The World-Wide Web as a medium for psychoacoustical demonstrations and experiments: Experience and results

The World-Wide Web provides an inviting opportunity to reach large numbers of people, both as an audience for psychoacoustical discussions and demonstrations and as subjects for psychoacoustical experiments. Such use of the Web poses a unique set of challenges. We present the methodologies used to prepare a multimedia primer in auditory perception at McGill University. As well as instructional material, this primer includes acoustical experiments conducted over the Web. We discuss the response and experiences with this site in general and in a particular class situation at Hanover College.     

Reduction of the elevator illusion from continued hypergravity exposure and visual error-corrective feedback

Ten subjects served as their own controls in two conditions of continuous, centrifugally produced hypergravity (+2 Gz) and a 1-G control condition. Before and after exposure, open-loop measures were obtained of (1) motor control, (2) visual localization, and (3) hand-eye coordination. During exposure in the visual feedback/hypergravity condition, subjects received terminal visual error-corrective feedback from their target pointing, and in the no-visual feedback/hypergravity condition they pointed open loop. As expected, the motor control measures for both experimental conditions revealed very short lived underreaching (the muscle-loading effect) at the outset of hypergravity and an equally transient negative aftereffect on returning to 1 G. The substantial (approximately 17°) initial elevator illusion experienced in both hypergravity conditions declined over the course of the exposure period, whether or not visual feedback was provided. This effect was tentatively attributed to habituation of the otoliths. Visual feedback produced a smaller additional decrement and a postexposure negative aftereffect, possible evidence for visual recalibration. Surprisingly, the target-pointing error made during hypergravity in the no-visual-feedback condition was substantially less than that predicted by subjects’ elevator illusion. This finding calls into question the neural outflow model as a complete explanation of this illusion.     

The effect of alcoholic intoxication upon calorically induced oculogyral illusion

Ten male and 10 female subjects, half of whom were classified as “heavy” and half as “light” drinkers, ingested a 4-1 combination of tonic water and 80-proof vodka in an amount calculated to produce a state of moderate intoxication (average estimated peak blood alcohol level=.075). This resulted in an increased sensitivity (latency, magnitude, and duration) to the calorically induced “oculogyral illusion” (OGI) relative to a placebo (tonic water) condition. “Heavy” and “light” drinkers did not differ significantly on any of the measures. It was speculated that the alcoholic enhancement of the OGI was due either to a decreased ability to suppress vestibular nystagmus when attempting to fixate a visual stimulus or to the expenditure of extra-normal effort in order to maintain fixation.     

Credence for conclusions: a brief for Jeffrey’s rule

Synthese - Some arguments are good; others are not. How can we tell the difference? This article advances three proposals as a partial answer to this question. The proposals are keyed to arguments...     

Affirmation of personal values buffers neuroendocrine and psychological stress responses

Stress is implicated in the development and progression of a broad array of mental and physical health disorders. Theory and research on the self suggest that self-affirming activities may buffer these adverse effects. This study experimentally investigated whether affirmations of personal values attenuate physiological and psychological stress responses. Eighty-five participants completed either a value-affirmation task or a control task prior to participating in a laboratory stress challenge. Participants who affirmed their values had significantly lower cortisol responses to stress, compared with control participants. Dispositional self-resources (e.g., trait self-esteem and optimism) moderated the relation between value affirmation and psychological stress responses, such that participants who had high self-resources and had affirmed personal values reported the least stress. These findings suggest that reflecting on personal values can keep neuroendocrine and psychological responses to stress at low levels. Implications for research on the self, stress processes, health, and interventions are discussed.     

Studies of open-loop pointing in the presence of induced motion

In the present research, we examined the influence of induced motion (IM) on open-loop pointing responses and the possibility that IM alters the registration of either eye or trunk position. In two experiments, subjects tracked a dot that oscillated vertically while a rectangular stimulus oscillated horizontally. The pairing of frame and dot motion caused the dot to appear to move on a slant, due to IM. In the first experiment, the subjects made judgments of the apparent slant of the dot's motion and, on separate trials, pointed open loop at the apparent location of the dot at the endpoints of its motion. Both responses were influenced by IM, although the effect on dot localization was less than the amount predicted by the IM, as indicated by the slant responses. Results were similar immediately following IM and after a 5-sec delay. In the second experiment, the subjects pointed open loop either at the apparent location of the endpoints of the tracked dot's motion or at the apparent location of one of three other briefly flashed stationary dots. The pointing responses directed toward the fixated IM target were influenced by IM to a greater extent than the responses directed toward the stationary dots. The results of the two experiments are inconsistent with the hypothesis that the effect of IM on open-loop pointing at the IM target results completely from altered perception of either eye or trunk position, since misregistration of either would be expected to influence, in a similar fashion, pointing at both the tracked dot and the briefly flashed, stationary targets.     

Effects of goal-setting and feedback on memory performance and beliefs among older and younger adults

This research examined the impact of goal-setting conditions on memory beliefs and performance among older and younger adults. After baseline recall and assessment of beliefs, participants were assigned to goal-setting, goals plus feedback, or control. Then, additional recall trials were followed by repeated memory beliefs assessments. For both younger and older adults, performance, motivation, and self-efficacy were affected positively by goal-setting. The impact of goals plus feedback was mixed and varied as a function of age and dependent measure. Success rates for reaching memory goals, which were low for the older adults, may have been a factor in these results. Adults' self-set recall goals were predicted initially by baseline performance and self-efficacy. On the final trial, goals were predicted by last trial performance, self-efficacy, and control beliefs.