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Neglect and Motion Stimuli--Insights from a Touchscreen-Based Cancellation Task.

Hopfner S, Kesselring S, Cazzoli D, Gutbrod K, Laube-Rosenpflanzer A, Chechlacz M, Nef T, Mosimann U, Bohlhalter S, Müri RM, Nyffeler T - PLoS ONE (2015)

Bottom Line: In patients with an intact optic radiation, the severity of neglect significantly decreased in the dynamic condition.Conversely, in patients with damage to the optic radiation, the severity of neglect significantly increased in the dynamic condition.The integrity of the optic radiation may be a predictor of whether motion increases or decreases the severity of neglect symptoms.

View Article: PubMed Central - PubMed

Affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.

ABSTRACT

Background and purpose: In stroke patients, neglect diagnostic is often performed by means of paper-pencil cancellation tasks. These tasks entail static stimuli, and provide no information concerning possible changes in the severity of neglect symptoms when patients are confronted with motion. We therefore aimed to directly contrast the cancellation behaviour of neglect patients under static and dynamic conditions. Since visual field deficits often occur in neglect patients, we analysed whether the integrity of the optic radiation would influence cancellation behaviour.

Methods: Twenty-five patients with left spatial neglect after right-hemispheric stroke were tested with a touchscreen cancellation task, once when the evenly distributed targets were stationary, and once when the identic targets moved with constant speed on a random path. The integrity of the right optic radiation was analysed by means of a hodologic probabilistic approach.

Results: Motion influenced the cancellation behaviour of neglect patients, and the direction of this influence (i.e., an increase or decrease of neglect severity) was modulated by the integrity of the right optic radiation. In patients with an intact optic radiation, the severity of neglect significantly decreased in the dynamic condition. Conversely, in patients with damage to the optic radiation, the severity of neglect significantly increased in the dynamic condition.

Conclusion: Motion may influence neglect in stroke patients. The integrity of the optic radiation may be a predictor of whether motion increases or decreases the severity of neglect symptoms.

No MeSH data available.


Related in: MedlinePlus

Analysis in sub-groups.Mean time until first cancellation in neglect patients with intact optic radiation (A) and damaged optic radiation (B), in the four conditions (static, dynamic, dynamic left, and dynamic right), and in the respective columns: leftmost, left-central, right-central, and rightmost. Error bars represent the standard error of the mean (SEM). Asterisks depict significant post-hoc tests (* p < .05; ** p < .01).
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pone.0132025.g004: Analysis in sub-groups.Mean time until first cancellation in neglect patients with intact optic radiation (A) and damaged optic radiation (B), in the four conditions (static, dynamic, dynamic left, and dynamic right), and in the respective columns: leftmost, left-central, right-central, and rightmost. Error bars represent the standard error of the mean (SEM). Asterisks depict significant post-hoc tests (* p < .05; ** p < .01).

Mentions: Based on these results, sub-groups were created according to the integrity of the right optic radiation (i.e., patients with intact (n = 8) or damaged (n = 17) optic radiation), and the analysis of the performance was re-run with this additional factor. The analysis of the time needed until the first target was cancelled in the two sub-groups of patients revealed a significant main effect of the factor ‘condition’ (F(3, 69) = 2.973, p = .038), a significant main effect of the factor ‘column’ (F(3, 69) = 31.482, p < .001), and a significant interaction ‘condition x column’ (F(9, 207) = 3.131, p = .001). There was no significant effect of the factor ‘optic radiation integrity’ (F(1, 23) = .205, p = .655), or of the interactions ‘optic radiation integrity x condition’ (F(3, 69) = 2.089, p = .110) and ‘optic radiation integrity x column’ (F(3, 69) = .584, p = .627). However, there was a highly significant three-way interaction between the factors ‘condition x column x optic radiation integrity’ (F(9, 207) = 2.847, p = .003). The results concerning this interaction and the corresponding post-hoc tests are depicted in Fig 4. Neglect patients with an intact optic radiation (Fig 4a) started their search in the leftmost column significantly earlier in the dynamic condition and the dynamic left condition than in the static condition, i.e., their performance improved with motion. In the dynamic right condition, no significant difference was found as compared to the static condition. Differently, neglect patients with a damaged optic radiation (Fig 4b) started their search in the leftmost column significantly later in the dynamic condition and the dynamic right condition than in the static condition, i.e., their performance worsened with motion. This pattern was similar in the left-central column.


Neglect and Motion Stimuli--Insights from a Touchscreen-Based Cancellation Task.

Hopfner S, Kesselring S, Cazzoli D, Gutbrod K, Laube-Rosenpflanzer A, Chechlacz M, Nef T, Mosimann U, Bohlhalter S, Müri RM, Nyffeler T - PLoS ONE (2015)

Analysis in sub-groups.Mean time until first cancellation in neglect patients with intact optic radiation (A) and damaged optic radiation (B), in the four conditions (static, dynamic, dynamic left, and dynamic right), and in the respective columns: leftmost, left-central, right-central, and rightmost. Error bars represent the standard error of the mean (SEM). Asterisks depict significant post-hoc tests (* p < .05; ** p < .01).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4497636&req=5

pone.0132025.g004: Analysis in sub-groups.Mean time until first cancellation in neglect patients with intact optic radiation (A) and damaged optic radiation (B), in the four conditions (static, dynamic, dynamic left, and dynamic right), and in the respective columns: leftmost, left-central, right-central, and rightmost. Error bars represent the standard error of the mean (SEM). Asterisks depict significant post-hoc tests (* p < .05; ** p < .01).
Mentions: Based on these results, sub-groups were created according to the integrity of the right optic radiation (i.e., patients with intact (n = 8) or damaged (n = 17) optic radiation), and the analysis of the performance was re-run with this additional factor. The analysis of the time needed until the first target was cancelled in the two sub-groups of patients revealed a significant main effect of the factor ‘condition’ (F(3, 69) = 2.973, p = .038), a significant main effect of the factor ‘column’ (F(3, 69) = 31.482, p < .001), and a significant interaction ‘condition x column’ (F(9, 207) = 3.131, p = .001). There was no significant effect of the factor ‘optic radiation integrity’ (F(1, 23) = .205, p = .655), or of the interactions ‘optic radiation integrity x condition’ (F(3, 69) = 2.089, p = .110) and ‘optic radiation integrity x column’ (F(3, 69) = .584, p = .627). However, there was a highly significant three-way interaction between the factors ‘condition x column x optic radiation integrity’ (F(9, 207) = 2.847, p = .003). The results concerning this interaction and the corresponding post-hoc tests are depicted in Fig 4. Neglect patients with an intact optic radiation (Fig 4a) started their search in the leftmost column significantly earlier in the dynamic condition and the dynamic left condition than in the static condition, i.e., their performance improved with motion. In the dynamic right condition, no significant difference was found as compared to the static condition. Differently, neglect patients with a damaged optic radiation (Fig 4b) started their search in the leftmost column significantly later in the dynamic condition and the dynamic right condition than in the static condition, i.e., their performance worsened with motion. This pattern was similar in the left-central column.

Bottom Line: In patients with an intact optic radiation, the severity of neglect significantly decreased in the dynamic condition.Conversely, in patients with damage to the optic radiation, the severity of neglect significantly increased in the dynamic condition.The integrity of the optic radiation may be a predictor of whether motion increases or decreases the severity of neglect symptoms.

View Article: PubMed Central - PubMed

Affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.

ABSTRACT

Background and purpose: In stroke patients, neglect diagnostic is often performed by means of paper-pencil cancellation tasks. These tasks entail static stimuli, and provide no information concerning possible changes in the severity of neglect symptoms when patients are confronted with motion. We therefore aimed to directly contrast the cancellation behaviour of neglect patients under static and dynamic conditions. Since visual field deficits often occur in neglect patients, we analysed whether the integrity of the optic radiation would influence cancellation behaviour.

Methods: Twenty-five patients with left spatial neglect after right-hemispheric stroke were tested with a touchscreen cancellation task, once when the evenly distributed targets were stationary, and once when the identic targets moved with constant speed on a random path. The integrity of the right optic radiation was analysed by means of a hodologic probabilistic approach.

Results: Motion influenced the cancellation behaviour of neglect patients, and the direction of this influence (i.e., an increase or decrease of neglect severity) was modulated by the integrity of the right optic radiation. In patients with an intact optic radiation, the severity of neglect significantly decreased in the dynamic condition. Conversely, in patients with damage to the optic radiation, the severity of neglect significantly increased in the dynamic condition.

Conclusion: Motion may influence neglect in stroke patients. The integrity of the optic radiation may be a predictor of whether motion increases or decreases the severity of neglect symptoms.

No MeSH data available.


Related in: MedlinePlus