【摘 要】 目的:使用眼跳任务深入研究不同亚型注意缺陷多动障碍(Attention deficit hyperactivity disorder,ADHD)儿童的抑制损伤。方法:选取金华市2所小学1500人,使用DSM-Ⅳ诊断标准、Conners儿童行为量表(父母问卷和教师问卷),筛查出10～13岁儿童48名,其中注意缺陷型(I型)11人,混合型(C型)19人,对照组18人,全体进行了正向眼跳和反向眼跳。结果:⑴ 反向眼跳中对照组的错误率低于I型和C型[(37.97±13.14)% vs.(70.90±15.78)%,(84.04±12.84)%;均P0.1]。
1.2 仪器设备
实验使用加拿大SR Research有限公司的EYELINKⅡ型头盔式眼动仪,采用瞳孔+角膜反射模式记录,噪音
1.4 实验过程与数据处理
实验采取个别施测,被试者正向和反向实验顺序平衡。实验前使用ppt讲稿向被试讲解规则,通过提问确认被试理解后开始练习。当被试能做出3次正确反应后,就可开始正式实验[22]。有研究认为成绩与刺激特征关系不大,练习效应也不明显[7]。程序运行时间为正向眼跳100 s,反向眼跳140 s。实验后赠送小礼物。
眼跳数据记录为事件取样。眼跳定义为“速度超过22 °/s,加速度超过4000 °/s?2的眼动”。分析数据时又排除了小于2 °的眼跳,有效反应时段设定为从刺激呈现后90 ms到刺激消失后90 ms。反应时(潜伏期)定义为从刺激呈现到正确眼跳发动的时间间隔;精确性定义为正确眼跳最初落点的准确性,该指标用实际眼跳幅度与应该达到的眼跳幅度的角度差距来衡量;平均速度定义为正确眼跳的幅度与时间的比值;矫正性眼跳定义为在首次眼跳错误后、刺激呈现结束前(再延续90 ms),看向正确方向且幅度大于首次眼跳的眼跳。根据反应时长短可划分眼跳反应类型,一般反应时为0～90 ms时定义为先期性眼跳(Anticipatory);反应时90～135 ms为快速眼跳(Express);反应时135～250 ms为常规眼跳(Regular);反应时250 ms以上为长时眼跳(Long)[4]。先期性眼跳是衡量抑制水平的重要变量,实验重点分析了被试的先期性眼跳。
1.5 统计方法
总体上角度、眼跳方向(正向和反向)属于被试内变量,组别(对照组、ADHD-I、ADHD-C)属于被试间变量,因变量包括错误率、反应时、精确性、平均速度、先期性眼跳、矫正率和矫正反应时,指标选取视具体情况而定。极值处理排除了大于(±3)个标准差的数据,全部数据采用SPSS13.0进行分析。对于被试内设计和混合设计的检验采用重复测量方差分析,对于被试间设计的检验采用t检验或单因素方差分析,使用LSD进行事后比较,若方差不齐性则采用Kruskal-Wallis Test,使用Mann-Whitney Test进行比较。
2 结 果
2.1 正向眼跳
三组间正向眼跳的各项指标评分比较见表1。错误率的组间差异无统计学意义。重复测量方差分析发现反应时、精确性和平均速度的组别与角度都不存在交互作用(均P>0.1);角度主效应均具有统计学意义(均P0.1);角度主效应具有统计学意义(F=3.71,P0.1)(表1),而反向时差异具有统计学意义(P 正向眼跳的分析发现ADHD儿童存在更多的先期性眼跳。不是外在刺激引起的眼跳为先期性眼跳,这种眼跳是内源性的[4]。该结论与以往研究相一致,如Carr等曾发现ADHD存在更多的先期性眼跳[22]。但这并不能代表ADHD儿童的认知加工速度较快,相反一些研究证明ADHD儿童有较长的潜伏期[11-12],可见其内部加工速度并不快,只是比较草率。就生理损伤而言,因ADHD儿童的正向眼跳错误率相对正常,故不可以仅凭先期性眼跳较多就推断其上丘系统(负责凝视)有问题。考虑到在注意加工中前扣带回的重要作用[3],因此ADHD的主要问题还应出现在高级眼跳神经环路。
参考文献
?[1]Castellanos FX,Sonuga-Barke EJS,Milham MP,et al.Characterizing cognition in ADHD:beyond executive dysfunction?[J].Trends Cognit Sci,2006,10(3):117-123.
[2]Amador SC,Hood AJ,Schiess MC,et al.Dissociating cognitive deficits involved in voluntary eye movement dysfunctions in Parkinson" s disease patients?[J].Neuropsychologia,2006,44:1475-1482.
[3]Eenshuistra RM,Ridderinkhof KR,Weidema MA,et al.Developmental changes in oculomotor control and working-memory effciency?[J].Acta Psychol,2007,124:139-158.
[4]Feifel D,Farber RH,Clementz BA,et al.Inhibitory deficits in ocular motor behavior in adults with attention-deficit/hyperactivity disorder?[J].Biol Psychiatry,2004,56:333-339.
[5]Reuter B,Kathmann N.Using saccade tasks as a tool to analyze executive dysfunctions in schizophrenia?[J].Acta Psychol,2004,115:255-269.
[6]Asato MR,Sweeney JA,Luna B.Cognitive processes in the development of TOL performance?[J].Neuropsychologia,2006,44:2259-2269.
[7]Everling S,Fischer B.The antisaccade:a review of basic research and clinical studies?[J].Neuropsychologia,1998,36(9):774-788.
[8]Matsuda T,Matsuura M,Ohkubo T,et al.Functional MRI mapping of brain activation during visually guided saccades and antisaccades:cortical and subcortical networks?[J].Psychiatry Res Neuroimaging,2004,131:147-155.
[9]Ettinger U,Antonova E,Crawford TJ,et al.Structural neural correlates of prosaccade and antisaccade eye movements in healthy humans?[J].Neuroimage,2005,24:487-494.
?[10]O" Driscoll GA,Dépatie L,Holahan A-LV,et al.Executive functions and methylphenidate response in subtypes of attention-deficit/hyperactivity disorder?[J].Biol Psychiatry,2005,57:1452-1460.
[11]Munoz DP,Armstrong ZT,Hampton KA,et al.Altered control of visual fixation and saccadic eye movements in attention-deficit hyperactivity disorder?[J].J Neurophysiol,2003,90(1):503-514.
[12]Klein CH,Raschke A,Brandenbusch A.Development of pro-and antisaccades in children with attention-deficit hyperactivity disorder(ADHD)and healthy controls?[J].Psychophysiology,2003,40:17-28.
[13]Habeych ME,Folan MM,Luna B,et al.Impaired oculomotor response inhibition in children of alcoholics:the role of attention deficit hyperactivity disorder?[J].Drug Alcohol Depend,2006,82:11-17.
[14]Pasini A,Paloscia C,Alessandrelli R,et al.Attention and executive functions profile in drug naive ADHD subtypes?[J].Brain Dev,2007,29:400-408.
[15]Geurts HM,Verte S,Oosterlaan J,et al.ADHD subtypes:do they differ in their executive functioning profile??[J]Arch Clin Neuropsychol,2005,20:457-477.
[16]Riccio CA,Homack S,Jarratt KP,et al.Differences in academic and executive function domains among children with ADHD predominantly inattentive and combined types?[J].Arch Clin Neuropsychol,2006,21:657-667.
?[17]Nigg JT,Blaskey LG,Huang-pollock CL,et al.Neurop-sychological executive functions and DSM-Ⅳ ADHD subtypes?[J].J Am Acad Child Adolesc Psychiatry,2002,41(1):59-66.
[18]Oosterlaan J.Cognitive neuroscience research in attention deficit/hyperactivity disorder?[J].J Abnorm Psychol,2000,93(3):314-319.
[19]American Psychiatric Association.Diagnostic and Statistical Manual of mental disorders,The 4th ed?[M].Washton DC:American Psychiatric Press,1994:78-85.
[20]徐韬园.Conners儿童行为问卷?[J].中国心理卫生杂志,1999,(增刊):52-55.
?[21]Kramer AF,Gonzalez de Sather JCM,Cassavaugh ND.Development of attentional and oculomotor control?[J].Dev Psychol,2005,41(5):760-772.
[22]Carr LA,Nigg JT,Henderson JM.Attentional versus motor inhibition in adults with attention-deficit/hyperactivity disorder?[J].Neuropsychology,2006,20(4):430-441.
编辑:赵志宇
2009-11-28收稿,2010-03-05录用