Thesis--Ph. D., University of Hong Kong, 1983.

After multiple pairings of a cue and a rewarding event, animals will begin to attend to both the reward and the cue. Reports from Brown and Jenkins (1968) first described pigeons that began to track key lights predictive of food reward. Subsequently the phenomenon of conditioned cue approach has been reported across a variety of species including pigeons, quail, rats, monkeys, and stickleback fish (Brown and Jenkins, 1968; Cetinkaya and Domjan, 2006; Holland, 1977; Jenkins and Rowland, 1996; Sidman and Fletcher, 1968). More recently, investigations of individual differences in the expression of these behaviors have begun, as well as exploration into how these differences relate to other cognitive and neurological variations (Lesaint et al., 2014; Lovic et al., 2011; Meyer et al., 2012; Paolone et al., 2013). The objective of this dissertation was to characterize individual differences in rats’ propensity for orienting towards a light-cue predictive of reward. I also aimed to describe how these differences related to the behavior’s vulnerability to memory updating, extinction learning, a variety of cognitive functions, and behavioral and neurological responses to drug challenge. I report that all rats showed conditioned approach toward the site of food-reward delivery, but only a subset also showed robust rearing and/or orienting toward a light predictive of food (Orienters). Those rats that showed only conditioned reward approach were termed Nonorienters. Following memory update procedures, Orienters were more likely than Nonorienters to attenuate conditioned food approach, though conditioned rearing remains unaffected. Orienters were also more likely to make impulsive and risky decisions, enter a novel and risky environment, and be distracted during an attention assay. They also emitted more ultrasonic vocalizations than Nonorienters when exposed to amphetamine. Moreover, while both Orienters and Nonorienters preferred a context previously paired with drug to a context paired with saline, Orienters emitted more ultrasonic vocalizations during the preference test. Finally, while Orienters and Nonorienters showed behavioral differences after amphetamine injection, these differences were not reflected in the activity of the brain regions responsible for the conditioned orienting response. Overall, these findings suggest that Orienters are more apt to memory update, make more impulsive and risky decisions, are more vulnerable to distraction, and that amphetamine has more impact upon the behavior of Orienters. / text

published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

Prompted by oculomotor theories of attention, the present experiments explore the role of saccade activation in the generation of two cueing effects: exogenous capture (Experiment 1) and inhibition of return (IOR; Experiment 2). Exogenous capture is shortlived and marked by faster responding toward recently stimulated locations, whereas the longer-lasting IOR manifests as slower responding toward those locations. Within each experiment, Group A performed in a dual-task in which on most trials a peripheral target had to be identified but infrequently a central arrow probe called for an eye movement instead, while for Group B the tasks were the same except saccade trials were frequent and target identification trials were infrequent. In Experiment 1, for group A uninformative cues captured attention as measured by faster digit identification at the cued location, an effect not accompanied by saccade activation. For group B, cues generated saccade activation without capturing attention. Thus saccade activation need not accompany exogenous covert capture, and covert capture need not accompany saccade activation. In Experiment 2, group A exhibited IOR which slowed digit identification, but did not affect saccadic responding, while Group B exhibited no IOR in either digit identification or eye movement trials. This finding provides converging evidence that IOR can be dichotomized into two forms; one which delays motor production itself (Evidenced amply elsewhere, e.g., Taylor & Klein, 2000) and another which delays responding by applying inhibition at a perceptual-motor interface which can operate in independence from its motoric cousin.

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 194-204).

Fixational eye movements occur involuntarily during visual fixation of stationary scenes. The fastest components of these miniature eye movements are microsaccades, which can be observed about once per second. Recent studies demonstrated that microsaccades are linked to covert shifts of visual attention [e.g., Engbert & Kliegl (2003), Vision Res 43:1035-1045]. Here,we generalized this finding in two ways. First, we used peripheral cues, rather than the centrally presented cues of earlier studies. Second, we spatially cued attention in vision and audition to visual and auditory targets. An analysis of microsaccade responses revealed an equivalent impact of visual and auditory cues on microsaccade-rate signature (i.e., an initial inhibition followed by an overshoot and a final return to the pre-cue baseline rate). With visual cues or visual targets,microsaccades were briefly aligned with cue direction and then opposite to cue direction during the overshoot epoch, probably as a result of an inhibition of an automatic saccade to the peripheral cue. With left auditory cues and auditory targets microsaccades oriented in cue direction. Thus, microsaccades can be used to study crossmodal integration of sensory information and to map the time course of saccade preparation during covert shifts of visual and auditory attention.

Parts orienting is an important part of automated manufacturing. Sensorless manipulation has proven to be a useful paradigm in addressing parts orienting, and the manipulation of deformable objects is a growing area of interest. Until now, these areas have remained separate because existing orienting approaches utilize forces that if applied to deformable parts violate the assumptions used by existing algorithms, and could potentially break the part. We introduce a new algorithm and manipulator actions that, when provided with the geometric description and a deformation model of choice for the part, exploits the deformation and generates a Plan that consists of the shortest sequence of manipulator actions guaranteed to orient the part up to symmetry from any unknown initial orientation and pose. Additionally, the algorithm estimates whether a given manipulator is sufficiently precise to perform the actions which guarantee the final orientation. This is dictated by the particular part geometry, deformation model, and the manipulator action path planner which contains simple end-effector constraints and any standard motion planner. We illustrate the success of the algorithm with multiple parts through 192 trials of experiments that were performed with low-precision robot manipulators and six parts made of four types of materials. The experimental trials resulted in 154 successes, which show the feasibility of deformable parts orienting. The analysis of the failures showed that for success the assumptions of zero friction are essential for this work, increased manipulator precision would be beneficial but not necessary, and a simple deformation model can be sufficient. Finally, we note that the algorithm has applications to truly sensorless manipulation of non-deformable parts.

No description available.

An effective alarm system is a critical part of many different types of jobs. It is also important that the alarm signal can capture human attention and convey appropriate urgency. In the current study the effect of siren sounds with or without unexpected, deviant sounds represented by a change of speed (a temporal deviant) were tested to evaluate if such change could successfully capture attention. The results showed that distraction was more pronounced when the deviant within the sound was a change from fast to slow as compared with slow to fast. Therefore, an alarm signal using a temporal deviant – changing from fast to slow—can be effective in capturing human attention and might be factored into the design of alarm systems.