***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Smooth pursuit eye movement ( SPEM ) dysfunctions are considered a biological marker for schizophrenia and have been studied widely . In contrast , saccadic eye movements have received less attention , although disturbances have been described previously . Basic neurophysiologic parameters of saccades in schizophrenics , especially in unmedicated patients , have not been studied extensively . Methods Saccadic eye movements of 38 unmedicated schizophrenic patients , 32 patients with major depression and 42 non-psychiatric controls were examined using high-resolution infrared oculography . Two large-amplitude saccadic tasks were presented . The groups were compared on peak velocity , reaction time and accuracy . Results Peak velocity was significantly increased in schizophrenic patients . Depressive patients had a significantly longer reaction time . Both patient groups needed more corrective saccades to reach the target than controls . Conclusions Peak velocity distinguishes unmedicated schizophrenic patients from depressive patients and normal controls . This could be explained by deficits of the prefrontal cortex in the inhibitory control of saccades . Our findings suggest that schizophrenia affects not only SPEM but also saccadic eye movements The effects of α2-adrenoceptor agonists and antagonists on saccadic eye movements were studied in normal volunteers using the agonist  clonidine and the antagonist idazoxan .  Changes in blood pressure , heart rate , and several psychological self-ratings were also recorded . Clonidine produced marked slowing of peak saccade velocity , acceleration and deceleration , with deceleration affected more than acceleration , but had no effect on saccade error or latency measurements . In contrast , most saccade parameters were not altered by idazoxan , although fatigue effects were eliminated . Blood pressure , heart rate , and self ratings of alertness were increased by idazoxan and reduced by clonidine , with opposite effects noted on sedation self-ratings . There were no correlations between the clonidine-induced changes in saccade parameters and changes in self-ratings . Although the slowing of some saccade parameters by clonidine may imply that α2-adrenoceptors are involved in control of saccades , it may also be due to sedation . Although α2-adrenoceptor antagonists may abolish fatigue effects , they can not increase them over baseline values OBJECTIVE Acute administration of an antidepressant increases positive affective processing in healthy volunteers , an effect that may be relevant to the therapeutic actions of these medications . The authors investigated whether this effect is apparent in depressed patients early in treatment , prior to changes in mood and symptoms . METHOD In a double-blind , placebo-controlled , between-groups r and omized design , the authors examined the effect of a single 4-mg dose of the norepinephrine reuptake inhibitor reboxetine on emotional processing . Thirty-three depressed patients were recruited through primary care clinics and the community and matched to 31 healthy comparison subjects . Three hours after dosing , participants were given a battery of emotional processing tasks comprising facial expression recognition , emotional categorization , and memory . Ratings of mood , anxiety , and side effects were also obtained before and after treatment . RESULTS Depressed patients who received placebo showed reduced recognition of positive facial expressions , decreased speed in responding to positive self-relevant personality adjectives , and reduced memory for this positive information compared to healthy volunteers receiving placebo . However , this effect was reversed in patients who received a single dose of reboxetine , despite the absence of changes in subjective ratings of mood or anxiety . CONCLUSIONS Antidepressant drug administration modulates emotional processing in depressed patients very early in treatment , before changes occur in mood and symptoms . This effect may ameliorate the negative biases in information processing that characterize mood and anxiety disorders . It also suggests a mechanism of action compatible with cognitive theories of depression This study examined the cue detection in the non-focal event-based prospect i ve memory ( PM ) of individuals with and without a major depressive disorder using behavioural and eye tracking assessment s. The participants were instructed to search on each trial for a different target stimulus that could be present or absent and to make prospect i ve responses to the cue object . PM tasks included cue only and target plus cue , whereas ongoing tasks included target only and distracter only . The results showed that a ) participants with depression performed more poorly than those without depression in PM ; b ) participants with depression showed more fixations and longer total and average fixation duration s in both ongoing and PM conditions ; c ) participants with depression had lower scores on accuracy in target-plus-cue trials than in cue-only trials and had a higher gaze rate of targets on hits and misses in target-plus-cue trials than did those without depression . The results indicate that the state of depression may impair top-down cognitive control function , which in turn results in particular deficits in the engagement of monitoring for PM cues Recent evidence that the cerebellum and the basal ganglia are activated during the performance of cognitive and attention tasks challenges the prevailing view of their primary function in motor control . The specific roles of the basal ganglia and the cerebellum in cognition , however , have been difficult to identify . At least three functional hypotheses regarding their roles have been proposed . The first hypothesis suggests that their main function is to switch attentional set . The second hypothesis states that they provide error signals regarding stimuli or rewards . The third hypothesis is that they operate as an internal timing system , providing a precise representation of temporal information . Using functional magnetic resonance imaging , we tested these three hypotheses using a  task‐switching experiment  with a 2 × 2 factorial design varying timing ( r and om relative to fixed ) and task order ( unpredictable relative to predictable ) . This design allowed us to test whether switching between tasks , timing irregularity and /or task order unpredictability activate the basal ganglia and /or the cerebellum . We show that the cerebellum is primarily activated with timing irregularity while the anterior striatum is activated with task order unpredictability , supporting their distinctive roles in two forms of readjustment . Task order unpredictability alone , independent of reward delivery , is sufficient to induce striatal activation . In addition , activation of the cerebellum and basal ganglia were not specific to switching attention because these regions were both activated during switching between tasks and during the simultaneous maintenance of two tasks without switching between them PURPOSE The objective of this study was to determine whether the adverse effects of antiepileptic-drugs could be assessed by the eye movements of epilepsy patients . METHODS This study was performed prospect ively in a single tertiary hospital . The inclusion criteria for this study were as follows : ( 1 ) consecutive patients with epilepsy taking antiepileptic-drugs regularly for at least 1 year , ( 2 ) the absence of structural lesions on MRI , ( 3 ) an age ≥16 years old , ( 4 ) not using medications that could influence eye movement , and ( 5 ) a normal neurological examination .  The latency , peak velocity and accuracy of the saccades and the gain of the pursuits were recorded by video-based electro-oculography . We analyzed the differences in the parameters of the eye movements for 75 patients with epilepsy and 20 normal controls matched for age and sex . RESULTS The total latency ( 1017.7 ± 148.9 ms vs. 1150.7 ± 106.6 ms , p=0.0003 ) and accuracy [ 370.7 % ( 95 % CI 364.1 - 376.4 % , range 306 - 408.2 % ) , 92.7 % as total accuracy normalized value vs. 383.6 % ( 95 % CI 378.8 - 398 % , range 322.9 - 417.4 % ) , 95.9 % as total accuracy normalized value , p=0.0005 ] were significantly different between the patients with epilepsy and normal controls . For the detection of nystagmus with video-based electro-oculography , the clear cutoff values of total accuracy ( ≤388.7 % , 97.2 % as total accuracy normalized value ) revealed 93.4 % sensitivity and 28.6 % specificity , and the clear cutoff values of total latency ( ≤1005.5 ms ) showed 49.2 % sensitivity and 78.6 % specificity . CONCLUSIONS The total latency and accuracy of video-based electro-oculography may be screened to identify patients with a high risk of adverse effects with antiepileptic-drugs The metrics of eye saccades in response to r and om and predictable target motion were determined in 8 normal young subjects . The peak velocity of predictive saccades ( PS ) was significantly reduced when compared with r and omly elicited saccades ( RS ) of equal amplitude . Saccadic gain ( initial saccadic amplitude/target amplitude ) was also decreased in PS . Saccadic inaccuracy was extremely frequent in PS and , in contrast to RS , it was independent of target amplitude displacement . These stimulus-dependent changes in saccadic characteristics may reflect activation of the saccadic pontine generators by different supranuclear pathways Patients with major depressive disorder ( MDD ) usually suffer from altered cognitive functions of episodic memory , working memory , mental processing speed and motor response . Diverse studies suggest that different antidepressant agents may improve cognitive functions in patients with MDD . The aim of this work is to study the effects of serotonergic reuptake inhibitors ( SSRIs ) and serotonergic-noradrenergic reuptake inhibitors ( SNRIs ) treatments to improve the performance on memory tasks and mental processing speed in MDD . Seventy-three subjects meeting criteria for major depressive disorder were assessed with the Hamilton depression rating scale and a neuropsychological battery . The subjects were medicated with escitalopram ( n=36 ) or duloxetine ( n=37 ) for 24 weeks . At the end of the trial , the subjects were assessed again with the same neuropsychological battery used prior to the treatment . Both treatments improved importantly the episodic memory and to a lesser extent , working memory , mental processing speed and motor performance . Our results suggest that cognition is partially independent from improvement in clinical symptoms . Both groups achieved remission rates in the HAM-D-17 after 24 weeks of treatment , but SNRI was superior to SSRI  at improving episodic and working memory . Our work indicates that the superiority of SNRI over the SSRI  at episodic memory improvement is clinical ly relevant Risperidone is a novel and clinical ly effective atypical antipsychotic medication with a unique biochemical profile . To contrast the neurophysiological effects of this new medication with those of a typical antipsychotic medication , we performed quantitative measurements of saccadic eye movements in a series of antipsychotic-naive schizophrenic patients treated with either risperidone or haloperidol . Patients were tested before and after 1 month of treatment , and a matched group of healthy subjects was tested twice over a similar time interval . Risperidone , but not haloperidol , was associated with prolonged latency and decreased peak velocity and accuracy of saccadic eye movements that was detectable 4 weeks after treatment initiation . The adverse effects of risperidone may be due to the lack of development of acute tolerance to its powerful serotonergic ( 5-HT2A ) antagonism , which could be responsible for the disruption of brainstem physiology in regions controlling saccadic eye movements Bipolar disorder ( BPD ) is a severe psychiatric illness that is characterized by episodes of extreme mood states . The affective components of bipolar disorder have been studied extensively , but only recently have investigators begun to systematic ally examine its cognitive concomitants . Although executive dysfunction has been reported in this population , especially while patients are manic , the tasks administered in many previous studies have made it difficult to determine the specific executive abilities that were compromised . The present study examined 15 patients with bipolar disorder who were manic , 18 who were euthymic , and 18 healthy participants . Tests were selected to evaluate two specific aspects of executive functioning in these participants . The Object Alternation Task was given as a measure of inhibitory control , and the Delayed Response Task  was included as a measure of spatial delayed working memory . All groups performed similarly on the  Delayed Response Task . On the Object Alternation Task , however , the manic and euthymic patients committed significantly more perseverative errors than healthy participants . These results indicated that patients in the present sample had relatively normal working memory abilities , but had a deficit in behavioral self-regulation , which was evident across mood states Patients suffering from some psychiatric and neurological disorders demonstrate abnormally high levels of saccadic distractibility when carrying out the antisaccade task . This has been particularly thoroughly demonstrated in patients with schizophrenia . A large body of evidence has been accumulated from studies of patients which suggests that such eye movement abnormalities may arise from frontal lobe dysfunction . The psychopharmacology of saccadic distractibility is less well understood , but is relevant both to interpreting patient studies and to establishing the neurological basis of their findings . Twenty healthy subjects received lorazepam 0.5 mg , 1 mg and 2 mg , sertraline 50 mg and placebo in a balanced , repeated measures study design . Antisaccade , no-saccade , visually guided saccade and smooth pursuit tasks were carried out and the effects of practice and drugs measured .  Lorazepam increased direction errors in the antisaccade and no-saccade tasks in a dose-dependent manner . Sertraline had no effect on these measures . Correlation showed a statistically significant , but rather weak , association between direction errors and smooth pursuit measures . Practice was shown to have a powerful effect on antisaccade direction errors . This study supports our previous work by confirming that lorazepam reliably worsens saccadic distractibility , in contrast to other psychotropic drugs such as sertraline and chlorpromazine .  Our results also suggest that other studies in this field , particularly those using parallel groups design , should take account of practice effects Rationale : Impaired psychomotor function has been shown to be associated with clinical and functional outcome in schizophrenia . However , few studies have investigated the 
    Output:
    
Results : Findings regarding psychomotor disturbance showed an increase in reaction time in prosaccade and antisaccade tasks in both unipolar and bipolar disorders .
In both disorders , patients have been reported to have an attraction for negative emotions , especially for negative pictures in unipolar and threatening images in bipolar disorder .
However , the pattern could change with aging , elderly unipolar patients disengaging key features of sad and neutral stimuli .
Conclusion : Eye movement analysis can be used to discriminate patients with depressive disorders from controls , as well as patients with bipolar disorder from patients with unipolar depression .
General knowledge concerning psychomotor alterations and affective regulation strategies associated with each disorder can also be gained thanks to the analysis .