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thirty boys between the ages of 6 and 11 years diagnosed with adhd were compared with thirty age - matched normal boys .
the diagnosis of adhd was first made by a child and adolescent psychiatrist based on dsm - iv criteria and then confirmed using the persian version of k - sads - pl interview ( schedule for affective disorders and schizophrenia for school - age children present and lifetime version ) by a fellow in child and adolescent psychiatry .
the reliability and validity of this instrument was evaluated in a study done by shahrivar et al .
the control children recruited from the mainstream schools had no history of major psychiatric problems based on k - sads interview .
the two groups had iqs of above 80 and normal or corrected to normal visual acuity . a collection of pictures showing neutral
, pleasant and unpleasant scenes were selected from the international affective picture system - iaps . the selected pictures were used in a pilot study on 25 normal children to evaluate their arousals and valences .
there were no significant differences between the obtained scores in this pilot study and that of the iaps manual .
the pictures were divided in three categories of pleasant , unpleasant , and neutral based on their contents and valence according to iaps manual .
the pictures whose valence score was below 4.5 were considered as unpleasant , between 4.5 and 6 as neutral , and above 6 as pleasant .
then the pictures were paired in four groups : pleasant  neutral ( 16 pairs ) ; unpleasant - neutral ( 18 pairs ) ; pleasant - unpleasant ( 17 pairs ) ; and neutral  neutral ( 7 pairs ) . to prevent the directional bias ,
therefore , there were 116 trials in each block which was repeated twice with a short pause .
stimuli were presented on a 19  inch monitor with a resolution of 1400 by 900 pixels .
the participants ' visual directions were recorded by an eye link ii video base tracker ( sr research ltd , mississauga , ontario , canada ) .
the system had a head mounted tracking device which used infrared to detect corneal reflection and the changes in pupil size .
an eye position remaining within a 50 pixel area for more than 100 ms was considered as fixation .
the mean number and duration of first fixation on each emotion were considered as variables .
another variable was the duration of first gaze which is the time taken to fixate on one picture before moving to another picture .
a chin - rest was also used to minimize the unwanted head movements . before presenting the pictures ,
the child was asked to fixate on a black spot at the center of the screen for 3000 ms , and then he was asked to follow the spot through nine random places .
then , the paired pictures were presented for 3000 ms while the participant 's visual directions were recorded .
the two blocks of 116 trials with a 15-minute break were used in the study .
data analysis was done using the spss software 16.0 . the multivariate analysis ( manova )
was used to compare the two groups in terms of number and duration of first fixation on each emotion and the duration of first gaze .
the p value less than 0.05 were considered as significant . since the categories were not consistent , the friedman test was used to find the visual orientation towards different pictures within groups .
thirty boys between the ages of 6 and 11 years diagnosed with adhd were compared with thirty age - matched normal boys .
the diagnosis of adhd was first made by a child and adolescent psychiatrist based on dsm - iv criteria and then confirmed using the persian version of k - sads - pl interview ( schedule for affective disorders and schizophrenia for school - age children present and lifetime version ) by a fellow in child and adolescent psychiatry .
the reliability and validity of this instrument was evaluated in a study done by shahrivar et al .
the control children recruited from the mainstream schools had no history of major psychiatric problems based on k - sads interview .
the two groups had iqs of above 80 and normal or corrected to normal visual acuity .
a collection of pictures showing neutral , pleasant and unpleasant scenes were selected from the international affective picture system - iaps . the selected pictures were used in a pilot study on 25 normal children to evaluate their arousals and valences .
there were no significant differences between the obtained scores in this pilot study and that of the iaps manual .
the pictures were divided in three categories of pleasant , unpleasant , and neutral based on their contents and valence according to iaps manual .
the pictures whose valence score was below 4.5 were considered as unpleasant , between 4.5 and 6 as neutral , and above 6 as pleasant .
then the pictures were paired in four groups : pleasant  neutral ( 16 pairs ) ; unpleasant - neutral ( 18 pairs ) ; pleasant - unpleasant ( 17 pairs ) ; and neutral  neutral ( 7 pairs ) . to prevent the directional bias ,
therefore , there were 116 trials in each block which was repeated twice with a short pause .
stimuli were presented on a 19  inch monitor with a resolution of 1400 by 900 pixels .
the participants ' visual directions were recorded by an eye link ii video base tracker ( sr research ltd , mississauga , ontario , canada ) .
the system had a head mounted tracking device which used infrared to detect corneal reflection and the changes in pupil size .
the right eye was used to follow the participant 's gaze . an eye position remaining within a 50 pixel area for more than 100 ms
the mean number and duration of first fixation on each emotion were considered as variables .
another variable was the duration of first gaze which is the time taken to fixate on one picture before moving to another picture .
a chin - rest was also used to minimize the unwanted head movements . before presenting the pictures ,
the child was asked to fixate on a black spot at the center of the screen for 3000 ms , and then he was asked to follow the spot through nine random places .
then , the paired pictures were presented for 3000 ms while the participant 's visual directions were recorded .
the two blocks of 116 trials with a 15-minute break were used in the study .
data analysis was done using the spss software 16.0 . the multivariate analysis ( manova )
was used to compare the two groups in terms of number and duration of first fixation on each emotion and the duration of first gaze .
the p value less than 0.05 were considered as significant . since the categories were not consistent , the friedman test was used to find the visual orientation towards different pictures within groups .
there were no significant differences between the two groups in terms of age and iq ( table 1 ) . with regards to the number of first fixation on each emotion
further , no significant difference was found between the two groups in the duration of first fixation ( table 2 ) . 
 
demographic characteristics of two groups comparison of duration of first gaze on pictures between the two groups there was a significant difference between the two groups when the duration of first gaze was considered as a variable .
children with adhd spent less time on pleasant pictures while they were looking at the pleasant  neutral pairs ( f=4.95 , p=0.03 ) .
this time was also less on pleasant pictures while looking at the pleasant  unpleasant pairs in adhd children compared to normal group ( f=3.97 , p=0.05 ) ( table 2 ) . 
 
comparison of duration of first gaze on pictures among different emotional pairs of pictures within the two groups within the adhd group , the duration of first gaze on unpleasant pictures while looking at the unpleasant - neutral pairs was significantly longer compared to neutral pictures using the friedman analysis in each group ( x2=8.53 , p=0.03 ) .
on the other hand , both groups spent significantly more time in their first gazes on pleasant pictures while looking at pleasant - neutral pairs ( x2=30 , p<0.001 )
this study was conducted to assess the adhd boys attentions towards emotional scenes using the eye tracking system compared with normal boys .
children were examined in terms of their visual orientations while they were looking at paired pictures of pleasant - neutral , pleasant - unpleasant , pleasant  neutral and neutral  neutral groups .
the variables are the number and the duration of first fixation and duration of first gaze on pictures . in this study
, it was found that the duration of first gaze on pleasant pictures was lower in the adhd group compared to normal children .
it could be interpreted that children with adhd do not spent much time to look at pleasant pictures , so they may not recognize pleasant pictures properly compared to normal children .
this is in line with pelc 's study which showed that boys at risk of adhd have confusion in recognizing happy faces ( 12 ) .
the findings of a recent study which has not yet been published also showed that these children have difficulty detecting happy faces compared to normal children ( noorazar , tehrani - doost , khorrami , farhadbeigi , 2012 , unpublished ) . in this study
, we also found that boys with adhd spend more time on unpleasant pictures on their first gazes compared to neutral ones .
this is also in accordance with pelc and noorazar 's studies in which they found that boys at risk of adhd spent more time on recognizing emotional faces ( 12 & noorazar , tehrani - doost , khorrami , farhadbeigi , unpublished ) .
it could be interpreted that children with attention deficit / hyperactivity disorder have a tendency to look at unpleasant pictures and spend more time on them .
another interpretation is that these children need more time to recognize negative emotions compared to positive ones .
based on these findings , we can conclude that children with adhd orient preferably to unpleasant situations compared to normal children , so the induction of negative emotions could be increased based on their increased attentions to negative scenes .
this preference in orientation can not be interpreted by their inattentiveness per se because they should have had impairment in orienting to all emotional scenes .
therefore , their interest to unpleasant emotional situations may be due to another component which is different from core symptoms of adhd .
this finding could be considered as another interpretation to emotional reactivity seen in adhd children which is different from their inability to regulate their emotions ( 3 , 18 ) .
the barkley 's theory explains dysregulation of emotions after their expressions in individuals with adhd .
apparently , if people have different attention to emotional cues they will express their emotions differently .
this is in line with other studies showing that adhd children differ from normal children in recognizing emotional cues in faces ( 10 , 11 , and 14 ) .
based on this hypothesis , it could be concluded that the increased reactivity of adhd children may be due to their increased attention to unpleasant and negative situations .
this study is the first research on evaluating adhd children 's orientation towards emotional scenes using the eye tracking system , so we were not able to compare these findings to those of other studies. findings of this study should be reassessed by other studies with larger samples to confirm the mentioned hypothesis .
it is not clear whether this emotional deficit is based on oppositional symptoms accompanying adhd or is due to adhd per se . to answer this question we need to evaluate this hypothesis in a large group of children with adhd , to assess the oppositional symptoms and their association with these findings .
it should again be mentioned that this study was conducted only on boys with adhd .
therefore , further studies to examine this hypothesis in adhd girls compared to boys are recommended .
objectivechildren with attention - deficit / hyperactivity disorder ( adhd ) react explosively and inappropriately to emotional stimuli . 
 it could be hypothesized that these children have some impairment in attending to emotional cues . 
 based on this hypothesis , we conducted this study to evaluate visual directions of children with adhd towards paired emotional scenes.methodthirty boys between the ages of 6 and 11 years diagnosed with adhd were compared with 30 age - matched normal boys . 
 all participants were presented paired emotional and neutral scenes in the four following categories : pleasant - neutral ; pleasant - unpleasant ; unpleasant - neutral ; and neutral  neutral . meanwhile , their visual orientations towards these pictures were evaluated using the eye tracking system . 
 the number and duration of first fixation and duration of first gaze were compared between the two groups using the manova analysis . 
 the performance of each group in different categories was also analyzed using the friedman test.resultswith regards to duration of first gaze , which is the time taken to fixate on a picture before moving to another picture , adhd children spent less time on pleasant pictures compared to normal group , while they were looking at pleasant  neutral and unpleasant  pleasant pairs . 
 the duration of first gaze on unpleasant pictures was higher while children with adhd were looking at unpleasant  neutral pairs ( p<0.01).conclusionbased on the findings of this study it could be concluded that children with adhd attend to unpleasant conditions more than normal children which leads to their emotional reactivity .