Conjunctive Continuous Performance Task (CCPT)--a pure measure of sustained attention.

Among the large variety of attentional tasks that have been used to study sustained attention, the Continuous Performance Task (CPT) is perhaps the most widely used. Despite substantial differences in task characteristics and demands, all CPT paradigms have been referred to as measures of sustained attention. In the present study we introduce a new variant of CPT, which minimizes perceptual and memory components while maximizing the sustained attention components of the task. In addition, we tested the contention that the ability to sustain attention should not be overly dependent on the specific stimuli and task-modality. To this end, we used a new visual Conjunctive CPT (CCPT) developed by Tsal, Shalev, & Mevorach (2005) and its auditory analogue. Using a Multi-Trait-Multi-Method (MTMM) analysis investigating reliability coefficients, convergent validity coefficients and divergent (discriminant) validity coefficients, we established that the new CCPT is a valid measure of sustained attention. In particular, high correlations were obtained between mean RT and SD-RT within each sensory modality. High correlations were also found between performance across sensory modalities (mean convergent validity: .71). Finally, low correlations (mean correlation of .18) were found between performance in the CCPT tasks and performance in two additional visuospatial attention tasks, which do not rely on sustained attention. These findings suggest that independent of sensory modality, the two CCPT tasks used here tap the same stable construct, namely, sustained attention. We conclude that when a measure of sustained attention is required, researchers should be aware of the caveats of standard CPT's and should be careful in selecting a proper task. Moreover, clinicians should appreciate that some CPT measures may reflect a combination of different cognitive operations rather than pure sustained attention.

Anxiety and selective attention in obsessive-compulsive disorder.

Recently, there has been increasing evidence for information-processing deficits in individuals with obsessive-compulsive disorder (OCD). While impairments in selective attention have been identified to be central to the symptomatology of OCD, the role that situational anxiety plays in attentional processes has not been fully explored. Previous research findings were limited to tasks containing anxiety-relevant materials, only permitting for the evaluation of the impact of anxiety on simultaneous cognitive processing. Furthermore, it has not yet been determined whether the impact of anxiety is limited to selective attention or is indicative of a more general cognitive impairment. This study was designed to examine the role that situational anxiety plays in selective attention impairments. OCD participants and controls were presented with an anxiety producing statement and a neutral statement, followed by the Stroop Task. Results indicated that situational anxiety plays a significant role in the performance of tasks that require selective attention in OCD. A significant deterioration was detected in performance on selective attention tasks for the OCD participants after confronting anxiety-provoking scenarios, as compared to neutral scenarios. Anxiety did not impair performance on simple reading tasks. Possible explanations are discussed.