Abstract in English:The history of Brazilian neuropsychology is traced at different neuropsycholinguistic stages with a focus on the importance of sociocultural factors. We first focus on language disorders, the sequelae of injuries in the left hemisphere, and neuropsychology restricted to the medical field in Europe, the United States, and Brazil. In the middle of the last century, attention to the interdisciplinary importance of studies on the right hemisphere began. Studies consequently emerged on the individual variability of brain function with both biological and cultural origins. Based on this approach, Brazilian studies on aphasic children and illiterate aphasic persons were disseminated internationally. In the 1970s, cognitive neuropsychology began in England, highlighting dysfunctions in reading and writing processes. The characteristics of writing systems within each language became relevant for the manifestations of acquired dyslexia. Brazilian studies showed deficits in Portuguese and Japanese writing caused by brain lesions. During this scientific journey, scientific societies and postgraduate programs in Brazil were created to facilitate exchanges and communication among young researchers. By the end of the last century and in the early 2000s, the growth of the neuropsychology of aging raised awareness of the complexity of sociocultural factors, not only on language research but also according to the level of education, frequency of reading and writing habits, school type, and interactions among these factors and biological factors, especially between the level of education and age. From this historical standpoint, we outline future directions and perspectives in the field of Brazilian neuropsychology.
Abstract in English:Delay discounting, one element which underlies decision-making, can be defined as the depreciation of the value of a reward related to the time that it takes to be released. High rates of delay discounting are found in subjects who are willing to forgo greater rewards available only after some length of time and who show a preference for smaller rewards that are available immediately. Widely used as a measure of impulsiveness, delay discounting can be evaluated using experimental tasks. The present review evaluated tasks of delay discounting, their features, measures of evaluation and anomalies, and some variables that can affect delay discounting results and applications in the study of individual and intra-individual differences.
Abstract in English:The computerized version of the Wisconsin Card Sorting Test (WCST) is based on the same normative data developed previously for the manual version. However, equivalence of the measures of both versions is controversial. This study investigated the performance of a Brazilian student sample with subjects aged 6-15 years in the computerized version of the WCST. As a result of the analyses, the study pointed out that type of school (public or private) was significant in almost all measures and also that age and gender effects were similar to those previously described in the manual version. These results showed that the computerized WCST may not be free of cultural and socioeconomic influences and that the validation and standardization of this version is warranted.
Abstract in English:The present study established norms for the spelling and arithmetic subtests of the School Achievement Test (Teste do Desempenho Escolar [TDE]) in two Brazilian cities located in the state of Minas Gerais and compared the results with those obtained from the original normative sample. A stratified proportional sample of 1,034 students from Belo Horizonte and Mariana, from the 1st to 6th grades, was selected. The participants were assessed by the spelling and arithmetic subtests of the TDE. Significant differences were found between the results from Minas Gerais and Rio Grande do Sul, with moderate to high effect sizes. Significant differences were found in percentiles and classification parameters. The educational performance of the children from Minas Gerais was generally classified as less than expected (i.e., inferior) when the original norms were used as a classification parameter. Considering the high variability of educational data in different Brazilian regions, using norms for educational assessment based on only one Brazilian region is inappropriate.
Abstract in English:The purpose of the present study was to investigate different memory systems among children of different school ages. Ninety children who attend schools within the Rio de Janeiro municipality school system, ages 6 to 10 years, were studied. The study excluded children with learning disabilities. All children underwent a neuropsychological evaluation. A two-way analysis of variance revealed significant gender differences in the free delay episodic memory. Age differences were found for the free delay episodic memory and recognition on the Rey Auditory Verbal Learning Test (RAVLT) as well as the recall of the Rey Figure. Semantic memory correlated with Semantic Verbal Fluency. Working Memory as measured by Digit Span subtest of the WISC correlated with the first list learning of the RAVLT. Overall, study results indicated a lower performance among 6-year-old children and gender differences in children 8 and 10 years of age. Data are consistent with the literature and show a distinction in the evolution of different memory systems throughout life.
Abstract in English:The present study investigated cognitive function in children diagnosed with acute lymphoblastic leukemia (ALL). The subjects were 20 children between the ages of 6 and 12 years of both genders who were diagnosed with ALL and underwent exclusively triple intrathecal prophylactic chemotherapy of the central nervous system. The protocol used for the neuropsychological assessment included the following cognitive aspects: intellectual performance, attention, memory and executive function. Data were analyzed by descriptive and inferential statistics using the Mann-Whitney U test and Student t-test. The effects of gender, age at diagnosis, and time since the initiation of treatment on the children's performance were determined. The evaluation of intellectual performance revealed reduced scores in the group of children who were female and younger than 5 years of age at diagnosis, especially difficulty with verbal skills and working memory. With regard to attention systems, the different groups presented expected performance for their age. We observed lower scores in the different groups in executive function, aspects of the development of problem-solving strategies, self-regulation, cognitive flexibility and inhibitory control. Better performance was observed for episodic memory and semantic memory (immediate and recognition), but lower scores were found for learning and recall after interference. In conclusion, the present findings are both consistent and discordant with the literature in the field that alludes to the impact of chemotherapy on the maturation of the central nervous system.
Abstract in English:The present study compared decision-making processing between patients with traumatic brain injury (TBI) and healthy controls. The study also sought to identify dissociations in the frequency of deficits in executive functions (EF) tasks that mainly assess decision making (DM; hot component) and inhibition (cold component) following TBI. The sample was composed of 16 post-TBI adults aged between 18 and 68 years and 16 healthy controls matched by age and education. Decision-making was assessed with the Iowa Gambling Task (IGT), and inhibitory control was assessed with the Trail Making Task (TMT) and Hayling Test. No differences were found between groups in total scores and block scores on the IGT. However, TBI patients preferred the disadvantageous decks, with no evidence of learning during the task. Seven patients presented dissociations between deficient DM on the IGT and accurate inhibition on the Hayling Test and TMT. Conversely, five patients presented partial dissociations between deficits in the IGT and TMT and opposite performance in the Hayling Test. Only three patients exhibited deficits on all of the instruments. These results indicate that patients can maintain comparable performance on the IGT after TBI. Therefore we found dissociations in hot and cold executive components.
Abstract in English:When food is available recurrently at a particular time of day, several species increase their locomotion in the hours that precede food delivery, a phenomenon called food anticipatory activity (FAA). In mammals, many studies have shown that FAA is driven by a food-entrained circadian oscillator (FEO) that is distinct from the light-entrained pacemaker in the suprachiasmatic nucleus of the hypothalamus. Few studies have investigated the effect of sugar ingestion on food anticipatory rhythms and the FEO. We aimed to extend the understanding of the role of glucose on the emergence of food anticipatory rhythms by investigating whether glucose ingestion is sufficient to produce daily food anticipation, reflected by motor activity and core body temperature rhythms. Under a 12 h/12 h light/dark cycle, chow-deprived rats had glucose solution available between Zeitgeber Time (ZT) 6 and ZT 9 for 10 days (glucose restriction group), whereas control animals had chow available within the same time window (chow restriction group). Animals in both groups exhibited anticipatory motor activity and body temperature around the fourth day of the scheduled food restriction. Glucose-fed rats ingested ~15 kcal on the days immediately before FAA emergence and reached an intake of ~20 kcal/day, whereas chow-fed rats ingested ~40 kcal/day. The glucose restriction group exhibited a pattern of food anticipation (activity and temperature) that was extremely similar to that observed in the chow restriction group. We conclude that glucose ingestion is a sufficient temporal cue to produce recurrent food anticipation, reflected by activity and temperature rhythms, in rats.
Abstract in English:The effect produced by a warning stimulus(i) (WS) in reaction time (RT) tasks is commonly attributed to a facilitation of sensorimotor mechanisms by alertness. Recently, evidence was presented that this effect is also related to a proactive inhibition of motor control mechanisms. This inhibition would hinder responding to the WS instead of the target stimulus (TS). Some studies have shown that auditory WS produce a stronger facilitatory effect than visual WS. The present study investigated whether the former WS also produces a stronger inhibitory effect than the latter WS. In one session, the RTs to a visual target in two groups of volunteers were evaluated. In a second session, subjects reacted to the visual target both with (50% of the trials) and without (50% of the trials) a WS. During trials, when subjects received a WS, one group received a visual WS and the other group was presented with an auditory WS. In the first session, the mean RTs of the two groups did not differ significantly. In the second session, the mean RT of the two groups in the presence of the WS was shorter than in their absence. The mean RT in the absence of the auditory WS was significantly longer than the mean RT in the absence of the visual WS. Mean RTs did not differ significantly between the present conditions of the visual and auditory WS. The longer RTs of the auditory WS group as opposed to the visual WS group in the WS-absent trials suggest that auditory WS exert a stronger inhibitory influence on responsivity than visual WS.
Abstract in English:The mother-child relationship is fundamental to the establishment and maintenance of synaptic networks and physiological and emotional development. Animal models including maternal separation have been used to study changes at behavioral and neurobiochemical levels. Due to the relevance of glial cells during development, our aim was to determine if short periods of maternal separation during breastfeeding induce permanent changes in a number of astrocytes labeled with the glial fibrillary acidic protein in different brain areas. Wistar rats were housed under standard laboratory conditions with reversed light/dark cycle; food and water ad libitum. Pups were separated from their mothers for 6 h daily during breastfeeding period. On day 22, pups were separately housed according to gender and treatment. At day 60, subjects were evaluated in the elevated plus maze and, after processing for immunohistochemistry, 20-μm sections were made. Prefrontal cortex, paraventricular nucleus, preoptic area, hippocampus and amygdala were localized. Labeled cells were quantified using Image-J program. Results showed that separated females had more entries into open arms and spend more time as compared with the control groups. In the prefrontal cortex we identified a decrease in staining cells in separated females, whereas there was an increase in staining cells in separated males. In the hippocampus and preoptic area, we observed a decrease only in separated males. We did not find any differences in the paraventricular nucleus or amygdala. Our results indicate that maternal separation during breastfeeding induces permanent changes in the number of astrocytes in different brain areas of both males and females.
Abstract in English:The emergence and maintenance of maternal behavior are under the influence of environmental cues such as light and dark periods. This article discusses the characteristic neurobiology of the behavioral patterns of lactating rats. Specifically, the hormonal basis and neurocircuits that determine whether mother rats show typical sequential patterns of behavioral responses are discussed. During lactation, rats express a sequential pattern of behavioral parameters that may be determined by hormonal variations. Sensorial signals emitted by pups, as well as environmental cues, are suggested to serve as conditioned stimuli for these animals. Finally, the expression of maternal behavior is discussed under neuroeconomic and evolutionary perspectives.
Abstract in English:This study investigated the effects of perinatal cadmium exposure on sexual behavior, organ weight, and testosterone levels in adult rats. We examined whether immediate postpartum testosterone administration is able to reverse the toxic effects of the metal. Forty pregnant Wistar rats were divided into three groups: 1) control, 2) 10 mg kg-1 cadmium chloride per day, and 3) 20 mg kg-1 cadmium chloride per day. These dams were treated on gestational days 18 and 21 and from lactation 1 to 7. Immediately after birth, half of the offspring from the experimental and control groups received 50 μl (i.p.) of 0.2% testosterone. Male sexual behavior, histological analysis and weight of organs as well as serum testosterone levels were assessed. Results showed that both cadmium doses disrupted sexual behavior in male rats, and postnatal treatment with testosterone reversed the toxic effects of 10 mg kg-1 cadmium and attenuated the effects of 20 mg kg-1 cadmium. Body weight and absolute testis, epididymis, and seminal vesicle weight were decreased by the higher cadmium dose, and testosterone supplementation did not reverse these effects. Serum testosterone levels were unaffected by both cadmium doses. No histological changes were detected in all organs analyzed. Maternal cadmium exposure effects in sexual parameters of male rat offspring were explained by the altered masculinization of the hypothalamus. We suggest that cadmium damaged cerebral sexual differentiation by its actions as an endocrine disruptor and supported by the changes discretely observed from early life during sexual development to adult life, reflected by sexual behavior. Testosterone supplementation after birth reversed some crucial parameters directly related to sexual behavior.
Abstract in English:Among the many lines of research related to autism, investigations of sensory dysfunction have recently gained attention. The objective of this article is to briefly review the main findings of sensory deficits in autism, raise possibilities of early identification research in the area, and discuss the significance of these sensory problems for the understanding of autism. A review of the scientific literature with regard to sensory problems in autism was performed. A review of autobiographical reports of high-functioning autistic individuals was also performed. This review showed that sensory problems have always been mentioned in the autism literature, but their relevance has been underestimated. Scientific research and autobiographical reports suggest a high prevalence of sensory problems in autism. Although not yet considered in the official diagnosis of autism, sensory problems appear to not only exert a considerable impact on the configuration of the disorder but also directly influence autistic persons in their daily lives. Such impairments may begin to be thought of as fundamental in autism. However, these characteristics deserve to be further investigated by researchers who are dedicated to the study of autism.
Abstract in English:The purpose of this study was to verify discriminative control by segments of signs in adolescents with deafness who use Brazilian Sign Language (BSL). Four adolescent with bilateral deafness, with 3 years of BSL teaching, saw a video presenting a children's tale in BSL. After showing accurate understanding of the story, participants saw another video of the same story with 12 signs altered in one of their segments (hand configuration, place of articulation, or movement). They apparently did not detect the alterations. However, when the signs were presented in isolation in a matching-to-sample test, they virtually always selected the picture corresponding to the unaltered signs. Three participants selected an unfamiliar picture in 50% or more trials with an altered sign as a sample, showing that they could detect the majority of the altered signs.
Abstract in English:Background noise may impose deleterious effects on cognitive processing. However, noise below the threshold level may increase the ability to detect stimuli via stochastic resonance mechanisms (SR). The present study investigates whether task performance is deteriorated or enhanced by 5-dB SNR and, if the task performance is enhanced, whether this facilitation in performance points to a particular neural area that serves to attenuate noise and/or increase effective task performance. The areas of interest are the cerebellum and hippocampus due to their roles in working memory (WM) and their links with attention. Fifteen healthy young Malay adults performed three tasks during fMRI scanning: listening to babble noise (N), WM task in quiet (WMQ), and WM task in noise (WMN). Activated regions during N are bilateral STG and MTG. Both WM tasks produced similar activation in a network of areas in the frontal, temporal and parietal lobes. However, the two tasks demonstrated marked differences in the left hippocampus, right posterior cerebellum, and bilateral anterior cerebellum. Moreover, the results obtained from the behavioral task demonstrated that participants responded better in the presence of noise. These results support the hypothesis that the left hippocampus, right posterior cerebellum, and bilateral anterior cerebellum may be involved in attenuating noise and/or increasing attention to task performance, which could be due to SR mechanisms operating in the presence of noise. These results collectively suggest leftward asymmetries during the tasks with the right posterior cerebellum, bilateral anterior cerebellum, and left hippocampus providing compensatory attention processes, at least in the context of this study.
Abstract in English:The aim of this study was to characterize the sleep-wake cycle, daytime sleepiness and sleep quality of high school teachers. Ninety-eight high school teachers participated in this study. They were asked to complete the Health and Sleep, Horne & Ostberg, Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index questionnaires and to keep a 14-day sleep diary. This study showed that high-school teachers wake up on average 1 h 12 min earlier (ANOVA; p < 0.05) and go to bed on average 34 min earlier (ANOVA; p < 0.05) during the week than on the weekend. This results in an average of 42 min less time in bed (ANOVA; p < 0.05) on weekdays and characterizes partial sleep deprivation. Moreover, 46% and 51% of teachers were diagnosed with excessive daytime sleepiness and poor sleep quality (χ2; p > 0.05), respectively. Therefore, high-school teachers show characteristics of partial sleep deprivation that may contribute to excessive daytime sleepiness and poor sleep quality. This situation may compromise health and quality of life, in addition to teaching performance that can affect the education of their students.
Abstract in English:The reinforcement omission effect (ROE) has been attributed to both motivational and attentional consequences of surprising reinforcement omission. Recent evidence suggests that the basolateral complex of the amygdala is involved in motivational components related to reinforcement value, whereas the central nucleus of the amygdala is involved in the processing of the attentional consequences of surprise. This study was designed to verify whether the mechanisms involved in the ROE depend on the integrity of either the basolateral amygdala complex or central nucleus of the amygdala. The ROE was evaluated in rats with lesions of either the central nucleus or basolateral complex of the amygdala and trained on a fixed-interval schedule procedure (Experiment 1) and fixed-interval with limited hold signaled schedule procedure (Experiment 2). The results of Experiment 1 showed that sham-operated rats and rats with lesions of either the central nucleus or basolateral area displayed the ROE. In contrast, in Experiment 2, subjects with lesions of the central nucleus or basolateral complex of the amygdala exhibited a smaller ROE compared with sham-operated subjects. Thus, the effects of selective lesions of amygdala subregions on the ROE in rats depended on the training procedure. Furthermore, the absence of differences between the lesioned groups in either experiment did not allow the dissociation of attentional or motivational components of the ROE with functions of specific areas of the amygdala. Thus, results did not show a functional double-dissociation between the central nucleus and basolateral area in the ROE.