The Effect of Age and Fixation Instability on Retinotopic Mapping of Primary Visual Cortex

Crossland, Michael D.; Morland, Antony B.; Feely, Mary; Hagen, Elisabeth von dem; Rubin, Gary S.

doi:10.1167/iovs.07-1621

Cited by 32 publications

(46 citation statements)

References 34 publications

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“…6). These findings differ from those of other studies which found no significant differences in fixation stability were found between young and old observers when fixating a target presented on a uniform background (Crossland et al, 2008;Kosnik, Fikre, & Sekuler, 1986). In our study, observers experienced perceptual rivalry and reported the dominant percept.…”

Section: Control Testscontrasting

confidence: 99%

Age-related deficits in attentional control of perceptual rivalry

2013

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Some aspects of attentional processing are known to decline with normal aging. To understand how age affects the attentional control of perceptual stability, we investigated age-related changes in voluntarily controlled perceptual rivalry. Durations of the dominant percept, produced by an ambiguous Rubin vase-faces figure, were measured in conditions that required passive viewing and attentional control: holding and switching the dominant percept. During passive viewing, mean dominance duration in the older group was significantly longer (63%) than the dominance duration found in the young group. This age-related deficit could be due to a decline in the apparent strength of the alternating percepts as a result of higher contrast gain of visual cortical activity and a reduction in the amount of attentional resources allocated to the ambiguous stimulus in older people compared to young adults. In comparison to passive viewing, holding the dominant percept did not significantly alter the dominance durations in the older group, while the dominance durations in the young group were increased (∼100%). The dominance durations for both age groups in switch conditions were reduced compared to their passive viewing durations (∼40%). The inability of older people to voluntarily prolong the duration of the dominant percept suggests that they may have abnormal attentional mechanisms, which are inefficient at enhancing the effective strength of the dominant percept. Results suggest that older adults have difficulty holding attended visual objects in focus, a problem that could affect their ability to carry out everyday tasks.

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Section: Control Testscontrasting

confidence: 99%

Age-related deficits in attentional control of perceptual rivalry

2013

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“…As in the individual age groups, significant main effects of visual status (F = 23.40, p < 10 -5 ) and ROI (F = 60.00, p < 10 -15 ) were found, as well as a significant interaction between them (F = 7.18, p < 0.01). There was also a main effect of age (F = 8.82, p < 0.01), a feature we have noted previously 27 . However, there were no significant interactions between age and visual status (F = 2.09, p = 0.15) or age and ROI (F = 2.31, p = 0.11).…”

Section: Group Effectssupporting

confidence: 76%

Large-scale remapping of visual cortex is absent in adult humans with macular degeneration

et al. 2011

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International audienceThe occipital lobe contains a retinotopic representation of the visual field. The representation of the central retina in early visual areas (V1-3) is found at the occipital pole. When the central retina is lesioned in both eyes by macular degeneration, this region of visual cortex at the occipital pole is accordingly deprived of input. However, even when such lesions occur in adulthood, some visually driven activity in and around the occipital pole can be observed. It has been suggested that this activity is due to remapping of this area, so that it now responds to inputs from intact, peripheral retina. We evaluated whether or not remapping of visual cortex underlies this activity. Our fMRI results provide no evidence of remapping, questioning the contemporary view that early visual areas of the adult human brain have the capacity to reorganize extensively

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“…The intersubject variability in the patient group may also be due to a combination of factors such age, lesion size, and acuity, as well as differences in cognitive strategies. 51 Even among control subjects who achieve very similar performance levels in each paradigm, and are of similar age and acuities (as in the case of control subjects 101 and 102), the activation patterns analyzed across the lobes of the brain show differences that suggest different networking strategies for processing visual tasks.…”

Section: Intersubject Reproducibilitymentioning

confidence: 99%

Reproducibility of Activation Maps for Longitudinal Studies of Visual Function by Functional Magnetic Resonance Imaging

Ming

Thulborn

Szlyk

2012

Invest. Ophthalmol. Vis. Sci.

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PURPOSE.To test the intra-and intersubject reproducibility of brain activation patterns that underlie visually guided saccades and word recognition in normally sighted subjects and patients with macular degeneration using functional magnetic resonance imaging (fMRI). METHODS.Ten normally sighted subjects and five patients with macular degeneration were asked to perform two visually guided saccade tasks and two word-recognition tasks during fMRI with behavioral monitoring. The fMRI measurements were repeated three times at intervals of at least 4 weeks between sessions. The intrasubject reproducibility of the brain activation patterns was examined in a model-independent manner by comparing the distributions of activation across the frontal, parietal, temporal, and occipital brain lobes using Intraclass Correlation Coefficients (ICCs). Intersubject reproducibility was examined by repeated-measure ANOVA.RESULTS. Control subjects showed overall higher intrasubject reproducibility of brain activation patterns (75% ICCs > 0.5) than that of patients with macular degeneration (56% ICCs > 0.5). The intrasubject reproducibility for the patients improved when the target location was fixed, as in the word-recognition tasks (75% ICCs > 0.5), compared with the visually saccade tasks (37% ICCs > 0.5). Intersubject variability of brain activation patterns was strikingly high for both the control and patient groups.CONCLUSIONS. The fMRI method can serve as a reliable withinsubjects measure of brain activation that has potential for measuring longitudinal changes in brain networks associated with rehabilitation training. Striking intersubject variability reflected at the level of lobes of the brain among control subjects with similar behavioral performance, suggests individual analysis is necessary when implementing longitudinal brain activation studies. (Invest Ophthalmol Vis Sci.

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The Effect of Age and Fixation Instability on Retinotopic Mapping of Primary Visual Cortex

Abstract: Although the cortical area remains unchanged, healthy older persons show less BOLD activity in V1 than do younger persons. Normal variations in fixation stability do not have a significant effect on the accuracy of experiments to determine the retinotopic structure of the visual cortex.

Cited by 32 publications

References 34 publications

Age-related deficits in attentional control of perceptual rivalry

Age-related deficits in attentional control of perceptual rivalry

Large-scale remapping of visual cortex is absent in adult humans with macular degeneration

Reproducibility of Activation Maps for Longitudinal Studies of Visual Function by Functional Magnetic Resonance Imaging

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