The repeatability of cognitive performance: a meta-analysis.

Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we gathered 44 studies on individual performance of 25 species across six animal classes and used meta-analysis to assess whether cognitive performance is repeatable. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeatability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cognition across a range of taxa which, like behaviour, may be associated with fitness outcomes.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.

Other better versus self better in baboons: an evolutionary approach of social comparison.

Comparing oneself with others is an important characteristic of human social life, but the link between human and non-human forms of social comparison remains largely unknown. The present study used a computerized task presented in a social context to explore psychological mechanisms supporting social comparison in baboons and compare major findings with those usually observed in humans. We found that the effects of social comparison on subject's performance were guided both by similarity (same versus different sex) and by task complexity. Comparing oneself with a better-off other (upward comparison) increased performance when the other was similar rather than dissimilar, and a reverse effect was obtained when the self was better (downward comparison). Furthermore, when the other was similar, upward comparison led to a better performance than downward comparison. Interestingly, the beneficial effect of upward comparison on baboons' performance was only observed during simple task. Our results support the hypothesis of shared social comparison mechanisms in human and non-human primates.

Pioglitazone and risk of bladder cancer among diabetic patients in France: a population-based cohort study.

AIMS/HYPOTHESIS: Previous studies have suggested an increased risk of bladder cancer with pioglitazone exposure. We aimed to investigate the association between pioglitazone exposure and bladder cancer in France. METHODS: This cohort study involved use of data from the French national health insurance information system (Système National d'Information Inter-régimes de l'Assurance Maladie; SNIIRAM) linked with the French hospital discharge database (Programme de Médicalisation des Systèmes d'Information; PMSI). The cohort included patients aged 40 to 79 years who filled a prescription for a glucose-lowering drug in 2006. The cohort was followed for up to 42 months. Pioglitazone exposure was modelled as a time-dependent variable and defined by having filled at least two prescriptions over a 6-month period. Incident cases of bladder cancer were identified by a discharge diagnosis of bladder cancer combined with specific aggressive treatment. Statistical analyses involved a multivariate Cox model adjusted for age, sex and exposure to other glucose-lowering drugs. RESULTS: The cohort included 1,491,060 diabetic patients, 155,535 of whom were exposed to pioglitazone. We found 175 cases of bladder cancer among exposed patients and 1,841 among non-exposed patients. Incidence rates were 49.4 and 42.8 per 100,000 person-years, respectively. Pioglitazone exposure was significantly associated with bladder cancer incidence (adjusted HR 1.22 [95% CI 1.05, 1.43]). We observed a dose-effect relationship, with a significantly increased risk for high cumulative doses (≥ 28,000 mg, adjusted HR 1.75 [95% CI 1.22, 2.50]) and long duration of exposure (≥ 24 months, adjusted HR 1.36 [1.04, 1.79]). CONCLUSIONS/INTERPRETATION: In this cohort of diabetic patients from France, pioglitazone exposure was significantly associated with increased risk of bladder cancer.

Local and regional adverse reactions to BCG-SSI vaccination: a 12-month cohort follow-up study.

In a 12-month cohort follow-up study of 2435 children vaccinated in 2007 by Statens Serum Institute BCG strain (BCG SSI, 17.8% had an adverse event (AE): erythema 12.4%, induration 12.2%, abscesses 2.5%, ulceration 0.9%, lymphadenitis 0.1%. The factors associated with a lower risk of AE were: age at vaccination <1 year compared to age >1 year (OR=0.35 [0.2-0.6] for age <28 days, 0.29 [0.2-0.42] for age 29 days to 2 months, and 0.53 [0.37-0.74] for age 3-11 months), a visible papule (OR=0.48 [0.36-0.63]), and a low vaccine dose (OR=0.42 [0.31-0.58]). AE to BCG SSI vaccination were frequent but rarely severe.

Risk factors for acute generalized exanthematous pustulosis (AGEP)-results of a multinational case-control study (EuroSCAR).

BACKGROUND: Acute generalized exanthematous pustulosis (AGEP) is a disease characterized by the rapid occurrence of many sterile, nonfollicular pustules usually arising on an oedematous erythema often accompanied by leucocytosis and fever. It is usually attributed to drugs. OBJECTIVES: To evaluate the risk for different drugs of causing AGEP. PATIENTS AND METHODS: A multinational case-control study (EuroSCAR) conducted to evaluate the risk for different drugs of causing severe cutaneous adverse reactions; the study included 97 validated community cases of AGEP and 1009 controls. Results Strongly associated drugs, i.e. drugs with a lower bound of the 95% confidence interval (CI) of the odds ratio (OR) > 5 were pristinamycin (CI 26-infinity), ampicillin/amoxicillin (CI 10-infinity), quinolones (CI 8.5-infinity), (hydroxy)chloroquine (CI 8-infinity), anti-infective sulphonamides (CI 7.1-infinity), terbinafine (CI 7.1-infinity) and diltiazem (CI 5.0-infinity). No significant risk was found for infections and a personal or family history of psoriasis (CI 0.7-2.2). CONCLUSIONS: Medications associated with AGEP differ from those associated with Stevens-Johnson syndrome or toxic epidermal necrolysis. Different timing patterns from drug intake to reaction onset were observed for different drugs. Infections, although possible triggers, played no prominent role in causing AGEP and there was no evidence that AGEP is a variant of pustular psoriasis.

Nevirapine and the risk of Stevens-Johnson syndrome or toxic epidermal necrolysis.

OBJECTIVE: To draw attention to the many cases of Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) related to nevirapine detected in a multinational case-control study of SJS and TEN. METHODS: Actively detected cases and matched hospital controls were interviewed for exposure to drugs and other risk factors. Data were analysed with case-control and case-crossover methods. RESULTS: Between May 1997 and November 1999, a diagnosis of SJS or TEN was established in 246 patients. Eighteen were known to be infected by HIV-1 (7.3%), 15 out of these 18 had been exposed to nevirapine. The reaction began 10-240 days after the introduction of nevirapine (median, 12 days) and all patients had received escalating doses. In 10 patients the reaction occurred with the initial dosage. All but one patients received simultaneously a variety of other antiretroviral agents but no specific drug combination emerged, and nevirapine was the only drug significantly associated with an increased risk of SJS or TEN in HIV-infected persons [odds ratio, 62 (10.4; +infinity) in the case-control analysis; odds ratio, +infinity (2.8; +infinity) in the case-crossover analysis]. CONCLUSIONS: In European countries the risk of SJS or TEN in the context of HIV infection appears to be associated with nevirapine. The respect of a lead-in period does not appear to prevent SJS or TEN. Because of the severity of these reactions and the long elimination half-life of nevirapine, we suggest discontinuation of the drug as soon as any eruption occurs.

Discriminating the relation between relations: the role of entropy in abstract conceptualization by baboons (Papio papio) and humans (Homo sapiens).

Two baboons (Papio papio) successfully learned relational matching-to-sample: They picked the choice display that involved the same relation among 16 pictures (same or different) as the sample display, although the sample display shared no pictures with the choice displays. The baboons generalized relational matching behavior to sample displays created from novel pictures. Further experiments varying the number of sample pictures and the mixture of same and different sample pictures suggested that entropy plays a key role in the baboons' conceptual behavior. Two humans (Homo sapiens) were similarly trained and tested; their behavior was both similar to and different from the baboons' behavior. The results suggest that animals other than humans and chimpanzees can discriminate the relation between relations. They further suggest that entropy detection may underlie same-different conceptualization, but that additional processes may participate in human conceptualization.

Postdischarge adverse drug reactions in primary care originating from hospital care in France: a nationwide prospective study.

OBJECTIVE: To describe and estimate the incidence and preventability of postdischarge adverse drug reactions (ADRs) detected in primary care in France. DESIGN: Prospective study of patients referred to hospital by participating general practitioners (GPs). These GPs reported all cases of an adverse reaction to a drug instituted in hospital among patients who consulted them within 30 days of discharge. SETTING: 305 general practices from all French regions. PATIENTS: 7540 patients referred by GPs to private or public hospitals. MAIN OUTCOME MEASURES: The incidence for postdischarge ADRs in primary care, and their preventability. RESULTS: 30 cases of postdischarge ADR were detected in 29 re-consulting patients, yielding a minimal incidence for France of 0.4 per 100 admissions (95% confidence interval 0.3 to 0.6). The ADRs were assessed as serious in 60% of cases. The main drug classes implicated were cardiovascular drugs (8 ADRs), oral anticoagulants (6), psychoactive drugs (4), antidiabetics (3), and opioid analgesics (3). Patients experiencing a postdischarge ADR were older than patients not experiencing one (median age: 77 vs 68 years; p = 0.004). Detected ADRs were considered preventable in 59% of cases. CONCLUSIONS: Physicians and patients should be aware of the possible occurrence of postdischarge ADRs. Patient information in hospital, close postdischarge follow-up of patients at risk, and appropriate transmission of information between hospital physicians and GPs can help to prevent them.

Same-different conceptualization by baboons (Papio papio): the role of entropy.

The authors trained 6 baboons (Papio papio) to make 1 of 2 report responses to 16-icon same arrays versus 16-icon different arrays. In the same arrays, the icons were all the same as one another, whereas in the different arrays the icons were all different from one another. In Experiment 1, the baboons discriminated the same arrays from the different arrays, and they transferred their discriminative responding to arrays of novel icons. In Experiments 2 and 3, the baboons exhibited strong sensitivity to the degree of display variability when they were shown mixed arrays that comprised some same and some different items. The information theoretic measure "entropy" systematically described these results and outperformed several rival metrics. Finally, in Experiments 4 and 5, the baboons' responses to displays that contained jittered and blurred icons suggested that their same-different conceptual behavior was not based on the spatial orderliness of the visual arrays.

Cross-modal integration and conceptual categorization in baboons.

This study investigates concept formation and cross-modal integration in baboons. Response times were recorded in a categorical task involving discrimination between human and baboon vocalizations. We show that a brief presentation of human or baboon prime pictures conceptually related to the target sound shortened response speed of one baboon. Cross-modal priming effects were replicated with degraded pictures, and were also found in a sample of humans. Cross-modal priming demonstrates that this baboon had formed amodal abstract concepts of the human and baboon categories.

[Prophylactic prescription of low-molecular-weight heparin in the non-surgical setting: impact of recommendations]. / Prescription préventive des héparines de bas poids moléculaire en milieu non chirurgical: l'impact de recommandations.

OBJECTIVE: Low-molecular-weight heparins (LMWH) had official approval for use for venous thromboembolism prophylaxis only for surgery patients when this survey was conducted, but were nevertheless often used in non-surgery patients. We conducted this "before and after" survey from May 1998 to April 1999 to assess the impact of the recommendations implemented in the beginning of 1999. METHODS: Data on the use of LMWH were collected on three different days within a three week interval in all non-surgery departments at the Tenon hospital before distribution of expert recommendations early in 1999. Published in La Presse Médicale in January 2000, these recommendations issued from an external panel of 43 experts who were contacted to establish a consensus opinion using the Delphi method. Data were again collected on three different days after implementation of the recommendations. Implementation was based on a patient-specific prescription order form requested by the hospital pharmacy for delivery to the department. RESULTS: Data were collected for 121 prescriptions prior to the recommendations and for 158 after. Sex-ratio, mean age and percentage of LMWH prescriptions did not differ significantly between the two periods. There was a lower number of non-appropriate prescriptions after implementation of the recommendations from 54.5% to 35.4% (p = 0.01) with better conformity for recommendation A (high-risk patients) (36% versus 43%, NS) and for recommendation B (= 2 risk situations or = 1 risk situation and = 2 aggravating factors) (10% versus 22%, p = 0.01). Better conformity of LMWH prescriptions in oncology and radiotherapy departments partially explained this general improvement, but the difference remained significant when excluding these two departments (p = 0.04). CONCLUSION: This study shows that physician compliance with recognized expert recommendations can improve their implementation. This procedure is now in general use in the Tenon hospital.

Effects of number of items on the baboon's discrimination of same from different visual displays.

Three experiments explored the baboon's discrimination of visual displays that comprised 2 to 24 black-and-white computer icons; the displayed icons were either the same as (same) or different from one another (different). The baboons' discrimination of same from different displays was a positive function of the number of icons. When the number of icons was decreased to 2 or 4, the baboons responded indiscriminately to the same and different displays, exhibiting strong position preferences. These results are both similar to and different from those of pigeons that were trained and tested under comparable conditions.

Effects of element separation on perceptual grouping by humans (Homo sapiens) and chimpanzees (Pan troglodytes): perception of Kanizsa illusory figures.

The processing of Kanizsa-square illusory figures was studied in two experiments with four humans and two chimpanzees. Subjects of the two species were initially trained to select a Kanizsa-square illusory figure presented in a computerized two-alternative forced choice task. After training, adding narrow closing segments to the pacman inducers that composed the Kanisza illusory figures lowered performance in both chimpanzees and humans, suggesting that the discrimination could be controlled by the perception of illusory forms. A second experiment assessed transfer of performance with five sets of figures in which the size of the inducers and their separation were manipulated. Only for chimpanzees was performance directly controlled by separation, suggesting that chimpanzees are more sensitive than humans to the separation between visual elements.

[Prevention of venous thromboembolism in a non-surgical medical ward. Proposed indications for low molecular weight heparin]. / Prévention de la maladie thromboembolique veineuse en milieu hospitalier non chirurgical. Propositions d'indications des héparines de bas poids moléculaire.

OBJECTIVE: The efficiency of venous thromboembolism prophylaxis with low molecular weight heparins (LMWH) has not been established in non surgical patients, so their official preventive use has been limited in France since 1995 to surgery. However, a survey conducted in 5 university hospitals in non surgical patients showed that 21-29% of patients still received a LMWH prescription. It seemed necessary to define the medical conditions for which the practical use of these heparins would be justified. We contacted external experts to obtain a consensus by using the Delphi method. METHODS: The Delphi method, created by the "Rand Corporation" in the USA and used in medicine since the nineteen seventies, is based on a light logistic, with questionnaires been sent by mail with a feed-back report A total of 48 experts were chosen by local staff teams in the 5 hospitals. For the 3 rounds, from March to October 1998, questions were devised by a multicentred staff team. RESULTS: Among the 48 experts contacted, 32 completed the 3 questionnaires, 7 of them did for 2, and 43 did for at least one questionnaire. The experts first defined a list of 12 risk or high risk situations and 11 aggravating factors. For any high risk situation, prescription is justified. For other cases, 2 risk situations are required, or one risk situation with at least 2 aggravating factors, to justify a prescription. If no risk situation is present, prescription is, according to experts, usually not justified. CONCLUSION: The maximal agreement defines the situations in which one use of low molecular weight heparins is proposed to prevent deep venous thrombosis in non surgical inpatients, in most current hospital situations and for more than 24 hours of hospitalization. Clinical trials are needed, to validate their effectiveness and define the optimal dose in these indications. To date, epidemiological studies should be conducted to evaluate the experts proposals by estimating risk factors for deep venous thrombosis.

Perception of partly occluded figures by baboons (Papio papio).

Comparative literature provides conflicting findings whether animals experience amodal completion. Five experiments were conducted to verify if baboons perceive partly occluded objects as complete. The first three experiments used a go/no-go procedure and a video monitor for stimulus presentation. These experiments failed to reveal amodal completion, suggesting that the stimuli were processed as 2-D images rather than 3-D objects. In contrast, completion was demonstrated in a fourth experiment with cardboard stimuli in a two-alternative forced-choice (2AFC) discrimination task presented in a Wisconsin General Test Apparatus. Although in experiment 5 the same 2AFC procedure was used as in experiment 4, completion was absent when the stimuli were shown with a computer graphic system. The results suggest that baboons share with humans the ability for amodal completion, but also underline some procedural factors that might affect the elicitation of this capacity.

Processing of above/below categorical spatial relations by baboons (Papiopapio).

Three video-formatted experiments investigated the categorization of 'above' and 'below' spatial relations in baboons (Papio papio). Using an identity matching-to-sample task, six baboons correctly matched line-dot stimuli based on the 'above' or 'below' location of the dot relative to the line (Experiment 1). Positive transfer of performance was then observed when the line-dot distance depicted in the sample stimulus differed from that of the two comparison stimuli (Experiment 2). Using a go/nogo procedure, two baboons were further trained to discriminate whether a 'B' character was displayed 'above' or 'below' a '3' character (Experiment 3). After training, a positive transfer of performance was observed with the same type of stimuli depicted in different type fonts. Altogether, these results suggest that baboons may form conceptual representations of 'above' and 'below' spatial relations, and categorize visual forms on that basis.

Comparative assessment of distance processing and hemispheric specialization in humans and baboons (Papio papio).

This comparative study explored the ability to process distance and its lateralization in humans and baboons. Using a conditional matching-to-sample procedure in a divided-field format, subjects had to decide whether or not the distance between a line and a dot belonged to a short- or a long-distance category. Experiments 1, 2, and 4 demonstrated the ability of baboons to process and categorize distances. Moreover, humans showed better distance processing for right visual field/left hemisphere presentations than for left visual field/right hemisphere (LVF-RH) displays (Experiments 1-2). The same bias was found in baboons (Experiment 1), but in a weaker way. In Experiment 3, naive human individuals were tested and the difficulty of the discrimination was enhanced. There was a LVF-RH advantage which vanished with practice. Results are discussed by referring to theories (i.e., Kosslyn, 1987) of visuospatial processing for coordinate and categorical judgments.

Associative learning in baboons (Papio papio) and humans (Homo sapiens): species differences in learned attention to visual features.

We examined attention shifting in baboons and humans during the learning of visual categories. Within a conditional matching-to-sample task, participants of the two species sequentially learned two two-feature categories which shared a common feature. Results showed that humans encoded both features of the initially learned category, but predominantly only the distinctive feature of the subsequently learned category. Although baboons initially encoded both features of the first category, they ultimately retained only the distinctive features of each category. Empirical data from the two species were analyzed with the 1996 ADIT connectionist model of Kruschke. ADIT fits the baboon data when the attentional shift rate is zero, and the human data when the attentional shift rate is not zero. These empirical and modeling results suggest species differences in learned attention to visual features.