title: Age-related effects of increasing postural challenge on eye movement onset latencies to visual targets.
abstract: When a single light cue is given in the visual field, our eyes orient towards it with an average latency of 200 ms. If a second cue is presented at or around the time of the response to the first, a secondary eye movement occurs that represents a reorientation to the new target. While studies have shown that eye movement latencies to 'single-step' targets may or may not be lengthened with age, secondary eye movements (during 'double-step' displacements) are significantly delayed with increasing age. The aim of this study was to investigate whether the postural challenge posed simply by standing (as opposed to sitting) results in significantly longer eye movement latencies in older adults compared to the young. Ten young (<35 years) and 10 older healthy adults (>65 years) participated in the study. They were required to fixate upon a central target and move their eyes in response to 2 types of stimuli: (1) a single-step perturbation of target position either 15° to the right or left and (2) a double-step target displacement incorporating an initial target jump to the right or left by 15°, followed after 200 ms, by a shift of target position to the opposite side (e.g. +15° then -15°). All target displacement conditions were executed in sit and stand positions with the participant at the same distance from the targets. Eye movements were recorded using electro-oculography. Older adults did not show significantly longer eye movement latencies than the younger adults for single-step target displacements, and postural configuration (stand compared to sit) had no effect upon latencies for either group. We categorised double-step trials into those during which the second light changed after or before the onset of the eye shift to the first light. For the former category, young participants showed faster secondary eye shifts to the second light in the standing position, while the older adults did not. For the latter category of double-step trial, young participants showed no significant difference between sit and stand secondary eye movement latencies, but older adults were significantly longer standing compared to sitting. The older adults were significantly longer than the younger adults across both postural conditions, regardless of when the second light change occurred during the eye shift to the first light. We suggest that older adults require greater time and perhaps attentional processes to execute eye movements to unexpected changes in target position when faced with the need to maintain standing balance.
authors.affiliation: Neural Control of Movement Laboratory, School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.
authors.forename: Sergio
authors.initials: S
authors.lastname: Jimenez
authors.affiliation: School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Hollands
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW, 2522, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Palmisano
authors.affiliation: Faculty of Science, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Juno
authors.initials: J
authors.lastname: Kim
authors.affiliation: Faculty of Science, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Maria
authors.initials: M
authors.lastname: Markoulli
authors.affiliation: Neural Control of Movement Laboratory, School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.
authors.forename: Darryl
authors.initials: D
authors.lastname: McAndrew
authors.affiliation: Neural Control of Movement Laboratory, School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Stamenkovic
authors.affiliation: Neural Control of Movement Laboratory, School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.
authors.forename: Joel
authors.initials: J
authors.lastname: Walsh
authors.affiliation: Neural Control of Movement Laboratory, School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.
authors.forename: Sophie
authors.initials: S
authors.lastname: Bos
authors.affiliation: Neural Control of Movement Laboratory, School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia. pstapley@uow.edu.au.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Stapley
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D004585:Electrooculography; D005133:Eye Movements / Q000502:physiology*; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D011187:Posture / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D055815:Young Adult
keywords: Ageing; Balance; Electro-oculography; Gaze; Target perturbations
references.citation: Science. 1992 Jan 3;255(5040):90-2
references.pmid: 1553535
references.citation: Exp Brain Res. 2010 Apr;202(2):493-7
references.pmid: 20041233
references.citation: Exp Brain Res. 2012 Oct;222(1-2):55-64
references.pmid: 22850925
references.citation: Exp Brain Res. 2013 May;227(1):63-78
references.pmid: 23529512
references.citation: Hum Mov Sci. 2002 Apr;21(1):61-84
references.pmid: 11983434
references.citation: Exp Brain Res. 2000 Nov;135(2):141-54
references.pmid: 11131498
references.citation: Neuropsychologia. 2014 Mar;55:25-40
references.pmid: 24334110
references.citation: Gait Posture. 2002 Aug;16(1):20-30
references.pmid: 12127183
references.citation: Exp Brain Res. 2013 Jun;227(3):397-405
references.pmid: 23649967
references.citation: Vision Res. 2000;40(18):2499-516
references.pmid: 10915889
references.citation: Neurosci Biobehav Rev. 2010 Jul;34(8):1103-20
references.pmid: 20026351
references.citation: J Gerontol. 1983 May;38(3):318-20
references.pmid: 6841926
references.citation: Exp Brain Res. 2004 Jan;154(2):261-6
references.pmid: 14639471
references.citation: Vision Res. 2013 Jan 15;78:1-5
references.pmid: 23206549
references.citation: J Neural Transm (Vienna). 2007;114(10):1339-48
references.pmid: 17393068
references.citation: J Cogn Neurosci. 2011 Nov;23(11):3669-80
references.pmid: 21563883
references.citation: Neurophysiol Clin. 2008 Dec;38(6):391-8
references.pmid: 19026959
references.citation: Invest Ophthalmol Vis Sci. 1978 May;17(5):465-8
references.pmid: 640792
references.citation: Age Ageing. 2006 Sep;35 Suppl 2:ii55-ii59
references.pmid: 16926207
references.citation: Ann Neurol. 1985 Jan;17(1):2-10
references.pmid: 3885841
references.citation: Exp Brain Res. 1998 Nov;123(1-2):159-63
references.pmid: 9835405
references.citation: Cortex. 1999 Sep;35(4):573-82
references.pmid: 10574082
references.citation: Acta Otorhinolaryngol Ital. 2005 Aug;25(4):224-32
references.pmid: 16482980
references.citation: PLoS One. 2012;7(11):e49765
references.pmid: 23185432
references.citation: J Bone Miner Metab. 2005;23(2):152-6
references.pmid: 15750694
references.citation: Vision Res. 1983;23(1):33-7
references.pmid: 6868379
references.citation: Tohoku J Exp Med. 2008 Nov;216(3):277-85
references.pmid: 18987462
references.citation: Arch Neurol. 1980 Sep;37(9):575-6
references.pmid: 7417059
references.citation: Exp Brain Res. 1998 Aug;121(4):391-400
references.pmid: 9746145
references.citation: Neurosci Lett. 2014 Apr 30;566:27-31
references.pmid: 24582906
references.citation: Vision Res. 2006 Mar;46(5):751-9
references.pmid: 16236337
references.citation: J Gerontol B Psychol Sci Soc Sci. 1996 May;51(3):P143-54
references.pmid: 8620354
references.citation: Arch Gerontol Geriatr. 1996 May-Jun;22(3):261-9
references.pmid: 15374175
references.citation: Vision Res. 2013 Aug 30;89:54-64
references.pmid: 23891705
references.citation: Vision Res. 1979;19(9):967-83
references.pmid: 532123
references.citation: Neurosci Lett. 1979 Aug;13(3):253-8
references.pmid: 530477
references.citation: Neurophysiol Clin. 2006 Jul-Aug;36(4):235-43
references.pmid: 17095413
references.citation: J Gerontol. 1994 Sep;49(5):M235-8
references.pmid: 8056943
references.citation: Ann Neurol. 1984 Oct;16(4):449-54
references.pmid: 6497354
references.citation: Acta Otolaryngol. 1993 Mar;113(2):119-22
references.pmid: 8475724
references.citation: Exp Brain Res. 2009 Mar;193(3):323-36
references.pmid: 19002676
references.citation: Vision Res. 2011 Jul 1;51(13):1610-22
references.pmid: 20974168
references.citation: Hum Mov Sci. 2004 Nov;23(5):699-746
references.pmid: 15589629
references.citation: Invest Ophthalmol Vis Sci. 1993 Jul;34(8):2588-95
references.pmid: 8325760
references.citation: Curr Opin Neurobiol. 2011 Aug;21(4):553-8
references.pmid: 21646014
references.citation: J Opt Soc Am. 1966 Jul;56(7):956-60
references.pmid: 5953831
references.citation: Neurosci Lett. 2006 Aug 7;403(3):309-14
references.pmid: 16723186