Authors' update Translational and reflectional priming invariance: a retrospective

Biederman and Cooper (1991a) showed that the presentation of a briefly presented image of an object at one position in the visual field facilitated its identification, as assessed by naming speed and accuracy, several minutes later. The facilitation was unaffected by a translation or a reflection of the stimulus. A component of this priming was visual rather than basic-level conceptual or lexical in that there was less facilitation for an object with the same name (and basic-level class) but a different shape. The invariance of priming to view variables has stood up well over the years and appears to be a general phenomenonöas long as the original structural description can be readily resolvedöin that it has also been observed for variations in size and orientation in depth. Although priming was unaffected by a change in position, we documented that there was explicit memory for the position (and orientation and size) of the stimulus. The existence of two forms of representation from the identical stimulus presentationöone invariant and the other dependent on view variablesöposes a challenge as to what can be concluded about view invariance from single-unit activity. Introduction In 1991 Biederman and Cooper (1991a) reported an experiment in which subjects named briefly presented, masked pictures (line drawings) of objects and then, in a second block about 7 min later, they would name the identical picture or a same name, different shaped exemplar (eg a grand piano followed by an upright piano). The pictures were either in the same or different positions and had the same or different left ^ right mirror orientations (figure 1). There was marked facilitation on the second block compared to the first for the identical pictures and this facilitation was greater for the identical pictures compared to the different exemplars (which also showed some facilitation). We interpreted the advantage of the identical images compared to the different exemplar images to be evidence of visual priming and the facilitation of the different exemplars as composed of a combination of non-visual priming, ie lexical and basic-level concept priming, and general practice in the task. (Because the different exemplars were physically more similar in shape to the original object than randomly selected objects, our partitioning could actually be regarded as a lower-bounds estimate of the visual priming component and, therefore, an upper-bounds estimate of the nonvisual priming and general practice components. Also, with high-quality stimuli, the magnitude of visual priming would be expected to be modest. With degraded stimuli, eg contour-deleted line drawings, the contribution of a prior exposure is considerably greater, as indicated in figure 2.) The major contribution of the paper was in showing that the priming was unaffected by a left ^ right translation of 8.8 deg of an object. (The maximum extent of the objects was 4 deg and the nearest contour to fixation was 2.4 deg so the 8.8 deg translation was with respect to the objects' centers.) The translation invariance also held for vertical displacements, above or below fixation. Moreover, there was also invariance to the mirror reflection of the object. It is important to note that not only was there facilitation to translated and/or reflected images but there was virtually no cost as a result of the translation or the reflection in that such images were as quickly and as accurately named as those in their original position and orientation. These effects were replicated by Fiser and Biederman (2001) with grey-level images. DiCarlo and Maunsell (2003) reported that strong behavioral invariance to translation was evident in the object-matching performance of monkeys. Biederman and Cooper's 1991 paper [Biederman I, Cooper E E, 1991 `̀ Evidence for complete translational and reflectional invariance in visual object priming'' Perception 20 585 ^ 593. Original paper reprinted in the appendix.] Perception, 2009, volume 38, pages 809 ^ 825 doi:10.1068/ldmk-bie