Santiago H C, Matos I
Inter American University School of Optometry, Hato Rey, Puerto Rico 00919.
J Am Optom Assoc. 1994 Oct;65(10):690-700.
Reading depends on the efficient storage and retrieval of visual and verbal information. Some studies have shown deficits of specific learning-disabled children in the recall and recognition of visual stimuli. This deficit is usually interpreted to be secondary to a verbal labelling deficiency. In this experiment, we presented serial lists of complex geometric stimuli to a group of specific learning-disabled children (LD) and a non-disabled control group (NLD) at both the elementary and secondary school levels. We hypothesized that the NLD visual recognition performance would be superior to that of the LD group at the elementary school level, but not at the secondary school level. We further hypothesized that the difference was related to inefficient primary visual rehearsal strategies.
20 elementary school children (11 LD and 9 NLD) and 31 secondary school children (15 LD and 16 NLD) were presented serial lists of four geometric figures. A probe was presented after a 1 second delay. The subjects pressed a key if the probe was in the list ("same" response) or another key if the probe was not in the list ("different" response). Type of response (correct or incorrect) and reaction time was measured at each serial position for "same" and "different" responses.
At the elementary school level, there was a significant visual recognition memory advantage of the NLD group over the LD group (F(1,8) = 6.83, p = 0.018), but there was no significant difference between these groups at the secondary school level. There was no significant difference in the reaction time between the groups at either of the two levels.
LD children have poorer visual recognition memory performance than NLD children for complex geometric patterns. Since there was no difference in reaction time between the two groups, attentional or encoding deficits can not adequately explain the recognition memory differences. The results can best be explained by inefficient visual rehearsal strategies with a small pool of visual items that are unfamiliar and difficult to code verbally. The serial recognition task can be used effectively by the optometrist to discriminate the performance of LD and NLD children.
阅读依赖于视觉和言语信息的有效存储与提取。一些研究表明，特定学习障碍儿童在回忆和识别视觉刺激方面存在缺陷。这种缺陷通常被解释为继发于言语标记缺陷。在本实验中，我们向一组小学和中学阶段的特定学习障碍儿童（LD）以及非学习障碍对照组（NLD）呈现了一系列复杂几何刺激列表。我们假设，在小学阶段，NLD组的视觉识别表现将优于LD组，但在中学阶段则不然。我们进一步假设，这种差异与低效的初级视觉复述策略有关。
向20名小学生（11名LD和9名NLD）和31名中学生（15名LD和16名NLD）呈现包含四个几何图形的系列列表。延迟1秒后呈现一个探测图形。如果探测图形在列表中，受试者按一个键（“相同”反应）；如果探测图形不在列表中，则按另一个键（“不同”反应）。在每个系列位置测量“相同”和“不同”反应的反应类型（正确或错误）及反应时间。
在小学阶段，NLD组在视觉识别记忆方面显著优于LD组（F(1,8) = 6.83，p = 0.018），但在中学阶段，两组之间无显著差异。在两个水平上，两组之间的反应时间均无显著差异。
对于复杂几何图案，LD儿童的视觉识别记忆表现比NLD儿童差。由于两组之间的反应时间没有差异，注意力或编码缺陷无法充分解释识别记忆差异。结果最好用低效的视觉复述策略来解释，即一小部分不熟悉且难以用言语编码的视觉项目。验光师可以有效地使用系列识别任务来区分LD和NLD儿童的表现。
