Knowledge domain and emerging trends in visual hallucination research: A scientometric analysis

Table 1 Major clusters of co-cited references

Cluster	Size	Silhouette	Mean (year)	Label (LLR)
0	154	0.727	2011	Body disease
1	110	0.883	1997	Senile dementia
2	82	0.715	2001	Hallucinosis
3	71	0.77	2005	Incident dementia
4	70	0.903	2014	Parkinson's disease dementia
5	57	0.957	2001	Charles bonnet syndrome
6	52	0.968	2014	Schizophrenia
7	47	0.822	2008	Impulse control disorder
9	11	0.975	2006	Rem sleep behavior disorder
10	11	0.99	2010	5 HT2a receptor

Ten major clusters were selected from the total 69 clusters. Each cluster represents a research subfield. The size is the number of cited articles in one cluster. The Silhouettre value indicates the homogeneity or consistency of the cluster. Mean year stands for the mean publication year of the cited articles. The label of cluster is based on log-likelihood ratio.