The Experts below are selected from a list of 354 Experts worldwide ranked by ideXlab platform
Theodor Landis - One of the best experts on this subject based on the ideXlab platform.
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submillisecond unmasked subliminal visual stimuli evoke electrical brain responses
Human Brain Mapping, 2015Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking.
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Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.
Human Brain Mapping, 2014Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional infor- mation and has mostly been studied using visual masking. In this study, we used high density 256- channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio- temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 ms (partially visible), and 250 ms (sublimi- nal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 ms evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post- stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or mean- ingfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. Hum Brain Mapp 00:000-000, 2014. V C 2014 Wiley Periodicals, Inc.
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An LCD Tachistoscope with submillisecond precision
Behavior Research Methods, 2013Co-Authors: Holger F. Sperdin, Marc Repnow, Michael H. Herzog, Theodor LandisAbstract:Tachistoscopes allow brief visual stimulation delivery, which is crucial for experiments in which subliminal presentation is required. Up to now, Tachistoscopes have had shortcomings with respect to timing accuracy, reliability, and flexibility of use. Here, we present a new and inexpensive two-channel Tachistoscope that allows for exposure durations in the submillisecond range with an extremely high timing accuracy. The Tachistoscope consists of two standard liquid-crystal display (LCD) monitors of the light-emitting diode (LED) backlight type, a semipermeable mirror, a mounting rack, and an experimental personal computer (PC). The monitors have been modified to provide external access to the LED backlights, which are controlled by the PC via the standard parallel port. Photodiode measurements confirmed reliable operation of the Tachistoscope and revealed switching times of 3 μ s. Our method may also be of great advantage in single-monitor setups, in which it allows for manipulating the stimulus timing with submillisecond precision in many experimental situations. Where this is not applicable, the monitor can be operated in standard mode by disabling the external backlight control instantaneously.
Holger Franz Sperdin - One of the best experts on this subject based on the ideXlab platform.
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submillisecond unmasked subliminal visual stimuli evoke electrical brain responses
Human Brain Mapping, 2015Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking.
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Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.
Human Brain Mapping, 2014Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional infor- mation and has mostly been studied using visual masking. In this study, we used high density 256- channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio- temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 ms (partially visible), and 250 ms (sublimi- nal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 ms evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post- stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or mean- ingfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. Hum Brain Mapp 00:000-000, 2014. V C 2014 Wiley Periodicals, Inc.
Robert Becker - One of the best experts on this subject based on the ideXlab platform.
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submillisecond unmasked subliminal visual stimuli evoke electrical brain responses
Human Brain Mapping, 2015Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking.
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Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.
Human Brain Mapping, 2014Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional infor- mation and has mostly been studied using visual masking. In this study, we used high density 256- channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio- temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 ms (partially visible), and 250 ms (sublimi- nal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 ms evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post- stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or mean- ingfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. Hum Brain Mapp 00:000-000, 2014. V C 2014 Wiley Periodicals, Inc.
Lucas Spierer - One of the best experts on this subject based on the ideXlab platform.
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submillisecond unmasked subliminal visual stimuli evoke electrical brain responses
Human Brain Mapping, 2015Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking.
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Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.
Human Brain Mapping, 2014Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional infor- mation and has mostly been studied using visual masking. In this study, we used high density 256- channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio- temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 ms (partially visible), and 250 ms (sublimi- nal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 ms evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post- stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or mean- ingfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. Hum Brain Mapp 00:000-000, 2014. V C 2014 Wiley Periodicals, Inc.
Christoph M Michel - One of the best experts on this subject based on the ideXlab platform.
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submillisecond unmasked subliminal visual stimuli evoke electrical brain responses
Human Brain Mapping, 2015Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking.
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Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.
Human Brain Mapping, 2014Co-Authors: Holger Franz Sperdin, Lucas Spierer, Robert Becker, Christoph M Michel, Theodor LandisAbstract:Subliminal perception is strongly associated to the processing of meaningful or emotional infor- mation and has mostly been studied using visual masking. In this study, we used high density 256- channel EEG coupled with an liquid crystal display (LCD) Tachistoscope to characterize the spatio- temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 ms (partially visible), and 250 ms (sublimi- nal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 ms evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post- stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or mean- ingfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. Hum Brain Mapp 00:000-000, 2014. V C 2014 Wiley Periodicals, Inc.
