An automated system for administering continuous workload and for measuring sustained continuous performance

Sustained continuous performance for up to 42 h was studied with 60 male volunteers in two separate protocols. The recuperative value of six 1-h nap breaks and a single 6-h nap break were contrasted in 20 subjects, 10 in each nap group. Forty other subjects attempted to work continuously with no breaks for 42 h. Twenty of these subjects worked simultaneously on separate parallel computer-based tasks, but worked in the same room in pairs. All subjects in the two nap groups (N=10 and N=10), as well as 20 who had no scheduled breaks, worked alone, almost isolated, with minimal interaction with the experimenters. During each 10 min, subjects performed a tracking task, a pattern-memory task, and an addition task and provided subjective ratings on sleepiness and attention/fantasy. Results showed that computerized tasks demanding sustained continuous performance without naps cause more rapid performance deterioration than previously tested intermittent-work paradigms.     

An operating subsystem for continuous monitoring studies

A set of programs has been developed to allow efficient operator control over the recording of physiological and behavioral measures in experiments of several hours’ duration. Important features include menu-driven selection among possible measurements, minimal data loss in the event of system failure, on-line correction or deletion of incorrect data both during and after collection, and selective reporting of individual statistics and time periods. These programs can be extended to include new measurements with minimal interference with existing measurements.     

An integrated circuit for stepwise or continuous microdrive advancement

A circuit for inexpensive automation of a hydraulic microdrive is described. The circuit uses two integrated timing circuits with output periods defined by resistance-capacitance circuits. The output of this circuit operates a relay that controls a small electric motor that runs the microdrive. This system can operate in either a continuous mode for long-term infusion of solutions or in a stepwise fashion for lowering electrodes. When attached to an appropriate microdrive, the circuit can be employed in experiments in which brain-behavior relationships are investigated within anatomical, pharmacological, or electrophysiological paradigms.     

Performative contradiction and the regrounding for philosophical paradigms

As a unique method of philosophical argument, performative contradiction attracted general attention after the change in direction of pragmatics in the twentieth century. Hintikka used this method to conduct an in-depth analysis of Descartes’ proposition “I think, therefore I am,” providing a proof which is a model in the philosophical history; Apel absorbed performative contradiction into his own framework of a priori pragmatics; and Habermas introduced it into the theory of formal pragmatics and rendered it an effective weapon of debate. Wittgenstein, who had fallen into the trap of performative contradiction in Tractatus Logico-Philosophicus, later managed to extract himself from it and indeed used the methodology of performative contradiction to cure the ills of philosophy, making it a general philosophical method. Through analysis of its connotations and classic examples of its use we can see that it is crucial in refuting extreme relativism and skepticism, and hence provides methodological support for a new foundation for philosophical paradigms. Translated by Wang Xuan from Zhongguo Shehui Kexue 中国社会科学 (Social Sciences in China), 2007, (3): 67–76     

A microcomputer-based system for continuous measurement of rodent food intake

A microcomputer-based system is described for the automatic acquisition, storage, and analysis of rodent food intakes. The feed-o-meter provides reliable, valid measurements of consumption, with minute-by-minute accuracy of ?.03 g.     

A general framework for defining evoked potential paradigms

We have developed a framework for defining a range of evoked potential paradigms through the completion of screen forms rather than through the modification of program code. Within this framework, an experimenter can specify stimulus events and their timing, randomization of different stimuli, collection of responses, rejection of artifacts, and detection of peaks within the averaged waveforms. Printed copies of the screen forms and of timing diagrams derived from them can later be incorporated into the documentation of the experiment.     

视觉注意离散性的实验范式

注意离散性是注意间歇性地采集外界信息的特性。文章综述了视觉注意离散性的4种实验范式:(1)车轮错觉范式,刺激强度大、实验条件少、被试任务量小,较早地证实了视觉注意的离散性;(2)视觉探测范式,同时观察了被试的行为表现与电生理信号,确定了视觉注意离散性与神经振荡的关联;(3)线索靶子范式和视觉搜索范式,通过系统地变化SOA大幅提高了行为数据的时间分辨率,直观地探测到注意离散性调制的行为振荡。     

Experimental evidence supporting simpler Action Point paradigms for car-following

The Action Point theory is one of the paradigms that can be applied to understand and reproduce car-following behaviour. Several different approaches to this theory have been proposed, some more simple and others more complex. In particular, the reference point in this field is still the paradigm from Wiedemann, which requires the identification of four action-point thresholds. In this paper we review Action Point theories in order to highlight similarities and differences and to ascertain whether all the thresholds proposed by Wiedemann actually bind the driving behaviour. Based on a large-scale experiment in which car-following data were collected, we identified all candidate action points assuming that the more complex (four-threshold) theory holds. Then we tested these points with respect to the large data set of available observations, in order to check whether actual actions are performed at the points. The results show that very often simpler approaches better match the observed data and that in order to explain car-following behaviour it is sufficient in most cases to refer to two thresholds. The results obtained by real-world observation were also tested in virtual environments (two different kinds of driving simulators) and were confirmed.     

The snake in the grass revisited: An experimental comparison of threat detection paradigms

The current investigation compares the results of two commonly used visual detection paradigms—the standard adult button-press detection paradigm used in Öhman, Flykt, and Esteves (2001), and the new child-friendly touch-screen detection paradigm used in LoBue and DeLoache (2008)—within the same samples of adult participants. Results suggest that both paradigms produce the same pattern of findings with regard to detection latency for threat-relevant versus threat-irrelevant stimuli: Adults detected threat-relevant targets more quickly than threat-irrelevant targets across the varying procedures. However, results with respect to automaticity of detection as suggested by Öhman et al. (2001) were only replicated with the classic button-press paradigm. The findings validate the touch-screen visual search procedure and have important implications for choosing an appropriate methodology for studying threat detection.     

Stroop interference: An input and an output phenomenon

Three theories of Stroop interference are considered: perceptual conflict theory (Hock and Egeth, 1970), response competition theory (Morton, 1969) and conceptual encoding theory (Seymour, 1977). The first two fail to provide a full explanation of the available data, and Seymour's evidence is incomplete. Two experiments are reported. In the first, typical Stroop interference occurs in naming colour patches. In the second, subjects responded to colour patches with learned letter name responses. Both stimulus-related (incongruent colour names) and response-related (incongruent letters) distractors produced interference. These results indicate that any theory which assumes only a single locus for interference is incomplete. Conceptual encoding conflict and a modified form of response competition are suggested as possible dual mechanisms for Stroop interference effects.     

An interface system for asynchronous data

This article describes a system for interfacing items of computing equipment in circum-stances where the short-term data rate of the source exceeds that of the receiver device. Outline circuitry is given for an application permitting high-speed input to an event-driven time and event data logger.     

Discrete versus continuous stage models of human information processing: in search of partial output

This article introduces a new technique designed to study the flow of information through processing stages in choice reaction time tasks. The technique was designed to determine whether response preparation can begin before stimulus identification is complete ("continuous" models), or if a stimulus must be fully identified prior to any response activation ("discrete" models). To control the information available at various times during stimulus identification, some relevant stimulus characteristics were made easy to discriminate and some were made hard to discriminate. The experimental strategy was to look for effects of partial output based on information conveyed by characteristics that were easy to discriminate. The technique capitalized on the fact, demonstrated in Experiment 1, that preparation of two response fingers on the same hand is more effective than preparation of two response fingers on different hands. The usefulness of partial output was varied by manipulating the assignments of stimuli to responses. For some mappings partial information could contribute to effective response preparation because the responses consistent with partial information were assigned to fingers on the same hand. For other mappings partial information could not contribute to effective response preparation because the responses consistent with partial information were assigned to fingers of different hands. Performance differences between these mappings were considered evidence that partial information about a stimulus was transmitted to response activation processes before the stimulus was uniquely identified, and thus were considered evidence against discrete transmission of information about the stimulus as a whole. A variety of stimulus sets were studied; the results suggest that information is transmitted discretely with respect to stimulus codes, although distinct codes activated by a single stimulus may be transmitted at different times.