■这项研究的目的是调查在中间街区人行道上行走时,具有同义偏盲(HH)的行人的凝视扫描。
■右同义偏盲(RHH)的行人,在没有和没有左空间忽略(LHSN)的情况下,左同义偏盲(LHH)戴着视线跟踪系统在城市街道上行走。通过结合头部运动和眼睛在头部运动获得凝视点。混合效应回归模型用于比较水平凝视扫描幅度和半球损失侧(BlindSide)和观察侧(SeeingSide)之间的速率。在三个主题组中,在中间街区步行和过街路段之间。
■从19名参与者341分钟的中间街区步行视频中获得了总共7021次凝视扫描(6名LHH,7与RHH,和6与LHSN)。LHH中块段的平均凝视幅度和扫描速率明显高于盲侧(幅度大1.9°(度),P=0.006;扫描速率提高4.2次/分钟,P<0.001)和RHH受试者(幅度大3.3°,P<0.001;扫描速率提高3.2扫描/分钟,P=0.002),但它们在LHSN受试者中没有显著差异。扫描速率,就扫描/分钟而言(平均,LHSN受试者(平均=6.9,95%CI=5.6-8.7)的95%置信区间[CI])显着低于LHH(平均=10.2,95%CI=8.0-13.1;P=0.03)和RHH(平均=11.1,95%CI=9.0-13.7;P=0.007)受试者。与过马路相比,在3组中,中块段的扫描速率降低了3.5次扫描/分钟(P<0.001),凝视幅度降低了3.8°(P<0.001).
■补偿性扫描的证据表明,自上而下的机构在HH中驾驶凝视。空间忽略(SN)的存在似乎对自上而下的过程产生了负面影响。
UNASSIGNED: The purpose of this study was to investigate gaze-scanning by pedestrians with homonymous hemianopia (HH) when walking on mid-block sidewalks.
UNASSIGNED: Pedestrians with right homonymous hemianopia (RHH), and left homonymous hemianopia (LHH) without and with left spatial neglect (LHSN) walked on city streets wearing a gaze-tracking system. Gaze points were obtained by combining head movement and eye-in-head movement. Mixed-effects regression models were used to compare horizontal gaze scan magnitudes and rates between the side of the hemi-field loss (BlindSide) and the seeing side (SeeingSide), among the three subject groups, and between mid-block walking and street crossing segments.
UNASSIGNED: A total of 7021 gaze scans were obtained from 341 minutes of mid-block walking videos by 19 participants (6 with LHH, 7 with RHH, and 6 with LHSN). The average gaze magnitude and scanning rate in mid-block segments were significantly higher towards the BlindSide than the SeeingSide in LHH (magnitude larger by 1.9° (degrees), P = 0.006; scan rate higher by 4.2 scans/minute, P < 0.001) and RHH subjects (magnitude larger by 3.3°, P < 0.001; scan rate higher by 3.2 scans/minute, P = 0.002), but they were not significantly different in LHSN subjects. The scanning rate, in terms of scans/minute (mean, 95% confidence interval [CI]) was significantly lower in LHSN subjects (mean = 6.9, 95% CI = 5.6-8.7) than LHH (mean = 10.2, 95% CI = 8.0-13.1; P = 0.03) and RHH (mean = 11.1, 95% CI = 9.0-13.7; P = 0.007) subjects. Compared to street-crossings, the scan rate during the mid-block segments was lower by 3.5 scans/minute (P < 0.001) and the gaze magnitude was smaller by 3.8° (P < 0.001) over the 3 groups.
UNASSIGNED: Evidence of compensatory scanning suggests a proactive, top-down mechanism driving gaze in HH. The presence of spatial neglect (SN) appeared to negatively impact the top-down process.