Resumo em Inglês:

Conde et al. (2011) reported a finding that their article title characterized as "stimulus affective valence reverses the spatial compatibility effect." In their study, participants performed a choice-reaction task in which the stimulus was a soccer player from their "Favorite" team or from a "Rival" team, presented in a left or right location. The team signaled whether a spatially compatible or incompatible keypress was to be made in response to the stimulus location. The Favorite team showed a benefit for the spatially compatible response, but the Rival team showed a benefit for the spatially incompatible response. In the present commentary, the data of Conde et al. are reorganized according to the two mixed-mapping conditions under which participants performed: Favorite→compatible/Rival→incompatible and Rival→compatible/Favorite→ incompatible. This reorganization shows the typical finding of no spatial compatibility effect for mixed mappings in both conditions but an overall advantage for the Favorite→compatible/Rival→incompatible mapping of teams to mapping rules. This compatibility effect for team preference to mapping rule may be a consequence of positive and negative affect, although other accounts are possible. Regardless of its basis, that compatibility effect did not modulate the spatial compatibility effect.

Resumo em Inglês:

A visual stimulus (e.g., a letter, word, or object) may have a lasting effect on the processing of subsequent stimuli. The present study verified the priming effect of a figure (i.e., five-petal daisy) on manual reaction time (MRT) to another equal or different five-petal daisy. Two distinct groups were tested. One group was instructed that the five-petal daisy represented a human hand. The other group was instructed that the five-petal daisy represented a flower. The figures in the pairs of stimuli could share or not share some features such as handedness and view. In both groups, after being informed whether the five-petal daisy represented a flower or human hand, an uninformative flower was presented for 200 ms in the center of the screen. After 1000 ms, a second flower was presented in the same location until the observer responded by pressing a left or right switch. The results showed that prior presentation of the five-petal daisy affected MRT only when the figure represented a human hand. Furthermore, an opposite effect of view on MRT was found. The shorter MRT to the back (dorsal) view of the figure that represented a human hand could be attributable to a faster response to the dorsal view of a hand figure made with a prone posture of the participants' hand than to a front (palm) view. The longer MRT to the back view of the figure that represented a flower may be due to a mental rotation of the object along its vertical axis before selecting the correct response because the response was based on the position of the asymmetrical petal in the canonical front view of the daisy.

Resumo em Inglês:

Selective attention directs cognitive resources to relevant objects or events through either voluntary (top-down) or automatic (bottom-up) control. This paper analyzes voluntary and automatic orienting of attention during childhood development. Seventy-four children (6 to 10 years old) were asked to press a key in response to a visual target presented in a previously oriented position (voluntary orienting; Experiment 1) or after a peripheral unpredictable cue (automatic orienting; Experiment 2). A systematic reduction of reaction times was observed in older children in both experiments. For automatic orienting in Experiment 2, reaction times were shorter in the ipsilateral condition than in the contralateral condition. However, for older children, the differences in reaction times between these conditions decreased. This may be attributable to the appearance of Inhibition of Return as a result of the maturation of the attentional system derived from childhood development, which contributes to more effective exploration of the environment.

Resumo em Inglês:

Adolescence is a developmental period frequently characterized by impulsive behavior and suboptimal decision making, aspects that often result in increased rates of substance abuse, unprotected sex, and several other harmful behaviors. Functional magnetic resonance imaging (fMRI) studies have attempted to reveal the brain mechanisms that underlie the typical inhibitory control limitations associated with this developmental period. In the present review, all available studies in the PsycINFO, PubMed, and Web of Science databases that investigated this issue utilizing fMRI were analyzed. In contrast to adults, adolescents exhibited decreased activity in several brain regions associated with inhibitory control such as the dorsolateral prefrontal cortex, anterior cingulate cortex, and fronto-striatal regions. The decreased activity found in these regions may underlie the diminished inhibitory control abilities associated with this development period.

Resumo em Inglês:

The present study investigated whether late maternal inflammation disrupts the mother/pup interaction, resulting in long-lasting effects on pup behavior and alterations in biological pathways, thereby programming prepubertal behavior and the pups' inflammatory responses after bacterial endotoxin treatment. Female rats received 100 μg/kg lipopolysaccharide (LPS) or .9% saline solution on gestation day 18. Reproductive performance was observed at birth. On lactation days (LD) 5 and LD 6, respectively, maternal behavior and maternal aggressive behavior were assessed. In pups, maternal odor preference on LD 7, open field behavior on LD 21, and serum tumor necrosis factor α (TNF-α) levels after LPS challenge on LD 21 were investigated. The results showed that prenatal LPS exposure improved maternal care and reduced maternal aggressive behavior but did not alter maternal reproductive performance. Male offspring exhibited increased body weights at birth and reduced maternal odor preference. Lipopolysaccharide challenge increased the duration of immobility in the open field and induced a slight increase in serum TNF-α levels. Prenatal exposure to LPS during late pregnancy improved maternal care, reduced maternal olfactory preference, and induced TNF-α hyporesponsiveness to a single dose of LPS in pups.

Resumo em Inglês:

During early life, animals are sensitive to environmental events that may lead to short-term and long-lasting changes in their neurobiology and behavior, which could be related to increased risk for psychopathology. Neonatal handling is an experimental intervention in the mother-infant relationship. Based on previous studies, it is known to decrease rat pups' preference for maternal cues. Handling also reduces social, sexual, and fear behavior in adult animals, which is related to underlying neuroendocrine alterations. One prominent feature of adolescence is the high frequency of social behaviors such as play that appear to be necessary for proper socioemotional development. The objective of the present study was to investigate the effect of repeatedly handling pups on social play behavior during the neonatal period in juvenile Wistar rats. We found that handling consistently decreased pouncing, wrestling, and chasing play behavior on postnatal days (PND) 25, 30, and 35 compared with non-handled juveniles. As expected, sex differences were also found. Consistent with previous studies in infant and adult rats, the neonatal handling procedure also reduced affiliative behaviors in juvenile animals. The precise mechanisms by which this early intervention leads to these alterations in offspring remain to be determined, but the cumulative effects of briefly disrupting the mother-infant relationship that caused the neonatal handling may be one possible explanation.

Resumo em Inglês:

In the past few years the study of music from a neuroscientific perspective has considerably improved, allowing the evolution of both theoretical knowledge and constructs related to cognitive musical processing. Both neuroimaging studies and studies of individuals who suffer from selective deficits of musical abilities have favored the construction of useful models to understand the mechanisms of musical processing, thus revealing its complexity and eliciting the hypothesis of the modular organization of music in the brain. This article reviews studies of cognitive musical processing with a focus on deficits in musical abilities and the neuropsychological model of cognitive musical processing developed by Isabelle Peretz. This model is an important contribution to neuroscientific studies of music because it furthers the understanding of selective deficits in different components of musical processing that occur in both individuals who incur brain damage and those with congenital amusia. The model also serves as theoretical support for diagnosing different types of amusia.

Resumo em Inglês:

Recent behavioral and electrocortical studies have found that shy and socially anxious adults are hypersensitive to the processing of negative and ambiguous facial emotions. We attempted to extend these findings by examining the neural correlates of affective face processing in shy adults using an event-related fMRI design. We presented pairs of faces that varied in affective valence and intensity. The faces were morphed to alter the degree of intensity of the emotional expressive faces. Twenty-four (12 shy and 12 non-shy) young adult participants then made same/different judgments to these faces while in an MR scanner. We found that shy adults exhibited greater neural activation across a distinct range of brain regions to pairs of faces expressing negative emotions, moderate levels of emotional intensity, and emotional faces that were incongruent with one another. In contrast, non-shy individuals exhibited greater neural activation across a distinct range of brain regions to pairs of faces expressing positive emotions, low levels of emotional intensity, and emotional faces that were congruent with one another. Findings suggest that there are differences in neural responses between shy and non-shy adults when viewing affective faces that vary in valence, intensity, and discrepancy.

Resumo em Inglês:

Research results with regard to handedness and dyslexia have been ambiguous. The present study investigated the relationship between handedness and dyslexia in secondary school students based on genetic (Right-Shift) and hormonal-developmental theories of handedness. A total of 135 students (45 dyslexics and 70 age- and sex-matched controls) participated in the study. Handedness was defined according to the Edinburgh Handedness Inventory. We developed several classifications that represented various levels of handedness. Both continuous and dichotomous classifications of handedness revealed a small but reliable increase in the proportion of non-right-handers among dyslexics, likely because of the increased proportion of dyslexics among pure left-handers. Dyslexics did not display precisely the same pattern of right and left responses as controls, with some differences at the extremes of the continuum. The present results provide empirical support for Annett's (1985) Right-Shift theory predictions. Additionally, the present study indicates that using a numerical scoring system or dichotomous classifications with restricted criteria that permit the measurement of several degrees of handedness appears to better determine hand preference than using broad classifications into handedness groups.

Resumo em Inglês:

The present study analyzed the effects of age and gender on performance on the Conners' Continuous Performance Test (CCPT II) in a sample of Brazilian adolescents aged 12-17 years. The sample consisted of 480 participants (210 boys) with a mean age of 14.34 years (SD ± 1.61 years) who were representative of the socioeconomic class distribution of the city of São Paulo, Brazil. The participants were prescreened for attention-deficit/hyperactivity disorder. The present results found effects of age and gender that were similar to other Brazilian age groups. Compared with males, female participants presented a lower rate of responding to non-target stimuli (i.e., commission errors), a greater ability to discriminate signals (d'), and fewer impulsive responses (i.e., less perseveration) but longer reaction times (Hit RT and Hit RT Std Error). A significant effect of age was found on RTs (Hit RT, Hit RT Sdt Error, Variability, Hit RT Block Change), commission errors, and perseveration. As age increased, the differences diminished. The present results may be useful for research and clinical studies with Brazilian adolescents.

Resumo em Inglês:

Executive functions (EF) have been a major focus of interest in neuropsychology. However, there are few studies about their development in healthy children. To fill this gap in the literature, the current study aims to compare the performance in EF tasks in children from 6 to 12 (n=90) years old. Three age groups (6-7, 8-10 and 11-12 years-old) were assessed using the following instruments: verbal fluency, narrative discourse, random number generation, N-Back, Bells Test and Hayling Test. Analyses of variance were used to compare the scores among groups. There was a significant effect of age in all executive performance scores, especially between the youngest and oldest groups. The most significant differences were observed in the central executive component of working memory and inhibition, which showed a marked development between 6-7 and 8-10 years of age. In addition, a remarkable peak was observed in the tasks that assess planning and processing speed in the group of 11-12 year-old children. The current results suggest that the development of all components of EF should be further investigated in school-aged children in normative studies so that possible dissociations in the development of these abilities can be better understood.

Resumo em Inglês:

Limited information is available about subjective memory and strategy use in seniors with mild cognitive impairment (MCI). We investigated whether differences exist in the perception of changes in memory, perceived frequency of forgetting, overall memory evaluation, and strategy use between seniors with MCI and unimpaired older adults. The study included 56 participants, aged 60 years and older, including 28 normal controls (NC) and 28 MCI patients. The participants completed the Short Cognitive Performance Test, the Story and Grocery list recall tasks, the 15-item Geriatric Depression Scale, the Memory Complaint Questionnaire for the perception of changes in episodic memory, the McNair Frequency of Forgetting Questionnaire, and a single question that evaluated overall memory. The Bousfield semantic clustering measure was calculated to assess semantic clustering for list recall. The number of underlined words during story encoding was calculated to assess strategy use. Participants with MCI had significantly worse scores on Story and Grocery list recall, semantic clustering, and overall memory evaluation. No differences were found in the number of underlined words. List recall was significantly correlated with semantic clustering in both groups (NC: r = .58, p = .001; MCI: r = .57, p = .002). Participants with MCI appeared to be less efficacious when using memory strategies, which may be associated with poor memory performance.

Resumo em Inglês:

The study of food practices in Brazil faces important problems because of the nonexistence of properly tested methods and lack of a gold-standard instrument. Furthermore, only one instrument is capable of measuring food choice or knowledge in this specific population. In the present study we sought to develop a rapid assessment tool for food choice, consumption, and knowledge about healthy foods and test the reliability of the assessment tool in young adults as an initial step in the validation process. The scale was composed of 22 photographs of foods that were ready to consume, divided into "healthy" and "unhealthy" groups typically eaten as an afternoon snack in our region. To test the reliability of the instrument, 101 college students (51 males) were asked to select three items in response to three questions: "What would you like to eat as an afternoon snack?" "What do you consider healthy?" "What do you usually eat?" The procedure was repeated in the same subjects 1 month after the first application of the instrument. Results indicated a perfect reliability (κ = 1.0) among men when asked to select what they would like to eat, and perfect reliability was found among men and women when asked to select foods that they considered healthy. Excellent reliability (κ > .75) was found among women and the total sample for foods they would like to eat and among men and women for what they usually eat. As an initial step in validating the instrument, the results suggested that it was properly developed and had reliability in the present context for studies that involve eating behavior.

Resumo em Inglês:

Four rats were subjected to chained fixed-ratio (FR), fixed-interval (FI) schedules of reinforcement (chain FR 5 FI). A FR schedule at one lever produced a discriminative stimulus (i.e., light) associated with an FI schedule of primary reinforcement (water) at the second response lever. The FR schedule was kept constant, whereas the FI length was changed from 10 to 60 s under five different experimental conditions. Increases in the FI length resulted in increases in pre-ratio pauses, but pauses in the FI tended to be a constant percentage of FI length. Data from this experiment indicate that pre-ratio pauses are also a function of the interreinforcement interval (IRI). Data from three experiments with chained FR 5 FI 60-s schedules indicate that pausing in the FI component of chained FR FI schedules with the FI as the second component of the chain may tend to disappear as the IRI duration increases.

Resumo em Inglês:

Lamotrigine is indicated according to several recent treatment guidelines as a first-line medication for the treatment of bipolar depression. However, its efficacy in acute bipolar depression has not been well established. In the present naturalistic study, patients with bipolar depression (n = 20), predominantly bipolar type I, were treated with lamotrigine in addition to their prior treatment for 8 weeks. The Young Mania Rating Scale (YMRS), 17-item Hamilton Rating Scale for Depression (HAM-D-17), and Clinical Global Impressions-Bipolar Disorder (CGI-BD) scale were applied at baseline, week 4, and week 8. With regard to the primary measure of efficacy, mean total HAM-D-17 scores significantly decreased (p < .01) at the end of treatment. Eight patients (40%) exhibited a positive response (i.e., at least a 50% reduction of baseline scores). Additionally, eight (40%) and 11 (55%) patients exhibited complete remission, reflected by HAM-D-17 and CGI-BP scores, respectively. Episodes of switching to mania or hypomania occurred in five patients (25%). No skin rash or any other significant adverse events were reported. Our results indicate that the addition of lamotrigine to a mood stabilizer can be useful in the treatment of acute depressive episodes in bipolar I disorder.

Resumo em Inglês:

Females are often less aggressive than males, but they exhibit high levels of agonistic behavior against an intruder in the area of the nest during lactation. This behavior is referred to as maternal aggression. In rats, maternal aggressive behavior occurs more often from postpartum day 3 (PPD 3) to PPD 12. Social instigation is an experimental protocol used to increase the levels of aggression that are typical of the species. In the present study we used social instigation to analyze the expression of a marker of neuronal activity, c-fos. Lactating rats on PPD 5, in the presence of their pups, were divided into four groups: (1) no social instigation and no aggressive behavior, (2) social instigation and no aggressive behavior, (3) no social instigation and aggressive behavior, and (4) social instigation and aggressive behavior. Sixty minutes after the aggression test we used immunohistochemistry to detect Fos in two brain regions, the ventral-orbital region of the prefrontal cortex (VO PFC) and dorsal raphe nucleus (DRN). Our results showed that rats with aggressive behavior that were provoked exhibited an increase in Fos expression in the VO PFC compared with the control group (i.e., no social instigation and no aggressive behavior). No change in Fos expression was found in the DRN. These results complement previous findings with microinjection of serotonin 5-hydroxytryptamine-1B receptor agonists into the same region, demonstrating that the VO PFC is an important region in the modulation of maternal aggressive behavior.

Resumo em Inglês:

Methylmercury (MeHg) is present in the environment because of natural and anthropogenic causes. MeHg can reach the central nervous system (CNS) and cause neurological damage in humans and animals. Electric organ discharges (EODs) in the weak electric fish Gymnotus sylvius are produced by the electric organ and modulated by the CNS. These discharges are used for electrolocation and communication. The purpose of the present study was to investigate the effects of dietary MeHg exposure on EOD rate in G. sylvius. An oscilloscope was used to record the EOD rate. Two treatments were investigated: chronic MeHg administration (4 µg/kg MeHg every 2 days, with a total of nine dietary exposures to MeHg) and acute MeHg administration (a single dose of 20 µg/kg MeHg). The control data for both treatments were collected every 2 days for 18 days, with a total of nine sessions (day 1 until day 18). Data of fish exposed to MeHg were collected every 2 days, totaling nine sessions (day 19 until day 36). Chronic treatment significantly increased the EOD rate in G. sylvius (p < .05), especially with the final treatment (day 32 until day 36). Acute treatment resulted in an initial increase in the EOD rate, which was maintained midway through the experiment (day 26 until day 30; p < .05). The present study provides the first insights into the effects of MeHg on EODs in weak electric fish. The EOD rate is a novel response of the fish to MeHg administration.