The Influence of Concept Training on Letter Discrimination

Mirror-image confusability in adults.

“…Gesell and Ames (1947) report that handedness does not become definitely established in the child until the age of five. The success of Caldwell and Hall's (1969) training procedures in decreasing confusion between mirror-image letter pairs is possibly explained by the fact that their kindergarten 5s have just reached the age where directional differences, especially left-right discriminations, can be successfully processed when a training task relevant to these differences is used.…”

“…While Caldwell and Hall's (1969) explanation has the advantage of simplicity, it violates the fact that adults are known to confuse mirror-image stimuli, as, for example, in writing d for b or d for g, and direction, as in the case of a driver who signals a left turn and then turns right. There is, however, almost no empirical evidence concerning the discrimination of mirror-image stimuli for adults.…”

“…If, as Caldwell and Hall (1969) propose, children's mirror-image confusions simply reflect a definitional problem arising from the tendency of the child to call different orientations of a figure the same figure, then adults who thoroughly understand the requirements of the task should compare mirror-image stimulus pairs as quickly as aligned pairs.…”

Symmetry in Vision

“…Adults do not show as many errors, but show similar patterns in reaction time, such that same-different judgments on left-right mirror symmetric U-shaped objects are slower than for up-down mirror symmetric objects [122] (see [120] for a review). Children can learn to make left-right mirror discriminations at a young age if given detailed feedback [7,[123][124][125]. However, these results are task dependent, with some tasks in which mirror discriminations must be learned being harder than others [69,115,123].…”

“…Children can learn to make left-right mirror discriminations at a young age if given detailed feedback [7,[123][124][125]. However, these results are task dependent, with some tasks in which mirror discriminations must be learned being harder than others [69,115,123]. Overall, children, even before they learn to read, can use orientation and facing direction as a form cue, but it is not the most salient feature, especially when contour and color information can be used instead [126][127][128][129][130].…”