Abstract

Imaging of the human body by any non-invasive technique has been an appropriate goal of physics and medicine, and great success has been obtained with both Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) in brain imaging. Non-imaging responses to functional activation using near infrared spectroscopy of brain (fNIR) obtained in 1993 (Chance, et al. [1]) and in 1994 (Tamura, et al. [2]) are now complemented with images of pre-frontal and parietal stimulation in adults and pre-term neonates in this communication (see also [3]). Prior studies used continuous [4], pulsed [3] or modulated [5] light. The amplitude and phase cancellation of optical patterns as demonstrated for single source detector pairs affords remarkable sensitivity of small object detection in model systems [6]. The methods have now been elaborated with multiple source detector combinations (nine sources, four detectors). Using simple back projection algorithms it is now possible to image sensorimotor and cognitive activation of adult and pre- and full-term neonate human brain function in times < 30 sec and with two dimensional resolutions of < 1 cm in two dimensional displays. The method can be used in evaluation of adult and neonatal cerebral dysfunction in a simple, portable and affordable method that does not require immobilization, as contrasted to MRI and PET.

© Optical Society of America

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References

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  1. B. Chance, Z. Zhuang, UnAh Chu, C. Alter, and L. Lipton, "Cognition activated low frequency modulation of light absorption in human brain," Proc. Natl. Acad. Sci. USA 90, 2660-2774 (1993).
    [CrossRef]
  2. Y. Hoshi, H. Onoe, Y. Watanabe, J. Andersson, M. Bergstrom, A. Lilja, B. Langstom, and M. Tamura, "Non-synchronous behavior of neuronal activity, oxidative metabolism and blood supply during mental tasks in man," Neurosci. Lett. 172, 129-133 (1994).
    [CrossRef] [PubMed]
  3. D. A. Benaron, J. P. Van Houten, W.-F. Cheong, E.L. Kermit, and R.A. King, "Early clinical results of time-of-flight optical tomography in a neonatal intensive care unit," in Optical Tomography, Photon Migration, and Spectroscopy of Tissue and Model Media: Theory, Human Studies, and Instrumentation, B. Chance, R.R. Alfano, eds. Proc. SPIE 2389, 582-596 (1995).
    [CrossRef]
  4. B. Chance, Q. Luo, S. Nioka, D.C. Alsop, and J.A. Detre, "Optical investigations of physiology: A study of biomedical intrinsic and extrinsic contrast," Phil. Trans. R. Soc. Lond. B 352, 707-716 (1997).
    [CrossRef]
  5. M. A. Franceschini, K.T. Moesta, S. Fantini, G. Gaida, E. Gratton, H. Jess, W.W. Mantulin, M. Seeber, P. M. Schlag, and M. Kaschke, "Frequency-domain techniques enhance optical mammography: Initial clinical results," Proc. Natl. Acad. Sci. USA 94, 6468-6473 (1997).
    [CrossRef] [PubMed]
  6. B. Chance, K. Kang, L. He, H. Liu, and S. Zhou, "Precision localization of hidden absorbers in body tissues with phased-array optical systems," Rev. Sci. Instrum. 67, 4324-4332 (1996).
    [CrossRef]
  7. B. Chance and M. Baltscheffsky, "Spectroscopic effect of adenosine diphosphate upon the respiratory pigments of ra- heart-muscle Sarcosome," Biochem. J. 68, 283-295 (1958).
    [PubMed]
  8. B. Chance and H. Thorell, "Localization and kinetics of reduced pyridine nucleotide in living cells by microfluorometry," J. Biol. Chem. 234, 3044-3050 (1959).
    [PubMed]
  9. B. Chance, P. Cohen, F. Jobsis, and B. Schoener, "Intracellular oxidation-reduction states In Vivo," Science 137, 499-508 (1962).
    [CrossRef] [PubMed]
  10. B. Chance and G. Williams, "Respiratory enzymes in oxidative phosphorylation. I. Kinetics of oxygen utilization," J. Biol. Chem. 217, 383-393 (1955).
    [PubMed]
  11. R. P. Perry, B. Thorell, L. Akerman, and B. Chance, "Localization and Assay of Respiratory Enzymes in Single Living Cells, Absorbancy Measurements on the Nebenkern," Nature 184, 929-935 (1959).
    [CrossRef] [PubMed]
  12. B. H. Stuart and B. Chance, "NADH brain surface scanning and 3D computer display," Brain Res. 76, 473-479 (1974).
    [CrossRef] [PubMed]
  13. S. Nioka, B. Chance, M. Hilberman, H.V. Subramanian, J. S. Leigh, Jr., R.L. Veech, and R. Forster, "The relationship between intracellular pH and energy metabolism in dog brain as measured by 31 PNMR," J. Appl. Physiol. 62, 2094-2102 (1987).
    [PubMed]
  14. K. Kramer, "Verfahren zur fortlaufenden messung des sauerstoffgehaltes im stromenden blute an uneroffneten gefassen," Z. Biol. 96, 61-75 (1935).
  15. S. Nioka, A. Zaman, H., Yoshioka, M. Masumura, H. Miyake, S. Lockard and B. Chance, "31 P MRS study of cerebral metabolism in developing dog brain and its relationship to neuronal function," Developmental Neurosci. 13,61-68 (1987).
    [CrossRef]
  16. J. E. Brazy, D. V. Lewis, M. H. Mitnick, and Jobsis-Vander Vliet., "Noninvasive monitoring of cerebral oxygenation in preterm infants: Preliminary observations," Pediatrics 75, 217-225 (1985).
    [PubMed]
  17. Y. Hoshi, and M. Tamura, "Detection of dynamic changes in cerebral oxygenation coupled to neuronal function during mental work in man," J. Neurosci. Lett. 155, 5-8 (993).
  18. A. Villringer, and B. Chance, "Noninvasive optical spectroscopy and imaging of human brain function," Trends in Neuroscience 20, 435-442 (1997).
    [CrossRef]
  19. G. Gratton, P. M. Corballis, E. Cho, M. Fabiani and D. C. Hood, "Shades of gray matter: noninvasive optical images of human brain responses during visual stimulation," Psychophysiology 32, 505-509 (1995).
    [CrossRef] [PubMed]
  20. H. R. Heekeren, R. Wenzel, H. Obrig, J. Ruben, J-P. Ndayisaba, Q. Luo, A. Dale, S. Nioka, M. Kohl, U. Dirnagl, A. Villringer, and B. Chance, "Towards noninvasive optical human brain mapping--Improvements of the spectral, temporal and spatial resolution of near-infrared spectroscopy," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., Proc. SPIE 2979, 847-857 (1997).
    [CrossRef]
  21. J. Haselgrove, J. Leigh, C. Yee, N-G. Wang, M. Maris, and B. Chance, "Monte Carlo and diffusion calculations of photon migration in non-infinite highly scattering media, in: Time-Resolved Spectroscopy and Imaging of Tissues," B. Chance, ed., Proc. SPIE, 1431:30-41 (1991).
    [CrossRef]
  22. M. S. Patterson, B. Chance and B.C. Wilson, "Time resolved reflectance and transmittance for the noninvasive measurement of tissue optical properties," Appl. Optics 28, 2331-2336 (1989).
    [CrossRef]
  23. C. S. Robertson, S. P. Gopinath and B. Chance, "Use of near infrared spectroscopy to identify traumatic intracranial hematomas," J. Biomed. Optics 2, 31-41 (1997).
    [CrossRef]
  24. H. Y. Ma., C. W. Du, and B. Chance, "A homodyne frequency-domain instrument -- I&Q phase detection system," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., Proc. SPIE 2979:826-937 (1997).
    [CrossRef]
  25. J. W. Belliveau, D. N. Kennedy, R. C. McKinstry, B. R. Buchbinder, R. M. Weisskoff, M. S. Cohen, J. M., Vevea, T. J. Brady and B. R. Rosen, "Functional mapping of the human visual cortex by magnetic resonance imaging," Science 254, 716-719 (1991).
    [CrossRef] [PubMed]
  26. Q. Luo, S. Nioka and B. Chance, "Functional near-infrared image," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., Proc. SPIE 2979, 84-93 (1997).
    [CrossRef]
  27. S. Ogawa, T. M. Lee, A.R. Kay and D. W. Tank, "Brain magnetic resonance with contrast dependent on blood oxygenation," Proc. Natl. Acad. Sci. (USA) 87, 9868-9872 (1990).
    [CrossRef] [PubMed]
  28. B. Chance, B. Hughes, E. F. MacNichol, D. Sayre and F. C. Williams, Waveforms Vol. 19, (MIT Radiation Laboratories Series, Boston Technical Publ., Lexington, MA 1949).
  29. Q. Zhu, B. Chance and D. Sullivan, "Optically Guided Ultrasound Imaging System," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., SPIE 2979, 48-58 (1997).
    [CrossRef]
  30. A. Knttel, J. M. Schmitt and J. R. Knutson, "Spatial localization of absorbing bodies by interfering diffusive photon density waves," Appl. Opt. 32, 381-389 (1992).
    [CrossRef]
  31. X. D. Li, J. P. Culver, D. N. Pattanayak, B. Chance and A. G. Yodh, "Diffraction tomography with diffuse-photon density waves: Clinical studies and background subtraction," Optical Society of America (Spring Topical Meeting, March 8-12), in press (1998).
  32. S. Zhao, M. A. O'Leary, S. Nioka and B. Chance, "Breast tumor detection using continuous wave light source," in Optical Tomography, Photon Migration, and Spectroscopy of Tissue and Model Media: Theory, Human Studies, and Instrumentation, Britton Chance, Robert R. Alfano, eds., SPIE, 2389, (The Optical Society of America, Washington, DC, 1995) p. 809-817.
    [CrossRef]
  33. B. Chance, S. Nioka, S. Zhou. and Y. Chen (1998) "Functional Mapping with Near Infrared," 4th Intl. Conf. on Functional Mapping of the human Brain (June 7-12) Montreal, Quebec, Canada, in press.
  34. B. Chance, M. Cope, E. Gratton, N. Ramanujam and B. Tromberg, "Phase measurement of absorbers/scatters in human tissue," Rev. Sci. Instrum. (accepted with revision )(1998).
  35. B. Chance, J. S. Leigh, H. Miyake, D. S. Smith, S. Nioka, R. Greenfeld, M. Finander, K. Kaufmann, W. Levy, M. Young, P. Cohen, H. Yoshioka, and R. Boretsky, "Comparison of time-resolved and -unresolved measurements of deoxyhemoglobin in brain," Proc. Natl. Acad. Sci. USA 85, 4971-4975 (1988).
    [CrossRef] [PubMed]
  36. B. J. Tromberg, O. Coquoz, J. B. Fishkin, T. Pham, E. R. Anderson, J. Butler, M. Cahn, J. D. Gross, V. Venugopalan and D. Pham, "Non-invasive measurements of breast tissue optical properties using frequency-domain photon migration," Phil. Trans. Royal Society London B 352, 661-668 (1997).
    [CrossRef]
  37. Q. Luo, S. Nioka and B. Chance, "Imaging on Brain Model by a Novel Optical Probe - Fiber Hairbrush," in Adv. Optical Imaging and Photon Migration (March 18-20, Orlando FL), R.R. Alfano and J.G. Fumiomoto, eds. II, (The Optical Society of America, Washington, DC, 1996) p. 183-185.
  38. S. Zhou, Ch. Xie, S. Zhao and B. Chance, "Precision localization of hidden absorbers with phase-array optical systems," in Adv. Optical Imaging and Photon Migration. (March 18-20, Orlando FL), R.R. Alfano and J.G. Fumiomoto, eds., II (The Optical Society of America, Washington, DC, 1996) p. 130-136.
  39. G. Taubes, "Play of light opens a new window into the body," Science 276, 1991-1993 (1997)
    [CrossRef] [PubMed]

Other

B. Chance, Z. Zhuang, UnAh Chu, C. Alter, and L. Lipton, "Cognition activated low frequency modulation of light absorption in human brain," Proc. Natl. Acad. Sci. USA 90, 2660-2774 (1993).
[CrossRef]

Y. Hoshi, H. Onoe, Y. Watanabe, J. Andersson, M. Bergstrom, A. Lilja, B. Langstom, and M. Tamura, "Non-synchronous behavior of neuronal activity, oxidative metabolism and blood supply during mental tasks in man," Neurosci. Lett. 172, 129-133 (1994).
[CrossRef] [PubMed]

D. A. Benaron, J. P. Van Houten, W.-F. Cheong, E.L. Kermit, and R.A. King, "Early clinical results of time-of-flight optical tomography in a neonatal intensive care unit," in Optical Tomography, Photon Migration, and Spectroscopy of Tissue and Model Media: Theory, Human Studies, and Instrumentation, B. Chance, R.R. Alfano, eds. Proc. SPIE 2389, 582-596 (1995).
[CrossRef]

B. Chance, Q. Luo, S. Nioka, D.C. Alsop, and J.A. Detre, "Optical investigations of physiology: A study of biomedical intrinsic and extrinsic contrast," Phil. Trans. R. Soc. Lond. B 352, 707-716 (1997).
[CrossRef]

M. A. Franceschini, K.T. Moesta, S. Fantini, G. Gaida, E. Gratton, H. Jess, W.W. Mantulin, M. Seeber, P. M. Schlag, and M. Kaschke, "Frequency-domain techniques enhance optical mammography: Initial clinical results," Proc. Natl. Acad. Sci. USA 94, 6468-6473 (1997).
[CrossRef] [PubMed]

B. Chance, K. Kang, L. He, H. Liu, and S. Zhou, "Precision localization of hidden absorbers in body tissues with phased-array optical systems," Rev. Sci. Instrum. 67, 4324-4332 (1996).
[CrossRef]

B. Chance and M. Baltscheffsky, "Spectroscopic effect of adenosine diphosphate upon the respiratory pigments of ra- heart-muscle Sarcosome," Biochem. J. 68, 283-295 (1958).
[PubMed]

B. Chance and H. Thorell, "Localization and kinetics of reduced pyridine nucleotide in living cells by microfluorometry," J. Biol. Chem. 234, 3044-3050 (1959).
[PubMed]

B. Chance, P. Cohen, F. Jobsis, and B. Schoener, "Intracellular oxidation-reduction states In Vivo," Science 137, 499-508 (1962).
[CrossRef] [PubMed]

B. Chance and G. Williams, "Respiratory enzymes in oxidative phosphorylation. I. Kinetics of oxygen utilization," J. Biol. Chem. 217, 383-393 (1955).
[PubMed]

R. P. Perry, B. Thorell, L. Akerman, and B. Chance, "Localization and Assay of Respiratory Enzymes in Single Living Cells, Absorbancy Measurements on the Nebenkern," Nature 184, 929-935 (1959).
[CrossRef] [PubMed]

B. H. Stuart and B. Chance, "NADH brain surface scanning and 3D computer display," Brain Res. 76, 473-479 (1974).
[CrossRef] [PubMed]

S. Nioka, B. Chance, M. Hilberman, H.V. Subramanian, J. S. Leigh, Jr., R.L. Veech, and R. Forster, "The relationship between intracellular pH and energy metabolism in dog brain as measured by 31 PNMR," J. Appl. Physiol. 62, 2094-2102 (1987).
[PubMed]

K. Kramer, "Verfahren zur fortlaufenden messung des sauerstoffgehaltes im stromenden blute an uneroffneten gefassen," Z. Biol. 96, 61-75 (1935).

S. Nioka, A. Zaman, H., Yoshioka, M. Masumura, H. Miyake, S. Lockard and B. Chance, "31 P MRS study of cerebral metabolism in developing dog brain and its relationship to neuronal function," Developmental Neurosci. 13,61-68 (1987).
[CrossRef]

J. E. Brazy, D. V. Lewis, M. H. Mitnick, and Jobsis-Vander Vliet., "Noninvasive monitoring of cerebral oxygenation in preterm infants: Preliminary observations," Pediatrics 75, 217-225 (1985).
[PubMed]

Y. Hoshi, and M. Tamura, "Detection of dynamic changes in cerebral oxygenation coupled to neuronal function during mental work in man," J. Neurosci. Lett. 155, 5-8 (993).

A. Villringer, and B. Chance, "Noninvasive optical spectroscopy and imaging of human brain function," Trends in Neuroscience 20, 435-442 (1997).
[CrossRef]

G. Gratton, P. M. Corballis, E. Cho, M. Fabiani and D. C. Hood, "Shades of gray matter: noninvasive optical images of human brain responses during visual stimulation," Psychophysiology 32, 505-509 (1995).
[CrossRef] [PubMed]

H. R. Heekeren, R. Wenzel, H. Obrig, J. Ruben, J-P. Ndayisaba, Q. Luo, A. Dale, S. Nioka, M. Kohl, U. Dirnagl, A. Villringer, and B. Chance, "Towards noninvasive optical human brain mapping--Improvements of the spectral, temporal and spatial resolution of near-infrared spectroscopy," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., Proc. SPIE 2979, 847-857 (1997).
[CrossRef]

J. Haselgrove, J. Leigh, C. Yee, N-G. Wang, M. Maris, and B. Chance, "Monte Carlo and diffusion calculations of photon migration in non-infinite highly scattering media, in: Time-Resolved Spectroscopy and Imaging of Tissues," B. Chance, ed., Proc. SPIE, 1431:30-41 (1991).
[CrossRef]

M. S. Patterson, B. Chance and B.C. Wilson, "Time resolved reflectance and transmittance for the noninvasive measurement of tissue optical properties," Appl. Optics 28, 2331-2336 (1989).
[CrossRef]

C. S. Robertson, S. P. Gopinath and B. Chance, "Use of near infrared spectroscopy to identify traumatic intracranial hematomas," J. Biomed. Optics 2, 31-41 (1997).
[CrossRef]

H. Y. Ma., C. W. Du, and B. Chance, "A homodyne frequency-domain instrument -- I&Q phase detection system," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., Proc. SPIE 2979:826-937 (1997).
[CrossRef]

J. W. Belliveau, D. N. Kennedy, R. C. McKinstry, B. R. Buchbinder, R. M. Weisskoff, M. S. Cohen, J. M., Vevea, T. J. Brady and B. R. Rosen, "Functional mapping of the human visual cortex by magnetic resonance imaging," Science 254, 716-719 (1991).
[CrossRef] [PubMed]

Q. Luo, S. Nioka and B. Chance, "Functional near-infrared image," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., Proc. SPIE 2979, 84-93 (1997).
[CrossRef]

S. Ogawa, T. M. Lee, A.R. Kay and D. W. Tank, "Brain magnetic resonance with contrast dependent on blood oxygenation," Proc. Natl. Acad. Sci. (USA) 87, 9868-9872 (1990).
[CrossRef] [PubMed]

B. Chance, B. Hughes, E. F. MacNichol, D. Sayre and F. C. Williams, Waveforms Vol. 19, (MIT Radiation Laboratories Series, Boston Technical Publ., Lexington, MA 1949).

Q. Zhu, B. Chance and D. Sullivan, "Optically Guided Ultrasound Imaging System," in Optical Tomography and Spectroscopy of Tissue: Theory, Instrumentation, Model, and Human Studies II, Britton Chance, Robert Alfano, eds., SPIE 2979, 48-58 (1997).
[CrossRef]

A. Knttel, J. M. Schmitt and J. R. Knutson, "Spatial localization of absorbing bodies by interfering diffusive photon density waves," Appl. Opt. 32, 381-389 (1992).
[CrossRef]

X. D. Li, J. P. Culver, D. N. Pattanayak, B. Chance and A. G. Yodh, "Diffraction tomography with diffuse-photon density waves: Clinical studies and background subtraction," Optical Society of America (Spring Topical Meeting, March 8-12), in press (1998).

S. Zhao, M. A. O'Leary, S. Nioka and B. Chance, "Breast tumor detection using continuous wave light source," in Optical Tomography, Photon Migration, and Spectroscopy of Tissue and Model Media: Theory, Human Studies, and Instrumentation, Britton Chance, Robert R. Alfano, eds., SPIE, 2389, (The Optical Society of America, Washington, DC, 1995) p. 809-817.
[CrossRef]

B. Chance, S. Nioka, S. Zhou. and Y. Chen (1998) "Functional Mapping with Near Infrared," 4th Intl. Conf. on Functional Mapping of the human Brain (June 7-12) Montreal, Quebec, Canada, in press.

B. Chance, M. Cope, E. Gratton, N. Ramanujam and B. Tromberg, "Phase measurement of absorbers/scatters in human tissue," Rev. Sci. Instrum. (accepted with revision )(1998).

B. Chance, J. S. Leigh, H. Miyake, D. S. Smith, S. Nioka, R. Greenfeld, M. Finander, K. Kaufmann, W. Levy, M. Young, P. Cohen, H. Yoshioka, and R. Boretsky, "Comparison of time-resolved and -unresolved measurements of deoxyhemoglobin in brain," Proc. Natl. Acad. Sci. USA 85, 4971-4975 (1988).
[CrossRef] [PubMed]

B. J. Tromberg, O. Coquoz, J. B. Fishkin, T. Pham, E. R. Anderson, J. Butler, M. Cahn, J. D. Gross, V. Venugopalan and D. Pham, "Non-invasive measurements of breast tissue optical properties using frequency-domain photon migration," Phil. Trans. Royal Society London B 352, 661-668 (1997).
[CrossRef]

Q. Luo, S. Nioka and B. Chance, "Imaging on Brain Model by a Novel Optical Probe - Fiber Hairbrush," in Adv. Optical Imaging and Photon Migration (March 18-20, Orlando FL), R.R. Alfano and J.G. Fumiomoto, eds. II, (The Optical Society of America, Washington, DC, 1996) p. 183-185.

S. Zhou, Ch. Xie, S. Zhao and B. Chance, "Precision localization of hidden absorbers with phase-array optical systems," in Adv. Optical Imaging and Photon Migration. (March 18-20, Orlando FL), R.R. Alfano and J.G. Fumiomoto, eds., II (The Optical Society of America, Washington, DC, 1996) p. 130-136.

G. Taubes, "Play of light opens a new window into the body," Science 276, 1991-1993 (1997)
[CrossRef] [PubMed]

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Figures (7)

Fig. 1.
Fig. 1.

Demonstration of the existence of amplitude null and phase transition in adult human brain. The detector is scanned between two sources placed at 4 cm apart and excited by 0° and 180 ° phase r-f at 200 MHz.

Fig. 2.
Fig. 2.

Single wavelength phase array, single side band (SSB) phase modulation PMS image system. The layout of the sources and detectors is in the upper left and nine combinations of equidistant sources and four detectors are in a 9 × 4 cm array. Parts of the circuit are labeled and described in the text. The imager pad is used in the remission mode on tissues, and is shown in remission geometry on the model for clarity.

Fig. 3.
Fig. 3.

Illustrating a 50 MHz phased array image test of the neurovascular coupling in human brain through blond hair, contralateral, simulation for 48 sec. The image represents the increment of phase shift caused by contralateral finger touching. Calibrations with models verify that this signal is due to an increase of hemoglobin concentration (see section 5.3).

Fig. 4.
Fig. 4.

The co-registration of a phased array image (PAI) with a concurrent fMRI image, water and CuSO4 in capillaries define the four corners of the PAI imager on the head and were imaged by MRI allowing co-registration of the shape of the images on the brain (rectangle shown over the MRI). Fitting into this rectangle is the phased array image (PAI). Thus, the larger part of the two activation areas are superimposed (~80%).

Fig. 5.
Fig. 5.

Illustrates repetitive, pre-frontal, cognitive responses to backwards spelling for 30 sec, rest, and test repeated three times for two different subjects (A and B). The 9 × 4 cm pad is centered at the nose bridge and extends roughly from 1–2 cm above the eyebrow to the hairline and from temple to temple on the two subjects.

Fig. 6.
Fig. 6.

Histogram display of the position on the forehead of response greater than 20° for backward spelling in 25 and 33 studies of two individuals, one a high school junior (left) and the other a college graduate (right). The forehead is divided into 9 squares (each 2×2 cm), centered at the nosebridge, center middle (CM) and extending ± 4.5 cm therefrom and 4 cm above the frontal sinuses. The positions are abbreviated as shown. CL = center left, etc. The colors refer to the four test intervals. over ~20 days.

Figs. 7.
Figs. 7.

NIR images of the increment of phase shift (< values) caused by sensorimotor stimulation of the brain by stroking the left (A) and right fingers (B) of a 1 Kg pre-term neonate illustrating responses as expected on the respective contralateral sides.

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