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I Biederman

Publications and source records attributed to I Biederman.

12 recordsLinked to original sources
PubMed1992

Discrimination of contour-deleted images by pigeons.

Three experiments attempted to determine which properties of pictorial representations of objects control their discrimination by pigeons. A particular focus was whether the representation mediating such discriminations could be described by the simple viewpoint-invariant primitive volumes of Biederman's (1987) recognition-by-components theory of object recognition or by Cerella's (1990) particulate features. In all 3 experiments, pigeons were first trained to discriminate drawings of 4 stimulus objects with half of the contour deleted but with the component geons postulated by Biederman's theory recoverable. Discrimination accuracy was then compared for test items containing the original particulate features, affording the retrieval of the original component geons, or having neither of these properties of the training stimuli. Although response accuracy was significantly greater when the component geons of the original objects were retrievable, measurable control over recognition by the particulate features of the objects and by their specific locations was also found. The results are consistent with the idea of component geon recognition as one of the important factors in object discrimination.

Animals↗
PubMed1992

Unexceptional spatial memory in an exceptional memorist.

Rajan Mahadevan evidences an exceptional memory for arrays of digits. We tested whether Rajan's spatial memory was likewise exceptional. Eight control Ss and Rajan were instructed to remember the position and orientation of 48 images of common objects shown either to the left or the right of fixation and facing either left or right. Rajan's accuracy for judging whether the position and orientation of these pictures had changed when they were shown in a different sequence was lower than that of control Ss for both judgments. Rajan's exceptional memory capacity apparently does not extend to spatial relations.

Adult↗
PubMed1992

Dynamic binding in a neural network for shape recognition.

Given a single view of an object, humans can readily recognize that object from other views that preserve the parts in the original view. Empirical evidence suggests that this capacity reflects the activation of a viewpoint-invariant structural description specifying the object's parts and the relations among them. This article presents a neural network that generates such a description. Structural description is made possible through a solution to the dynamic binding problem: Temporary conjunctions of attributes (parts and relations) are represented by synchronized oscillatory activity among independent units representing those attributes. Specifically, the model uses synchrony (a) to parse images into their constituent parts, (b) to bind together the attributes of a part, and (c) to bind the relations to the parts to which they apply. Because it conjoins independent units temporarily, dynamic binding allows tremendous economy of representation and permits the representation to reflect the attribute structure of the shapes represented.

Depth Perception↗
PubMed1992

Metric invariance in object recognition: a review and further evidence.

Phenomenologically, human shape recognition appears to be invariant with changes of orientation in depth (up to parts occlusion), position in the visual field, and size. Recent versions of template theories (e.g., Ullman, 1989; Lowe, 1987) assume that these invariances are achieved through the application of transformations such as rotation, translation, and scaling of the image so that it can be matched metrically to a stored template. Presumably, such transformations would require time for their execution. We describe recent priming experiments in which the effects of a prior brief presentation of an image on its subsequent recognition are assessed. The results of these experiments indicate that the invariance is complete: The magnitude of visual priming (as distinct from name or basic level concept priming) is not affected by a change in position, size, orientation in depth, or the particular lines and vertices present in the image, as long as representations of the same components can be activated. An implemented seven layer neural network model (Hummel & Biederman, 1992) that captures these fundamental properties of human object recognition is described. Given a line drawing of an object, the model activates a viewpoint-invariant structural description of the object, specifying its parts and their interrelations. Visual priming is interpreted as a change in the connection weights for the activation of: a) cells, termed geon feature assemblies (GFAs), that conjoin the output of units that represent invariant, independent properties of a single geon and its relations (such as its type, aspect ratio, relations to other geons), or b) a change in the connection weights by which several GFAs activate a cell representing an object.

Adult↗
PubMed1991

Priming contour-deleted images: evidence for intermediate representations in visual object recognition.

The speed and accuracy of perceptual recognition of a briefly presented picture of an object is facilitated by its prior presentation. Picture priming tasks were used to assess whether the facilitation is a function of the repetition of: (a) the object's image features (viz., vertices and edges), (b) the object model (e.g., that it is a grand piano), or (c) a representation intermediate between (a) and (b) consisting of convex or singly concave components of the object, roughly corresponding to the object's parts. Subjects viewed pictures with half their contour removed by deleting either (a) every other image feature from each part, or (b) half the components. On a second (primed) block of trials, subjects saw: (a) the identical image that they viewed on the first block, (b) the complement which had the missing contours, or (c) a same name-different exemplar of the object class (e.g., a grand piano when an upright piano had been shown on the first block). With deletion of features, speed and accuracy of naming identical and complementary images were equivalent, indicating that none of the priming could be attributed to the features actually present in the image. Performance with both types of image enjoyed an advantage over that with the different exemplars, establishing that the priming was visual rather than verbal or conceptual. With deletion of the components, performance with identical images was much better than that with their complements. The latter were equivalent to the different exemplars, indicating that all the visual priming of an image of an object is through the activation of a representation of its components in specified relations. In terms of a recent neural net implementation of object recognition (Hummel & Biederman, in press), the results suggest that the locus of object priming may be at changes in the weight matrix for a geon assembly layer, where units have self-organized to represent combinations of convex or singly concave components (or geons) and their attributes (e.g., aspect ratio, orientation, and relations with other geons such as TOP-OF). The results of these experiments provide evidence for the psychological reality of intermediate representations in real-time visual object recognition.

Adult↗
PubMed1991

Object recognition and laterality: null effects.

In two experiments, normal subjects named briefly presented pictures of objects that were shown either to the left or to the right of fixation. The net effects attributable to hemifield were negligible: naming RTs were 12 msec lower for pictures shown in the left visual field but error rates were slightly lower, by 0.8%, for pictures shown in the right visual field. In both experiments, a second block of trials was run to assess whether hemifield effects would be revealed in object priming. Naming RTs to same name--different shaped exemplar pictures were significantly longer than RTs for identical pictures, thus establishing that a component of the priming was visual, rather than only verbal or conceptual, but hemifield effects on priming were absent. Allowing for the (unlikely) possibility that variables with large differential left-right hemifield effects may be balancing and cancelling each other out, we conclude that there are no differential hemifield effects in either object recognition or object priming.

Female↗
PubMed1991

Evidence for complete translational and reflectional invariance in visual object priming.

The magnitude of priming on naming reaction times and on the error rates, resulting from the perception of a briefly presented picture of an object approximately 7 min before the primed object, was found to be independent of whether the primed object was originally viewed in the same hemifield, left-right or upper-lower, or in the same left-right orientation. Performance for same-name, different-examplar images was worse than for identical images, indicating that not only was there priming from block one to block two, but that some of the priming was visual, rather than purely verbal or conceptual. These results provide evidence for complete translational and reflectional invariance in the representation of objects for purposes of visual recognition. Explicit recognition memory for position and orientation was above chance, suggesting that the representation of objects for recognition is independent of the representations of the location and left-right orientation of objects in space.

Adult↗
PubMed1991

Hand movement speed and accuracy in detoxified alcoholics.

Detoxified alcoholics (n = 192) were found to be 9.3% slower than age-matched controls (n = 112) with regard to the composite speed (movement time, MT) with which they were able to strike targets of various sizes and distances with a hand-held stylus at onset of a light stimulus (Fitts's Task). Females (n = 102) were 8% slower than males (n = 202), and blacks (n = 103) about 15.6% slower than whites (n = 201). Gender was the only significant factor with regard to errors (target misses), with women committing 28% fewer errors than men. Women, in contrast to men, appear to trade speed for accuracy in this task. Favorable socioeconomic/medical status and target misses were directly related to movement speed. Thus, when the MT data were corrected for lifestyle variables, the significance of the alcohol effects on MT disappeared, but gender differences persisted. The alcohol effect became statistically significant, the ethnic group differences remained statistically significant, and the gender effect became insignificant when MT scores were corrected for accuracy of performance (target misses). The slope of the linear function relating MT to target difficulty was similar for all subgroups. Prior knowledge of the direction of movement was found to affect MT performance more in white than in black subjects. With regard to reaction times, ethnic group and alcohol use effects remained statistically significant after corrections for lifestyle and errors were made, with values for blacks about 5% slower than values for whites, and values for alcoholics about 4.6% slower than those for controls. Prior knowledge of the direction of movement significantly improved (shortened) reaction time in all subgroups (14%-19%).

Adult↗
PubMed1990

Effects of age and sex on reciprocal tapping performance.

Using a reciprocal tapping task (Fitts's task), the speed and accuracy of small-amplitude motor movements of the hand were measured for 62 men and 84 women, 20 to 89 yr. of age. Men and women in their 20s and 30s performed similarly, although men in their 20s displayed a tendency to trade accuracy in favor of speed. Movement time increased noticeably for both men and women beginning with the 40s decade and continued to increase through the 80s decade. Error rates were lower for women than men and were relatively uniform for both men and women across all age decades past 30 yr. Older subjects of both sexes appeared to sacrifice speed (slowed down) to maintain accuracy on the task. The slope of the linear regression relating movement time to task difficulty was steeper for men than for women and increased more for men than women with advancing age, indicating that older men slowed down relatively more than older women on more difficult tasks.

Adult↗
PubMed1988

Motor performance in detoxified alcoholics.

Detoxified male and female alcoholics (aged 20-49 years) and age-matched controls performed a series of 15-sec target-tapping tasks in which they alternatively marked two target strips with a felt marker as rapidly and as accurately as possible. Consistent with "Fitts' Law" (Fitts PM: J Exp Psych 47:381-391, 1954), a highly linear relationship between movement time and task difficulty was observed in all four groups. Overall, the alcoholics were slower and made more errors than the controls, although the pattern of deficit differed for males and females. Accuracy, but not speed, was impaired in male alcoholics. The production of undershoot errors was increased more in alcoholics than nonalcoholics in targets of narrower width, whereas the production of overshoot errors was increased more in alcoholics as target separation decreased. Female alcoholics displayed impairment in speed of movement, but not accuracy. However, both alcoholic groups displayed elevated error rates for the more difficult targets. It is thus possible that detoxified alcoholics might mimic the speed functions of nonalcoholic individuals at the occasional cost of an erroneous response at a difficult target.

Adult↗