Exploring cortical attentional system by using fMRI during a Continuous Perfomance Test.

M G Tana,E Montin,S Cerutti,A M Bianchi

doi:10.1155/2010/329213

Abstract

Functional magnetic resonance imaging (fMRI) was performed in eight healthy subjects to identify the localization, magnitude, and volume extent of activation in brain regions that are involved in blood oxygen level-dependent (BOLD) response during the performance of Conners' Continuous Performance Test (CPT). An extensive brain network was activated during the task including frontal, temporal, and occipital cortical areas and left cerebellum. The more activated cluster in terms of volume extent and magnitude was located in the right anterior cingulate cortex (ACC). Analyzing the dynamic trend of the activation in the identified areas during the entire duration of the sustained attention test, we found a progressive decreasing of BOLD response probably due to a habituation effect without any deterioration of the performances. The observed brain network is consistent with existing models of visual object processing and attentional control and may serve as a basis for fMRI studies in clinical populations with neuropsychological deficits in Conners' CPT performance.

Highlights

Sustained attention is defined as the ability to maintain a high vigilance level for a long time, allowing the subject to respond against presentation of infrequent and unpredictable events
The first aim of our work is to study the neural networks of brain regions involved during the Conners Continuous Performance Test (CPT) paradigm, by using functional magnetic resonance imaging in order to identify the different contributes to task performance coming from different brain regions
blood oxygen level-dependent (BOLD) activation in the cingulate cortex is almost entirely located in the anterior division and the greatest brain activation, in terms of volume extent of BOLD response and magnitude, is located in the right anterior cingulate cortex (ACC)

Summary

Introduction

Sustained attention is defined as the ability to maintain a high vigilance level for a long time, allowing the subject to respond against presentation of infrequent and unpredictable events. One of the most widely used neuropsychological tests for the study of sustained attention is the Conners’ Continuous Performance Test (CPT) [1]. In the Rosvold CPT, the stimuli are letters which are presented visually one at a time, at a fixed rate and the subject’s task is to respond whenever the letter representing the target stimulus appears and to inhibit a response when any other letter appears. Several neuropsychological tests are derived from the X-CPT and the fundamental paradigm on which all these are based is the serial presentation of target and nontarget stimuli and the subject’s task is to respond or inhibit response to infrequent visual target stimuli

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