The Open Neuroimaging Journal




ISSN: 1874-4400 ― Volume 13, 2019

Long-Wave Infrared Functional Brain Imaging in Human: A Pilot Study



Christian C Joyal*, 1, Mylene Henry2
1 Université du Québec à Trois-Rivières, Canada
2 Institut Philippe-Pinel de Montréal, Canada

Abstract

Although some authors suggest to use Long-Wave Infrared (LWIR) sensors to evaluate brain functioning, the link between emissions of LWIR and mental effort is not established. The goal of this pilot study was to determine whether frontal LWIR emissions vary during execution of neuropsychological tasks known to differentially activate the pre-frontal cortex (simple color presentations, induction of the Stroop effect, and a gambling task with real money). Surprisingly, LWIR emissions as measured with bilateral frontal sensors in 47 participants significantly differed between tasks, in the supposed direction (Color<Stroop<Gambling), in spite of counterbalanced presentations. This pilot study suggests that investigations of convergent validity with other types of brain imaging techniques can be initiated with LWIR imaging. If confirmed, this technique would offer a simple and accessible method to evaluate frontal cortex activation.

Keywords: Long-wave, passive, infrared, brain imaging.


Article Information


Identifiers and Pagination:

Year: 2013
Volume: 7
First Page: 1
Last Page: 3
Publisher Id: TONIJ-7-1
DOI: 10.2174/1874440001307010001
PMID: 23400426
PMCID: PMC3565228

Article History:

Received Date: 10/11/2012
Revision Received Date: 6/12/2012
Acceptance Date: 7/12/2012
Electronic publication date: 16/1/2013
Collection year: 2013

Article Metrics:

CrossRef Citations:
0

Total Statistics:

Full-Text HTML Views: 1368
Abstract HTML Views: 891
PDF Downloads: 229
Total Views/Downloads: 2488

Unique Statistics:

Full-Text HTML Views: 593
Abstract HTML Views: 499
PDF Downloads: 131
Total Views/Downloads: 1223
Geographical View

© Joyal and Henry; Licensee Bentham Open

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.


* Address correspondence to this author at the Université du Québec à Trois-Rivières, Canada; Tel: 819-376-5011; Fax: 819-376-5195; E-mail: christian.joyal@uqtr.ca




INTRODUCTION

Infrared (IR) light is electromagnetic radiation of wavelengths invisible to the human eye (0.75 to 300 µm). Long-Wave Infrared (LWIR) emissions represent a IR specific spectrum (8 to15 µm) associated with thermal modification. The development of infrared cameras and sensors sensitive to LWIR allows Infrared Thermography (IRT), a temperature-based imaging technique used in different domains, including military (e.g. target acquisition, guiding missile technology, night human detection), industrial (e.g. thermal efficiency analyses, remote temperature sensing, localization of over-heating parts), domestic (e.g. alarm systems and movement detection), and emergency services (e.g. nonvisual and distant localization of fire bases, heat leaks, warm-blooded animal; see [1Carosena M. Infrared thermography: recent advances and future trends Bentham eBooks DOI 102174/978160805- 14341120101 2012.] for a review). IRT is also used in medicine as a diagnostic aid for vascular, tumor, or cancer-related pathologies [2Arora N, Martins D, Ruggerio D, et al. Effectiveness of a noninvasive digital infrared thermal imaging system in the detection of breast cancer Am J Surgery 2008; 196: 523-6.
[http://dx.doi.org/10.1016/j.amjsurg.2008.06.015] [PMID: 18809055]
, 3Kateba B, Yamamotod V, Yua C, Grundfest W, Gruena JP. Infrared thermal imaging: a review of the literature and case report Neuroimage 2009; 47: T154-62.
[http://dx.doi.org/10.1016/j.neuroimage.2009.03.043] [PMID: 19332140]
]. Given that brain activation is associated with small variations of local cerebral blood flow [4Villringer A, Dirnagl U. Coupling of brain activity and cerebral blood flow: basis of functional neuroimaging Cerebrovasc Brain Metab Rev 1995; 7: 240-76.
[PMID: 8519605]
] and thermal radiation [5Kiyatkin EA, Brown PL, Wise RA. Brain temperature fluctuation: a reflection of neural activation Eur J Neuroscience 2002; 16: 164-8.
[http://dx.doi.org/10.1046/j.1460-9568.2002.02066.x] [PMID: 12153543]
], it is theoretically possible to use IRT as a crude technique of brain functional imaging [6Schevelev IA. Functional imaging of the brain by infrared radiation (thermoencephaloscopy) Prog Neurobiol 1998; 56: 269-305.
[http://dx.doi.org/10.1016/S0301-0082(98)00038-0]
]. This idea is certainly not new [7Lombard JS, Ed. Experimental researches on the regional temperature of the head under conditions of rest, intellectual activity, and emotion London: H.K. Lewis 1879.], but it was abandoned because of methodological difficulties [8Zago S, Ferrucci R, Marceglia S, Priori A. The Mosso method for recording brain pulsation: the forerunner of functional neuroimaging Neuroimage 2009; 48: 652-.]. More recently, some authors proposed the use of infrared cameras to deduce human brain functioning from temperature variation of the scalp [6Schevelev IA. Functional imaging of the brain by infrared radiation (thermoencephaloscopy) Prog Neurobiol 1998; 56: 269-305.
[http://dx.doi.org/10.1016/S0301-0082(98)00038-0]
, 9Coben R, Padolsky I. Infrared imaging and neurofeedback: Initial reliability and validity J Neurother 2007; 11: 3-13.
[http://dx.doi.org/10.1080/10874200802126100]
, 10Coben R, Myers TE. Sensitivity and specificity of Long Wave Infrared Imaging for attention-deficit/hyperactivity disorder J Attention Disord 2009; 13: 56-65.
[http://dx.doi.org/10.1177/1087054708329778] [PMID: 19429882]
], and multiple-contact [11Iznak AF, Nikishova MB. Thermoencephaloscopy of brain responses to emotionally significant visual stimuli in depressive patients Hum Physiol 2007; 33: 370-2.
[http://dx.doi.org/10.1134/S0362119707030152]
] or single non-contact [12Toomim H, Carmen J. Hemoencephalography: Photon-based blood flow neurofeedback In: Budzynski TH, Budzynski HK, Evans JR, Abarbanel A, Eds. Introduction to quantitative EEG and neurofeedback: advanced theory and applica. 2nd ed.. NY: Academic Press: NY: Academic Press 2009.
[http://dx.doi.org/10.1016/B978-0-12-374534-7.00007-1]
] infrared head-mounted sensors have also been used. Still, the link between functional activation of the cortex and temperature modification of the scalp is not established. Temperature increases of the skin might be associated with other factors, including ambient temperature, peripheral activation, waking state, etc. Another issue is that functional cortical T increases might be less localised than previously believed, affecting adjacent areas as well [13Suktanskii AL, Yablonskiy DA. Theoretical model of temperature regulation in the brain changes in functional activity Proc Natl Acad Sci 2006; 103: 12144-9.
[http://dx.doi.org/10.1073/pnas.0604376103] [PMID: 16880401] [PMCID: PMC1567709]
]. Thus, before conducting concomitant or construct validity studies with the LWIR and other types of functional brain imaging, basic assumptions related with the approach should be tested. The first assumption to assess is that frontal LWIR emissions vary as a function of the cognitive load. The goal of this pilot study was to determine whether frontal LWIR emissions would significantly change during the execution of neuropsychological tests known to differentially activate the prefrontal cortex.

MATERIALS AND METHODOLOGY

Forty-seven volunteers participated in this study (36♀-11 ♂, mean age: 27.4 ± 11.0, range 21 to 63; mean number of years of education: 16.8 ± 2.4, range 14 to 27). Each participant was individually assessed in a closed, mildly lit, sound-attenuated experimental room at constant ambient temperature (200 C). Participants were seated behind a desk, in front of a 52” flat screen monitor (2 m), connected to two control computers placed in the back of the room. Two LWIR sensitive sensors embedded in a headgear (TT-pIR HEG device, Thought Technology Ltd, Montreal) were placed at a one-inch distance from the skin on each side of the forehead midline (Fp1 and Fp2 positions of the 10-20 international EEG system corresponding to left and right prefrontal regions). The signal was transformed with a ProComp Infinity encoder, processed in real time with the Biograph software, and analysed offline with the Physiology suite (Thought Technology, Ltd). A block design experiment with counterbalanced presentations of three classic neuropsychological tasks was used with Stim2 (Neuroscan Inc, Charlotte, NC). The first task was a simple presentation of colored rectangles (25 X 40 cm) placed in the center of the screen (colors: blue, red or green, presented in pseudo-random order during 2000 ms with an inter-trial interval of 1000 ms, 64 stimuli, total duration of approximately 5 minutes). Passive presentation of colors is classically associated with activation of posterior parts of the cortex, especially occipital regions (e.g. [14Beauchamp MS, Haxby JV, Jennings JE, DeYoe EA. An fMRI version of the Farnsworth-Munsell 100-Hue test reveals multiple color-selective areas in human ventral occipitotemporal cortex Cereb Cortex 1999; 9: 257-63.
[http://dx.doi.org/10.1093/cercor/9.3.257] [PMID: 10355906]
, 15Kastner S, De Weerd P, Desimone R, Ungerleider LG. Mechanisms of directed attention in the human extrastriate cortex as revealed by functional MRI Science 1998; 282()(5386 ): 108-1.
[http://dx.doi.org/10.1126/science.282.5386.108] [PMID: 9756472]
]). The second task involved the well-known Stroop effect, closely associated with fronto-medial structures (most notably the anterior cingulate and the medial frontal cortices), and the posterior parietal cortex [16Bush G, Whalen PJ, Rosen BR, Jenike MA, McInerney SC, Rauch SL. The counting stroop: an interference task specialized for neuroimaging-validation studies with functional MRI Hum Brain Mapp 1998; 6: 270-82.
[http://dx.doi.org/10.1002/(SICI)1097-0193(1998)6:4<270::AID-HBM6>3.0.CO;2-0]
-18Pujol J, Vendrell P, Deus J, et al. The effects of medial frontal and posterior parietal demyelinating lesions on Stroop interference Neuroimage 2001; 13: 68-75.
[http://dx.doi.org/10.1006/nimg.2000.0662] [PMID: 11133310]
]. In the present study, a virtual version of the Stroop task was used [19Henry M, Joyal CC, Nolin P. Development and initial assessment of a new paradigm for assessing cognitive and motor inhibition: the bimodal virtual-reality Stroop J Neurosci Methods 2012; 210: 125-31.
[http://dx.doi.org/10.1016/j.jneumeth.2012.07.025] [PMID: 22897988]
], in which color blocks (blue, red or green) or color words (blue, red or green) were visually presented while names of colors (blue, red or green) were simultaneously and verbally enunciated (72 stimuli, 36 congruent and 36 non congruent; total duration of 10 minutes). Participants had to click the left (or right) button of a mouse only when visual and audio stimuli matched. The third task was an improved version of the Balloon Analog Risk Task (www.millisecond.com), a gambling game known to recruit widespread prefrontal regions, including the ventral, medial, and dorsolateral cortices [20Fecteau S, Pascual-Leone A, Zald DH, et al. Activation of prefrontal cortex by transcranial direct current reduces appetite for risk during ambiguous decision making J Neurosci 2007; 27: 6212-8.
[http://dx.doi.org/10.1523/JNEUROSCI.0314-07.2007] [PMID: 17553993]
, 21Rao H, Korcykowski M, Pluta J, Hoang A, Detre JA. Neural correlates of voluntary and involuntary risk taking in the human brain: an fMRI study of the Balloon Analog Task (BART) Neuroimage 2008; 42: 902-10.
[http://dx.doi.org/10.1016/j.neuroimage.2008.05.046] [PMID: 18582578]
]. A balloon (blue, red or green) was presented in the center of the screen and participants had to click the left (or right) button of the mouse to put virtual air into it. Each click corresponded to a pump, which gradually inflated the balloon. The goal of the game is to maximally inflate the balloon without exploding it. The maximal number of pumps allowed before explosion varied pseudo-randomly between each trial. Each pump was associated with real money (25 cents) to enhance interest or anxiety related with the task, and an explosion was related with the loss of money gain for that trial (participants made $13.00 on average, $1.25 min and $25.50 max, total duration of approximately 10 min). Thus, the three task were chosen as a function of their various association with frontal cortex activation (lowest to highest: color bock < Stroop < Balloon). The order of presentation of the tasks was counter-balanced across participants so that half of the group received the color block condition first and the other half received the Balloon condition first. Given the exploratory nature of this preliminary experiment, there was no a priori hypothesis. However, if infrared sensors are sensitive to any frontal lobe activation, the average amplitude of frontal LWIR emissions (area under the curve) should significantly differ across conditions as a function of their known frontal lobe activation properties.

RESULTS

The dependant variable was the area under the curve recorded during the experiment. On average, it differed between each condition in the expected directions: color presentation (98.2 ± 3.1) < Stroop task (102.6 ± 26.4) < Balloon task (129.2 ± 99.3). The differences were significant F (2, 138) = 3.67, p < 0.05 with a medium effect size (η2 = 0.052; [22Cohen J. Statistical power analysis for the behavior sciences 1988.]). LSD post-hoc analyses confirmed the presence of significant differences between the Balloon and both the Color (p = 0.01) and the Stroop conditions (p = 0.03). Order of presentation had no effect upon these differences (Fig. 1). Given that variation of the variable (standard deviations) also differed across the conditions (increasing as a function of the complexity: Color<Stroop<Balloon), behavioral results were taken into consideration, and a significant positive correlation was found between reaction time at the Stroop task and the T area under the curve (2-tailed Pearson r = 0.46; p < 0.01).

Fig. (1)

Area under the curve (mean) during the three conditions after merging (dashed bar) the two subgroups of participants. (counter balanced order of presentations; n=23 in each order).



CONCLUSION

These preliminary data suggest that LWIR emitted from the forehead might vary as a function of cortical frontal activation (perhaps reflecting blood flow modification), as it was first proposed by Lombard [7Lombard JS, Ed. Experimental researches on the regional temperature of the head under conditions of rest, intellectual activity, and emotion London: H.K. Lewis 1879.]. Concomitant validity studies using other brain imaging approaches with LWIR are warranted. If LWIR emitted from the scalp are truly associated with cortical activation, the use of sensors sensitive to LWIR might not only serve as a neuromodulating technique (e.g. to treat migraine; [12Toomim H, Carmen J. Hemoencephalography: Photon-based blood flow neurofeedback In: Budzynski TH, Budzynski HK, Evans JR, Abarbanel A, Eds. Introduction to quantitative EEG and neurofeedback: advanced theory and applica. 2nd ed.. NY: Academic Press: NY: Academic Press 2009.
[http://dx.doi.org/10.1016/B978-0-12-374534-7.00007-1]
]), but also as a crude, yet simple, low-cost, easy-to-use instrument to evaluate cortical response in clinical settings. Only studies with larger groups of clinical and nonclinical participants will allow to test this possibility.

CONFLICT OF INTEREST

The authors confirm that this article content has no conflicts of interest.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

[1] Carosena M. Infrared thermography: recent advances and future trends Bentham eBooks DOI 102174/978160805- 14341120101 2012.
[2] Arora N, Martins D, Ruggerio D, et al. Effectiveness of a noninvasive digital infrared thermal imaging system in the detection of breast cancer Am J Surgery 2008; 196: 523-6.
[http://dx.doi.org/10.1016/j.amjsurg.2008.06.015] [PMID: 18809055]
[3] Kateba B, Yamamotod V, Yua C, Grundfest W, Gruena JP. Infrared thermal imaging: a review of the literature and case report Neuroimage 2009; 47: T154-62.
[http://dx.doi.org/10.1016/j.neuroimage.2009.03.043] [PMID: 19332140]
[4] Villringer A, Dirnagl U. Coupling of brain activity and cerebral blood flow: basis of functional neuroimaging Cerebrovasc Brain Metab Rev 1995; 7: 240-76.
[PMID: 8519605]
[5] Kiyatkin EA, Brown PL, Wise RA. Brain temperature fluctuation: a reflection of neural activation Eur J Neuroscience 2002; 16: 164-8.
[http://dx.doi.org/10.1046/j.1460-9568.2002.02066.x] [PMID: 12153543]
[6] Schevelev IA. Functional imaging of the brain by infrared radiation (thermoencephaloscopy) Prog Neurobiol 1998; 56: 269-305.
[http://dx.doi.org/10.1016/S0301-0082(98)00038-0]
[7] Lombard JS, Ed. Experimental researches on the regional temperature of the head under conditions of rest, intellectual activity, and emotion London: H.K. Lewis 1879.
[8] Zago S, Ferrucci R, Marceglia S, Priori A. The Mosso method for recording brain pulsation: the forerunner of functional neuroimaging Neuroimage 2009; 48: 652-.
[9] Coben R, Padolsky I. Infrared imaging and neurofeedback: Initial reliability and validity J Neurother 2007; 11: 3-13.
[http://dx.doi.org/10.1080/10874200802126100]
[10] Coben R, Myers TE. Sensitivity and specificity of Long Wave Infrared Imaging for attention-deficit/hyperactivity disorder J Attention Disord 2009; 13: 56-65.
[http://dx.doi.org/10.1177/1087054708329778] [PMID: 19429882]
[11] Iznak AF, Nikishova MB. Thermoencephaloscopy of brain responses to emotionally significant visual stimuli in depressive patients Hum Physiol 2007; 33: 370-2.
[http://dx.doi.org/10.1134/S0362119707030152]
[12] Toomim H, Carmen J. Hemoencephalography: Photon-based blood flow neurofeedback In: Budzynski TH, Budzynski HK, Evans JR, Abarbanel A, Eds. Introduction to quantitative EEG and neurofeedback: advanced theory and applica. 2nd ed.. NY: Academic Press: NY: Academic Press 2009.
[http://dx.doi.org/10.1016/B978-0-12-374534-7.00007-1]
[13] Suktanskii AL, Yablonskiy DA. Theoretical model of temperature regulation in the brain changes in functional activity Proc Natl Acad Sci 2006; 103: 12144-9.
[http://dx.doi.org/10.1073/pnas.0604376103] [PMID: 16880401] [PMCID: PMC1567709]
[14] Beauchamp MS, Haxby JV, Jennings JE, DeYoe EA. An fMRI version of the Farnsworth-Munsell 100-Hue test reveals multiple color-selective areas in human ventral occipitotemporal cortex Cereb Cortex 1999; 9: 257-63.
[http://dx.doi.org/10.1093/cercor/9.3.257] [PMID: 10355906]
[15] Kastner S, De Weerd P, Desimone R, Ungerleider LG. Mechanisms of directed attention in the human extrastriate cortex as revealed by functional MRI Science 1998; 282()(5386 ): 108-1.
[http://dx.doi.org/10.1126/science.282.5386.108] [PMID: 9756472]
[16] Bush G, Whalen PJ, Rosen BR, Jenike MA, McInerney SC, Rauch SL. The counting stroop: an interference task specialized for neuroimaging-validation studies with functional MRI Hum Brain Mapp 1998; 6: 270-82.
[http://dx.doi.org/10.1002/(SICI)1097-0193(1998)6:4<270::AID-HBM6>3.0.CO;2-0]
[17] Peterson BS, Skudlarski P, Gatenby JC, Zhang H, Anderson AW, Gore JC. An fMRI study of stroop word-color interference: evidence for cingulate subregions subserving multiple distributed attentional systems Biol Psychiatr 1999; 45: 1237-58.
[http://dx.doi.org/10.1016/S0006-3223(99)00056-6]
[18] Pujol J, Vendrell P, Deus J, et al. The effects of medial frontal and posterior parietal demyelinating lesions on Stroop interference Neuroimage 2001; 13: 68-75.
[http://dx.doi.org/10.1006/nimg.2000.0662] [PMID: 11133310]
[19] Henry M, Joyal CC, Nolin P. Development and initial assessment of a new paradigm for assessing cognitive and motor inhibition: the bimodal virtual-reality Stroop J Neurosci Methods 2012; 210: 125-31.
[http://dx.doi.org/10.1016/j.jneumeth.2012.07.025] [PMID: 22897988]
[20] Fecteau S, Pascual-Leone A, Zald DH, et al. Activation of prefrontal cortex by transcranial direct current reduces appetite for risk during ambiguous decision making J Neurosci 2007; 27: 6212-8.
[http://dx.doi.org/10.1523/JNEUROSCI.0314-07.2007] [PMID: 17553993]
[21] Rao H, Korcykowski M, Pluta J, Hoang A, Detre JA. Neural correlates of voluntary and involuntary risk taking in the human brain: an fMRI study of the Balloon Analog Task (BART) Neuroimage 2008; 42: 902-10.
[http://dx.doi.org/10.1016/j.neuroimage.2008.05.046] [PMID: 18582578]
[22] Cohen J. Statistical power analysis for the behavior sciences 1988.

Endorsements



"Open access will revolutionize 21st century knowledge work and accelerate the diffusion of ideas and evidence that support just in time learning and the evolution of thinking in a number of disciplines."


Daniel Pesut
(Indiana University School of Nursing, USA)

"It is important that students and researchers from all over the world can have easy access to relevant, high-standard and timely scientific information. This is exactly what Open Access Journals provide and this is the reason why I support this endeavor."


Jacques Descotes
(Centre Antipoison-Centre de Pharmacovigilance, France)

"Publishing research articles is the key for future scientific progress. Open Access publishing is therefore of utmost importance for wider dissemination of information, and will help serving the best interest of the scientific community."


Patrice Talaga
(UCB S.A., Belgium)

"Open access journals are a novel concept in the medical literature. They offer accessible information to a wide variety of individuals, including physicians, medical students, clinical investigators, and the general public. They are an outstanding source of medical and scientific information."


Jeffrey M. Weinberg
(St. Luke's-Roosevelt Hospital Center, USA)

"Open access journals are extremely useful for graduate students, investigators and all other interested persons to read important scientific articles and subscribe scientific journals. Indeed, the research articles span a wide range of area and of high quality. This is specially a must for researchers belonging to institutions with limited library facility and funding to subscribe scientific journals."


Debomoy K. Lahiri
(Indiana University School of Medicine, USA)

"Open access journals represent a major break-through in publishing. They provide easy access to the latest research on a wide variety of issues. Relevant and timely articles are made available in a fraction of the time taken by more conventional publishers. Articles are of uniformly high quality and written by the world's leading authorities."


Robert Looney
(Naval Postgraduate School, USA)

"Open access journals have transformed the way scientific data is published and disseminated: particularly, whilst ensuring a high quality standard and transparency in the editorial process, they have increased the access to the scientific literature by those researchers that have limited library support or that are working on small budgets."


Richard Reithinger
(Westat, USA)

"Not only do open access journals greatly improve the access to high quality information for scientists in the developing world, it also provides extra exposure for our papers."


J. Ferwerda
(University of Oxford, UK)

"Open Access 'Chemistry' Journals allow the dissemination of knowledge at your finger tips without paying for the scientific content."


Sean L. Kitson
(Almac Sciences, Northern Ireland)

"In principle, all scientific journals should have open access, as should be science itself. Open access journals are very helpful for students, researchers and the general public including people from institutions which do not have library or cannot afford to subscribe scientific journals. The articles are high standard and cover a wide area."


Hubert Wolterbeek
(Delft University of Technology, The Netherlands)

"The widest possible diffusion of information is critical for the advancement of science. In this perspective, open access journals are instrumental in fostering researches and achievements."


Alessandro Laviano
(Sapienza - University of Rome, Italy)

"Open access journals are very useful for all scientists as they can have quick information in the different fields of science."


Philippe Hernigou
(Paris University, France)

"There are many scientists who can not afford the rather expensive subscriptions to scientific journals. Open access journals offer a good alternative for free access to good quality scientific information."


Fidel Toldrá
(Instituto de Agroquimica y Tecnologia de Alimentos, Spain)

"Open access journals have become a fundamental tool for students, researchers, patients and the general public. Many people from institutions which do not have library or cannot afford to subscribe scientific journals benefit of them on a daily basis. The articles are among the best and cover most scientific areas."


M. Bendandi
(University Clinic of Navarre, Spain)

"These journals provide researchers with a platform for rapid, open access scientific communication. The articles are of high quality and broad scope."


Peter Chiba
(University of Vienna, Austria)

"Open access journals are probably one of the most important contributions to promote and diffuse science worldwide."


Jaime Sampaio
(University of Trás-os-Montes e Alto Douro, Portugal)

"Open access journals make up a new and rather revolutionary way to scientific publication. This option opens several quite interesting possibilities to disseminate openly and freely new knowledge and even to facilitate interpersonal communication among scientists."


Eduardo A. Castro
(INIFTA, Argentina)

"Open access journals are freely available online throughout the world, for you to read, download, copy, distribute, and use. The articles published in the open access journals are high quality and cover a wide range of fields."


Kenji Hashimoto
(Chiba University, Japan)

"Open Access journals offer an innovative and efficient way of publication for academics and professionals in a wide range of disciplines. The papers published are of high quality after rigorous peer review and they are Indexed in: major international databases. I read Open Access journals to keep abreast of the recent development in my field of study."


Daniel Shek
(Chinese University of Hong Kong, Hong Kong)

"It is a modern trend for publishers to establish open access journals. Researchers, faculty members, and students will be greatly benefited by the new journals of Bentham Science Publishers Ltd. in this category."


Jih Ru Hwu
(National Central University, Taiwan)


Browse Contents



Webmaster Contact: info@benthamopen.net
Copyright © 2019 Bentham Open