Objective: To evaluate the cognitive deficits which have been linked with schizophrenia, particularly those related to selective attention from a neurocognitive point of view.
Development: We present a concept of attention consistent with a system of control of information processing composed of a group of neurone networks which carry out specific functions. Some functions are related to visual orientation, while others are involved in executive functions which are at the root of many cognitive skills. The convergence of data from behaviour studies and those made available by neuroimaging techniques have facilitated the identification of neuroanatomical areas responsible for these functions. Thus, the posterior parietal lobe, superior colliculus and pulvinar nucleus of the thalamus are responsible for directing visual attention to different spatial locations. The singular cortex, parts of the medial prefrontal area and supplementary motor area will be involved in executive functions. The question arises as to whether schizophrenia is related to a general attention deficit or to specific deficits linked to the different attention neurone networks. In the studies reviewed attention tasks for the evaluation of facilitatory and inhibitory functions related to the different attention networks were used.
Conclusions: The studies showed that schizophrenic patients present deficits in inhibitory mechanisms which depend on the executive attention network. These results may contribute to a better understanding of the cognitive problems which occur in schizophrenia and also to design more effective strategies for the treatment of this disorder.