000502:physiology*; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D009434:Neural Pathways / Q000254:growth & development; D009801:Oculomotor Muscles / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D012438:Saccades / Q000502:physiology*
Brain Dev. 2000 May;22(3):173-80
10814900
J Autism Dev Disord. 1994 Aug;24(4):413-31
7961328
Exp Brain Res. 2004 Apr;155(4):439-49
14730413
Neuroimage. 2001 May;13(5):786-93
11304075
J Neurophysiol. 1993 Aug;70(2):576-89
8410158
J Opt Soc Am. 1967 Aug;57(8):1024-9
6035296
Behav Brain Sci. 1999 Aug;22(4):661-74; discussion 674-721
11301526
Percept Psychophys. 1994 Sep;56(3):251-60
7971125
Vision Res. 1995 Dec;35(23-24):3335-58
8560804
J Neurophysiol. 1996 Jul;76(1):199-214
8836219
Cortex. 2000 Dec;36(5):715-31
11195917
Exp Brain Res. 1998 Aug;121(4):391-400
9746145
J Neurophysiol. 1996 Dec;76(6):3666-81
8985865
J Neurosci. 1997 Nov 1;17(21):8566-79
9334428
Psychophysiology. 2001 Mar;38(2):179-89
11347863
Exp Brain Res. 2004 Feb;154(3):368-81
14557910
Vision Res. 1995 Dec;35(23-24):3373-88
8560806
Brain Res. 1997 Apr 18;754(1-2):285-97
9134986
Brain Res. 1983 Jan 31;260(1):21-6
6402272
Exp Brain Res. 1984;57(1):191-5
6519226
Brain Res Cogn Brain Res. 2001 Jan;10(3):317-22
11167054
Ann Neurol. 1995 May;37(5):557-67
7755349
Acta Ophthalmol (Copenh). 1993 Feb;71(1):10-21
8475702
Percept Psychophys. 1991 Feb;49(2):167-75
2017353
J Neurophysiol. 1992 Nov;68(5):1624-41
1479435
J Exp Psychol Hum Percept Perform. 1993 Dec;19(6):1251-65
8294890
Strabismus. 2003 Jun;11(2):95-107
12854017
Ann N Y Acad Sci. 2002 Apr;956:216-29
11960806
Invest Ophthalmol Vis Sci. 2002 Sep;43(9):2939-49
12202513