stroke patients suffer neurotransmission problems , decreases in cognitive and visual 
 perceptions , damage to the sensitivity of sight , decrease in peripheral sensory sensitivity , 
 and disorders in the vestibular system .
stroke can 
 result in various problems when performing activities of daily life , such as eating , 
 clothing , bathing and moving , eventually leading to partial or complete dependency2 , 3 . 

stroke limits body function , and its effects vary depending on the location of the affected 
 area and the level of injury sustained , and it often induces other disorders involving 
 cognition , visual perception , sensation , and linguistic abilities4 . cognitive impairment often accompanies various neurological disorders such as stroke . 

mobility is also affected when stroke patients experience cognitive disorders over a long 
 period .
as cognitive impairment increases the difficulty of rehabilitation , a therapeutic 
 approach involving cognitive impairment is vital for rehabilitation training , and cognitive 
 rehabilitation using an integrated treatment method is essential .
there are many methods of treatment for increase of cognitive functions , such as music 
 therapy , reminiscence therapy , methods for compensating cognitive functions such as memory 
 assistants , methods for improving memory capability using picture cards or family photos , 
 methods for inducing improvement in learning ability through virtual reality for people with 
 memory damage , and computer assisted cognitive rehabilitation ( cacr)2 .
it provides objective evaluation and instant feedback on the 
 patients task performance , and also gives cognitive training based on the 
 neuropsychological patterns of patients to stimulate the damaged location2 , 6 . 

clinical use of cacr has increased in the treatment of neurological patients , since its 
 level of difficulty can be adjusted to suit an individual s cognitive level , which reduces 
 treatment time and costs7 , 8 . in order to eliminate problems arising from cultural and 
 linguistic differences , cacr has been translated into the korean language and is being used 
 in clinics , and investigations on the effectiveness of cacr for brain - damaged patients are 
 continuing9 , 10 .
recent developments in medical engineering have led to increased clinical use of cacr in 
 the cognitive rehabilitation field .
however , only a limited number of studies have 
 investigated the effectiveness of brain wave changes and cognitive improvements using this 
 training method to treat stroke patients . this study aimed to determine the most effective 
 treatment method for clinicians in the cognitive rehabilitation field by investigating the 
 changes in stroke patients brain waves , memory and attention elicited by cacr , and the 
 manner in which these changes affect daily life .
the study participants were chosen from among thirty stroke patients who were hospitalized 
 and receiving occupational therapy and physical therapy at a general hospital in kyeongki 
 province between december 2013 and january 2014 .
the general characteristics of the 
 participants are shown in the table 1table 1.general characteristicscacrcongender ( male / female)7/59/4age ( years)60.04.763.76.3lesion side ( right / left)9/38/5duration ( month)5.32.36.02.2mmse ( score)18.84.120.53.2education ( years)11.01.610.71.8all variables are the meanstandard deviation ( sd ) .
cacr : computer assisted cognitive 
 rehabilitation training group ; con : control group ; mmse : mini mental state 
 examination .
participant selection criteria were : hemiparetic stroke patients with stroke 
 onset within 3 months to 1  year , who were able to follow verbal instructions , and 
 communicate to a certain level .
in addition , participants were chosen from among patients 
 who were able to perform all tests and had experienced light cognitive function failures 
 that scored between 18 and 23 on the mini mental state examination ( mmse ) .
subjects were 
 excluded if they had diplegia , had never attended a school , were biased , or had received 
 cacr within the past year .
all the patients who participated in this study signed a written 
 consent form after receiving a full explanation of the expected result and side effects of 
 the study .
cacr training was conducted over a period of 6 weeks , in consideration of the 
 hospitalization period .
as the participants were recruited successively , the training was 
 conducted over 8 weeks .
the control group received occupational therapy and physical therapy , for half an 
 hour 5 times a week for 6 weeks .
the cacr group received the same rehabilitation as the 
 control group with extra cacr training for half an hour 5 times a week for 6 weeks .
all of the protocols 
 used in this study were approved by gachon university . before beginning the study , the 
 procedures , risks and benefits
the cacr program used in the present study , rehacom ( hospi , seoul , korea ) , 
 was developed in 1989 , and has been used for clinical purposes and in previous research11 .
it provides cognitive rehabilitation 
 treatment for patients with cognitive disorders or deficiency with the help of a computer . 

feedback on the result during and after the treatment is provided , which is helpful for 
 completing the training and developing the right learning strategies for the patient .
a 
 joystick and touch screen can be used as the input device in rehacom , and the patients could 
 complete the training using a reaction board while seated and watching the screen .
the 
 attention and concentration programs were chosen from the various cacr programs of rehacom 
 and performed for 30 minutes each time according to each patient s functional ability ; the 
 awakening , reactivity , attention and concentration , simultaneous attention , and selective 
 attention programs were used .
cacr : computer assisted cognitive 
 rehabilitation training group ; con : control group ; mmse : mini mental state 
 examination qeeg-8 ( laxtha inc . ,
the participants 
 were seated in a comfortable chair , and the method of the trial was explained before brain 
 wave measurements were performed .
the poles were checked after being attached to the 
 participant s scalp to determine if they were functioning properly . after a 3-minute break , 
 brain waves were measured for 3 minutes while the participants stared at a designated spot 
 to the front in a fixed posture .
the brain wave poles were attached to 8 regions of the 
 scalp , and brain waves were measured using the monopolar derivation method .
eight poles were 
 attached in the following order : left frontopolar lobe ( fp1 ) , right frontopolar lobe ( fp2 ) , 
 left frontal lobe ( f3 ) , right frontal lobe ( f4 ) , left temporal lobe ( t3 ) , right temporal 
 lobe ( t4 ) , left parietal lobe ( p3 ) , and right parietal lobe ( p4 ) .
the reference electrode 
 was attached behind the right earlobe , and the ground electrode was attached to the left 
 earlobe .
a computerized neurocognitive function test ( cnt ) was used to assess memory and attention . 

it is comprised of 5 main categories and 17 sub - test for brain disorders . among these 
 sub - tests ,
the digit span test ( dst ) and visual span test ( vst ) , which test memory , and the 
 visual continuous performance test ( vcpt ) and auditory controlled continuous performance 
 test ( accpt ) , which test attention , were used .
these four tests , dst , vst , vcpt , and accpt 
 were performed in order from the easiest to the hardest , and they were performed by everyone 
 in the same order . when the patients used the touch screen , we let the patients use their 
 non - paralyzed arms12 .
12.0 was used to calculate the averages and standard deviations . the significance 
 of brain wave , memory and attention differences within a group , before and after the 
 treatment ,
was tested using the paired t - test , and the significance of differences between 
 the groups was tested using the independent t - test .
change of brain waves at the eight channels and cnt with respect to cacr training are shown 
 in tables 2table 2.comparison of relative beta waveseegchannelcacrconprepostprepostrelative beta wave ( hz)fp10.090.050.150.080.090.060.100.06fp20.080.040.130.080.080.060.090.06f30.100.040.150.070.090.020.090.03f40.100.030.160.080.100.050.100.05t30.160.070.180.080.140.050.160.05t40.140.050.180.070.140.050.140.05p30.100.020.140.070.090.01470.090.01p40.090.020.130.070.090.010.090.02all variables are the meanstandard deviation ( sd ) ; p<0.05 ; 
 p<0.01 ; cacr : computer assisted cognitive rehabilitation training 
 group ; con : control group ; fp1 : left frontopolar ; fp2 : right frontopolar ; f3 : left 
 frontal ; f4 : right frontal ; t3 : left temporal ; t4 : right temporal ; p3 : left parietal ; 
 p4 : right parietal and   3table 3.comparison of memory and attentioncntsubtestcacrconprepostprepostmemory ( digit)dstforward test3.430.534.590.774.091.204.101.22backward test2.270.683.281.042.551.182.791.44vstforward test3.980.925.171.443.960.754.070.96backward test2.931.093.721.603.211.153.301.13attention ( digit)vcptcorrect response119.834.26123.001.70121.071.49122.003.48reaction time ( sec)0.780.070.610.150.680.130.590.09accptcorrect response57.411.8856.911.1657.841.5757.762.31reaction time ( sec)0.650.140.620.140.620.170.610.18all variables are the meanstandard deviation ( sd ) ; p<0.05 ; 
 p<0.01 ; cnt : computerized neurocognitive function test ; cacr : 
 computer assisted cognitive rehabilitation training group ; con : control group ; dst : 
 digit span test ; vst : visual span test ; vcpt : visual continuous performance test ; 
 accpt : auditory controlled continuous performance test .
the cacr group showed before and after test changes ( p<0.05 ) in the 
 frontal lobe ( fp1 , fp2 and f4 ) and the parietal lobe ( p3 and p4 ) , but no notable changes 
 were observed in control group .
the cacr group showed a statistically significant difference 
 in cnt memory ( dst & vst forward / backward test ) ( p<0.01 ) and attention ( vcpt correct 
 response ) ( p<0.05 ) , but no notable changes were observed in the control group .
all variables are the meanstandard deviation ( sd ) ; p<0.05 ; 
 p<0.01 ; cacr : computer assisted cognitive rehabilitation training 
 group ; con : control group ; fp1 : left frontopolar ; fp2 : right frontopolar ; f3 : left 
 frontal ; f4 : right frontal ; t3 : left temporal ; t4 : right temporal ; p3 : left parietal ; 
 p4 : right parietal all variables are the meanstandard deviation ( sd ) ; p<0.05 ; 
 p<0.01 ; cnt : computerized neurocognitive function test ; cacr : 
 computer assisted cognitive rehabilitation training group ; con : control group ; dst : 
 digit span test ; vst : visual span test ; vcpt : visual continuous performance test ; 
 accpt : auditory controlled continuous performance test
this study investigated the beta wave , memory and attention changes in stroke subjects 
 after cacr training .
the activities that affect brain activation in each part of the brain include attention and 
 judgement related which are processed in assignments for the frontal lobe and assignments 
 that require perception for spatial and temporal information and which are processed in 
 language for the parietal lobe13 , 14 .
the main role of the prefrontal cortex 
 includes cognitive activities such as dealing with new situations , whereas the 
 frontoparietal cortex is concerned with space and controlling intended motions15 , 16 .
the relative beta waves of each channel following training showed 
 that the frontal lobe ( fp1 , fp2 , f4 ) and the parietal lobe ( p3 , p4 ) had higher brain 
 activity in the cacr group . moreover , the relative beta wave exhibited increased activation 
 in the frontal lobe ( f3 ) and the parietal lobe ( p4 ) in the cacr group compared to the 
 control group . in a study by kim et al.17 ,
brain injury 
 patients and healthy individuals performed 10 attention assignments of comcog cacr training . 

functional mri showed that the frontal and temporoparietal lobes were more activated than 
 the temporooccipital lobe , supplementary motor area , and anterior cingulate gyrus before the 
 intervention than in healthy controls .
however , after the cognitive training the frontal 
 lobe activation had decreased and the anterior cingulate gyrus and right parietal lobe were 
 more activated .
this result reflects the improvement in the patients cognition elicited by 
 cacr , and continuing the cacr may have spread the activation to other parts of the brain . 

moreover , a difference in the level of brain activation could be predicted based on the 
 extent of injury that had been sustained by the patient , indicating the necessity of more 
 subdivided and specialized research into the differences in brain activation depending on 
 which area of the brain is injured .
cacr can be performed by patients with a wide range of 
 cognitive function . however , for a more effective treatment , it will be necessary to select 
 different treatments for different diagnoses , inhibitory vs. reward brain waves as 
 appropriate for the diagnosis . to obtain better evidence of the effects of cacr training , 
 standardized and accurate eeg measurement and analysis of more than 8 channels will be 
 necessary .
cnt concentration assessments can check the attention deficit of brain damaged patients , 
 and it can also be used as an indicator of the degree of brain damage or recovery of a 
 patient12 .
shim et al.9 conducted comcog cacr , with traditional 
 rehabilitation therapy for stroke hemiplegic patients , and the results of cognitive function 
 assessments with cnt showed that the cacr group showed significant improvements in memory 
 and attention compared to the group that only received traditional rehabilitation therapy . 
 in our study
, the cacr group showed a significant difference in cnt memory ( dst and vst 
 forward / back ward test ) ( p<0.05 ) attention ( vcpt correct response ) ( p<0.05 ) , but no 
 notable changes were observed in the control group .
cacr practice based on cognitive rehabilitation therapy usually focuses on memory and 
 attention , and kim et al.10 reported 
 significant improvements in long - term and short - term memory after cacr memory training , and 
 gilsky18 showed that even though 
 brain - damaged patients are slower than normal people , they can still acquire a great deal of 
 knowledge and skills related to everyday life .
the results cited above indicate that cacr is more helpful at improving the cognitive 
 function of stroke patients than the use of traditional rehabilitation alone .
besides these 
 effects , cacr , which use computer games , is a helpful therapeutic mediation method , 
 considering the convenience and appeal of games .
the recovery depends on the injured area 
 and the injury period ; however , intensive rehabilitation , duration , and the patients will 
 to recover also play important roles19 .
a 
 rehabilitation method , which is performed over a long period , should be easy and interesting 
 to maintain the active participation of the patient .
the average age of the participants in 
 this study was 60.0  years , and thus , most patients were unfamiliar with computers and 
 electronic devices . however , the patients were familiar with program selection and the 
 assignment after the second run , and most of the participants actively participated in the 
 cacr .
standardized and more accurate brain wave measurement and analysis are required to provide 
 sufficient evidence of the benefits of cacr training .
in addition , if cognitive function 
 recovery can be expedited by conducting cacr for stroke patients with cognitive injury , the 
 patients would be expected to have a quicker rehabilitation .
thus , cacr program development 
 and activation are required , and more specialized research based on the location of the 
 brain lesion in patients with cognitive injury would be beneficial .
 [ purpose ] this study investigated brain wave , memory and attention changes in adult 
 stroke patients using computer assisted cognitive rehabilitation ( cacr ) . [ subjects ] 
 twenty - five stroke patients were randomly allocated to either the cacr group ( n=12 ) or the 
 control group ( n=13 ) . 
 [ methods ] two expert therapists provided the cacr group and the 
 control group with traditional rehabilitation therapy in 30-minute sessions , semi - weekly , 
 for 6 weeks . 
 cacr was provided only to the cacr group . 
 the control group received 
 traditional rehabilitation therapy only . before and after the 6 weeks of intervention , 
 electroencephalography ( eeg ) and a computerized neurocognitive function test ( cnt ) were 
 performed , and the results were analyzed . [ results ] after the intervention , the cacr group 
 showed significant differences in the frontal lobe ( fp1 , fp2 , and f4 ) and in the parietal 
 lobe ( p3 and p4 ) , and also showed significant differences in cnt memory ( dst and vst 
 forward / backward test ) and attention ( vcpt correct responses ) , but no notable changes were 
 observed in the control group . 
 [ conclusion ] these results suggest that cacr is feasible 
 and suitable for individuals with stroke . 
 detailed and diverse investigations should be 
 performed considering the numbers and characteristics of subjects , and the limitations 
 affecting the cacr training period . 