Biomedical subjects

Thomas A Busey

Publications and source records attributed to Thomas A Busey.

6 recordsLinked to original sources

PubMed2006

Recognizing distinctive faces: a hybrid-similarity exemplar model account.

In recognition memory experiments, Nosofsky and Zaki (2003) found that adding discrete distinctive features to continuous-dimension color stimuli helped participants to identify old items as old (the old-item distinctiveness effect), as well as to identify new items as new. The present study tests the extent to which these results generalize to the domain of face recognition. Two experiments were conducted, one using artificial faces and one using natural faces. Artificial faces were used to test memory for faces with discrete distinctive features while controlling the similarity of the faces themselves on more continuous dimensions. The natural-face experiment used the faces of 40 bald men categorized into three groups (typical, isolated, and distinctive) based on experimental ratings of distinctiveness. In both experiments, there were strong effects of the distinctive features on recognition performance. The data were accounted for reasonably well by a hybrid-similarity version of an exemplar recognition model (Nosofsky and Zaki, 2003), which includes a feature-matching mechanism that can provide boosts to an item's self-similarity.

Face↗

PubMed2005

Relationship between steady-state and induced gamma activity to motion.

When a moving stimulus is presented at a specific temporal frequency, both steady-state responses and induced gamma activity may be elicited in the electroencephalogram. The electroencephalogram was recorded when study participants viewed random dot kinematograms under three conditions: coherent motion, incoherent motion and stationary. Dot position was changed at a rate of 9.3 Hz in the coherent and incoherent conditions. Induced power at 40 Hz was increased during coherent motion compared with the other conditions. In contrast, the steady-state response at 9.3 Hz showed a trend for increased power during the incoherent condition. These results suggest that steady-state responses to moving stimuli reflect sensory activation, while the induced gamma activity indexes perceptual processes.

Adult↗

PubMed2005

Behavioral and electrophysiological evidence for configural processing in fingerprint experts.

Visual expertise in fingerprint examiners was addressed in one behavioral and one electrophysiological experiment. In an X-AB matching task with fingerprint fragments, experts demonstrated better overall performance, immunity to longer delays, and evidence of configural processing when fragments were presented in noise. Novices were affected by longer delays and showed no evidence of configural processing. In Experiment 2, upright and inverted faces and fingerprints were shown to experts and novices. The N170 EEG component was reliably delayed over the right parietal/temporal regions when faces were inverted, replicating an effect that in the literature has been interpreted as a signature of configural processing. The inverted fingerprints showed a similar delay of the N170 over the right parietal/temporal region, but only in experts, providing converging evidence for configural processing when experts view fingerprints. Together the results of both experiments point to the role configural processing in the development of visual expertise, possibly supported by idiosyncratic relational information among fingerprint features.

Adult↗

PubMed2004

Seeing faces in the noise: stochastic activity in perceptual regions of the brain may influence the perception of ambiguous stimuli.

Research on binocular rivalry and motion direction discrimination suggests that stochastic activity early in visual processing influences the perception of ambiguous stimuli. Here, we extend this to higher level tasks of word and face processing. In Experiment 1, we used blocked gender and word discrimination tasks, and in Experiment 2, we used a face versus word discrimination task. Stimuli were embedded in noise, and some trials contained only noise. In Experiment 1, we found a larger response in the N170, an ERP component associated with faces, to the noise-alone stimulus when observers were performing the gender discrimination task. The noise-alone trials in Experiment 2 were binned according to the observer's behavioral response, and there was a greater response in the N170 when they reported seeing a face. After considering various top-down and priming-related explanations, we raise the possibility that seeing a face in noise may result from greater stochastic activity in neural face-processing regions.

Discrimination, Psychological↗

PubMed2004

The contribution of symmetry and motion to the recognition of faces at novel orientations.

In three experiments, we examined the recognition of faces at novel orientations. Although performance tended to decay as difference between the study and the test angles increased, an orientation that was symmetric with respect to the study orientation showed strong performance--in many cases, better than the frontal view. We investigated the properties of this particular facility in perception and memory tasks. Symmetrized faces showed surprisingly different patterns of behavior than did unsymmetrized faces, despite the fact that many faces were already fairly symmetric. In memory experiments, the subjects showed robust symmetric orientation effects and could differentiate between the original study views and the symmetric orientation. In a third experiment, we demonstrated that smooth motion improved performance at the symmetric orientation, whereas two control motions did not. Together, the three experiments support the view that multiple representations are at work during the recognition of faces at the symmetric orientation and that, during memory tasks, subjects tend to rely on representations that are more robust against texture asymmetries and that may include limited depth information.

Face↗

PubMed2003

The effect of motion on tactile and visual temporal order judgments.

Four experiments were conducted, three with tactile stimuli and one with visual stimuli, in which subjects made temporal order judgments (TOJs). The tactile stimuli were patterns that moved laterally across the fingerpads. The subject's task was to judge which finger received the pattern first. Even though the movement was irrelevant to the task, the subjects' TOJs were greatly affected by the direction of movement of the patterns. Accuracy in judging temporal order was enhanced when the patterns moved in a direction that was consistent with the temporal order of presentation--for example, when the movement on each fingerpad was from right to left and the temporally leading site of stimulation was to the right of the temporally trailing site of stimulation. When movement was inconsistent with the temporal order of presentation, accuracy was considerably reduced, often well below chance. The bias in TOJs was unaffected by training or by presenting the stimuli to fingers on opposite hands. In a fourth experiment, subjects judged the temporal order of visual stimuli that, like the tactile stimuli, moved in a direction that was either consistent or inconsistent with the TOJ. The results were similar to those obtained with tactile stimuli. It is suggested that the bias may be affected by attentional mechanisms and by apparent motion generated between the two sites on the skin.

Humans↗