The Miraculous Choice Argument for Realism

The miracle argument for scientific realism can be cast in two forms: according to the miraculous theory argument, realism is the only position which does not make the empirical successes of particular theories miraculous. According to the miraculous choice argument, realism is the only position which does not render the fact that empirically successful theories have been chosen a miracle. A vast literature discusses the miraculous theory argument, but the miraculous choice argument has been unjustifiably neglected. I raise two objections to Richard Boyd's defense of the latter: (1) we have no miracle free account of the emergence of take-off theories and (2) the anti-realist can account for the non-miraculous choice of empirically successful theories by attributing mere empirical adequacy to background theory. I argue that the availability of extra-empirical criteria that are arguably truth conductive but not theory-laden suffices to answer (1), and the unavailability of extra-empirical criteria that are conductive to empirical adequacy but not necessarily to truth (and are also not theory-laden) constitutes to reply to (2). The prospects for a realist victory are at least somewhat promising, on a controversial assumption about the rate at which empirically successful theories emerge.     

Using high frame rate CMOS sensors for three-dimensional eye tracking

A novel three-dimensional eye tracker is described and its performance evaluated. In contrast to previous devices based on conventional video standards, the present eye tracker is based on programmable CMOS image sensors, interfaced directly to digital processing circuitry to permit real-time image acquisition and processing. This architecture provides a number of important advantages, including image sampling rates of up to 400/sec measurement, direct pixel addressing for preprocessing and acquisition, and hard-disk storage of relevant image data. The reconfigurable digital processing circuitry also facilitatesin-line optimization of the front-end, time-critical processes. The primary acquisition algorithm for tracking the pupil and other eye features is designed around the generalized Hough transform. The tracker permits comprehensive measurement of eye movement (three degrees of freedom) and head movement (six degrees of freedom), and thus provides the basis for many types of vestibulo-oculomotor and visual research. The device has been qualified by the German Space Agency (DLR) and NASA for deployment on the International Space Station. It is foreseen that the device will be used together with appropriate stimulus generators as a general purpose facility for visual and vestibular experiments. Initial verification studies with an artificial eye demonstrate a measurement resolution of better than 0.1° in all three components (i.e., system noise for each of the components measured as 0.006° H, 0.005° V, and 0.016° T. Over a range of ±20° eye rotation, linearity was found to be <0.5% (H), <0.5% (V), and <2.0% (T). A comparison with the scierai search coil technique yieldednear equivalent values for the systemnoise and the thickness of Listing’s plane.     

Perception onset time during fixations in free viewing

In this study, we investigated when visual perception begins in fixations. During picture viewing, the picture was degraded at the beginning of selected saccades and changed back to the original after varying intervals. Participants manually responded whenever they detected changes. The change-backs were undetected when they occurred <6 msec after the end of the saccade, marked by the peak of the overshoot in dual Purkinje image eyetracker data, and detection reached asymptote 32 msec after that marker. Eye velocity at the change-backtime also affected detection likelihood. Apparently, perception begins around the time at which the eyes stop rotating at the end of a saccade, giving a psychological justification for measuring fixation durations from then. This also specifies the deadline for gaze-contingent display changes to occur without detectable image motion. Investigators using the dual PurMnje image eyetracker should consider the peak of the overshoot as the fixation onset time and measure intrafixational presentation times from then.     

What's in a Forename? Cue Familiarity and Stereotypical Thinking

Recent research has characterized categorical thinking as an essential component of the person perception process. Yet relatively little is known about the myriad factors that moderate the accessibility of this mode of thought. With regard to this we hypothesized that the subjective familiarity of a person's forename may play an important role in triggering categorical thinking. Specifically, category-based knowledge may be more accessible when triggered by familiar than unfamiliar forenames. We report the results of three experiments that supported this prediction. Relative to unfamiliar names, participants required less time to verify the gender of familiar forenames (Experiment 1) and semantic priming was more pronounced when stereotype-related material followed the presentation of familiar than unfamiliar items (Experiment 2). Also, familiar forenames attracted more extreme gender-based evaluations than their unfamiliar counterparts (Experiment 3). We consider the theoretical and methodological implications of these findings for a variety of issues in person perception.     

Anxiety-related bias in the classification of emotionally ambiguous facial expressions

High- and low-trait socially anxious individuals classified the emotional expressions of photographic quality continua of interpolated ("morphed") facial images that were derived from combining 6 basic prototype emotional expressions to various degrees, with the 2 adjacent emotions arranged in an emotion hexagon. When fear was 1 of the 2 component emotions, the high-trait group displayed enhanced sensitivity for fear. In a 2nd experiment where a mood manipulation was incorporated, again, the high-trait group exhibited enhanced sensitivity for fear. The low-trait group was sensitive for happiness in the control condition. The mood-manipulated group had increased sensitivity for anger expressions, and trait anxiety did not moderate these effects. Interpretations of the results related to the classification of fearful expressions are discussed.     

An evaluation of simultaneous and sequential presentation of preferred and nonpreferred food to treat food selectivity

In the current investigation, we compared two methods of food presentation (simultaneous vs. sequential) to increase consumption of nonpreferred food for 3 children with food selectivity. In the simultaneous condition, preferred foods were presented at the same time as nonpreferred food (e.g., a piece of broccoli was presented on a chip). In the sequential condition, acceptance of the nonpreferred food resulted in presentation of the preferred food. Increases in consumption occurred immediately during the simultaneous condition for 2 of the 3 participants. For 1 participant, increases in consumption occurred in the simultaneous condition relative to the sequential condition, but only after physical guidance and re-presentation were added to treatment. Finally, consumption increased for 1 participant in the sequential condition, but only after several sessions. These results are discussed in terms of possible mechanisms that may alter preferences for food (i.e., establishing operations, flavor-flavor conditioning).