Evidence for a pre-match 'mental translation' on a form-matching task

Abstract

PURPOSE AND APPROACH. The aim was to explore whether there is a pre-match ‘mental translation’, analogous to ‘mental rotation’ and ‘mental scaling’, on a Same-Different simultaneous form-matching task. The basic approach was to vary the environmental separation of the forms, while holding constant everything else that might affect reaction time. METHOD. On a Same-Different task, subjects were presented with two forms flanking a fixation triangle, all shown in the same depth-plane. Distance (simulated) to the forms was varied. Viewing was in stereo. Total visual angle spanned by the centers of the bases of the two forms, in each eye, was held (essentially, effectively) constant as distance to the forms (and so environmental separation) varied. The forms and fixation triangle were shown resting on a bar that spanned a textured enclosure; the top of the bar crossed at eye-level and the bar was anchored to the floor of the enclosure by struts. The top half of the back of the enclosure was open, with the forms silhouetted against a blank field. So: form edge-information and gaze angle were both held constant as distance to the forms (and so environmental separation) varied, and there was no backing surface. In Experiment I, the forms were shown for 400msc; in Experiment II, the forms were shown for 300msc, and the Same-Different discrimination was made slightly easier. RESULTS AND CONCLUSION. In Experiment I, reaction time rose with increases in environmental separation (n = 34, p < .01, R-squared = .9295; Same trials). Results for the 16 subjects run so far in Experiment II also indicate a rise in reaction time with increases in environmental separation (p = .029; Same trials). In both cases, the slopes suggest a fast process. In sum, the results are evidence that comparisons of the forms were preceded by a fast ‘mental translation’, analogous to ‘mental rotation’ and ‘mental scaling’, with the locations of the forms coded in a non-retinal frame of reference.