Biomedical subjects

John E Hummel

Publications and source records attributed to John E Hummel.

8 recordsLinked to original sources

PubMed2006

Role of gamma-band synchronization in priming of form discrimination for multiobject displays.

Previous research has shown that synchronized flicker can facilitate detection of a single Kanizsa square. The present study investigated the role of temporally structured priming in discrimination tasks involving perceptual relations between multiple Kanizsa-type figures. Results indicate that visual information presented as temporally structured flicker in the gamma band can modulate the perception of multiple objects in a subsequent display. For judgments of both relative orientation and relative position of 2 rectangles, response time to identify and discriminate relations between the objects was consistently decreased when the vertices corresponding to distinct Kanizsa-type rectangles were primed asynchronously. Implications are discussed for models of the perception of objects and their interrelations.

Conditioning, Psychological↗

PubMed2006

Familiar interacting object pairs are perceptually grouped.

Identification of objects in a scene may be influenced by functional relations among those objects. In this study, observers indicated whether a target object matched a label. Each target was presented with a distractor object, and these were sometimes arranged to interact (as if being used together) and sometimes not to interact. When the distractor was semantically related to the label, identification was more accurate for targets arranged to interact with that distractor. This effect depended on observers' ability to perceptually integrate the stimulus objects, suggesting that it was perceptual in nature. The effect was not attributable to attentional cuing and did not depend on expectation of certain object pairs. These data suggest that familiar functional groupings of objects are perceptually grouped.

Attention↗

PubMed2005

Comparison-induced decoy effects.

Extant theories of decoy effects on evaluations of attribute values were assessed with respect to their ability to account for a one-dimensional analogue of the asymmetric dominance effect. Parducci's (1965, 1995) range-frequency theory, Krumhansl's (1978) distance-density model, Tversky's (1977) diagnosticity principle, and reference point theories (e.g., Holyoak & Mah, 1982) were unable to account for this effect. One version of Helson's (1964) adaptation-level theory and our comparison-induced distortion theory (Choplin & Hummel, 2002) were able to account for the qualitative effect. Quantitative fits revealed that comparison-induced distortion theory provides a better account of this effect than does adaptation-level theory. These results suggest that, in some cases, biases created by language-expressible magnitude comparisons mediate the effects of decoys on evaluation.

Bayes Theorem↗

PubMed2004

Evidence for holistic representations of ignored images and analytic representations of attended images.

According to the hybrid theory of object recognition (J. E. Hummel, 2001), ignored object images are represented holistically, and attended images are represented both holistically and analytically. This account correctly predicts patterns of visual priming as a function of translation, scale (B. J. Stankiewicz & J. E. Hummel, 2002), and left-right reflection (B. J. Stankiewicz, J. E. Hummel, & E. E. Cooper, 1998). The model also predicts that priming for attended images will generalize over configural distortions (split images), whereas priming for ignored images will not. Three experiments tested and confirmed this prediction. Split images visually primed their intact and split counterparts when they were attended but not when they were ignored, whereas intact images primed themselves whether they were attended or not. The data contribute to the growing body of evidence that 1 function of visual attention is to permit the generation of explicitly relational representations of object shape.

Attention↗

PubMed2004

Relational integration, inhibition, and analogical reasoning in older adults.

The difficulty of reasoning tasks depends on their relational complexity, which increases with the number of relations that must be considered simultaneously to make an inference, and on the number of irrelevant items that must be inhibited. The authors examined the ability of younger and older adults to integrate multiple relations and inhibit irrelevant stimuli. Young adults performed well at all but the highest level of relational complexity, whereas older adults performed poorly even at a medium level of relational complexity, especially when irrelevant information was presented. Simulations based on a neurocomputational model of analogical reasoning, Learning and Inference with Schemas and Analogies (LISA), suggest that the observed decline in reasoning performance may be explained by a decline in attention and inhibitory functions in older adults.

Adolescent↗

PubMed2004

A neurocomputational model of analogical reasoning and its breakdown in frontotemporal lobar degeneration.

Analogy is important for learning and discovery and is considered a core component of intelligence. We present a computational account of analogical reasoning that is compatible with data we have collected from patients with cortical degeneration of either their frontal or anterior temporal cortices due to frontotemporal lobar degeneration (FTLD). These two patient groups showed different deficits in picture and verbal analogies: frontal lobe FTLD patients tended to make errors due to impairments in working memory and inhibitory abilities, whereas temporal lobe FTLD patients tended to make errors due to semantic memory loss. Using the "Learning and Inference with Schemas and Analogies" model, we provide a specific account of how such deficits may arise within neural networks supporting analogical problem solving.

Aged↗

PubMed2003

A symbolic-connectionist theory of relational inference and generalization.

The authors present a theory of how relational inference and generalization can be accomplished within a cognitive architecture that is psychologically and neurally realistic. Their proposal is a form of symbolic connectionism: a connectionist system based on distributed representations of concept meanings, using temporal synchrony to bind fillers and roles into relational structures. The authors present a specific instantiation of their theory in the form of a computer simulation model, Learning and Inference with Schemas and Analogies (LISA). By using a kind of self-supervised learning, LISA can make specific inferences and form new relational generalizations and can hence acquire new schemas by induction from examples. The authors demonstrate the sufficiency of the model by using it to simulate a body of empirical phenomena concerning analogical inference and relational generalization.

Generalization, Psychological↗

PubMed2002

Magnitude comparisons distort mental representations of magnitude.

Many cognitive processes rely on representations of magnitude, yet these representations are often malleable (H. Helson, 1964; J. Huttenlocher, L. V. Hedges, & J. L. Vevea, 2000; A. Parducci, 1965). It is likely that factors that affect these representations in turn affect the psychological processes that rely on them. The authors conducted 4 experiments to investigate whether language-expressible magnitude comparisons distort mental representations of compared magnitudes. Participants compared magnitudes and estimated those magnitudes in a variety of tasks. Experiments 1 through 3 demonstrated systematic comparison-induced distortions. Experiment 4 demonstrated that comparison-induced distortions might account for the asymmetric dominance effect discussed in the decision-making literature. Potential effects of comparison-induced distortions on other psychological processes (e.g., density effects, order effects, body-size estimation, pain estimation, and consumer decision making) are discussed.

Cognition↗