The need for a revised version of the Benton judgment of line orientation test

The Judgment of Line Orientation Test (JLOT) is considered a valid task for the assessment of visuospatial perception, and, for this reason, it is also considered to be a sensitive tool able to discriminate between right-hemisphere-damaged (RHD) patients and left-hemisphere-damaged (LHD) patients. In contrast with this view, we report evidence that the greater impairment in JLOT usually shown by RHD patients is unrelated to the supposed JLOT effectiveness in measuring visuospatial judgment ability and to the putative dominant role of the right hemisphere in visuospatial processing. JLOT is characterized by a left-right structural asymmetry (i.e., left-side lines are easier to judge) that seriously undermines the test validity: This asymmetry interacts with ipsilesional attentional biases of brain-damaged patients and affects their performance. Results obtained with a JLOT version composed of both the original items and their mirror-reversed versions clearly indicate that the cognitive functions tested by the JLOT are distributed across the two hemispheres: LHD and RHD patients did not differ from each other or from their matched controls when their performances were compared on this balanced JLOT version. Impaired performances of either RHD or LHD patients were found only when performances in original and mirror-reversed items were considered separately. This suggests that the original JLOT cannot assess visuospatial perception independently from attentional biases. The test can be a powerful clinical tool, as long as both original and mirror-reversed items are used, and the standard scoring method is replaced by the evaluation of the individual lines of stimulus pairs.