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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 25 (1988), S. 0 
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: We attempted to test the hypothetical involvement of gender, cerebral laterality, and repeated trials in the performance of a heartbeat tracking task similar to ones previously reported. Subjects were told to press a key in synchrony with their heartbeats or with counter clicks for 250 trials with each hand. Key presses were sorted into six 100-ms bins following each R-wave; so, unlike previous heartbeat tracking studies which simply looked for similar rate properties of key press and heartbeat latencies, we sought congruence between the two distributions. No evidence of nonrandom key pressing could be adduced while subjects attempted to track heartbeats; whereas subjects did display nonrandom key presses with respect to heart driven counter clicks. It is concluded that such heartbeat tracking procedures are unsuited to assess cardiac perception, much less to detect any presumed correlate of such perception.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 23 (1986), S. 0 
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Following three sessions of instructed HR control with exteroceptive HR feedback (Group IFB) or without feedback (Group IC), subjects were required, on a fourth session, to increase and decrease HR whilst engaging in isometric arm exercises at 10%, 30%, and 50% of their maximal voluntary contractions. Significant increases and decreases from resting levels in HR were recorded during the first three sessions in which no exercise demands were made. When required to control HR whilst exercising, significant increases in HR above exercise-only baselines were recorded but subjects were unable to decrease HR significantly below exercise-only baselines. The extent of “voluntary’ HR control was inversely related to the concurrent level of isometric exercise and was unaffected by the provision of exteroceptive HR feedback. Since all significant variations in HR were accompanied by significant parallel variations in oxygen consumption and breathing patterns, it is concluded that subjects were unable to modulate the HR response to exercise.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 21 (1984), S. 0 
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Three experiments are reported which were designed to define optimal placements of S+ signals in Whitehead-type discrimination procedures by asking when in the cardiac cycle signals are perceived as most coincident with heartbeats. In Experiment I subjects discriminated signals delayed either 0 or 100 ms from the R-wave from signals delayed 400 ms. In Experiment II subjects chose signals delayed 0, 100, or 200 ms as more synchronous with heartbeats than signals delayed 300 or 400 ms. In Experiment III no central tendency emerged when subjects adjusted a signal through delays of 0, 60, 120, 180, and 240 ms seeking the value most synchronous with heartbeats. It is concluded that subjects can reliably discriminate events in the first quarter second of the cardiac cycle from events occurring later (although the functional significance of this ability remains obscure) and that S+ signals in such procedures should be placed within that time period.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 16 (1979), S. 0 
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: To test the hypothesis that voluntary heart rate (HR) control is possible with simultaneous muscular effort, 8 male subjects were trained in feedback assisted bidirectional HR control, and also practiced hand grip exercises requiring different levels of effort for 3 consecutive daily sessions. In a fourth session subjects were required to increase and decrease HR while simultaneously performing muscle contractions of 0%, 10%, 30% and 50% of maximum voluntary contractions. Substantial and reliable variations in HR were produced by instructions and by muscular effort during the first 3 sessions; and in the fourth session bidirectional HR control continued even with the relatively elevated baselines induced by muscular effort. Concomitant chin EMG levels did not vary with degree of muscular effort nor with instructions to increase or decrease HR, but increased over the course of any type of trial. Discussion suggests the use of artificially elevated baselines as a strategy for studying HR deceleration and concludes that the present study provides strong evidence of subjects' abilities to voluntarily control HR during muscular effort. This conclusion lends support to the notion that biofeedback therapies may be of clinical utility in real life by modulating the eliciting effects of stressors.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 16 (1979), S. 0 
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: In order to answer questions about the stability, trainability, and maintenance of heart beat discrimination, 32 subjects were given tests of heart beat discrimination on 2 days before and on 2 days after discrimination training, and 28 of those subjects were again tested at a mean of 34 days following the fifth consecutive session. Subjects were tested in a successive discrimination procedure in which they chose whether signal trains were contingent or noncontingent upon heart beats. On successive blocks of trials noncontingent signals were either of variable or invariant interpulse interval in order to determine if relative pulse train variability could provide a basis for correct choices.During training half of the subjects reached a pre-established criterion, and these subjects maintained higher levels of discrimination for the next 3 sessions. Relative pulse train variability was not a useful basis of judgment initially, although it may have aided subjects in the fifth session. Reliability of discrimination scores was low and discussion centers around this and other problems inherent in procedures reported to assess cardiac perception.
    Type of Medium: Electronic Resource
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  • 6
    Publication Date: 2023-07-06
    Description: The optical inspection of the surfaces of diode lasers, especially the p-sides and facets, is an essential part of the quality control in the laser fabrication procedure. With reliable, fast, and flexible optical inspection processes, it is possible to identify and eliminate defects, accelerate device selection, reduce production costs, and shorten the cycle time for product development. Due to a vast range of rapidly changing designs, structures, and coatings, however, it is impossible to realize a practical inspection with conventional software. In this work, we therefore suggest a deep learning based defect detection algorithm that builds on a Faster Regional Convolutional Neural Network (Faster R-CNN) as a core component. While for related, more general object detection problems, the application of such models is straightforward, it turns out that our task exhibits some additional challenges. On the one hand, a sophisticated pre- and postprocessing of the data has to be deployed to make the application of the deep learning model feasible. On the other hand, we find that creating labeled training data is not a trivial task in our scenario, and one has to be extra careful with model evaluation. We can demonstrate in multiple empirical assessments that our algorithm can detect defects in diode lasers accurately and reliably in most cases. We analyze the results of our production-ready pipeline in detail, discuss its limitations and provide some proposals for further improvements.
    Language: English
    Type: conferenceobject , doc-type:conferenceObject
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