Infrared Imaging of Brain Function

Gorbach, Alexander M.

doi:10.1007/978-1-4899-2468-1_11

Cited by 21 publications

(11 citation statements)

References 41 publications

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“…1 Recent near-infrared measurements of brain activity following visual [2][3][4] and motor [5][6][7][8][9][10] stimulations confirmed the positron emission tomography 11 and functional magnetic resonance imaging 12 observations of a significant hemodynamic response at the activated brain area. Several important features of cerebral hemodynamics were discovered.…”

Section: Introductionmentioning

confidence: 78%

Near‐infrared study of fluctuations in cerebral hemodynamics during rest and motor stimulation: Temporal analysis and spatial mapping

et al. 2000

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We have noninvasively studied the motor cortex hemodynamics in human subjects under rest and motor stimulation conditions using a multichannel near‐infrared tissue spectrometer. Our instrument measures optical maps of the cerebral cortex at two wavelengths (758 and 830 nm), with an acquisition time of 160 ms per map. We obtained optical maps of oxy‐ and deoxy‐hemoglobin concentration changes in terms of amplitudes of folding average, power spectrum and coherence at the stimulation repetition frequency, and the phase synchronization index. Under periodic motor stimulation conditions, we observed coherence and frequency or phase synchronization of the local hemodynamic changes with stimulation. Our main findings are the following: (1) The amplitude of the hemodynamic response to the motor stimulation is comparable to the amplitude of the fluctuations at rest. (2) The spatial patterns of the oxy‐ and deoxy‐hemoglobin responses to the stimulation are different. (3) The hemodynamic response to stimulation shows a spatial localization and a level of phase synchronization with the motor stimulation that depends on the stimulation period.

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Section: Introductionmentioning

confidence: 78%

Near‐infrared study of fluctuations in cerebral hemodynamics during rest and motor stimulation: Temporal analysis and spatial mapping

et al. 2000

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“…The temperature from activated brain regions has been reported to increase slowly by ~0.1°C during 2 min forepaw stimulation with α -chloralose anesthetized rats (Trubel et al 2006). An infrared mapping technique (Gorbach 1993) was used to detect thermal changes on the surface of rat brain and differences in temperature of up to 0.5°C were registered in different cortical areas during the resting state (Shevelev 1998). Short visual stimulation invoked a temperature rise on the order of 0.1°C on the surface of the skull covering the visual cortex as measured with this technique.…”

Section: Discussionmentioning

confidence: 99%

Body and brain temperature coupling: the critical role of cerebral blood flow

2009

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Direct measurements of deep-brain and body-core temperature were performed on rats to determine the influence of cerebral blood flow (CBF) on brain temperature regulation under static and dynamic conditions. Static changes of CBF were achieved using different anesthetics (chloral hydrate, CH; α-chloralose, αCS; and isoflurane, IF) with αCS causing larger decreases in CBF than CH and IF; dynamic changes were achieved by inducing transient hypercapnia (5% CO2 in 40% O2 and 55% N2). Initial deep-brain/body-core temperature differentials were anesthetic-type dependent with the largest differential observed with rats under αCS anesthesia (ca. 2°C). Hypercapnia induction raised rat brain temperature under all three anesthesia regimes, but by different anesthetic-dependent amounts correlated with the initial differentials—αCS anesthesia resulted in the largest brain temperature increase (0.32 ± 0.08°C), while CH and IF anesthesia lead to smaller increases (0.12 ± 0.03 and 0.16 ± 0.05°C, respectively). The characteristic temperature transition time for the hypercapnia-induced temperature increase was 2–3 min under CH and IF anesthesia and ~4 min under αCS anesthesia. We conclude that both, the deep-brain/body-core temperature differential and the characteristic temperature transition time correlate with CBF: a lower CBF promotes higher deep-brain/body-core temperature differentials and, upon hypercapnia challenge, longer characteristic transition times to increased temperatures.

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“…Thermography is a technique used for measuring heat (infrared) emission from the human body. 12,13 Using infrared (IR) radiometry, heat measurements from large areas of the body surface can be made without skin contact. Skin surface temperature (SST) is affected by changes in underlying muscle activity and microcirculation, 1,9 suggesting that it might bridge the gaps among behavioral studies of facial expression, emotion, and the ANS measures traditionally used to score polygraph tests.…”

Section: Introductionmentioning

confidence: 99%

Facial Skin Surface Temperature Changes During a “Concealed Information” Test

Pollina¹,

Dollins²,

Senter³

et al. 2006

Ann Biomed Eng

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When individuals who commit a crime are questioned, they often show involuntary physiological responses to remembered details of that crime. This phenomenon is the basis for the concealed information test, in which rarely occurring crime-related details are embedded in a series of more frequently occurring crime-irrelevant items while respiratory, cardiovascular, and electrodermal responses are recorded. Two experiments were completed to investigate the feasibility of using facial skin surface temperature (SST) measures recorded using high definition thermographic images as the physiological measure during a concealed information test. Participants were randomly assigned to nondeceptive or deceptive groups. Deceptive participants completed a mock-crime paradigm. A focal plane array thermal imaging radiometer was used to monitor SST while crime-relevant and crime-irrelevant items were verbally presented to each participant. During both experiments, there were significant facial SST differences between deceptive and nondeceptive participants early in the analysis interval. In the second experiment, hemifacial (i.e., "half-face" divided along the longitudinal axis) effects were combined with the bilateral responses to correctly classify 91.7% of participants. These results suggest that thermal image analysis can be effective in discriminating deceptive and nondeceptive individuals during a concealed information test.

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Infrared Imaging of Brain Function

Cited by 21 publications

References 41 publications

Near‐infrared study of fluctuations in cerebral hemodynamics during rest and motor stimulation: Temporal analysis and spatial mapping

Near‐infrared study of fluctuations in cerebral hemodynamics during rest and motor stimulation: Temporal analysis and spatial mapping

Body and brain temperature coupling: the critical role of cerebral blood flow

Facial Skin Surface Temperature Changes During a “Concealed Information” Test

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