We presented subjects with an unpredictive cue that was followed after a 150- to 900-msec interstimulus interval (ISI) by a detection target. Cue and target were blue or red squares that appeared at fixation and in an otherwise uniform black field. In a filler condition, a task-irrelevant filler stimulus (magenta square) was presented during the ISI; in a no-filler condition, no stimulus appeared during the ISI. Using only a 900-msec ISI, Law, Pratt, and Abrams (1995) reported slower reaction times (RTs) when cue and target were the same color, but only when the task-irrelevant filler was presented during the ISI. They argued that attention is first drawn to the cue color and that inhibition of return (IOR; see Posner & Cohen, 1984) is established when attention is drawn away from that cue color representation by the task-irrelevant filler. Critical to their view is the assumption that IOR occurs only after attention is drawn away from the cue color by the filler. Assuming a time course for the withdrawal of attention from the cue color representation, Law et al. ’s view predicts growth of the inhibitory effect as a function of ISI in the filler condition as well as facilitation at early ISIs in the no-filler condition (because there is no filler to withdraw attention from the cue color). Contrary to these predictions, we found that the inhibitory effect observed by Law et al. at the 900-msec ISI was present at—and did not vary in magnitude across—the range of ISIs tested. And there was never facilitation in the no-filler condition. These results challenge Law et al. ’s inference that IOR for foveally presented colors was operating in their paradigm. 相似文献
The purpose of this study was to provide a partial test of the Hollenbeck and Klein (1987) model of goal commitment. Four variables from that model (reward structure, social influence, type-A behavior, and self-esteem) were examined as to their relationships with the expectancy and attractiveness of goal attainment and goal commitment. The results, based on 88 college students performing an anagram task, were generally supportive. Significant person by situation interactions were also observed. 相似文献
Results from an investigation of the relationship between habitual awareness of oneself as a social object (Public self-consciousness) and speed of processing information about the overt self are reported. Since high public self-consciousness subjects report themselves to be concerned about their physical appearance, they were expected to have more readily retrievable evaluative judgments concerning their physical characteristics. Consistent with this prediction, high compared to low public consciousness subjects required significantly less time to report their evaluations of eleven of their physical features. In a second study, high public self-consciousness was shown to be positively related to judged physical attractiveness in two geographically diverse samples. The quicker evaluations of the high public self-consciousness group were discussed in terms of information processing model recently described by Markus (1977). 相似文献
When a fixation point is removed 200 msec prior to target onset (the gap condition), human subjects are said to produce eye movements that have a short latency (80–120 msec), that form the early peak of a bimodal latency distribution, and that have been labeled “human express saccades” (see, e.g., Fischer, 1987; Fischer & Breitmeyer, 1987; Fischer & Ramsperger, 1984, 1986). In three experiments, we sought to obtain this express saccade diagnostic pattern in the gap condition, We orthogonally combined target location predictability with the presence versus absence of catch trials (Experiment 1). When target location was fixed and catch trials were not used, we found mostly anticipations. In the remaining conditions, where responses were under stimulus control, bimodality was not frequently observed, and, whether it was or not, latencies were not in the express saccade range. Using random target locations, we then varied stimulus luminance and the mode of stimulus presentation (LEDs vs. oscilloscope) in the gap and overlap (fixation is not removed) conditions (Experiment2). Bimodality was rarely observed, the gap effect (overlap minus gap reaction time) was additive with luminance, and only the brightest targets elicited saccades in the express range. When fixed locations and no catch trials were combined with latency feedback (Experiment 3), we observed many responses in the express saccade range and some evidence for bimodality, but the sudden introduction of catch trials revealed that many early responses were not under stimulus control. Humanscan make stimulus-controlled saccades that are initiated very rapidly (80–120 msec), but unless catch trials or choice reaction time is used, it is not possible to distinguish such saccades from anticipatory responses that are prepared in advance and timed to occur shortly after target onset. Because the express saccade diagnostic pattern is not a characteristic feature of human saccadic performance, we urge investigators to focus their attention on the robustgap effect相似文献
A new and innovative approach to treating fear of flying has been developed using Virtual Reality Exposure Therapy. This article discusses the development of Virtual Reality Exposure Therapy and reviews a case study of a fear of flying patient seen in our practice. Early results are very promising and may indicate that Virtual Reality Exposure Therapy may also lead to creative interventions with other anxiety disorders. 相似文献
This paper focuses on (an interpretation of) the Enkratic principle of rationality, according to which rationality requires that if an agent sincerely and with conviction believes she ought to X, then X-ing is a goal in her plan. We analyze the logical structure of Enkrasia and its implications for deontic logic. To do so, we elaborate on the distinction between basic and derived oughts, and provide a multi-modal neighborhood logic with three characteristic operators: a non-normal operator for basic oughts, a non-normal operator for goals in plans, and a normal operator for derived oughts. We prove two completeness theorems for the resulting logic, and provide a dynamic extension of the logic by means of product updates. We illustrate how this setting informs deontic logic by considering issues related to the filtering of inconsistent oughts, the restricted validity of deontic closure, and the stability of oughts and goals under dynamics.
Science and Engineering Ethics - Devices that record from and stimulate the brain are currently available for consumer use. The increasing sophistication and resolution of these devices provide... 相似文献
When two masked, to-be-attended targets are presented within approximately half a second of each other, performance on the second target (T2) suffers, relative to when the targets are presented further apart in time or when the first target (T1) can be ignored. This pattern of results is known as the attentional blink (AB). Typically, participants differ with respect to the magnitude of their AB and their overall target accuracy. Despite investigations as to what participant characteristics may influence AB performance (e.g., age, brain damage, or mood state), there has been no focused examination of whether individual differences in cognitive performance measures predict the magnitude of the AB or overall rapid serial visual presentation(RSVP) target accuracy. Our university studentparticipants performed single-target and dual-target RSVP tasks, as well as a selection of cognitive tasks that did not use RSVP presentations, with color, letter, digit, and object stimuli. Overall performance on each of the RSVP targets (T1, T2, and single target) was predicted by speeded manual and vocal identification times to isolated stimuli and by performance with other RSVP targets. However, the magnitude of the AB was predicted only by T1 accuracy, not by any other performance measures. The results suggest that individual differences in AB magnitude do not result from differences in effective RSVP target encoding and are not well explained by varied information-processing abilities. 相似文献
Benjamin Libet compared the perceived time of direct brain stimulation to the perceived time of skin stimulation. His results are among the most controversial experiments at the interface between psychology and philosophy. The new element that I bring to this discussion is a reanalysis of Libet's raw data. Libet's original data were difficult to interpret because of the manner in which they were presented in tables. Plotting the data as psychometric functions shows that the observers have great uncertainty about the relative timing of events, as seen the shallow psychometric slopes. A second indication of uncertainty comes from Libet's use of three response categories, A first; B first; and A and B simultaneous. The large number of "perceptually simultaneous" responses provides a further measure of the difficulty of the judgment. There are thus a very broad range of stimulus delays in which the subject is unable to make an accurate ordering response. These points provide evidence that there is no compelling reason to invent exotic or ad hoc mechanisms to account for Libet's data since the uncertainty window is large enough to allow simple mechanism such as memory shifts. Libet argued that his data provide evidence for a backward referral in time. I argue that even though Libet's own data are weak, there are good arguments for a backward referral mechanism to help the subject make sense out of the tangled chaos of asynchronous information associated with experienced events. 相似文献