Episodic memory in patients with attention-deficit/hyperactivity disorder (ADHD)

Krauel, K.1, Baving, L.2, Santel, S.1, Düzel, E.3, and Hinrichs, H.3
1Klinik fuer Kinder- und Jugendpsychiatrie, University of Magdeburg, Germany; 2Afdeling Kinder- en Jeugdpsychiatrie, Universitair Medisch Centrum Utrecht, The Netherlands; 3Klinik fuer Neurologie II, University of Magdeburg, Germany
E-mail: kerstin.krauel@medizin.uni-magdeburg.de

Patients with attention-deficit/hyperactivity disorder (ADHD) have been reported to show significant episodic memory impairments beside attentional deficits. Attentional deficits in ADHD are mainly attributed to a dysfunction of the executive attentional control system. The aim of the current study was to separate whether episodic memory deficits in ADHD patients are due to a general prefrontal executive control deficit or whether basal, mediotemporal memory processes are affected.

ADHD patients (age 11-17) and age-matched controls performed a "levels-of-processing" (LOP) paradigm posing different demands on cognitive control. In LOP-paradigms, the depth of processing during encoding is manipulated by the instruction to either attend to perceptual or semantic aspects of a stimulus. Healthy subjects, in general, show better memory performance after semantic instructions ("LOP-effect"). In the current experiment we used visual stimuli of low and high emotional salience (e.g. stimuli from the International Affective Picture System) to induce different needs for cognitive control, namely to process stimuli independent of their salience according to the instruction. During encoding, the EEG was recorded from 30 electrodes (Neuroscan). Recognition of old (n = 240) and new stimuli (n = 120) was immediately assessed after the study phase. First data show that a group of patients showed severely reduced recognition rates, although the LOP effect was intact for both neutral and emotional pictures. Further behavioral and ERP data in response to perceptually and semantically processed stimuli in dependence of emotional salience are reported and discussed.