精神分裂症患者线段等分和数字等分加工的分离

目的探讨精神分裂症患者是否同时存在空间注意障碍和数字空间表征障碍。方法对年龄、文化程度、简易精神状态量表(MMSE)评分等相匹配的30例精神分裂症患者和30名正常对照进行线段等分试验和数字等分试验。结果在线段等分试验中,线段长度分别为4、6、8、10、12、14、16、18、20cm时,患者组的偏移率均比正常对照组高,差异均有统计学差异(P0.01)。在数字等分试验中,所呈现数字对的间距为3、5、7、9时,无论是顺向还是反向提问,患者组平均偏移率与对照组的差异均无统计学意义(P0.05)。患者组的顺向与反向提问之间测试结果的差异无统计学意义(P0.05)。结论精神分裂症患者在线段等分试验中表现为左偏而数字等分试验中无偏移,提示其存在单侧注意障碍但无数字空间表征障碍。     

线等分试验与忽视症、偏盲的研究

目的了解中国老年人、忽视症、忽视症伴偏盲、单纯偏盲患者线等分试验的表现，探讨线等分试验对忽视症与偏盲的诊断价值及其神经心理学机制。方法对30例身体健康的中国老年人（正常对照组）以及73例单侧脑损伤患者（试验组）进行线等分试验检查，同时对73例单侧脑损伤患者进行忽视、偏盲检查。结果据忽视、偏盲检查结果将试验组分为单纯忽视症组、忽视症伴偏盲组和单纯偏盲组进行分析。正常对照组线等分试验无论左手、右手皆左向偏移，且左手偏移明显，两者相比差异有显著性（P〈0．001）。单纯忽视症组线等分试验多半偏向脑损伤的同侧，与正常对照组相比差异有显著性（P〈0．001）；忽视症伴偏盲组与单纯忽视症组线等分试验都偏向脑损伤的同侧，且前者偏移明显，两者相比差异有显著性（P〈0．001）；单纯偏盲组线等分试验偏向脑损伤的对侧，与正常对照组相比差异有显著性（P〈0．05）。结论线等分试验存在左、右手侧别的差别，线等分试验是忽视症较好的检查方法之一．线等分试验不完全和其它忽视症试验相关联．偏盲加重水平线索忽视程度，偏盲不影响线等分试验对忽视症的检测率。线等分试验可用来鉴别单纯偏盲和忽视。     

利用情绪面孔嵌合图形研究精神分裂症的注意偏向

目的探讨精神分裂症患者的注意偏向情况。方法利用情绪面孔嵌合图形试验和线段等分试验对年龄、文化程度、简易精神状态量表(mini-mental state examination,MMSE)评分等相匹配的32例精神分裂症患者和32名正常对照进行测试。结果精神分裂症患者在本顿面孔识别试验中和对照组差异无统计学意义(t=-0.85,P>0.05)。情绪(喜)面孔嵌合试验和20 cm线段等分试验,患者组的偏移率均比对照组高[-18.75(-31.25,-6.25)vs.-12.50(-23.44,4.69);-1.40(-2.65,-0.93)vs.-0.45(-1.50,0.30)],差异有统计学意义。患者组的情绪(喜)面孔嵌合和线段等分之间的偏移率相关(r=0.68,P<0.01)。结论精神分裂症患者在情绪(喜)面孔嵌合试验中注意左偏,这与线段等分试验结果相同,提示患者右侧空间注意受损,可能与左侧脑半球功能障碍有关。     

持续性躯体形式疼痛障碍患者的感觉门控电位P50研究

目的研究持续性躯体形式疼痛障碍(PSPD)患者的感觉门控电位(P50)的特点。方法选取2013年9月-2014年6月就诊于四川大学华西医院心理卫生中心门诊并确诊为躯体形式疼痛障碍的患者,共64例,运用汉密尔顿抑郁量表(HAMD-24)、汉密尔顿焦虑量表(HAMA-14)及疼痛数字评价量表(NRS)对64例PSPD患者进行评定;应用脑电生理仪和反应时间技术,检测这64例PSPD患者的P50,与60名健康对照组的P50进行比较。结果 PSPD组HAMD、HAMA、NRS评分分别为(37.89±10.61)分、(25.58±7.49)分、(7.09±1.51)分;PSPD组S2-P50波幅为(10.23±0.33)u V,健康对照组为(7.53±3.86)u V,差异有统计学意义(t=3.882,P=0.000);PSPD组和健康对照组P50抑制率分别为(0.53±0.19)和(0.43±0.17),差异有统计学意义(t=3.113,P0.01);PSPD组P50异常百分率为56.25%,健康对照组为33.33%,差异有统计学差异(χ2=6.567,P=0.01)。结论PSPD患者疼痛较重,存在严重抑郁及明显焦虑;PSPD患者的P50抑制异常百分率较高,S2-P50波幅增高,P50抑制率增高,PSPD患者存在感觉门控功能缺损。     

帕金森病患者记忆监测与情景记忆的相关研究

目的 研究帕金森病患者( Parkinson's disease,PD)对情景记忆监测情况,并进一步探讨PD患者情景记忆障碍的可能机制.方法 建立情景记忆知晓感(feeling of knowing-episodic memory,FOK-EM)判断的试验范式,对25例PD患者和25名年龄及教育程度相匹配的健康对照(HC)者进行研究.结果 与HC组的FOK-EM的回忆率(39.67％±6.11％)、再认率(58.42％±7.50％)以及FOK判断准确率(0.61 ±0.22)比较,PD患者组FOK-EM的回忆率(19.33％±5.10％)、再认率(45.93％±7.82％)以及FOK判断准确率(-0.18±0.46)显著降低,差异均有统计学意义(t=-4.833,P＜0.01;t=-2.497,P＜0.05;t=-5.986,P＜0.01);FOK-EM的肯定判断/正确再认成绩(20.47％±10.78％)以及肯定判断/错误再认成绩(即高估,29.53％±5.62％)与HC组的肯定判断/正确再认成绩(39.47％±9.47％)以及肯定判断/错误再认成绩(即高估,13.90％±5.50％)之间差异有统计学意义(t =3.564,P＜0.05;t=2.306,P＜0.05),且Stroop效应与FOK-EM的肯定判断/错误再认成绩呈正相关(r =0.640,P＜0.01).结论 PD患者的情景记忆监测受损,表现为对自身再认能力的高估.这种记忆监测受损与执行功能的损害相关,提示此机制可能是导致PD患者情景记忆障碍的重要因素.     

度洛西汀治疗躯体形式障碍对照研究的Meta分析

目的探讨度洛西汀治疗躯体形式障碍的疗效。方法用Meta分析对4项度洛西汀与其他抗抑郁剂治疗躯体形式障碍对照研究的文章进行再分析,评价其合并效应量大小和综合显著性检验。结果度洛西汀治疗前后的自身对照,合并效应量d=-3．67,95％CI（-4．80,-2．55）,综合显著性检验（r=6．39,P〈0．01）,提示度洛西汀治疗躯体形式障碍前后症状学变化有非常显著性差异,效应极强;度洛西汀与对照药在第2周末和治疗结束后的组间比较,分别为d=-0．12,95％CI（-0．80,0．56）,Х^2=0．35,P〉0．05;y合并=-0．52,95％CI（-1．55,0．52）,Х^2=0．98,P〉0．05,提示两组疗效相当,差异无统计学意义。结论度洛西汀与对照药的疗效相当。     

双相障碍稳定期患者认知损害的性别差异

目的 探讨双相障碍Ⅰ型稳定期患者认知损害的性别差异.方法 采用数字符号、数字广度、视觉再生、连线测验A(TMT-A)、连线测验B(TMT-B)、威斯康星测验(WSCT)和汉诺塔测验(TOH),检测218例双相障碍Ⅰ型患者(患者组)和318名正常对照(对照组)的注意、记忆和执行功能,并比较2组间的性别差异.结果 分组主效应:患者组在数字符号、数字广度顺背、数字广度倒背、数字广度总分、TMT-A时间、TMT-B时间、视觉再生、WSCT分类数、言语流畅性动物总数、TOH总分、TOH任务数、TOH平均计划时间、TOH平均执行时间、WSCT总错误数、WSCT持续错误数、言语流畅性重复数的成绩均低于对照组(F=66.60、16.10、17.06、20.38、98.77、66.33、23.75、5.65、62.08、21.51、22.08、10.15、19.33,x2=21.53、33.17、12.78),差异有统计学意义(P均＜0.05).性别主效应:患者组与对照组女性在数字符号测验中的成绩优于男性(F=7.13,P＜0.05),其中男性对照组和患者组分别为(53.30±12.30)分和(46.14±11.72)分,女性分别为(55.38±14.30)分和(47.82±11.95)分;在汉诺塔平均计划时间均短于男性,差异有统计学意义(F=5.13,P＜0.05),其中男性对照组和患者组分别为(5.28±2.65)分和(6.36±3.77)分,女性分别为(5.15±2.82)分和(5.52±3.07)分;2组在分组和性别的交互作用无统计学意义(P＞0.05).结论 稳定期双相障碍患者存在认知损害,其某些注意和执行功能可能存在性别差异.     

早期帕金森病患者语言工作记忆特点

目的探讨帕金森病(PD)患者视觉语言工作记忆损害及其特点。方法仿制并修订了Smith工作记忆检查软件,对确诊的PD患者和对照组进行语言工作记忆检查。结果PD组(31例)语义性语言工作记忆检查的成绩(84.8%±9.1%)较对照组(30例)成绩(88.9%±7.2%)低,但差异无统计学意义(t=-1.935,P=0.058),PD组(28例)语音性语言工作记忆检查的成绩(83.6%±7.7%)较对照组(30例)成绩(88.4%±6.2%)显著下降,差异有统计学意义(t=-2.298,P=0.034)。右侧肢体起病的患者语义性(t=-2.075,P=0.044)和语音性(t=-2.593,P=0.013)语言工作记忆的成绩较左侧肢体起病的患者下降,差异有统计学意义。结论早期的PD患者存在语音性语言工作记忆的损害,语义性语言工作记忆相对保留。提示语音和语义性语言工作记忆加工应用不同的神经环路。     

重症肌无力患者外周血Th17和调节性T细胞分析

目的 观察重症肌无力(myasthenia gravis,MG)患者Th17细胞和调节性T细胞的水平,并研究甲强龙冲击治疗对其影响.方法 应用四色流式细胞仪检测66例MG患者及35名健康对照者外周血Th17细胞和CD4+CD25highT细胞百分率;分析其中18例患者外周血Th17细胞与美国MG协会(MGFA)评分相关性;观察8例MG患者甲强龙冲击治疗2周后上述细胞的变化.结果 MG患者与健康对照者外周血Th17细胞百分率分别为2.61%±0.28%与0.94%±0.12%(Z=4.059,P=0.0001);甲强龙治疗前后8例MG患者Th17细胞百分率分别为4.72%±1.21%与1.81%±0.69%,差异有统计学意义(Z=1.995,P=0.0460);患者外周血Th17细胞水平与MGFA评分呈正相关(r=0.5359,P=0.0219).结论 MG患者外周血中Th17细胞升高,甲强龙冲击治疗可降低其水平,这可能是改善MG患者病情的有效机制.     

应用轻躁狂检测清单甄别抑郁症中可能存在的双相障碍

目的 通过轻躁狂检测清单(HCL-32)测评结果甄别抑郁症中可能存在的双相障碍.方法 对128例抑郁症患者应用软双相建议性诊断标准进行诊断,并比较软双相与非软双相抑郁症患者HCL-32的差异.结果 (1)128例抑郁症患者中,HCL-32评分0～19(5.7±4.7)分;(2)是否软双相抑郁者分别为15例和113例,HCL-32评分分别为[(9.4±6.7)分vs(5.2±4.2)分,t=3.40,P=0.001],是否宽松软双相抑郁者HCL-32评分分别为[(7.8±5.6)分vs(4.3±3.4)分,t=4.34,P=0.000],有无双相障碍家族史者HCL-32评分分别为[(9.2±6.8)分vs(5.4±4.4)分,t=2.39,P=0.018],有无躁狂转相史者HCL-32评分分别为[(8.6±7.3)分vs(5.3±4.3)分,t=2.05,P=0.043],有无环性人格或明显外向者HCL-32评分分别为[(8.4±5.7)分vs(5.3±4.4)分,t=2.58,P=0.011],有无旺盛性人格素质者HCL-32评分分别为[(9.0±6.7)分vs(5.0±3.9)分,t=3.90,P=0.000],有无边缘性人格者HCL-32评分分别为[(8.6±4.3)分vs(5.4±4.7)分,t=2.22,P=0.028],是否呈发作性病程者HCL-32评分分别为[(8.9±5.7)分vs(5.2±4.3)分,t=3.19,P=0.002];(3)男女患者HCL-32评分分别为[(4.3±3.7)分vs(6.6±5.1)分,t=2.87,P=0.005];(4)有抑郁症家族史者、有自杀家族史者、发病年龄≤25岁者、有非典型抑郁者、有精神运动抑制者、有精神病性抑郁者、有生物节律明显者HCL-32评分与对应组的差异无统计学意义;(5)HCL-32＞7分37例(28.9%),＞10分17例(13.3%),＞14分7例(5.5%),其中＞10分者所占比例与软双相所占比例接近.结论 HCL-32＞10分可能有助于在抑郁症患者中筛选诊断双相障碍.     

Effects of visible and invisible cueing on line bisection and Landmark performance in hemispatial neglect.

A total of 12 patients with hemispatial neglect (and two control groups) were tested to examine the effects of lateralized cues on line bisection and Landmark judgements. The experiment was designed to investigate whether bisection and landmark biases induced by cueing are simply a result of a direct perceptual lengthening of the cued part of the line caused by the fact that the cue is visible, thus creating a composite 'line plus cue' or whether cueing indeed induces an attentional bias. Secondly, earlier work by Harvey et al. [Harvey M, Milner AD, Roberts RC. An investigation of hemispatial neglect using the landmark task, Brain and Cognition 1995; 27: 59-78] has shown that in neglect patients cues work by inducing orientational biases rather than via the alteration of subjective length perception. An attempt was made to replicate this finding and extend it to cues that are not physically present. The bisection data clearly showed that cues bias attention rather than work via a direct lengthening of the line: both visible and invisible cues biased bisection performance equally well. The Landmark data, however, revealed much less clear-cut results and we failed to repeat the earlier observation by Harvey et al. that cues induce orientational biases. Even when the neglect patients were categorised into premotor and perceptual categories a clear effect failed to emerge. It is hypothesised that the earlier reported effect may be linked to neglect severity rather than to perceptual type neglect.     

Line versus representational bisections in unilateral spatial neglect

OBJECTIVES: To clarify the mechanisms of left unilateral spatial neglect found in the bisection of lines after cueing to the left end point and to determine whether neglect occurs for the mental representation of a line. METHODS: A new representational bisection task was developed to eliminate the influence of the right segment of the physical line that would attract attention. Eight patients with typical left unilateral spatial neglect underwent line and representational bisection tasks on a computer display with a touch panel. In the line bisection with cueing, they bisected a line after touching the left end point. In the representational bisection, the patients were presented with a line until they touched the left end point. On the blank display, they pointed to the subjective midpoint of the erased line. The performances of the two bisection tasks were compared when the length and position of stimulus lines were varied. RESULTS: The rightward errors in the representational bisection were greater than or equivalent to those in the line bisection with cueing. The effect of line length in which the errors became greater for the longer lines was equally found in the line bisection with cueing and the representational bisection. This was confirmed in the condition where the right end point was placed at a fixed position and the line length was varied. CONCLUSIONS: After cueing to the left end point, rightward bisection errors of patients with neglect are not caused by overattention to the right segment of the physical line. Left neglect occurs mainly for the mental representation formed at the time of cueing or seeing the whole extent of a line.     

Biases in attentional orientation and magnitude estimation explain crossover: neglect is a disorder of both

Crossover refers to a pattern of performance on the line bisection test in which short lines are bisected on the side opposite the true center of long lines. Although most patients with spatial neglect demonstrate crossover, contemporary theories of neglect cannot explain it. In contrast, we show that blending the psychophysical construct of magnitude estimation with neglect theory not only explains crossover, but also addresses a quantitative feature of neglect that is independent of spatial deficits. We report a prospective validation study of the orientation/estimation hypothesis of crossover. Forty subjects (17 patients with and without neglect following unilateral brain injury and 23 normal controls) completed four experiments that examined crossover using line bisection, line bisection with cueing, and reproducing line lengths from both memory and a standard. Replicating earlier findings, all except one subject group exhibited crossover on the standard line bisection test, all groups showed a spontaneous preference to orient attention to one end of the lines, and all groups overestimated the length of short lines and underestimated long lines. Biases in attentional orientation and magnitude estimation are exaggerated in patients with neglect. The truly novel finding of this study occurred when, after removing the line from the bisection task, the direction of crossover was completely reversed in all subject groups depending on where attention was oriented. These findings are consistent with our hypothesis of crossover: (1) crossover is a normal component of performance on line bisection; (2) crossover results from the interplay of biases in attentional orientation and magnitude estimation; and (3) attentional orientation predicts the direction of crossover, whereas a disorder of magnitude estimation, not previously emphasized in neglect, accounts for the quantitative changes in length estimation that make crossover more obvious in neglect subjects. Paradoxically, we observed that the traditional line bisection test is suboptimal for exploring crossover because lines elicit spontaneous orientation responses from subjects that confound experimental manipulations of attention. We conclude that attentional orientation and magnitude estimation are necessary and sufficient to explain crossover and that bias in magnitude estimation is a core component of neglect.     

Does spatial cueing affect line bisection in chronic hemianopia?

Patients with homonymous hemianopia often show a contralesional shift towards their blind field when bisecting horizontal lines ("hemianopic line bisection error", HLBE). The reasons for this spatial bias are not well understood and debated. Cueing of spatial attention modulates line bisection significantly in patients with visuospatial neglect. Moreover, recent evidence showed that attention training significantly improves deficits of visual search in hemianopia. Here, we tested in 20 patients with chronic homonymous hemianopia (10 left-sided, 10 right-sided) without visual neglect, 10 healthy control subjects, 10 neurological control patients, and 3 patients with left visuospatial neglect and leftsided hemianopia whether spatial cueing influences the HLBE. Subjects indicated verbally the midpoint of horizontal lines in a computerized line bisection task under four experimental cue positions (cue far left, mid-left, mid-right or far-right within the horizontal line). All 20 hemianopic patients showed the typical HLBE towards their blind field, while the two control samples showed only a small but significant leftward shift (pseudoneglect). None of the 4 cueing manipulations had a significant effect on the HLBE in the hemianopic patients. Moreover, no differential effects of cueing on line bisection results were obtained when analyzed in lesion subgroups of hemianopic patients with circumscribed occipital lesions (N=8) as contrasted with patients having more extended (occipito-temporal or temporal) lesions (N=12). This null-effect contrasts with marked cueing effects observed in 3 neglect patients with left hemianopia in the same tasks, showing the principal efficacy of our cueing manipulation. These results argue against attentional explanations of the HLBE.     

Crossover is not a consequence of neglect: a test of the orientation/estimation hypothesis.

Most patients with neglect demonstrate a crossover effect on line bisection. Crossover refers to a pattern of performance in which long lines (>10 cm) are bisected ipsilateral to brain injury and short lines (<2 cm) are bisected contralateral to brain injury. Crossover bisections on short lines are of interest because they are not predicted by contemporary theories concerning neglect. However, we propose that the effect depends on two independent factors that normally influence bisection performance but are merely exaggerated in neglect--a tendency to overestimate the length of short lines and underestimate long lines and a tendency to orient attention preferentially in one spatial direction. We predicted that both patients with unilateral left and right hemisphere injury would demonstrate crossover on line bisection and that they would overestimate short lines and underestimate long lines upon direct visual inspection. Further, the 2 groups were predicted to demonstrate crossover in opposite directions owing to different lesion-induced biases in attentional orientation. Testing 5 patients with right hemisphere injury and 7 patients with left hemisphere injury confirmed each prediction. Additionally, errors in length estimation were exaggerated among patients with right hemisphere injury, most of whom had neglect. It is concluded that while crossover is accentuated in cases of neglect, it is not a consequence of neglect per se. As such, crossover bisections are not at odds with contemporary neglect theory.     

Ipsilesional Attentional-Approach Neglect or Crossover Effect*

Patients with ipsilateral neglect (IN) bisect lines toward contralesional space. It has been posited that IN might be induced by an attempt at compensation, as part of the crossover effect, where patients with an ipsilesional bias when bisecting long lines, cross over and develop a contralesional bias on short lines or as a release of an approach (grasp) behavior that might be attentional or intentional. To test these alternative hypotheses we had a patient with IN from a right medial frontal lesion bisect lines that contained no cue, a left-sided cue, a right-sided cue, and bilateral cues. If this patient had ipsilateral neglect (IN) because of a crossover effect or compensation, right-sided cues should have influenced bisection more than left-sided cues. We, however, found that only left-sided cues induced a significant change (left-sided deviation) providing support for the attentional-approach (grasp) hypothesis. Further support of this contralesional attentional grasp hypothesis comes from the observation that this patient also had ipsilesional extinction to simultaneous stimuli.     

Ipsilesional attentional-approach neglect or crossover effect

Patients with ipsilateral neglect (IN) bisect lines toward contralesional space. It has been posited that IN might be induced by an attempt at compensation, as part of the crossover effect, where patients with an ipsilesional bias when bisecting long lines, cross over and develop a contralesional bias on short lines or as a release of an approach (grasp) behavior that might be attentional or intentional. To test these alternative hypotheses we had a patient with IN from a right medial frontal lesion bisect lines that contained no cue, a left-sided cue, a right-sided cue, and bilateral cues. If this patient had ipsilateral neglect (IN) because of a crossover effect or compensation, right-sided cues should have influenced bisection more than left-sided cues. We, however, found that only left-sided cues induced a significant change (left-sided deviation) providing support for the attentional-approach (grasp) hypothesis. Further support of this contralesional attentional grasp hypothesis comes from the observation that this patient also had ipsilesional extinction to simultaneous stimuli.     

Contralesional cross-over in chronic neglect: Visual search patterns reveal neglect of the ipsilesional hemispace

Introduction: With neuropsychological rehabilitation approaches neglect patients can learn to compensate for the reduced awareness of the contralesional hemispace that is often observed after right brain damage. Here, we report contralesional "cross-over" deviations in line bisection that are hypothesized to be a result of focusing on the contralesional hemispace while the intact hemispace is "neglected". We investigate whether this unexpected pattern of deviation is related to defects in the visual field, motor intention/hypokinesia deficits or deficits in working memory.Methods: Neglect patients with and without homonymous field defects were screened for contralesional cross-over deviations in line bisection of long lines. During line bisection eye movements were recorded in two conditions with and without requiring hand movements in order to search for directional hypokinesia. Visual fields were tested with near-threshold perimetry and with supra-threshold campimetry.Results: Of 53 chronic neglect patients only 8 showed cross-over in line bisection. Evidence for directional hypokinesia was found in only one patient. Patients with cross-over focused more often to the left than to the right of the objective line midpoint. Patients with and without visual field defects did not differ in the extent of cross-over deviations. Cross-over deviation and inconsistent stimulus detection in left hemispace were correlated irrespective of the presence of a visual field deficit. Larger cross-over deviations were associated with poorer verbal working memory span, and disorganized patterns of eye movement were related to reduced visuo-spatial working memory capacity.Conclusion: Increasing awareness of the disorder and the use of compensatory strategies may have led to a cross-over shift of visual search dominance towards the neglected side resulting in an exploration deficit of the ipsilesional side.     

Dissociated neglect for objective and subjective sizes

We examined the effect of line length and viewing distance on the line bisection performance in near space in five patients with left unilateral spatial neglect following right parietal lesions. A line bisection task by fixation was devised to avoid the influence of manual responses. The rightward deviation measured in visual angle increased linearly as a function of the visual angle of lines 150 mm or more long. This linearity, however, did not hold for lines of 100 mm or less. The deviation measured in length was nearly constant for each of these short lengths, even when the visual angle was varied at different viewing distances. The patients therefore discriminated the objective lengths of the short lines. For small objects, neglect patients may distribute attention mainly on the coordinates scaled for objective size. Received: 16 May 1996 Received in revised form: 1 August 1997 Accepted: 12 August 1997     

"Mind the gap": the size-distance dissociation in visual neglect is a cueing effect

There is a growing body of evidence that the processes mediating the allocation of spatial attention within objects may be separable from those governing attentional distribution between objects. In the neglect literature, a related proposal has been made regarding the perception of (within-object) sizes and (between-object) distances. This proposal follows observations that, in size-matching and bisection tasks, neglect is more strongly expressed when patients are required to attend to the sizes of discrete objects than to the (unfilled) distances between objects. These findings are consistent with a partial dissociation between size and distance processing, but a simpler alternative must also be considered. Whilst a neglect patient may fail to explore the full extent of a solid stimulus, the estimation of an unfilled distance requires that both endpoints be inspected before the task can be attempted at all. The attentional cueing implicit in distance estimation tasks might thus account for their superior performance by neglect patients. We report two bisection studies that address this issue. The first confirmed, amongst patients with left visual neglect, a reliable reduction of rightward error for unfilled "gap" stimuli as compared with solid lines. The second study assessed the cause of this reduction, deconfounding the effects of stimulus type (lines vs. gaps) and attentional cueing, by applying an explicit cueing manipulation to line and gap bisection tasks. Under these matched cueing conditions, all patients performed similarly on line and gap bisection tasks, suggesting that the reduction of neglect typically observed for gap stimuli may be attributable entirely to cueing effects. We found no evidence that a spatial extent, once fully attended, is judged any differently according to whether it is filled or unfilled.