Aim:The development of attention function in children is still not sufficiently clear. Although it is difficult to objectively assess attention function, continuous performance tests (CPT) can be used to objectively assess cognitive function along with attention. The development of cognitive and attention functions was examined in children using a CPT.Methods: A total of 541 healthy girls aged 5-12 years participated. Ten parameters were calculated: numbers of cancellations for either target stimuli (T-cancel) or non-target stimuli (N-cancel), numbers of omission errors (Omission) and commission errors (Commission), hit rate (Hit), false alarm rate (False), mean reaction time for correct response (RT), coefficient of variance for mean reaction time (CVRT), sensitivity index (d′), and lnb. Results:The parameters were divided into three types based on pattern of change. T-cancel, False, and Commission, which are related to inhibition of response, N-cancel, Hit, and Omission, which are related to inattention to stimuli, and CVRT, which is related to stability of processing time, exhibited significant change until 5 or 6 years of age. d′, which is related to ability to discriminate between target or non-target, exhibited significant change until 8 years of age. RT, which is related to processing time, exhibited significant change until 11 years of age. lnb exhibited no significant differences among age groups. Conclusions:These findings indicate that inhibition function, inattention to stimuli, and stability of processing time develop first. Discrimination ability subsequently increases based on these developments, and finally processing time is reduced.

Aims: Antisaccadic eye movements, requiring inhibition of a saccade toward a briefly appearing peripheral target, are known to be impaired in schizophrenia. Previous neuroimaging studies have indicated that patients with schizophrenia show diminished activations in the frontal cortex and basal ganglia. These studies used target fixation as a baseline condition. However, if the levels of brain activities at baseline are not compatible between patients and healthy subjects, between-group comparison on antisaccade-related activations is consequently invalidated. One possibility is that patients with schizophrenia may present with greater activation during fixation than healthy subjects. In order to examine this possibility, here we investigated brain activities associated with antisaccade in the two groups without using target fixation at baseline.Methods: Functional brain images were acquired during prosaccades and antisaccades in 18 healthy subjects and 18 schizophrenia patients using a boxcar functional magnetic resonance imaging design. Eye movements were measured during scanning. Results:In the patient group, the elevated activities in the dorsolateral prefrontal cortex (DLPFC) and thalamus, normally seen in antisaccade tasks relative to saccade tasks, were no longer observed. Moreover, in normal subjects, activities in the DLPFC and thalamus were greater during the antisaccade task than during the saccade task. In patients, no such difference was observed between the two tasks, suggesting that these brain regions are likely to be highly activated even by a simple task such as fixation. In particular, the DLPFC and thalamus in patients were not activated at a level commensurate with the difficulty of the tasks presented. Conclusions:From these results, it is suggested that schizophrenia entails dysfunctions in the frontostriato-thalamo-cortical network associated with motor function control.

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