S. J. W. Willems

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OBJECTIVE To investigate the neural and cognitive bases of upper limb apraxia in corticobasal degeneration (CBD). METHODS Eighteen patients with CBD underwent a cognitive neuropsychological assessment of apraxia and resting [(18)F]-fluorodeoxyglucose PET scanning. Two complementary measures of apraxia were computed for each modality of gesture production.(More)
BACKGROUND This prospective study evaluated memory function during general anesthesia for elective surgery and its relation to depth of hypnotic state. The authors also compared memory function in anesthetized and nonanesthetized subjects. METHODS Words were played for 70 min via headphones to 48 patients (aged 18-70 yr) after induction of general(More)
The purpose of the present study was to explore the possibility of a procedural learning deficit among children with developmental coordination disorder (DCD). We tested 34 children aged 6-12 years with and without DCD using the serial reaction time task, in which the standard keyboard was replaced by a touch screen in order to minimize the impact of(More)
Recognition memory can rely on recollection (recall of the details from the encoding episode) and familiarity (feeling that some information is old without any recollection). In Alzheimer's disease (AD), where there is a clear deficit of recollection, the evidence regarding familiarity is mixed, with some studies showing preserved familiarity and others(More)
The aim of this study was to explore the role of prior explicit sequence knowledge by comparing its influence on serial reaction time (SRT) performance with either a deterministic or a probabilistic sequence. The results confirm that, with a deterministic sequence, preliminary explicit learning improves SRT performance. On the other hand, with a(More)
In three experiments, picture quality between test items was manipulated to examine whether subjects' expectations about the fluency normally associated with these different stimuli might influence the effects of fluency on preference or familiarity-based recognition responses. The results showed that fluency due to pre-exposure influenced responses less(More)
Dual-process theories of recognition posit that perceptual fluency contributes to both familiarity-based explicit recognition and perceptual priming. However, the priming-without-recognition dissociation, as observed through the intact mere exposure effect and impaired recognition in patients with Alzheimer's disease (AD), might indicate that familiarity(More)
We investigated the mere exposure effect and the explicit memory in Alzheimer's disease (AD) patients and elderly control subjects, using unfamiliar faces. During the exposure phase, the subjects estimated the age of briefly flashed faces. The mere exposure effect was examined by presenting pairs of faces (old and new) and asking participants to select the(More)
Patients with Alzheimer's disease (AD) relying predominantly on familiarity for recognition, research has suggested that they may be particularly susceptible to memory illusions driven by conceptual fluency. Using the Jacoby and Whitehouse [Jacoby, L.L., & Whitehouse, K. (1989). An illusion of memory: False recognition influenced by unconscious perception.(More)
We examined the mechanisms involved in the development of the easily learned, easily remembered (ELER) heuristic in three groups of young children (4-5 years, 6-7 years, and 8-9 years). A trial-to-acquisition procedure was used to evaluate how much these children's judgment of learning depended on the ELER heuristic. Moreover, a new experimental paradigm,(More)