Humans can recollect past events in details (recollection) and/or know that an object, person, or place has been encountered before (familiarity). During the last two decades, there has been intense debate about how recollection and familiarity are organized in the brain. Here, we propose an integrative memory model which describes the distributed and interactive neurocognitive architecture of representations and operations underlying recollection and familiarity. In this architecture, the subjective experience of recollection and familiarity arises from the interaction between core systems (storing particular kinds of representations shaped by specific computational mechanisms) and an attribution system. By integrating principles from current theoretical views about memory functioning, we provide a testable framework to refine the prediction of deficient versus preserved mechanisms in memory-impaired populations. The case of Alzheimer's disease (AD) is considered as an example because it entails progressive lesions starting with limited damage to core systems before invading step-by-step most parts of the model-related network. We suggest a chronological scheme of cognitive impairments along the course of AD, where the inaugurating deficit would relate early neurodegeneration of the perirhinal/anterolateral entorhinal cortex to impaired familiarity for items that need to be discriminated as viewpoint-invariant conjunctive entities. The integrative memory model can guide future neuropsychological and neuroimaging studies aiming to understand how such a network allows humans to remember past events, to project into the future, and possibly also to share experiences.

In three experiments, picture quality between test items was manipulated to examine whether subjectsÕ 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 when objects were presented with high picture quality, suggesting that attributions of fluency to preference and familiarity are adjusted according to expectations about the different test pictures. However, this expectations influence depended on subjectsÕ awareness of these different quality levels. Indeed, imperceptible differences seemed not to induce expectations about the test item fluency. In this context, fluency due to both picture quality and pre-exposure influenced direct responses. Conversely, obvious, and noticed, differences in test picture quality did no affect responses, suggesting that expectations moderated attributions of fluency only when fluency normally associated with these different stimuli was perceptible but difficult to assess.

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Impulsivity is an important and multifaceted psychological construct. Recently, Whiteside and Lynam (2001) have developed the UPPS Impulsive Behavior Scale that distinguishes four dimensions of impulsivity: Urgency, lack of Premeditation, lack of Perseverance, and Sensation seeking. In the present study, we investigated the psychometric properties of a French adaptation of the UPPS Impulsive Behavior Scale. Two hundred and thirty-four undergraduate students completed the UPPS Scale. Exploratory and confirmatory analyses revealed a four factors solution similar to that found in the original study. Also, the results indicated that there was good to very good internal reliability for the four subscales.

During general anesthesia for elective surgery, implicit memory persists even in adequate hypnotic states, to a comparable degree as in nonanesthetized subjects.

Distinct neural networks underlie distinct aspects of the upper limb apraxic deficits in CBD. Extending previous findings of gesture production deficits in CBD, the use of complementary measures of apraxic behavior discloses a visuoimitative upper limb apraxia in CBD, underlain by a metabolic decrease in a parietofrontal neural network.

Fluency is one of many cues that are involved in memory decisions. To date, however, the extent to which fluency-based decisions are preserved in amnesia is not yet clear. In this study, we tested and found differences in how patients with amnesia (n=8) and control participants (n=16) use fluency when making recognition decisions (Experiment 1). Our results suggested that these differences could be due to changes in the readiness with which patients attribute the subjective feeling of fluency to pre-exposure when an alternative explanation is available (i.e., the perceptual quality of the item). Secondly, we explored the hypothesis that changes in attribution processes in patients with amnesia are explained by a decrease in contingency between processing fluency and previous occurrence of stimuli in patients' daily lives, leading them to consider that fluency is not a relevant cue for memory (Experiment 2). Specifically, 42 healthy participants were put either in a condition where the positive contingency between fluent processing and previous encounters with an item was systematically confirmed (classic condition) or in a condition where the classical association between fluency and prior exposure was systematically reversed (reversed condition). Results indicated that participants more readily attribute fluency to the alternative external source than to past experience in the reversed condition than in the classic condition, mimicking the pattern of results shown by participants with amnesia in Experiment 1. Implications of these findings are discussed.

Dual-process theories of recognition posit that perceptual fluency contributes to both familiaritybased 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 and perceptual priming are functionally distinct. This study investigated whether the AD patients' processing strategies at testing may explain this priming-without-recognition dissociation. Firstly, we replicated the priming-without-recognition effect in 16 patients who exhibited intact exposure effects despite null recognition. Secondly, we showed that, under identical conditions, inducing a holistic processing strategy during recognition testing increased AD patients' recognition -performance was similar for AD patients and healthy control participants. Furthermore, prompting analytic processing during both priming and recognition tasks decreased AD patients' performance in both tasks. These findings suggest that the extent to which AD patients use perceptual fluency in priming and recognition tasks is contingent on their processing approach. The choice of processing strategy may depend on how difficult patients perceive the task to be.