cognitive dysfunction is a strong predictor of long - term functional 
 outcomes such as work performance and independent activities of daily living2 . thus , the evaluation and recovery of 
 cognitive function after a stroke is critical for the maintenance of independent living3 . the literature generally classifies 
 intervention methods for cognitive rehabilitation into conventional cognitive rehabilitation 
 and computer - based cognitive rehabilitation ( cbcr)4 . cbcr is a technique that can enhance attention , concentration , 
 implementation skills , and perception - motor skills through various programs5 . cbcr provides standardized and 
 structuralized training programs and also allows users to adjust the degree of difficulty to 
 their individual cognitive levels4 . in 
 addition , cbcr has been proven to be effective in treating the cognitive 
 impairments of the elderly and of patients with brain injury , dementia , schizophrenia , and 
 stroke7 . recently developed cbcr 
 programs have focused on the activities of daily living such as calculating numbers , 
 remembering names , and shopping activities in addition to conventional approaches focused on 
 training for attention , concentration , and memory improvement8 . however , cbcr programs used in korea are mostly imported from 
 abroad , and many aspects of these programs do not fit the korean culture . in 2011 , kim developed a korean cbcr program called cotras ; however , there is still 
 insufficient evidence for the clinical effectiveness of this program9 . therefore , there is an urgent need to verify whether the 
 efficiency of cotras is sufficient , by using comprehensive and objective methods . accordingly , in this study , we attempted to investigate the effects of the korean cbcr 
 program cotras on cognitive function and visual perception ability by conducting a 
 randomized controlled trial . the subjects were recruited from a local rehabilitation hospital . all subjects gave their 
 voluntary consent to participate after receiving a detailed explanation of the purpose and 
 methods of the study . we screened the volunteers by using the following study criteria 
 derived from a previous cbcr study9 : ( i ) 
 history of no more than one stroke ; ( ii ) stroke with an onset duration of < 3 months ; 
 ( iii ) a score of 23 on the korean version of mini - mental status examination ( k - mmse ) ; ( iv ) 
 ability to understand instructions ; ( v ) ability to use the controller with the unaffected 
 upper limb ; and ( vi ) without unilateral hemispatial neglect and hemianopsia . all subjects 
 provided written informed consent before study inclusion according to the code of ethics of 
 the world medical association ( declaration of helsinki , version 2004 ) . the first is the lowenstein occupational therapy 
 cognitive assessment ( lotca ) consisting of 26 sub - tests and can be used to assess six 
 domains ( orientation , visual perception , spatial perception , motor praxis , visuomotor 
 organization , and thinking operation ) . the lotca has been standardized , and its reliability and validity in various populations 
 have been investigated since 198910 . the 
 second measure is the motor - free visual perception test-3 ( mvpt-3 ) , a tool used to evaluate 
 visual perception abilities without motor function use ; this was devised for screening , 
 diagnosis , and research purposes11 . after the previous testing session , all subjects were randomly assigned to either the 
 control group ( cg ) or the experimental group ( eg ) in accordance with a random - numbers table . all outcome measures were administered to the patients at baseline and at the end of 
 treatment ( after the 4-week intervention ) by the assistant researcher with 5  years 
 experience in using the measures . during the sessions , all subjects participated in a standard rehabilitation program 
 according to a daily inpatient treatment schedule . in addition to standard rehabilitation , 
 all subjects received 30-min daily sessions of either the cg or the eg treatment . subjects from the eg group performed 20 sessions ( 5 days a week for 4 weeks ) of cbcr with 
 the cotras program ( netblue co. , ltd , korea ) made for koreans . cotras consists of a diverse 
 training program including visual perception , attention , memory , orientation , and others 
 ( categorization , sequencing ) . a joystick and a large button on the cotras panel make the 
 training easy for patients who are unfamiliar with computer use . the training allows 
 adjusting to individual patient s abilities at all levels of the program . training data are 
 automatically stored for accurate analysis , aimed at establishing treatment plans9 . in this study , eg subjects received the 
 visual perception training consisting of object recognition , object constancy , figure - ground 
 organization , visual discrimination , and visual organization . the therapy for cg subjects 
 was designed to match that for the eg subjects in terms of duration ( in minutes ) . the cg 
 subjects received conventional cognitive rehabilitation with a pencil and paper with 
 emphasis on visual perception ability . the independent t - test was 
 used to compare the difference between group means and changes in values , and the paired 
 t - test was used to test differences in continuous variables within groups . after applying the inclusion criteria , 37 subjects were screened for this study , with 7 
 excluded for the following reasons : ( i ) insufficient motor function ( n = 2 ) and ( ii ) 
 inability to understand instructions ( n = 5 ) . consequently , 30 subjects were included and 
 their characteristics are summarized in table 
 1table 1.subjects characteristicseg ( n = 15)cg ( n = 15)gendermale68female97age ( years)64.7 ( 8.9)65.2 ( 8.0)onset period ( months)1.5 ( 0.5)1.8 ( 0.6)k - mmse20.6 ( 2.3)20.5 ( 2.0)data are mean ( sd ) . k - mmse : korean version of mini - mental status examination the lotca and mvpt scores at baseline and at the end of treatment are shown in table 2table 2.patients lotca and mvpt-3 scores before and after the interventionslotcamvpt-3prepostchangeprepostchangeeg ( n = 15)71.6 ( 3.1)86.0 ( 4.4)14.4 ( 2.0)39.1 ( 1.9)42.8 ( 11.6)6.6 ( 0.5)cg ( n = 15)71.2 ( 2.8)76.5 ( 3.6)5.3 ( 2.3)38.9 ( 1.8)41.4 ( 2.3)2.5 ( 1.7)data are mean ( sd ) . after treatment , the lotca and mvpt scores , measuring the cognitive function 
 of both groups significantly increased ( p < 0.05 ) , and there was a statistically 
 significant difference between both groups at the end of treatment ( p < 0.05 ) . cbcr is increasingly being used in rehabilitation settings recently because of its many 
 advantages12 . one of the advantages of 
 cbcr is the cost - effectiveness by providing individualized treatments to continuously and 
 repeatedly stimulate impaired cognitive areas13 . the results of this study showed that cbcr with cotras may 
 significantly improve cognitive function and visual perception ability of patients with 
 acute stroke , with a statistically significant improvement in lotca and mvpt in both groups 
 of subjects . the improvement in lotca and mvpt was higher in eg than in cg subjects after 20 
 sessions , confirming that cbcr contributes to obtaining better results than those of 
 conventional cognitive rehabilitation at the early stage of recovery7 , 8 . the effects of cbcr with rehacom have been 
 proved in several studies4 , 6 , 14 , 15 . however , in some parts of rehacom , the stimuli presented 
 on the screen do not fit the culture and situation in korea ; therefore , it is difficult to 
 use in korean9 . to solve this problem , the effectiveness of cbcr with cotras for the 
 rehabilitation of patients with cognitive dysfunction has been proved in several 
 studies9 , 16 , 
 17 . especially , kim , in 2011 , indicated 
 that subjects who received cbcr with cotras showed improvement in lotca and mvpt after 
 treatment , which is consistent with the results of this study . we conclude that cbcr with cotras can be used as a therapeutic approach for restoring the 
 cognitive function and visual perception ability of patients with acute stroke . furthermore , 
 cotras can be used as an alternative to other cbcr programs aimed at improving cognitive 
 function and visual perception ability . the focus on the early stage of stroke recovery makes this study useful in clinical 
 practice . although the sample size is small , the results of this study have potential 
 significance in terms of effectiveness and suggest a potential large clinical use of 
 cotras . the long - term effects of cbcr with cotras were not identified in this study . therefore , 
 further controlled studies with a larger sample size and longer interventions are needed to 
 clarify the clinical benefits of cotras as a rehabilitation treatment for cognitive 
 dysfunction in patients with acute stroke .
[ purpose ] the purpose of this study is to investigate the effects of a korean 
 computer - based cognitive rehabilitation program ( cbcr ) on the cognitive function and 
 visual perception ability of patients with acute stroke . 
 [ subjects ] the subjects were 30 
 patients with acute stroke . [ methods ] the subjects were randomly assigned to either the 
 experimental group ( eg ) or the control group ( cg ) . the eg subjects received cbcr with the 
 cotras program . 
 the cg subjects received conventional cognitive rehabilitation . 
 all 
 subjects participated in a standard rehabilitation program according to a daily inpatient 
 treatment schedule . 
 in addition to standard rehabilitation , the subjects received 20 
 sessions ( 5 days a week for 4 weeks ) of cbcr or conventional cognitive rehabilitation for 
 30  min . to compare the two groups , the lowenstein occupational therapy cognitive 
 assessment ( lotca ) and motor - free visual perception test-3 ( mvpt-3 ) 
 were performed . 
 [ results ] both groups showed significant improvement in lotca and mvpt-3 . 
 furthermore , 
 there were significant differences in lotca and mvpt-3 between the two groups . 
 [ conclusion ] cbcr with cotras may contribute toward the recovery of cognitive function and 
 visual perception in patients with acute stroke .