When, after being shown an initiating stimulus, the subject is required to respond to a symmetrical pair of silhouettes, either its facsimile or its enantiomorph may be chosen.
Each card showed one of the two alternative arrangements of its facsimile and enantiomorph silhouettes.
In the circumstances of facsimile and enantiomorph responses being equally frequent, the ratio has the value of 0.
2000) point out that the difficulties in discriminating between mutually enantiomorphic patterns show that the perceptual encodement of a pattern must necessarily involve encodement of its enantiomorph; a discrimination error occurs whenever an observer responds to the enantiomorph as if it were the facsimile of the original pattern.
Furthermore, as the sloping stimuli are more readily confused, the two postulated enantiomorphs by means of which each stimulus is encoded must differ much more markedly in the case of stimuli in the fronto-parallel plane than in the case of the stimuli in inclined planes.
After presentation of the last lamella the participant was presented with a set of 60 cards, 15 of which bore depictions of the stimulus pentagons as they would appear in the fronto-parallel plane, 15 of which bore enantiomorphs of these depictions, and 30 of which portrayed pentagons unrelated to the pentagons used as stimuli.
Thus three scores were obtained in response to the facsimile depictions and three to their enantiomorphs.