Our group examines the space-time dynamics in the cerebral cortex, i.e. the progression of membrane current changes, local field potential changes and spiking in the space made up of the cortical network of neurons, or in state space, with the purpose of finding principles of cortical mechanics.
Neuroscience does not have, as physics does, a standard model that serves as a conceptual structure in which gaps of knowledge and inconsistencies can be isolated and serve as impetus for experiments, technological improvements or elaborate calculations. In other words, we do not understand how mammalian brains work. Mammalian brains produce perception, thoughts and behavior over a wide spectrum ranging from a reflex to theory of relativity. So, far, explanations on how brains may produce percepts, thoughts or behavior relied on experimental results showing temporal dynamics of spiking activities and brain models explaining aspects of temporal dynamics of spiking and membrane conductances. For perspectives on which aspects a common brain theory should include see the special issue of Neuron on “How does the brain work?”, initiated by this unit.
Neuron, June 7, 2017
Neurons causally affect their target neurons by sending action potentials (spikes) through their axons thereby altering the membrane currents (MC) of their target neurons. Conversely, exposed to sufficiently strong excitatory membrane currents, a neuron emits a strong and fast membrane current, an action potential or spike. These two causal relations form the basic machinery of the brain (for an example see Movie 1 in 'Current projects'). Previous explanations of brain mechanics assumed particular neurons and particular subpopulations of neurons representing particular features or objects in the physical surround, or assumed specific relations between items or features in the surround and spiking patterns, spiking codes, spiking statistics, current or spiking synchronicity, noise, and internal models etc. in the brain. Our main hypothesis is that space-time dynamics of action potentials and membrane currents drive a mammalian brain to produce perception in less than 150 ms, and thoughts and behavior in less than 1500 ms.
Our group examines the space-time dynamics in the cerebral cortex, i.e. the progression of membrane current changes, local field potential changes and spiking in the space made up of the cortical network of neurons, or in state space, with the purpose of finding principles of cortical mechanics (for an example see Movie 2 below).
We also examine the dynamics of action potential sequences from single excitatory and single inhibitory neurons in the cerebral cortex of epilepsy patients, in the awake state, during simple task performance, during sleep, prior to epileptic auras and seizures, during seizures and in the post-ictal phase, with the purposes of understanding the mechanisms of perception, planning of movement and distinguish abnormal dynamical evolutions from normal.
Movie 1 Predictive depolarization and spiking. One animal exposed to a bar moving down from the peripheral field of view starting at 0 ms. The retina is stationary. Note that the bar then is mapped as moving excitation over the cortex. However, at 104 ms the neurons in area s 19/21 compute an excitation far ahead of the bar mapping. After feedback to areas 17/18 this repeats here. The black holes show the electrode penetration sites along the border between areas 17 and 18 corresponding to the vertical meridian. When the spiking at any layer of the cortex becomes statistically significant (p < 0.01) the hole turns white. Note the mapping of the future bar trajectory when the bar representation on the cortex has reached the left white arrow (155 ms). Note also how the object mapping, defined by the hot spot in area 17/18 actually follows the cortical route predicted already at 160 ms. Animal 410. (From Harvey et al. 2009).
Movie 2 State-space dynamics of spiking of 50 single trial trajectories in response to a bar moving down from center of field of view. Several projections of state space shown. The projections below the diagonal are redundant. The figures along the diagonal show the projections of the single trials for the first 4 principal components. The total variance accounted for by the two principal components is shown on the top of each state space projection in 2 dimensions. The trajectory of a single trial is represented by a red dot shoving the instantaneous position in state space. The dot has a tail showing where the trHent videoen i høj ajectory was up to 20 ms prior to actual time. The yellow dot is the instantaneous center of gravity. Electrode penetration in the cortex mapping the CFOV (center of field of view) (From Forsberg et al. 2016).
- Roland, P.E. (2017) Space-time dynamics of membrane currents evolve to shape excitation, spiking , and inhibition in the cortex at small and large scales. Neuron 94: 934-942.
- Roland, P.E., Bonde, L. H., Forsberg, L., Harvey, M (2017) Breaking the excitation-inhibition balance makes the cortical network’s space-time dynamics distinguish simple visual scenes. Front. Syst. Neurosci. 11:14 doi: 10.3389/fnsys. 2017.00014.
- Forsberg LE, Bonde LH, Harvey MA, Roland PE (2016) The second spiking threshold: Dynamics of laminar network spiking in the visual cortex. Front. Syst. Neurosci. Doi: 10.3389/fnsys.2016.00065.
- Huys, R., Jirsa, V.K., Darokhan, Z., Valentiniene, S., Roland, P.E. (2015). Visually evoked spiking evolves while spontaneous ongoing dynamics persist. Front. Syst. Neurosci. Doi: 10.3389/fnsys 2015 00183.
- Harvey, M.A., Valentiniene, S. ,and Roland, P.E. (2009). Cortical membrane potential dynamics and laminar firing during object motion. Front. Syst. Neurosci. 3:7. doi:10.3389/neuro.06.007.2009
Full name: Per Ebbe Roland
Birth day: November 21, 1943
Birth place: Copenhagen, Denmark
Title and position: Professor of Neurodynamics, M.D., PhD.,
PhD Thesis: An anatomical and physiological study of somatosensory detection of microgeometry, macrogeometry and kinaesthesia in man. 1987, University of Copenhagen.
Studied 2 years at McGill, Montreal Neurological Institute, Montreal, 1979-1980.
MD, University of Copenhagen, 1970
Certified Specialist in Neurology, Denmark 1983. Sweden 1988.
2013- Professor of Neurodynamics, Dept. Neuroscience, University of Copenhagen.
2011-2013 Professor of Neuroscience, Dept. Neuroscience and Pharmacology, University of Copenhagen, Denmark.
1988- 2010 Professor of Brain Research at the Karolinska Institute.
1984-1987 Visiting professor at the Karolinska Institute.
1979-1980 Research Fellow, Montreal Neurological Institute.
1972-1976 Scientific assistant. University Hospital Copenhagen (Rigshospitalet Dept. Neurology & Neurosurgery)
1968-1970 Scientific scholarship in Neuroscience, University of Copenhagen.
Senior lecturer at University of Copenhagen, Department of Neurology, 1982.
Voltage dye imaging in vivo
Local field potential measurements in vivo in humans
Action potential measurements in vivo min humans
140. Roland, P.E. (2017) Space-time dynamics of membrane currents evolve to shape excitation, spiking , and inhibition in the cortex at small and large scales. Neuron 94: 934-942.
139. Roland, P.E., Bonde, L. H., Forsberg, L., Harvey, M (2017) Breaking the excitation-inhibition balance makes the cortical network’s space-time dynamics distinguish simple visual scenes. Front. Syst. Neurosci. 11:14 doi: 10.3389/fnsys. 2017.00014.
138. Forsberg LE, Bonde LH, Harvey MA, Roland PE (2016) The second spiking threshold: Dynamics of laminar network spiking in the visual cortex. Front. Syst. Neurosci. Doi: 10.3389/fnsys.2016.00065.
137. .Huys R, Jirsa VK, Darokhan Z, Valentiniene S, Roland PE (2015) Visually evoked spiking evolves while spontaneous ongoing dynamics persist. Front. Syst. Neurosci. Doi: 10.3389/fnsys 2015 00183.
136. Roland PE , Hilgetag CC, Deco G (2014) Tracing evolution of spatio-temporal dynamics of the cerebral cortex. Front. Syst. Neurosci. Doi:10.3389/fnsys 2014 00076.
135. Harvey MA and Roland PE (2013) Laminar firing and membrane dynamics in four visual areas exposed to two objects moving to occlusion. Front. Syst. Neurosci. 7:23. doi: 10.3389/fnsys. 2013.00023.
134. Roland PE , Hilgetag CC, Deco G (2013) Cortico-cortical communication dynamics Front. Syst. Neurosci. Doi:10.3389/fnsys 2014 00019.
133. Roland PE (2010) Six principles of visual cortical dynamics. Front. Syst. Neurosci. 4:28. doi:10.3389/fnsys.2010.00028
132. Schmidt N, Peyré, Frégnac Y, Roland P (2010) Separation of of travelling waves in cortical networks using optical imaging. ISBI. DOI 10:1109/ISBI.2010.5490124
131. Deco G and Roland P (2010) The role of multi-area interactions for the computation of apparent motion. NeuroImage 51: 1018-1026. doi:10.1016/j.neuroimage.2010.03.032
130. 130.Harvey MA, Valentiniene S and Roland PE (2009) Cortical membrane potential dynamics and laminar firing during object motion. Front. Syst. Neurosci. 3:7. doi:10.3389/neuro.06.007.2009
129. Eriksson, D., Tompa, T., Roland, P.E. 2008. Non-Linear Population Firing Rates and Voltage Sensitive Dye Signals in Visual Areas 17 and 18 to Short Duration Stimuli. PLoS ONE 3(7): e2673. Doi: 10.1371/journal.pone.0002673
128. Ahmed, B., Hanazawa, A., Undeman, C., Eriksson, D., Valentiniene., S., Roland, P E. 2008. Cortical dynamics subserving visual apparent motion. Cerebral Cortex 18:2796-2810.
127. Naito E., Scheperjans F., Eickhoff S.B., Amunts K., Roland P.E., Zilles K., Ehrsson H.H. Human superior parietal lobule is involved in somatic perception of bimanual interaction with an external object. J Neurophysiol 99: 695-703, 2008.
126. Eriksson, D., Roland, P.E. Feed-forward, feedback and lateral interactions in membrane potentials and spike trains from the visual cortex in vivo. J Physiol Paris 100: 100-109, 2006.
125. Roland, P.E., Hanazawa, A., Undeman, C., Eriksson, D., Tompa, T., Nakamura, H., Valentiniene, S., Ahmed, B. Cortical feedback depolarization waves: a mechanism of top-down influence on early visual areas. Proc Natl Acad Sci USA. 103: 12586-12591, 2006.
124. Naito E., Roland P.E., Grefkes C., Choi H.J., Eickhoff S., Geyer S., Zilles K., Ehrsson H.H. Dominance of the right hemisphere and role of area 2 in human kinesthesia. Journal of Neurophysiology. 93: 1020-1034, 2005.
123. Young J., Herath P., Grefkes C., Eickhoff S., Choi, Zilles, Roland P. Somatotopy and attentional modulation of parietal and opercular regions. Journal of Neuroscience 24: 5391-5399, 2004
122. Keri, S., Decety, J., Roland, P.E., Gulyas, B. Feature uncertainty activates anterior cingulate cortex. Hum Brain Mapp. 21, 26-33, 2004.
121. Bodegard A. , Geyer, S. , Herath, P., Grefkes, C., Zilles, K. and Roland, P.E. Somatosensory areas engaged during discrimination of steady pressure, spring strength, and kinaesthesia. Human Brain Mapping 20: 103-115 (2003)
120. Young J.P., Amunts K., Grefkes C., Morosan P., Geyer S., Zilles K., Roland P.E. Regional cerebral blood flow correlations of somatosensory Areas 3a, 3b, 1 and 2 in humans during rest: A PET and cytoarchitectural study. Human Brain Mapping. 19: 183-196, 2003.
119. Naito E., Roland P.E., Ehrsson H. I feel my hand moving: A new role of the primary motor cortex in somatic perception of limb movement. Neuron. 36:979-988, 2002.
118. Crivello F., Schormann T., Tzourio-Mazoyer N., Roland P.E., Zilles K., Mazoyer B. M. Comparison of spatial normalization procedures and their impact on functional maps. Human Brain Mapping.16:228-250, 2002.
117. Herath P., Young J., Roland P.E. Two mechanisms of protracted reaction times mediated by dissociable cortical networks. European Journal of Neuroscience. 16:529-539, 2002.
116. Roland P.E. Dynamic depolarisation fields in the Cerebral Cortex. Trends Neuroscience., 25:183-190, 2002.
115. Larsson J. Amunts K, Gulyás B, Malikovic A, Zilles K, Roland P.E. Perceptual segregation of overlapping shapes activates posterior extrastriate visual cortex in man. Experimental Brain Research. 143:1-10, 2002.
114. Roland P, Svensson G, Lindeberg T, Risch T, Baumann P, Dehmel A. A database generator for human brain imaging. Trends Neurosci. 24:562-564, 2001.
113. Herath P, Klingberg T, Young J, Amunts K, Roland P. Neural correlates of dual task interference can be dissociated from those of divided attention: an fMRI study. Cereb Cortex. 11:796-805, 2001.
112. Savic I, Berglund H, Gulyas B, Roland P. Smelling of odorous sex hormone-like compounds causes sex-differentiated hypothalamic activations in humans. Neuron. 31:661-8, 2001.
111. Bodegard A, Geyer S, Grefkes C, Zilles K, Roland PE. Hierarchical processing of tactile shape in the human brain. Neuron. 31:317-28, 2001.
110. Rosbacke, Lindeberg T, Björkman E, Roland PE. Evaluation of using absolute versus relative base level when analyzing brain activation images using the scale-space primal sketch. Med Image Anal. 5:89- 110, 2001.
109. Cohen J, Dale A, Evans A, Mazziota J, Roland P. Neuroimaging databases. Science. 292:1-4, 2001.
108. Herath O, Kinomura S, Roland PE. Visual recognition: evidence for two distinctive mechanisms from a PET study. Hum Brain Mapp. 12:110-9, 2001.
107. Grefkes C, Geyer S, Schormann T, Roland P, Zilles K.Human somatosensory area 2: observer-independent cytoarchitectonic mapping, interindividual variability, and population map. Neuroimage. 14:617-31, 2001.
106. Geyer, S., Schleicher A., Schormann T., Mohlberg. Bodegård A., Roland P.E., Zilles K. Integration of microstructural and functional aspects of human somatosensory areas 3A, 3b and 1 on the basis of a computerized brain atlas. Anat Embryol. 204: 351-366, 2001.
105. Nilsson L-G, Nyberg L, Klingberg T Åberg C, Persson J and Roland P.E. Activity in motor areas while remembering action events. NeuroReport. 11:519-533, 2000.
104. Geyer S, Schleicher A, Schormann T, Mohlberg H, Bodegard A, Roland PE. Integration of microstructural and functional aspects of human somatosensory areas 3a, 3b, and 1 on the basis of a computerized brain atlas. Anat Embryol (Berl).2:351-66, 2001.
103. Grefkes C, Geyer S, Schormann T, Roland PE, Zilles K. Human somatosensory area 2: observer-independent cytoarchitectonic mapping, interindividual variability, and population map. Neuroimage. 14:617-31, 2001.
102. Vidnyanszky Z, Gulyas B, Roland PE. Visual exploration of form and position with identical stimuli: functional anatomy with PET. Human Brain Mapp. 11:104-16, 2000.
101. Ehrsson HH, Naito E, Geyer S, Amunts K, Zilles K, Forsberg H, Roland PE. Simultaneous movements of upper and lower limbs are coordinated by motor representations that are shared by both limbs: a PET study. Eur J Neurosci. 12:3385-98, 2000.
100. Savic I, Gulyas B, Larsson M, Roland PE. Olfactory functions are mediated by parallel and hierarchical processing. Neuron. 26:735-45, 2000.
99. Naito E, Kinomura s, Geyer S, Kawashima r, Roland PE and Zilles K: Fast reaction to different sensory modalities activates common fields in the motor areas, but the anterior cingulate cortex is involved in the speed of reaction. J. Neurophysiol., 83:1701-1709, 2000.
98. Bodegard A, Geyer S, Naito E, Zilles K, Roland PE. Somatosensory areas in man activated by moving stimuli: Cytoarchitectonic mapping and PET. Neuroreport. 11:187-91, 2000.
97. Bodegard A, Ledberg, A, Geyer S. Naito E, Zilles K, Roland PE: Object shape differences reflected by somatosensory cortical activation. J Neurosci. 20:RC51. 2000.
96. Naito E, Ehrsson HH, Geyer S, Zilles K, Roland P.E. Illusory arm movements activate cortical motor areas: A positron emission tomography study. J Neurosci. 19: 6134-6144 1999.
95. Larsson J, Amunts K, Gulyas B, Malikovic A, Zilles K, Roland PE. Neuronal correlates of real and illusory contour perception: functional anatomy with PET. Europ J Neurosci. 11: 4024-4036, 1999.
94. Lindeberg, T., Lidberg, P., and Roland, P.E.: Analysis of brain activation patterns using a 3-D scale-space primal sketch. Human Brain Mapping 7: 166-194, 1999.
93. Roland, P.E., and Zilles, K: Structural divisions and functional fields in the human cerebral cortex. Brain Research Reviews 26: 87-105, 1998.
92. Roland, P.E., O'Sullivan B., and Kawashima R.: Shape and roughness activate different somatosensory areas in the human brain. Proc. Natl. Acad. Sci. US. 95: 3295-3300, 1998.
91. Ledberg, A., Åkerman, S., and Roland, P.E.: Estimation of the probabilities of 3D clusters in functional brain images. NeuroImage. 8:113-128, 1998.
90. Gulyás, B., Cowey, A., Heywood, CA., Popplewell D., and Roland P.E. : Visual form discrimination from texture cues: A PET study. Human Brain Mapping. 6: 115-127, 1998.
89. Hadjikhani, N., and Roland, P.E.: Cross-modal transfer of information between the tactile and the visual representations in the human brain: A positron emission tomographic study. J. Neurosci., 18: 1072-1084, 1998.
88. Klingberg, T., Roland, P.E.: Right prefrontal activation during encoding but not during retrieval, in a non-verbal paired-associates task. Cerebral Cortex. 8: 73-79, 1998.
87. Zilles, K., Schleicher, A., Langemann, C., Amunts, K., Morosan P., Palomero-Gallagher, N., Schormann, T., Mohlberg, H., Bürgel, U., Steinmetz, H., Schlaug, G., Roland, PE: Quantitative analysis of sulci in the human cerebral cortex: Development, regional heterogeneity, gender difference, asymmetry, intersubject variability and cortical architecture. Human Brain Mapping. 5:218-221, 1997.
86. Roland, PE, Geyer S., Amunts, K., Schormann, T., Schleicher, A., Malikovic, A., and Zilles, K: Cytoarchitectural maps of the human brain in standard anatomical space. Human Brain Mapping 5:222-227, 1997.
85. Klingberg, T., Roland, P.E.: Interference between two concurrent tasks is associated with activation of overlapping fields in the cortex. Cogn. Brain Res. 6: 1-8, 1997.
84. Klingberg, T., O'Sullivan, B., and Roland, P.E.: Bilateral activation of frontoparietal networks by incrementing demand in a working memory task. Cereb. Cortex 7:465-471, 1997.
83. Geyer, S., Schleicher, A., Schormann, T., Roland, P.E. and Zilles, K Observer-independent cytoarchitectonic mapping and functional organisation of the human primary motor cortex. Annals Anat. 178:27-28, 1996.
82. Roland, P.E., and Zilles, K: Functions and structures of the motor cortices in humans. Curr Opin Neurobiol. 6: 773-781, 1996.
81. Roland PE., and Zilles K.: The developing European computerized human brain database for all imaging modalities. NeuroImage, 4:39-S47, 1996.
80. Amunts K., Schlaug G., Schleicher A., Stinmetz H., Dabringhaus A., Roland PE., and Zilles K.: Asymmetry in the human motor cortex and handedness. NeuroImage, 4: 216-222, 1996.
79. Klingberg, T., Kawashima R., and Roland PE : Activation of multi-modal cortical areas underlies short-term memory. Eur. J. Neurosci. 8: 1965-1971,1996.
78. Roland, P.E., and Gulyás, B.: Assumptions and validations of statistical tests for functional neuroimaging. Eur. J. Neurosci. 8:2232-2235,1996.
77. Larsson, J., Gulyás, B., and Roland, PE: Cortical representation of self-paced finger movement. NeuroReport , 7:463-468, 1996.
76. Geyer, S., Ledberg, A., Schleicher, A, Kinomura, S., Schormann, T., Larsson, J., Simon, U., Zilles, K., and Roland, PE: Two different areas within the primary motor cortex of man. Nature, 282: 805-807, 1996.
75. Kinomura, S., Larsson J., Gulyás B., and Roland PE: Attention activates the midbrain reticular formation and thalamic intralaminar nuclei in man. Science. 271: 512-515, 1996.
74. Zilles K, Schlaug G, Matelli M, Luppino G, Schleicher A, Qü M, Dabringhaus A, Seitz RJ, Roland PE: Mapping of human and macaque sensorimotor areas by integrating architectonic, transmitter receptor, MRI and PET data. J . Anat. 187: 515-537, 1995.
73. Roland, PE., and Gulyas, B: Visual memory, visual imagery and visual recognition of large field patterns by the human brain. Functional anatomy, by positron emission tomography. Cerebr. Cortex, 5:79-93, 1995.
72. Ledberg, A., O'Sullivan, BT., Kinomura, S., Roland, PE: Somato-sensory activations of the parietal operculum of man. A PET study. Eur. J. Neurosci. 7:1934-1941, 1995.
71. Kawashima, R., O'Sullivan, BT., and Roland, PE: Positron-emission tomography studies of cross modality inhibition in selective attentional tasks: Closing the "Mind's Eye". Proc. Natl. Acad. Sci. US 92:5969-5972, 1995b.
70. Kawashima, R., O'Sullivan, BT., and Roland, PE: Functional anatomy of reaching and visuomotor learning: A positron emission tomography study. Cerebr. Cortex. 5: 111-122, 1995a.
69. Gulyás, B., and Roland, PE: Cortical fields participating in spatial frequency and orientation discrimination: Functional anatomy by positron emission tomography. Human Brain Mapping. 3: 133-152, 1995.
68. Klingberg, T., Roland, PE., and Kawashima, R: The human entorhinal cortex participates in associative memory. NeuroReport, 6: 57-60, 1994.
67. Gulyás, B., Roland, PE., Heywood, CA., Popplewell, DB., Cowey, A: Visual form discrimination from luminance or disparity cues: Functional anatomy by PET. NeuroReport 5:2367-2371, 1994.
66. Gulyás, B., and Roland, PE: Processing and analysis of form, colour and binocular disparity in the human brain: functional anatomy by positron emission tomography. Eur. J. Neurosci. 6:1811-1828, 1994.
65. Roland, PE., and Zilles, K: Brain Atlases-A new research tool. Trends Neurosci., 17: 458-467, 1994.
64. Roland, PE., Graufelds, CJ., Wåhlin, J., Ingelman, L., Andersson, M., Ledberg, A., Pedersen, J., Åkerman, S., Dabringhaus, A., and Zilles, K: Human Brain Atlas: For high resolution functional and anatomical mapping. Human Brain Mapping 1:173-184,1994b.
63. Gulyás, B., Heywood, CA., Popplewell, DB., Cowey, A., and Roland, PE: Visual form discrimination from colour or motion cues: Functional anatomy by positrion emission tomography. Proc. Natl. Acad. Sci. US. 91:9965-9969, 1994.
62. Kawashima R, Roland PE, O'Sullivan BT: Activity in the human primary motor cortex related to ipsilateral hand movements. Brain Res., 663:251-256, 1994b.
61. Kawashima, R., O'Sullivan, BT., and Roland, PE: Fields in human motor areas involved in preparation for reaching, actual reaching and visuomotor learning: A positron emission tomography study. J. Neurosci. 14:3462-3474, 1994a.
60. Roland, PE., and Gulyás, B: Visual imagery and visual representation; Visual representations of scenes and objects: retinotopical or non-retinotopical TINS 17: 281-297, 1994.
59. O'Sullivan, BT., Roland, PE., and Kawashima, R: A PET study of somatosensory discrimination in man. Microgeometry versus macrogeometry. Eur. J. Neurosci.. 6: 137-148, 1994.
58. Gulyás, B., and Roland, PE: Binocular disparity detection in human visual cortex: Functional anatomy by positron emission tomography. Proc. Natl. Acad. Sci. US, 91: 1239-1243,1994.
57. Roland, PE: Obstacles on the way to a neuroscientific theory of mind. J. Theor. Biol. Med. 171:19-28, 1994.
56. Roland PE, Levin, B., Kawashima, B., and Åkerman, S: Three-dimensional analysis of clustered voxels in 15O-butanol brain activation images. Human Brain Mapping, 1:3-19, 1993.
55. Decety, J., Kawashima, R., Gulyás, B and Roland, PE: Preparation for reaching: A PET study of the participating structures in the human brain. NeuroReport 3:761-764, 1992.
54. Roland, PE: Reply to Pain and activation in the thalamus by G.H. Duncan et al. Trends Neurosci., 15:252-253, 1992.
53. Seitz R. J, and Roland P. E: Vibratory stimulation increases and decreases the regional cerebral blood flow and oxidative metabolism: a positron emission tomography study. Acta Neurol. Scand., 86:60-67, 1992c.
52. Seitz R. J, and Roland P. E: Variability of the regional cerebral blood flow pattern studied with [11C]-fluoromethane and positron emission tomography (PET). Comp. Med. Imaging Graphics 16:311-322, 1992b.
51. Seitz R. J, and Roland P. E: Learning of sequential finger movements in man: A combined kinematic and positron emission tomography (PET) study. Eur. J. Neurosci., 4: 154-165, 1992a.
50. Roland, PE: Cortical representation of pain. Trends Neurosci., 15, 3-5, 1992.
49. Stone-Elander, S., Roland,PE., Schwenner, E., Halldin, C., and Widen, L: Synthesis of [isopropyl- 11C]Nimodipine for in vivo studies of dihydropyridine binding in man using positron emission topography. Appl. Radiat. Isot. 42: 871-875, 1991.
48. Gulyás, B, Roland, PE, Decety, J: Cortical areas involved in the analysis of different visual submodalities. A PET study, IBRO Abstr., pp. 400, 1991.
47. Seitz R J., Roland P. E., Bohm C., Greitz T. and Stone-Elander S: Somatosensory discrimination of shape: tactile exploration and cerebral activation. Eur. J. Neurosci. 3:481-492, 1991.
46. Savic, I., Widén, L., Thorell, JO., Blomquist, G., Eriksson, L., Roland, PE: Cortical benzodiazepine binding in patients with generalized and partial epilepsy. Epilepsia, 31:724-730, 1990.
45. Seitz, RJ., Roland, PE, Bohm, C., Greitz, T., and Stone-Elander, S: Motor learning in man: a positron emission tomographic study. NeuroReport 1:17-20, 1990.
44. Roland, PE., Gulyás, B., Seitz, RJ., Bohm, C., and Stone-Elander, S: Functional anatomy of storage, recall, and recognition of a visual pattern in man. NeuroReport 1: 53-56, 1990.
43. Seitz, RJ., Bohm, C., Greitz, T., Roland, PE., Eriksson, L., Blomqvist, G., Rosenqvist, G., and Nordell, B: Accuracy and precision of the computerized brain atlas programme for localization and quantification in positron emission tomography. J. Cerebr. Blood Flow Metab. 10:443-457, 1990.
42. Stone-Elander, S., Roland, PE, Halldin, C, Hassan, M, and Seitz, RJ: Synthesis of [11C]sodium thiocyanate for in vivo studies of anion kinetics using positron emission tomography (PET). Nucl. Med. Biol. 16:741-746, 1989.
41. Stone-Elander, S., Roland, PE, Halldin, C, Boeshagen, H, and Widén, L: Synthesis of 11C-sodium thiocyanate and isopropyl-11-C- nimodipine for the in vivo study of ion channels using. PET. J. Lab. Comp. Radiopharm. 26:238-239, 1989.
40. Roland, PE, Eriksson, L., Widén, L., and Stone-Elander, S: Changes in regional cerebral oxidative metabolism induced by tactile learning and recognition in man. Eur. J. Neurosci. 1:3-18, 1989.
39. Savic, I., Roland, PE, Sedvall, G., Persson, A., Pauli, S and Widén, L: In-vivo demonstration of reduced benzodiazepine receptor binding in human epileptic foci. Lancet II, 8616:863-866, 1988.
38. Roland, PE and Friberg, L: The effect of the GABA-A Agonist THIP on Regional Cortical Blood Flow in humans. A new test of hemispheric dominance. J. Cerebr. Blood Flow Metab. 8:314-323, 1988.
37. Holden, JE., Eriksson, L., Roland, PE., Stone-Elander, S., Widén, L., and Kesselberg, M: Direct comparison of single-scan approaches with multiple-scan least-squares fitting approaches to PET CMRO2 estimation. J. Cerebr. Blood Flow Metab. 8:671-680, 1988.
36. Roland, PE: Changes in brain blood flow and oxidative metabolism accompanying mental activity. News in Physiol. Sci. 2:120-124, 1987.
35. Roland, PE, Eriksson, L., Stone-Elander, S and Widén, L: Does mental activity change the oxidative metabolism of the brain? J. Neurosci. 7:2373-2389, 1987.
34. Friberg, L., Olsen, TS., Roland, PE, and Lassen, NA: Cerebro-vascular tone instability causing focal ischemia during attacks of hemiplegic migraine. Brain 110: 917-934, 1987.
33. Roland, PE: Somatosensory detection in patients with circumscribed lesions of the brain. Exp. Brain Res. 66:303-317, 1987b.
32. Roland, PE: Somatosensory detection of microgeometry, macrogeometry and kinesthesia after localized lesions to the cerebral hemispheres in man. Brain Res. Rev. 12:43-94, 1987a.
31. Roland, PE: An anatomical and physiological study of somato-sensory detection of microgeometry, macrogeometry and kinesthesia in man. Brain Res. Rev. 12:1-94, 1987.
30. Roland, PE and Mortensen, E: Somatosensory detection of microgeometry, macrogeometry and kinesthesia in man. Brain Res. Rev. 12:1-42, 1987.
29. Stone-Elander, S., Roland P.E., Eriksson, L., Litton, JE, Johnström, J and Widén, L: The preparation of 11C-labelled fluoromethane for the study of regional cerebral blood flow using positron emission tomography. Eur. J. Nucl. Med. 12: 236-239, 1986.
28. Roland P.E.: Cortical organization of voluntary behavior in man. Human Neurobiol., 4:155-167, 1985.
27. Friberg, L., Olsen, TS., Roland P.E., Paulson, OB and Lassen, NA: Focal blood flow increase in the cerebral cortex of man during vestibular stimulation. Brain, 108: 609-623, 1985.
26. Roland P.E. and Friberg, L: Localization of cortical areas activated by thinking. J. Neurophysiol., 53:1219-1243, 1985.
25. Roland P.E: Somatosensory detection in man. Exp. Brain Res. Suppl. 10:93-110, 1985.
24. Roland P.E: Metabolic measurements of the working frontal cortex in man. Trends Neurosci., 7:430-435, 1984.
23. Roland P.E: Organization of motor control by the normal human brain. Human Neurobiol., 3:1-12, 1984.
22. Roland P.E., Meyer, E., Shibasaki, T., Yamamoto, YL, and Thompson, CJ: Regional cerebral blood flow changes in cerebral cortex and basal ganglia during voluntary movements in normal human volunteers. Three dimensional functional mapping with 77Kr-PET. J. Neurophysiol., 48:467-480, 1982.
21. Roland P.E: Cortical regulation of selective attention in man. A regional cerebral blood flow study. J. Neurophysiol., 48:1059-1078, 1982.
20. Roland P.E. and Skinhoj. E: Focal activation of the cerebral cortex during visual discrimination in man. Brain Res., 222, 166-171, 1981.
19. Roland P.E: Somatotopical tuning on the postcentral gyrus during focal attention in man. A regional cerebral blood flow study. J. Neurophysiol., 46:744-754, 1981.
18. Roland P.E., Skinhoj, E and Lassen, N.A: Focal activations of the human cerebral cortex during auditory discrimination. J. Neurophysiol., 45:1139-1151, 1981.
17. Roland P.E. and Nielsen, VK: Vibratory thresholds in the hands. Comparison of patients with suprathalmic lesions with normal subjects. Arch. Neurol., 37:775-779, 1980.
16. Roland P.E: Quantitative assessment of cortical motor dysfunctions by measurements of the regional cerebral blood flow. Scand. J. Rehab. Med. Suppl. 7: 27-41, 1980.
15. Roland P.E: The posterior parietal association cortex in man. Behav. Brain Sci. 3: 513-514, 1980.
14. Roland P.E., Skinhöj, E, Lassen, NA, and Larsen, B: Different cortical areas in man in the organization of voluntary movements in extrapersonal space. J. Neurophysiol., 43:137-150, 1980.
13. Roland P.E., Larsen, B., Lassen, NA and Skinhöj, E: Supplementary motor area and other cortical areas in the organization of voluntary movements in man. J. Neurophysiol.,43:118-136, 1980.
12. Roland P.E: Degrees of freedom between somatosensory and somatomotor processes. Behav. Brain Sci., 2:307-311, 1979.
11. Orgogozo, J. M., Larsen, B., Roland P.E. and Lassen, NA: Activations de l'aire motrice supplementaire au cours des mouvements volontaires chez l'homme. Rev. Neurol. (Paris), 135:705-717, 1979.
10. Roland P.E: Voluntary movement and perception in intra-personal and extrapersonal space. Behav. Brain Sci., 1:79-80, 1979.
9. Roland P.E: The cerebral cortex and conscious kinaesthetic and tensional information. Behav. Brain Sci., 1:163-171, 1978.
8. Roland P.E: Sensory feed-back of to the cerebral cortex during voluntary movement in man. Behavi. Brain Sci., 1:129-163, 1978.
7. Roland P.E., and Pedersen, H-L: Sensations of tension and kinaesthesia from musculotendinous receptors in man. Evidence for a muscular sense and sense of effort. Brain.100:671-692, 1977.
6. Roland P. E. and Larsen B: Focal increase of cerebral blood flow during stereognostic testing in man. Arch. Neurol., 33:551-558. 1976.
5. Roland, PE.: Astereognosis: Tactile discrimination after localized hemispheric lesions in man. Arch Neurol. 33:543-550,1976.
4. Roland P. E: Do muscular receptors in man evoke sensations of tension and kinaesthesia Brain Res., 99.162-165, 1975.
3. Roland P. E: Some principles and new methods of tactile stimulation. Behav. Res. Meth. Instr., 17:333-338, 1975.
2. Roland P. E: Lack of appreciation of consistence, akinaesthesia and adynamaesthesia. J.Neurol. Sci., 20:51-61, 1973.
1. Roland P. E: Tactile manual agnosia. Dan. Med. Bull., 19:1-44, 1972.
Developing a theory on how brains work
Developing a theory on how brains woroscience does not have, as physics does, a standard model that serves as a conceptual structure in which gaps of knowledge and inconsistencies can be isolated and serve as impetus for experiments, technological improvements or elaborate calculations. The purpose of this project is to produce embryos of brain theories that could develop into a “standard model of the functions of the mammalian brain”. As our current experimental knowledge of mechanisms of brain dynamics is sparse, the project will try to identify the gaps and bridge them by plausible hypotheses. The idea is that this exercise identifies crucial questions for brain science and produce hypotheses, of which some might be testable experimentally.
Supported by the Lundbeck Foundation.