Sabine Pompéia

Comparison of Brazilian and American norms for the International Affective Picture System (IAPS)

OBJECTIVE The present article compares Brazilian and American norms for the International Affective Picture System (IAPS), a set of normative emotional photographic slides for experimental investigations. METHODS Subjects were 1,062 Brazilian university students (364 men and 698 women) who rated 707 pictures from the IAPS in terms of pleasure, arousal, and dominance following the methodology of the original normative study in the US, enabling direct comparison of data from the two samples through Pearson product moment correlation and Student t test. RESULTS All correlations were highly significant with the highest level for the pleasure dimension, followed by dominance and arousal. However, contrary to the American normative values, our data showed that Brazilian subjects generally assigned higher arousal ratings overall. CONCLUSION Our findings confirm that this set of stimuli can be used in Brazil as an affective rating tool due to the high correlations found across the two populations, despite differences on the arousal dimension, which are discussed in detail.

A set of 400 pictures standardised for Portuguese: norms for name agreement, familiarity and visual complexity for children and adults

The present article provides normative measures for 400 pictured objects (Cycowicz et al., 1997) viewed by Portuguese speaking Brazilian University students and 5-7 year-old children. Name agreement, familiarity and visual complexity ratings were obtained. These variables have been shown to be important for the selection of adequate stimuli for cognitive studies. Childrens name agreement was lower than that of adults. The children also failed to provide adequate modal names for 103 concepts, rated drawings as less familiar and less complex, and chose shorter names for pictures. The differences in ratings between adults and children were higher than those observed in the literature employing smaller picture sets. The pattern of correlations among measures observed in the present study was consistent with previous reports, supporting the usefulness of the 400 picture set as a tool for cognitive research in different cultures and ages.

IAPS includes photographs that elicit low-arousal physiological responses in healthy volunteers.

This article describes pleasant IAPS pictures that elicit low-arousal rather than the high-arousal physiological responses previously reported in the literature. Thirty-two International Affective Picture System (IAPS) photographs were grouped into 4 sets of 8 photographs: highly pleasant-arousing (sexual content and adventures), highly pleasant-relaxing pictures (landscapes, flowers or babies), neutral on both valence/arousal, and highly unpleasant-arousing ones. These stimuli were shown to 24 healthy Brazilian University students (12 males) who had their physiological responses recorded [corrugator and zygomatic facial electromyography activity, skin conductance, heart rate, and peripheral temperature]. Zygomatic EMG differentiated low-arousal pleasant photographs from high-arousal pleasant stimuli of the same valence.

Cognition and biomarkers of oxidative stress in obstructive sleep apnea

OBJECTIVES: The aim of this study was to investigate neuropsychological performance and biomarkers of oxidative stress in patients with obstructive sleep apnea and the relationships between these factors. METHODS: This was an observational, cross-sectional study of 14 patients (36.0±6.5 years old) with obstructive sleep apnea and 13 controls (37.3±6.9 years old). All of the participants were clinically evaluated and underwent full-night polysomnography as well as neuropsychological tests. Blood samples were used to assay superoxide dismutase, catalase, glutathione and homocysteine, as well as vitamins E, C, B11 and B12. RESULTS: The patients performed poorly relative to the controls on several neuropsychological tests, such as the attention test and tests of long-term memory and working memory/executive function. They also had lower levels of vitamin E (p<0.006), superoxide dismutase (p<0.001) and vitamin B11 (p<0.001), as well as higher concentrations of homocysteine (p<0.02). Serum concentrations of vitamin C, catalase, glutathione and vitamin B12 were unaltered. Vitamin E levels were related to performance in the backward digit span task (F = 15.9; p = 0.002) and this correlation remained after controlling for age and body mass index (F = 6.3, p = 0.01). A relationship between superoxide dismutase concentrations and executive non-perseveration errors in the Wisconsin Card Sorting Test (F = 7.9; p = 0.01) was also observed. CONCLUSIONS: Decreased levels of antioxidants and lower performance on the neuropsychological tasks were observed in patients with obstructive sleep apnea. This study suggests that an imbalance between antioxidants and pro-oxidants may contribute to neuropsychological alterations in this patient population.

Acute cognitive effects of donepezil in young, healthy volunteers

The acute nootropic potential of donepezil in young healthy volunteers has not been adequately investigated mainly because in previous studies: (1) effects were assessed before peak‐plasma concentration (Tmax) was reached; (2) only a few cognitive processes were assessed. Here we investigated a myriad of cognitive effects of augmentation of acetylcholine using an acute dose of donepezil in healthy adults at theoretical Tmax.

A comparative study of performance in the Conners' Continuous Performance Test between Brazilian and North American children.

Objective: The present study investigated the performance of Brazilian children in the Continuous Performance Test, CPT-II, and compared results to those of the norms obtained in the United States. Method: The U.S. norms were compared to those of a Brazilian sample composed of 6- to 11-year-olds separated into 4 age-groups (half boys) that represented the socioeconomic class distribution of São Paulo City. The children were prescreened for attention deficit disorders (ADHD). Results: Age and gender effects in the Brazilian sample were similar to those previously described. However, the Brazilian sample showed better performance in almost all measures in all age-groups compared to that of the United States. Conclusion: It is discussed that differences between samples probably reflect lack of ADHD screening of the U.S. children. More studies are necessary to determine if the CPT-II is a cross-cultural test with participants from different samples matched for age, gender, and socioeconomic status screened for ADHD. (J. of Att. Dis. 2008; 11(5) 588-598)

Normas brasileiras para o International Affective Picture System (IAPS): comunicação breve

Este articulo presenta valores normativos brasilenos para el International Affective System (IAPS), un conjunto de estimulos con potencial de poner al descubierto emociones, que es ampliamente utilizado en la investigacion experimental. Ademas, se presentan los resultados de la comparacion entre las respuestas de hombres y mujeres brasilenos. Un total de 1062 universitarios brasilenos (364 hombres y 698 mujeres) han sido incluidos y evaluaron las 707 diapositivas del IAPS en los niveles placer, alerta y dominancia, utilizando el mismo procedimiento del estudio normativo original realizado por Lang et al. en Estados Unidos, en 1999.

Flunitrazepam-induced changes in neurophysiological, behavioural, and subjective measures used to assess sedation

INTRODUCTION Certain features of event-related potentials (ERPs), electroencephalographic (EEG), and behavioural measures vary with differing states of alertness and/or sedation. PURPOSE This study was conducted to investigate changes in several measures usually viewed as reflecting states of sedation/sleepiness associated with the use of a range of doses of the hypnotic benzodiazepine (BZD) flunitrazepam (FNZ). METHODS This was a double blind, independent group design study of the effects of acute oral doses of FNZ in young healthy volunteers. Forty-eight subjects were randomly allocated to one of four groups-FNZ (0.6, 0.8, and 1.0 mg) and placebo (PLAC)-and tested prior to treatment and then in a posttreatment session close to the theoretical peak plasma concentration. ERP latencies and amplitudes were measured at midfrontal (Fz), midcentral (Cz), and midparietal (Pz) using a standard auditory oddball paradigm. EEG changes were assessed at Pz. Behavioural measures included the digit-symbol substitution test (DSST), a cancellation task (CT), and subjective ratings of alertness and attentiveness by the subjects (SUB) and the experimenter (EXP). RESULTS FNZ led to psychomotor impairments and decreased alertness and attention; these effects were consistent with previous findings. A progressive, dose-related increase in P3 latency occurred in Fz, Cz, and Pz, and there was an increase in N1 (Fz, Cz) and N2 (Fz). N2-P3 amplitude decreased in Fz. EEG power bands beta 1 increased for the two highest doses, but no significant differences were noted in theta, delta, and alpha bands. P3 latencies, experimenter-rated levels of alertness, and DSST scores differentiated all three doses of FNZ from PLAC. CONCLUSION The most sensitive measures used were P3 latencies of the ERPs (which varied with FNZ dose), DSST, and the experimenter-rated levels of alertness. However, we found no evidence for the assumption that one single phenomenon was reflected in all measures and different mechanisms were probably involved. Further experiments will be needed for more in-depth probing of the finer mechanisms underlying sedation/sleepiness and how they affect behavioural and eletrophysiological measures of the central nervous system (CNS) function.

Benzodiazepine effects on memory tests : dependence on retrieval cues?

Acute effects of oral flunitrazepam (0.5 and 1 mg), nitrazepam (5 and 10 mg) and placebo were assessed on direct (free recall of words and prose, stem-cued recall) and indirect (stem and fragment completion) memory tasks. Fifty healthy volunteers took part in this double-blind, independent group study. The relative effects of the two benzodiazepines (BZs) on memory revealed a different pattern from their effects on alertness, indicating that their amnesic effects are not totally secondary to their sedative effects. The higher dose of flunitrazepam impaired free recall of words and prose but not cued recall, while neither drug affected the two indirect tasks. Differences in drug effects on the direct and indirect memory tasks were discussed in terms of resource demands of the various tests. We conclude that whether BZs impair performance on memory tasks depends more on the cues given at retrieval than the retrieval instructions (direct/indirect). The implications for this in terms of BZ amnestic effects are drawn out for contextual encoding deficits induced by BZs.

A double-dissociation of behavioural and event-related potential effects of two benzodiazepines with similar potencies

This study was designed to explore the role of benzodiazepine affinity to benzodiazepine binding site on acute psychomotor, subjective and memory effects, as well as auditory Event Related Potential (ERP) latencies, in healthy volunteers. Two benzodiazepines with similar affinity to benzodiazepine binding sites, or potency, were compared: the atypical compound lorazepam (2.0 mg), which has been reported to impair priming, and a standard benzodiazepine, flunitrazepam (0.6 mg, 0.8 mg, 1.0 mg). The study followed aplacebo-controlled, double-blind, parallel-group design. Sixty subjects completed a test battery before treatment and at theoretical peak plasma concentration of drugs. Lorazepam and 1.0 mg of flunitrazepam led to comparable alterations on psychomotor, subjective and auditory episodic memory measures. A double-dissociation was found for lorazepam and the equipotent dose of flunitrazepam (1.0 mg): lorazepam was more deleterious than flunitrazepam in time taken to identify fragmented shapes. Lorazepam also impaired direct and indirect stem-completion in comparison to placebo, but this effect was abolished when time to identify shapes was used as a covariate. By contrast, 1.0 mg of flunitrazepam prolonged auditory ERP latencies to a greater extent than lorazepam. High affinity to the benzodiazepine binding sites does not seem to explain the consistent lorazepam-induced impairment of indirect stem-completion. Differences in impairment profile between the benzodiazepines employed may relate to the modality (visual or not) of the tasks used.