Mapping of Indian neuroscience research: A scientometric analysis of research output during 1999-2008
Objective : This study analyses the research output in India in neurosciences during the period 1999-2008 and the analyses included research growth, rank, global publications' share, citation impact, share of international collaborative papers and major collaborative partner countries and patterns of research communication in most productive journals. It also analyses the characteristics of most productive institutions, authors and high-cited papers. The publication output and impact of India is also compared with China, Brazil and South Korea. Materials and Method s: Scopus Citation database was used for retrieving the publications' output of India and other countries in neurosciences during 1999-2008. Results : India's global publications' share in neurosciences during the study period was 0.99% (with 4503 papers) and it ranked 21 st among the top 26 countries in neurosciences. The average annual publication growth rate was 11.37%, shared 17.34% of international collaborative papers and the average citation per paper was 4.21. India was far behind China, Brazil and South Korea in terms of publication output, citation quality and share of international collaborative papers in neurosciences. Conclusion : India is far behind in terms of publication output, citation quality and share of international collaborative papers in neurosciences when compared to other countries with an emerging economy. There is an urgent need to substantially increase the research activities in the field of neurosciences in India.
Keywords: India, neuroscience, quantitative analysis, research output
Neuroscience is one of the most interdisciplinary and rapidly expanding fields devoted to the scientific study of the nervous system. The literature related to research in neurosciences is explosive. A few quantitative studies analyzing the neurosciences literature of a select few countries have been carried out in the past. Braun et al.,  analyzed the characteristics of publication activity and co-authorship pattern in world neurosciences literature. Evaluation of country research output in neurosciences has been carried out in Europe, , Spain, , Italy,  Sweden  China  and Cuba  by different scholars from time to time.
In the last one decade, the growth of neurosciences in India in terms of trained professionals, research scientists, specialized departments with state-of-the-art infrastructure, and institutes with research facilities has been impressive. A number of educational institutions and universities have been teaching and carrying out research in neurosciences, at undergraduate, graduate and postgraduate levels for a number of years. These institutions conduct various courses like DM in neurology, MCh in neurosurgery, Diploma in Neurological and Neurosurgical Nursing, Diploma in Clinical Neurophysiology Techniques, M.Sc. (Neuroscience), M. Phil (Neuroscience), M.D. in Neuroscience, PhD in Neuroscience, Post Doctoral Certificate Course in Neurosciences, etc. Several institutions are imparting neuroscience education in India. The national institutes include: National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, All India Institute of Medical Sciences (AIIMS), New Delhi, Post Graduate Institute of Medical Education and Research, Chandigarh. National Brain Research Center, a neurosciences institute with state-of-the-art facilities for basic science research in neurosciences was established in 2003. Professional bodies concerned with neurosciences include: Neurological Society of India (NSI) the apex body of neurologists, neurosurgeons, and allied specialties established in 1951, Indian Academy of Neurology (IAN) the apex body of neurologists established in 1991 and Indian Academy of Neurosciences established in 1982.
The main objective of this study is to analyze the research performance of India in neurosciences in the national and global context, as reflected in the publications' output during 1999-2008. In particular, the study focused on: (i) Indian research output, its growth, rank and global publications' share and impact; (ii) The patterns of international collaboration and major collaborative partners; (iii) The publications' productivity and impact of leading institutions of India; (iv) The characteristics of the most prolific authors and high cited-papers; and (v) The patterns of research communication in the most productive journals.
This study is based on the Indian publication data in neurosciences retrieved from the Scopus Citation database for 10 years (1999-2008). A three-year citations window has been used for counting the citations received and to access the impact of Indian research output, leading Indian institutions and authors. H-index derived from the database has been used to evaluate the research performance of top productive Indian institutions and prolific authors. H-Index is a more rational method suggested by J.E. Hirsch, to measure the scientific productivity and citation impact of an individual author or institution compared to simpler measures such as total number of citations or total number of publications.  It is based on the highest number of papers included that have had at least the same number of citations e.g. a scholar having h-index means has published h number of papers each of which has been cited by others at least h times.
Global publication share and rank
The global publication shares of the top 26 most productive countries in neurosciences during 1999-2008 varied between 0.84% and 36.13%. United States of America topped the list, with global publication share of 36.13% during 1999-2008. United Kingdom ranked second, followed by Germany, Japan, Canada, France and Italy (their global publications share ranging from 5-11%). Netherlands, Australia, Spain, Sweden and China ranked at 8 th to 12 th positions (their global publications' share ranging from 2-3%). The countries that rank between 13 th and 20 th positions included Switzerland, Columbia, Brazil, Israel, Belgium, South Korea, Finland and Turkey with their global publications' share ranging from 1-2%). The next six countries (India, Austria, Denmark, Poland, Russia and Taiwan) ranked from 21 st to 26 th positions, with their global publications share less than 1% [Table 1].
Among developed countries, the countries that have shown decline in their publications' share from the year 1999 to the year 2008 were United States, United Kingdom, Germany, Japan, France, Sweden, Finland and Russia. In contrast, the developed countries that have shown a rise in their publications' share during the same period were Canada, Netherlands, Australia, Spain, Switzerland, Belgium, Finland, Turkey, Austria, Denmark and Poland. In contrast, the developing countries that have shown a rise in their publications' share in neurosciences from 1999 to 2008 were China by 3.93% (from 0.86% to 4.79%), South Korea by 1.42% (0.57% to 1.99%), Brazil by 1.29% (from 1.09% to 2.38%), India by 0.63% (from 0.72% to 1.35%), Taiwan by 0.60% (0.56% to 1.16%) and Israel by 0.28% (from 1.42% to 1.70%) [Table 1].
India ranked at 21 st position among the top 26 most productive countries in neurosciences with its global publications' share of 0.99% during 1999-2008. Compared to India, China, Brazil and South Korea ranked at 12 th , 15 th and 18 th position, with global publications' share of 2.03%, 1.74% and 1.24% during 1999-2008. India's global publications' share increased from 0.72% to 1.35% and so also its world ranking from 23 rd to 19 th from 1999 to 2008. Compared to India, China, Brazil and South Korea's global publications' share increased from 0.86% to 4.79%, 1.09% to 2.38% and 0.57% to 1.99% and their global ranking improved from 12 th to 8 th , 15 th to 12 th and 18 th to 15 th from the year 1999 to 2008.
India's publications' output in neurosciences
India's cumulative publications' output during 1999-2008 consisted of 4503 papers, with an average of 450 papers per year. Compared to India, the publications' output of China, Brazil and South Korea during the same period consisted of 9184 papers, 7850 papers and 5625 papers, with the average number of papers per year as 918, 785 and 562 respectively. The cumulative publications' output of India increased from 1737 papers to 2766 papers from 1999-2003 to 2004-08, and witnessed a growth of 59.24% [Table 2]. Compared to India, the cumulative publications' output of China, Brazil and South Korea increased from 2182 to 7002 papers, 2871 to 4979 papers and 1788 to 3837 papers from 1999-2003 to 2004-08, witnessing a growth of 220.9%, 73.42% and 114.6%, respectively, as against 20.59% growth in the world's cumulative publications' output during the same period. India's annual average publications' growth rate during 1999-2008 was 11.37%, compared to 26.78% for China, 12.97% for Brazil and 10.31% for South Korea and 3.41% for world publications [Table 2].
In terms of impact and quality, the average citations per paper registered by India's publication output during 1999-06 was 4.21. Compared to India, China, Brazil and South Korea publications registered much higher citation impact of 7.24, 5.99 and 8.29 during the same period. The average citations per paper of India's cumulative publications decreased from 4.54 during 1999-02 to 4.21 during 2003-06. As against India, the average citations per paper for cumulative publications of China, Brazil and South Korea decreased from 7.70 to 7.24, 6.27 to 5.99 and 8.61 to 8.29 from 1999-02 to 2003-06 [Table 2].
International collaboration in India's publication output
Based on the publications' data, the total cumulative collaborative papers during 1999-2008 consisted of 781 papers, which accounted for a share of 17.34%. Compared to India, China's international collaborative papers' share in its cumulative publications' output during 1999-2008 was 35.52% (with 3262 collaborative papers), followed by Brazil with a 24.09% share (with 1891 collaborative papers) and South Korea with a 28.18% share (with 1585 collaborative papers). India witnessed a substantial increase in the share of its international collaborative papers from 13.59% during 1999-03 to 19.70% during 2004-08. Compared to India, the international collaborative publications' share of Brazil has increased from 22.78% to 24.84%, as against a decrease from 36.57% to 35.19% in case of China and from 28.35% to 28.09% in case of South Korea from 1999-2003 to 2004-08 [Table 3].
Among the major international collaborative partners, as reflected in its international co-authored papers, 15 countries have published more than 10 collaborative papers with India during 1999-2008. United States was the major collaborating partner for India during 1999-2008 by contributing 60.95% publications' share in India's total international collaborative papers, followed by United Kingdom (with 21.38% share), Germany, Australia, Canada and Japan (between 4.61-7.38% share), Italy, Spain, Columbia and Switzerland (between 2-3% share), China, France, Brazil, Israel and Netherlands (between 1-2% share). On analyzing the shift in international collaborative publications' share of the major collaborative partner countries of India from 1999-2003 to 2004-08, it has been found that the publications' share of United States has decreased by 8.00% (from 66.5% to 58.5%), followed by Japan by 3.11% (from 6.78% to 3.67%), Columbia by 1.37% (from 3.39% to 2.02%), China by 0.89% (from 2.54% to 1.65%) and France by 0.04% (from 1.69% to 1.65%), while the share of all other collaborating countries has increased by 5.1% (from 17.8% to 22.9%) United Kingdom, followed by Germany by 3.18% (from 5.08% to 8.26%), Australia by 1.28% (from 5.51% to 6.79%), Canada by 0.42% (from 5.08% to 5.50%), Italy by 0.03% (from 2.54% to 2.57%), Spain by 2.27% (from 0.85% to 3.12%), Switzerland by 1.48% (from 1.27% to 2.75%), Brazil and Israel each by 1.78% (from 0.42% to 2.20%) and Netherlands by 1.41% (from 0.42% to 1.83%).
Research profile of the most productive Indian institutions in neurosciences
The top 14 most productive Indian institutions involved in research in neurosciences have each published 60 and more papers during 1999-2008. The list of these Indian institutions along with their research output, collaborative papers, citations received and h-index values are presented in [Table 4]. These 14 Indian institutions together have contributed 46.41% share (with 2090 papers) of the publications' output of India in neurosciences, with an average of 149.29 papers per institution. Only six Indian institutions have registered higher publications' share than the group's average. These were All India Institute of Medical Sciences (AIIMS), New Delhi (with 490 papers), followed by National Institute of Mental Health and Neurosciences (NIHMANS), Bangalore (with 262 papers), Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh (with 260 papers), Indian Institute of Sciences (IISc), Bangalore (with 195 papers), Christian Medical College and Hospital (CMCH), Vellore (with 171 papers) and Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow (with 156 papers).
The average citations per paper registered by the total papers of these 14 Indian institutions are 2.46. Among these 14 institutions, UIPS, Chandigarh has scored the highest impact of 6.39 citations per paper, followed by IISc, Bangalore (with 4.46 citations per paper), NBRC, Manesar (with 4.32 citations per paper), IICB, Kolkata (with 4.12 citations per paper), University of Madras, Chennai (with 3.54 citations per paper) and NIMHANS, Bangalore (with 2.81 citations per paper).
The cumulative international collaborative papers' output of these 14 Indian institutes consisted of 274 international collaborative papers, accounting for 13.11% average share in the total publications' output. Of 14 institutions, seven institutions have scored higher share of international collaborative papers over the average share of total institutions. These seven institutions included NIMHANS, Bangalore (with international collaborative publications' share of 16.79%), CMC, Vellore (with 14.04% share), L V Prasad Eye Institute, Hyderabad (with 31.15%), NBRC, Manesar (with 45% share), IICB, Kolkata (with 24.62% share), University of Madras (with 13.11% share) and IIS, Bangalore (with 27.69% share).
The average h-index value of these 14 most productive Indian institutions is 13.86. Six Indian institutions have scored higher h-index value than group's average of 13.86.
Prolific authors in Indian neuroscience
Among the prominent authors contributing to neurosciences research in India, 16 Indian authors were identified as most productive and they have published more than 40 papers during 1999-2008. Of these 16 most productive authors, four were affiliated to AIIMS, New Delhi, two each to SGPIMS, Lucknow, NIMHANS, Bangalore, Metabolic Disorders Research Centre, Trivandrum and one each to PGIMER, Chandigarh, CMC Vellore, KEM, Mumbai, University Institute of Pharmaceutical Sciences, Chandigarh, SCTIMST, Trivandrum and Nizam's Institute of Medical Sciences, Hyderabad [Table 5].
These 16 authors together have contributed 916 papers, with an average contribution of 57 papers per author and accounting for a 20.34% share in the cumulative publications output of India during 1999-2008. Among the 16 most productive authors, only six authors have published higher number of papers than the group's average. These are A. Goel and A.K. Mahapatra (87 papers each), followed by J. Kalita (68 papers), U.K. Misra (67 papers), C. Sarkar (64 papers) and P.A. Kurup (61 papers).
These authors have together received an average of 5.44 citations per paper for the total papers. Seven authors out of 16 have scored higher citations per paper than the average citations per author. These were S.K. Kulkarni with 16.64 citations per paper, followed by V. Rajshekhar (8.41 citations per paper), K. Radhakrishnan (8.28 citations per paper), U.K. Misra (7.73 citations per paper), J. Kalita (7.37 citations per paper), M. Behari (6.65 citations per paper) and J.M.K. Murthy (5.74 citations per paper).
The average h-index value registered by these 16 authors is 9.13. Seven authors registered higher h-index value than the group's average. They were S.K. Kulkarni with h-index value of 18, followed by U.K. Misra (h-index value of 12), K. Radhakrishnan and J. Kalita (h-index value of 11 each) and V. Rajshekhar, J.M.K. Murthy and C. Sarkar (h-index value of 10 each).
Research communication in high productive journals
The top 19 most productive Indian and foreign journals together contributed the 2244 research papers in neurosciences, which accounts for a 54.27% share in the cumulative publications output of India during 1999-2008. Of these 19 journals, only one journal was an Indian journal, contributing a 24.89% share and 18 were international journals, contributing a 29.38% share in the total publications output of India in neurosciences during 1999-2008. The cumulative publications' output share of these 19 most productive journals showed a decrease in India's publications' output from 63.96% during 1999- 2003 to 48.19% during 2004-08 [Table 6].
Characteristics of highly cited papers in neurosciences
The characteristics of selected highly cited papers of India in neurosciences were evaluated in this section. Based on the publication output of India in this area, 100 papers were considered as highly cited ones, which have received citations (since their publications till 1 October 2009) from 38 to 253. Of these 100 papers, 84 appeared as articles, 11 as reviews, three as short surveys and two as conference papers. Of the 100 highly cited papers, 61% involved international collaboration (51 bilateral and 10 multilateral) and 3% national collaboration.
These 100 highly cited papers together have received 7044 citations, with an average of 704 citations per paper. Among the 100 highly cited papers, five papers were in the citation range of 201-300, six papers in citation range of 101-200, nine papers in citation range of 76-100, 42 in the citation range of 51-75 and 38 papers in the citation range of 26-50.
The authors of these highly cited papers are affiliated to 49 Indian institutions, including eight papers from University of Hyderabad, seven each from All India Institute of Medical Sciences, New Delhi, Indian Institute of Science, Bangalore, National Institute of Mental Health and Allied Sciences, Bangalore and Tata Institute of Fundamental Research and National Centre for Biological Sciences, Bangalore, six papers each from Panjab University, Chandigarh and Tata Institute of Fundamental Research, Department of Biological Sciences, Mumbai, five papers from Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, four papers from Jamia Hamdard University, Delhi, three papers each from Nagpur University, National Chemical Laboratory, Pune and SCTIMIST, Trivandrum, two papers each from Central Drug Research Institute, Lucknow, Centre for Ageing Research in India, Delhi, Christian Medical College and Hospital, Vellore, Indian Institute of Chemical Biology, Kolkata, Jaslok Hospital and Research Centre, Mumbai, National Brain Centre, Manesar, Gurgaon, National Centre for Cell Science, Pune and Rajiv Gandhi Centre for Biotechnology, Trivandrum and one paper each from 30 other Indian institutions.
These 100 highly cited papers have appeared in 49 journals, including eight in Brain Research, six papers each in Journal of Neurosciences and Neurology, five papers each in European Journal of Pharmacology and Neuron, four papers each in the British Journal of Psychiatry, Journal of Neurosciences Research and Journal of the Neurological Science, three papers each in Movement Disorders, Neuropharmacology and Pharmacology Biochemistry and Behavior and Schizophrenia Research, two papers each in Biological Psychiatry, Brain, Epilepsia, European Neuropsychopharmacology, Journal of Neurochemistry, Journal of Pain and Symptoms, Progress in Neuro- Psychopharmacology, Psychiatry Research and Stroke and one paper each in 27 other journals.
Indian scientists together have published 4503 papers in neurosciences during 1999-2008, compared to 9184 papers by China, 7850 papers by Brazil and 5725 papers by South Korea during the same period. India ranked at 21 st position among the top 26 countries in neurosciences, with its global publication share of 0.99% during 1999-2008. Compared to India, China, Brazil and South Korea ranked at 12 th , 15 th and 18 th position, with global publication share of 2.03%, 1.74% and 1.24% during 1999-2008. India has witnessed an increase in its global publications share, rising from 0.72% in 1999 to 1.35% in 2008. Correspondingly, India's world ranking improved from 23 rd position in 1999 to 19 th position in 2008. India's annual average publication growth rate during 1999-2008 was 11.37%, compared to 26.78% for China, 12.97% for Brazil and 10.31% for South Korea and 3.41% for world overall publications.
In terms of impact and quality, the average citations per paper registered by publications from India in neurosciences during 1999-2008 were 4.21. Compared to India, publications from China, Brazil and South Korea have registered a comparatively higher impact of 7.24, 5.99 and 8.29 during the same period.
The total international collaborative publications (781) in neurosciences accounted for a 17.34% share of total publications' output during 1999-2008. There was an increase in the share of total publications' output from 13.59% during 1999-2003 to 19.70% during 2004-08. Among India's major collaborative partners during 1999-2008, USA has contributed the largest publications' share, followed by United Kingdom, Germany, Australia, Canada and Japan, Italy, Spain, Columbia and Switzerland, China, France, Brazil, Israel and Netherlands.
The publications' output of the 14 most productive Indian institutions in neurosciences consisted of 2090 papers during 1999-2008, which accounted for a 46.41% share of the total publications' output. The publications' output of these 14 institutions had registered an average impact of 2.46 citations per paper, an average h-index value of 13.86 and a share of 36.83% international collaborative papers during 1999-2008. The 16 most productive Indian authors in neurosciences together have contributed 916 papers, with an average of 57 papers per author and have received an average of 5.44 citations per paper and an average h-index of 9.13 per author. Of the 100 highly cited papers in neurosciences from India, 61 involved international collaboration (51 bilateral and 10 multilateral) and three involved national collaboration. These 100 most highly cited papers have registered a citation impact with 704 citations per paper. The total publication output of the top 19 productive journals contributing to India's neuroscience research accounted for a 54.27% share of the total publications' output during 1999-2008.
India is far behind China, Brazil and South Korea in terms of publication output, citation quality and share of international papers in neurosciences. There is an urgent need for substantial increase in research and development investments, both at the institutional level as well as in terms of extramural funding from different scientific agencies. Academic institutes should take steps to create interest in research in neurosciences among graduate and postgraduate students and also among young clinicians and scientists. Such efforts should include specialised training programs with support from funding agencies. In addition, existing training programs at the institutional level need to be strengthened, besides building new and more comprehensive training programs to develop manpower needs. There should be a substantial increase in international collaboration to increase the output and also to improve the quality of research. In addition there should be more collaboration among the Indian institutions.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]