Does Schizophrenia Impair the Ability to Sustain Attention? Investigation of the Proactive and Reactive Modes of Control by Exploring the Underpinning Oscillatory Activity. Marc Hoonakker, Nadège Doignon-Camus, Anne Bonnefond INSERM U1114, Pôle de Psychiatrie-Hôpital Civil de Strasbourg, 1 place de l'Hôpital, Strasbourg, France
[email protected] The inability to achieve and maintain the focus of cognitive activity on a given stimulation source or task over extended periods of time, i.e. to sustain attention, is considered as a core cognitive deficit of schizophrenia (Nuechterlein et al., 2004). Nevertheless, experimental research results are inconsistent, depending notably on the methodological approaches used: - responding to infrequent targets (Traditionnaly Formatted Task: TFT) - inhibiting ongoing behavior (Go/No-Go task: GNG)
The ability to sustain attention relies on the proper functioning of cognitive control mechanisms. The Dual Mechanisms of Cognitive Control Theory, proposes that cognitive control operates via two distinct modes: the proactive mode which relies on the anticipation of critical events and the reactive mode (stimulus-related and responserelated) which is engaged after their occurrence (Braver, 2012). This framework is relevant for schizophrenia in the sense that proactive control and associated fronto-parietal dysfunction may represent a robust marker of schizophrenia (Lesh et al, 2013).
Aims of the present study : To assess sustained attention ability by using these two approaches (TFT / GNG) with a time-on-task perspective Group Patient (n=14) Control (n=14)
TFT
Sex (F/M) 3/11 3/11
Age 41.3 ± 9.1 39.9 ± 9.4
EEG recording :
Years of education 12.1 ± 2.4 12.6 ± 2.8
To investigate proactive and reactive modes of control by exploring the underpinning oscillatory activity Group Patient (n=24) Control (n=24)
64 electrodes, 10/20 system Bandpass filter: 0.01-500 Hz
ERP analysis : N2: negative peak (250-350 ms) FCz
GNG
P3a: mean amplitude (400-550 ms) FCz Pre-stimulus slow wave: mean amplitude (250-450 ms) Pz
Sex (F/M) 9/15 9/15
Age 37.7 ± 9.1 38.2 ± 7.5
Years of education 12.1 ± 2.8 12.3 ± 2.7
Statistical analysis : Performance and ERP data were submitted to ANOVA including the between-subject factor group (patients/controls) and the within-subject factors period (p1/p2/p3), stimulus type (Go/No-Go) and response type (correct/error).
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