Sylvie Willems

A French Adaptation of the UPPS Impulsive Behavior Scale

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.

Neural and cognitive bases of upper limb apraxia in corticobasal degeneration.

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 [18F]-fluorodeoxyglucose PET scanning. Two complementary measures of apraxia were computed for each modality of gesture production. First, a performance score measured error frequency during gesture execution. Second, as a more stringent test of the integrity of the praxis system, the correction score measured the patient’s ability to correct his or her errors on a second attempt. For each measure type, a cut-off score for the presence of apraxia was defined with regard to healthy controls. Using each cut-off score, the regional cerebral glucose metabolism of patients with CBD with apraxia (i.e., performing below cut-off score) was compared with that of patients with CBD without apraxia. Results: Mean performance scores were below normal values in all modalities. Anterior cingulate hypometabolism predominated in patients with CBD who performed below the cut-off performance score. At variance, mean correction scores were below normal values for gesture imitation only. Hypometabolism in superior parietal lobule and supplementary motor area characterized patients with CBD who were unable to correct their errors at the same rate as control subjects did. Conclusions: 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.

Investigation of implicit memory during isoflurane anesthesia for elective surgery using the process dissociation procedure

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 anesthesia for elective surgery. Patients were unpremedicated, and the anesthetic regimen was free. The Bispectral Index (BIS) was recorded throughout the study. Within 36 h after the word presentation, memory was assessed using an auditory word stem completion test with inclusion and exclusion instructions. Memory performance and the contribution of explicit and implicit memory were calculated using the process dissociation procedure. The authors applied the same memory task to a control group of nonanesthetized subjects. Results:Forty-seven patients received isoflurane, and one patient received propofol for anesthesia. The mean (± SD) BIS was 49 ± 9. There was evidence of memory for words presented during light (BIS 61–80) and adequate anesthesia (BIS 41–60) but not during deep anesthesia (BIS 21–40). The process dissociation procedure showed a significant implicit memory contribution but not reliable explicit memory contribution (mean explicit memory scores 0.05 ± 0.14, 0.04 ± 0.09, and 0.05 ± 0.14; mean automatic influence scores 0.14 ± 0.12, 0.17 ± 0.17, and 0.18 ± 0.21 at BIS 21–40, 41–60, and 61–80, respectively). Compared with anesthetized patients, the memory performance of nonanesthetized subjects was better, with a higher contribution by explicit memory and a comparable contribution by implicit memory. Conclusion:During general anesthesia for elective surgery, implicit memory persists even in adequate hypnotic states, to a comparable degree as in nonanesthetized subjects.

Normal mere exposure effect with impaired recognition in Alzheimer's disease.

We investigated the mere exposure effect and the explicit memory in Alzheimers 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 face they liked. The participants were then presented with a forced-choice explicit recognition task. Controls subjects exhibited above-chance preference and recognition scores for old faces. The AD patients also showed the mere exposure effect but no explicit recognition. These results suggest that the processes involved in the mere exposure effect are preserved in AD patients despite their impaired explicit recognition. The results are discussed in terms of Seamon et al.s (1995) proposal that processes involved in the mere exposure effect are equivalent to those subserving perceptual priming. These processes would depend on extrastriate areas which are relatively preserved in AD patients.

Intact procedural motor sequence learning in developmental coordination disorder.

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 perceptuomotor coordination difficulties that characterize this disorder. The results showed that children with DCD succeed as well as control children at the procedural sequence learning task. These findings challenge the hypothesis that a procedural learning impairment underlies the difficulties of DCD children in acquiring and automatizing daily activities. We suggest that the previously reported impairment of children with DCD on the serial reaction time task is not due to a sequence learning deficit per se, but rather due to methodological factors such as the response mode used in these studies.

What is the impact of the explicit knowledge of sequence regularities on both deterministic and probabilistic serial reaction time task performance

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 probabilistic sequence, the results show no advantage for SRT performance in explicitlearning conditions. In addition, by using the process dissociation procedure (Jacoby, 1991), we show that performance on a subsequent generation task was more sustained by controlled processes for participants in the explicit-learning conditions than for those in the incidental condition. On the whole, these results, showing that the influence of explicit knowledge can be suppressed in certain specific conditions, are consistent with the intervention of both implicit and explicit mechanisms in SRT tasks, and the results also show that their relative influence can be modulated by the particular demands of the task.

Beyond the experience: Detection of metamemorial regularities

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 childrens judgment of learning depended on the ELER heuristic. Moreover, a new experimental paradigm, composed of six phases-a pretest, four training phases, and a posttest-was employed to implicitly influence the validity of the ELER association that underlies this metacognitive rule. Results revealed that the ELER heuristic develops early (4-5years), but its use is reduced after implicit training. Furthermore, executive monitoring was found to account for the smaller changes observed in older children (8-9 years) after training. From a developmental perspective, these findings present a coherent picture of childrens learning of metacognitive heuristics, wherein early automatic and implicit learning is later followed by effortful control.

Patients with Alzheimer's disease use metamemory to attenuate the Jacoby-Whitehouse illusion.

Patients with Alzheimers 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. Journal of Experimental Psychology: General, 118, 126-135] illusion paradigm, we extended these findings and found that AD patients were also sensitive to perceptually driven false recognition. However, AD patients were equally able to disregard perceptual fluency when there was a shift in the sensory modality of the study and test stages. Overall, these findings support the notion that patients with AD can be susceptible to fluency-based memory illusions but these patients can strategically control the fluency attribution following their metamemory expectation in exactly the same way as elderly adults and young adults.

The contribution of processing fluency to preference: A comparison with familiarity-based recognition

There is a great deal of evidence supporting the idea that, when a stimulus is processed fluently, it is more likely to be judged as pleasant. However, this influence of fluency on preference judgement seems to depend on several experimental conditions. So we tried to better understand these conditions via a comparison with recognition and by manipulating some aspects of the procedure (test format) and material (similarity and figure–ground contrast of the stimuli). Two experiments showed that some conditions maximally induce the use of processing fluency in a preference judgement, as in a recognition task. We discuss the implications of these findings for the well-documented discrepancy-attribution hypothesis (Whittlesea & Williams, 1998, 2000).

Enhancing the Salience of Fluency Improves Recognition Memory Performance in Mild Alzheimer's Disease

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 Alzheimers disease (AD), where there is a clear deficit of recollection, the evidence regarding familiarity is mixed, with some studies showing preserved familiarity and others reporting impairment. The current study examined whether recognition memory performance can be improved in AD when the use of familiarity is facilitated by the salience of processing fluency due to an earlier encounter with the information. Fifteen AD patients and 16 healthy controls performed a verbal recognition memory task where the salience of fluency was manipulated by means of letters overlap. Studied and unstudied words were constituted of either two separate sets of letters (no-overlap condition, high fluency salience) or the same set of letters (overlap condition, low fluency salience). The results showed that, although performance was globally poorer in AD patients than in the controls, both groups performed significantly better in the no-overlap condition than in the overlap condition. This suggests that AD patients benefited as much as the controls from the salience of fluency.