The contribution of selective attention as measured by attentional blink (AB) tasks to performance on sustained attention and memory tests in schizophrenia

Schizophrenia is currently conceptualized as a brain disease with brain anomalies evident in structural imaging research and histopathological studies, and concomitant cognitive deficits resulting in broad-based disabilities in a number of functional domains. Attentional dysfunctional is considered one of the core cognitive deficits in schizophrenia and is evident in both visual and auditory (verbal) modalities, and emerges using a variety of neurocognitive, neuropsychological, and neurophysiological selective attention tasks. Other reliably-observed cognitive deficits include sustained attention and memory, with performance on these tasks having predictive validity for a number of functional outcomes. However, the underlying mechanism(s) responsible for sustained attention and memory deficits is a topic of debate, particularly with respect to whether selective attention contributes to impaired performance on these tasks. Attentional Blink (AB) tasks are conceptually and experimentally similar to some neurophysiological measures (sensory gating tasks) used to elicit selective attention deficits in current schizophrenia research. The purpose of this study was to examine whether selective attention, as measured by visual and auditory AB tasks, contributes to impaired performance on auditory and visual sustained attention and memory tests in a multiple-episode schizophrenia population. Results indicate that schizophrenia patients demonstrated impaired selective attention performance in both auditory and visual AB tasks, as well as impairments in sustained attention and memory tasks, compared to an age- and gender-matched non-psychiatric control group. Auditory AB performance was a significant predictor of visual sustained attention performance, and visual AB performance was a significant predictor of visual delayed memory performance. However, the unique variance accounted for by AB performance in these tasks was modest, even after controlling for other cognitive (premorbid IQ) and symptomatic (BPRS scores) variables. Most, but not all, of the AB variance was shared with group membership, suggesting that common factors, of which selective attention is one, contribute to performance in sustained attention and memory tasks. Findings are also discussed with respect to cognitive heterogeneity in schizophrenia, as well as the relative independence of attention and memory task deficits, especially across different sensory modalities.