Detection of nonlinear event-related potentials

Carrubba, Simona; Frilot, Clifton; Chesson, Andrew L.; Marino, Andrew A.

doi:10.1016/j.jneumeth.2006.03.022

Cited by 27 publications

(18 citation statements)

References 15 publications

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“…There is no general procedure for reliably identifying the optimal conditions and parameters, and they must therefore be chosen empirically. Those used here were originally chosen to maximize detection of magnetosensory evoked potentials (Carrubba et al, 2006), and we made no attempt to maximize sensitivity for detecting the presence effect due to sound or light because our main purpose was to describe the general method, not optimize it for each stimulus. We expect that other choices of embedding conditions and/or recurrence-parameter values would yield even stronger evidence of a presence effect due to sound, light, and other stimuli.…”

Section: Discussionmentioning

confidence: 99%

“…Light was obtained from a red-light-emitting diode that produced 50 cd; the source was 30 cm from the eye and the light could be seen by the subjects while their eyes were closed. Uniaxial magnetic fields, 2 gauss (200 T), 60 Hz were applied by means of coaxial coils; details regarding the field exposure system are given elsewhere (Carrubba et al, 2006). The field strengths were below the level that results in conscious perception, and were comparable to those in the general and workplace environments.…”

Section: Stimulimentioning

confidence: 99%

“…A recurrence plot was constructed for each epoch of interest, leading to values for %R and %D. Based on our previous studies (Carrubba et al, 2006;Carrubba et al, 2007) we used a fivedimensional phase space, a time delay of 5 points, a radius of 15%, the Euclidean norm for calculating distances, and defined a line as ≥2 points along a diagonal (Fig. 1a).…”

Section: Nonlinear Analysismentioning

confidence: 99%

“…For example (Fig. 1c), the latency of the onset potential evoked by the auditory stimulus was 0.1-0.7 s, depending on the subject (Carrubba et al, 2006); we analyzed 0.7-1.7 s (E epoch) for evidence of a presence effect due to sound. The sham (S) and control (C) epochs corresponding to an E epoch were located in the Organization of trials (subjects randomly assigned to receive one of the patterns).…”

Section: Experimental Design and Statisticsmentioning

confidence: 99%

“…Phase-space embedding of a time series followed by quantitative analysis of the system's recurrence plot permits detection of both linear and nonlinear evoked potentials (Carrubba et al, 2006). Our purpose was to extend this approach to the detection of a presence effect.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Method for detection of changes in the EEG induced by the presence of sensory stimuli

Carrubba¹,

Frilot²,

Chesson³

et al. 2008

Journal of Neuroscience Methods

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Section: Discussionmentioning

confidence: 99%

Section: Stimulimentioning

confidence: 99%

Section: Nonlinear Analysismentioning

confidence: 99%

Section: Experimental Design and Statisticsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Method for detection of changes in the EEG induced by the presence of sensory stimuli

Carrubba¹,

Frilot²,

Chesson³

et al. 2008

Journal of Neuroscience Methods

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Simulated MR magnetic field induces steady‐state changes in brain dynamics: Implications for interpretation of functional MR studies

Marino

Carrubba

Frilot

et al. 2010

Magnetic Resonance in Med

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We examined whether a magnetic field comparable to one of the fields produced during MRI induced steady-state changes in brain electrical activity while the field was applied (called a presence effect to distinguish it from evoked potentials). The electroencephalogram was measured from standard scalp locations in the presence and absence of 100-200 mT, 60 Hz, and the effect of the field was evaluated by nonlinear (recurrence analysis) and linear techniques; individual subjects served as their own controls. Using recurrence analysis, changes in brain activity lasting 1 sec (the longest interval considered) were found in 21 of 22 subjects (P < 0.05 for each subject). The presence effect was not detected using linear analysis and was reversible, as indicated by a return of brain activity to baseline levels in all subjects within 2 sec of field offset. The possible role of artifacts or systematic errors was ruled out by studies using electrical phantoms and by analyses of electroencephalograms recorded during sham exposure. It is reasonable to expect that actual scanner magnetic fields also produce nonlinear steady-state perturbations of brain dynamical activity. The effect may influence the picture of brain connectivity inferred in some functional MR studies. Magn Reson Med 64:349-357, 2010. V C 2010 Wiley-Liss, Inc.Key words: nonlinear analysis; brain electrical activity; limitation on fMRI; electric fields; magnetic fields Cognitive activity is mediated by temporal-spatial interactions involving specialized regions of the brain (1). The interactions are commonly studied using functional MRI (fMRI) employing blood-oxygen-level-dependent (BOLD) contrast imaging (2).Averaged images obtained when subjects were and were not performing particular tasks are typically used to identify brain regions that mediated task-related cognitive processing (3,4). This strategy is based on some problematical assumptions and has neuropsychological drawbacks (5), but it affords good statistical power for detecting BOLD signals (6).In MRI, static (0 Hz) magnetic fields of 1-9 T align nuclear spins, high-frequency magnetic fields (10-400 MHz) of about 0.2 mT induce transitions between spin states, and low-frequency magnetic fields (100-1000 Hz) of about 50 mT produce imaging gradients (7); in fMRI, gradient parameters produce additional magnetic fields. Physical law and physiologic conditions in the brain (blood flow, tissue motion, cell movement, motion of the head) result in the simultaneous presence of electric fields (8).Human subjects can detect magnetic fields, as evidenced by their ability to trigger onset and offset evoked potentials (9). We were interested in whether, in addition to these transient changes in brain electrical activity, magnetic fields relevant to those used in MRI also produced continuous changes during the time the field was applied (''presence effect''). Depending on the dynamical nature of the effect (see below), such a finding would enhance the possibility that BOLD data obtained during functional imaging c...

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Magnetosensory function in rats: Localization using positron emission tomography

Frilot

Carrubba

Marino

2009

Synapse

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The aim of this study was to show that low-strength electromagnetic fields (EMFs) produced evoked potentials in rats and to localize the activated region in the brain. In response to a 2.5-G, 60-Hz stimulus, onset- and offset-evoked potentials were detected (P < 0.05 in each of the 10 animals studied); the evoked potentials had the same magnitude, latency, and nonlinear relationship to the field seen in previous studies on rabbits and human subjects. The neuroanatomical region of activation associated with the electrophysiological effect was identified by positron emission tomography using fluorodeoxyglucose. Paired emission scans (the same animal with and without field treatment) from 10 additional rats were differenced and averaged to produce a t-statistic image using the pooled variance; the t value of each voxel was compared with a calculated critical t value to identify the activated voxels (P < 0.05). A brain volume of 13 mm(3) (15 voxels) located in the posterior, central cerebellum was found to have been activated by exposure to the field. Taken together, the results indicated that magnetosensory evoked potentials in the rats were associated with increased glucose utilization in the cerebellum, thereby supporting earlier evidence that EMF transduction occurred in the brain.

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Detection of nonlinear event-related potentials

Cited by 27 publications

References 15 publications

Method for detection of changes in the EEG induced by the presence of sensory stimuli

Method for detection of changes in the EEG induced by the presence of sensory stimuli

Simulated MR magnetic field induces steady‐state changes in brain dynamics: Implications for interpretation of functional MR studies

Magnetosensory function in rats: Localization using positron emission tomography

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