Abstract in English:The present study examined the structure of interrelations between brain event-related potentials and behavioral measures and temperament dimensions during an attention task. Three temperament questionnaires were used: Eysenck Personality Inventory, Strelau Temperament Inventory, and Rusalov Structure of Temperament Questionnaire. Event-related potentials were recorded using the active auditory oddball paradigm. The stimuli (85 dB; 1050 and 1000 Hz sinusoidal tones as targets and non-targets, respectively) were easily discriminated by all of the participants. A complex framework of interrelations between temperament and personality dimensions, behavioral measures, and event-related potentials was found. P3 amplitude was negatively correlated with the number of response omissions. Emotionality was positively correlated with P2 and N1-P2 complex amplitudes. Extraversion and Mobility of Nervous Processes were negatively correlated with the amplitude of the N1-P2 complex, and Social Ergonicity was negatively correlated with N2 latency. The results indicate that Extraversion tends to be associated with both the intensity and temporal aspects of temperament and suggest the importance of using a multidimensional approach in temperament studies.
Abstract in English:Previous research has shown that visual spatial attention can be modulated by emotional prosody cues, but it is not known whether such crossmodal modulation of visual attention is associated with the engagement or disengagement of attentional resources. To test this, we employed a modified spatial cueing task, where participants indicated whether a visual target appeared either on the left or the right, after hearing a spatially non-predictive peripheral sound. Prior studies using prosody cues have found that modulation of visual attention by emotional auditory cues was lateralized, but this may have been due to the speech content of the stimuli; here instead we used non-speech environmental sounds. The sound was either emotional (pleasant, unpleasant) or neutral, and was presented either on the same side as the visual target ('valid' trial) or on the opposite side ('invalid' trial). For the cue validity index (RT to invalid cue minus RT to valid cue), we found differences between emotional and neutral cues, but only for visual targets presented in the right hemifield; here the cue validity index was lower for unpleasant compared to neutral and pleasant cues. Absolute RTs for targets on the right were faster for invalid trials following unpleasant cues, compared to pleasant and neutral cues, indicating that the reduced cue validity effect was due to faster disengagement from unpleasant auditory cues. Further, our results show that the laterality effect is related to the emotional nature of the cues, rather than the speech content of the stimuli.
Abstract in English:The present study investigated whether low and high spatial frequency filtered images of faces were recognized differently when briefly presented in the right and the left visual fields of men and women. The method of confidence rating was applied to assess pooled Receiver Operating Characteristic curves based on z scores and the d´ parameter of Signal Detection Theory for recognition indices, in addition to response times. The results showed that men better recognized low spatial frequency filtered faces than high spatial frequency filtered faces in both visual fields, suggesting that both the right and left hemispheres in males prioritize low spatial frequencies to recognize faces. The results for women were similar to men only when the faces were shown in the left visual field. When the faces were presented in the right visual field, women better recognized high spatial frequency filtered faces, suggesting that the left hemisphere in females prioritizes high spatial frequencies, whereas the right hemisphere in females prioritizes low spatial frequencies to recognize faces.
Abstract in English:The present study investigated the influence of body movement implied by artwork on time estimation and its relationship with eye movement. In Experiment 1, the participants were presented with static photographic images of Edgar Degas sculptures that implied different movements. The participants were asked to estimate their exposure times. Overestimation was found for the dancer who represented the greater movement. Eye movements were more directed to legs and arms in the ballerina that implied more movement, indicating more dynamic eye movements for this dancer, which was also overestimated. Experiment 2 further investigated whether this effect was specific to body representation or whether it was linked to the perceptual feature of the images. The participants were presented with drawings that mimicked global shapes (lines) of the Degas sculptures. Differences in time estimation were not obtained under this experimental condition. The results suggest an embodied perception of body movement that modulates eye movements and time estimation.
Abstract in English:A personal history of childhood maltreatment has been associated with unfavorable outcomes in bipolar disorder (BD). The impact of early life stressors on the course of BD may be influenced by individual differences in coping skills. The coping construct relies on neurocognitive mechanisms that are usually influenced by childhood maltreatment. The objective of the present study was to verify the association between childhood maltreatment and coping skills in individuals with BD Type 1. Thirty female euthymic outpatients with BD Type 1 were evaluated using the Childhood Trauma Questionnaire and two additional instruments to measure their coping preferences: Ways of Coping Questionnaire (coping strategies) and Brief COPE (coping styles). Reports of physical abuse (B = .64, p < .01) and emotional abuse (B = .44, p = .01) were associated with the use of maladaptive strategies that focused on emotional control. Adaptive strategies and styles of coping, such as focusing on the problem, were chosen less frequently by women who had experienced emotional neglect (B = .53, p < .01) and physical abuse (B = -.48, p < .01) in childhood. The small sample size in the present study prevented subgroup analyses. The sample did not include male BD participants. Our results indicate that early traumatic events may have a long-lasting deleterious influence on coping abilities in female BD patients. Future prospective studies may investigate whether the negative impact of childhood maltreatment over the course of BD is mediated by individual differences in coping abilities.
Abstract in English:Maternal behavior is regulated by several neurotransmitters, neuropeptides, and hormones. This mini-review focuses on the role of cholecystokinin (CCK), a neuropeptide and gut hormone best known as a satiety signal, in mediating maternal behavior. In addition to the role of CCK in the infant in mother-infant interactions, maternal CCK appears to also be important. We discuss maternal behavior research, mainly in rats, that has examined the effect of administering CCK to dams, CCK-opioid interactions, and maternal behavior in rats that lack CCK1 receptors. We discuss the possibility that CCK might play a role in neurological adjustments during pregnancy that ultimately influence behavioral adaptations by the offspring during lactation. Finally, we hypothesize that maternal CCK is also involved in maternal memory and reward.
Abstract in English:Animals have neural structures that allow them to anticipate environmental changes and then regulate physiological and behavioral functions in response to these alterations. The suprachiasmatic nucleus of the hypothalamus (SCN) is the main circadian pacemaker in many mammalian species. This structure synchronizes the biological rhythm based on photic information that is transmitted to the SCN through the retinohypothalamic tract. The aging process changes the structural complexity of the nervous system, from individual nerve cells to global changes, including the atrophy of total gray matter. Aged animals show internal time disruptions caused by morphological and neurochemical changes in SCN components. The effects of aging on circadian rhythm range from effects on simple physiological functions to effects on complex cognitive performance, including many psychiatric disorders that influence the well-being of the elderly. In this review, we summarize the effects of aging on morphological, neurochemical, and circadian rhythmic functions coordinated by the main circadian pacemaker, the SCN.
Abstract in English:Bipolar disorder (BD) has been associated with marked cognitive impairment, including euthymic periods. Attention is among the most compromised functions in BD. Changes related to learning, memory, and visuospatial abilities can be derived from these attention impairments. The objective of this article is to review the scientific literature on the performance of BD patients in attention tests. A systematic review was performed of controlled studies that assessed attention in patients diagnosed with BD aged between 18 and 65 years. The databases included Medline, LILACS, Cochrane Library, Institute for Scientific Information Web of Knowledge, and Scientific Electronic Library Online (SciELO), and the search encompassed the period from 2008 to 2013. Only studies that had a minimum sample of 10 patients were included. A total of 110 articles fulfilled the inclusion criteria. Compared with healthy control subjects, bipolar patients showed poorer attention performance. Compared with other mental disorders, BD was associated with poorer performance than unipolar depression but better performance than schizophrenia. When bipolar patients in different phases of the disease were compared with one another, the performance of euthymic patients was similar to or better than patients in a depressive state; moreover, manic patients performed worse than depressive patients. Attention is significantly impaired in BD. Attention impairment in BD is milder than in schizophrenia but greater than in unipolar depression. Attention impairment is possibly more severe in manic and depressed episodes than in euthymic periods.
Abstract in English:This study presents a systematic review of validity evidence for neuropsychological batteries. Studies published in international databases between 2005 and 2012 were examined. Considering the specificity of neuropsychological batteries, the aim of the study was to review the statistical analyses and procedures that have been used to validate these instruments. A total of 1,218 abstracts were read, of which 147 involved studies of neuropsychological batteries or tests that evaluated at least three cognitive processes. The full text of each article was analyzed according to publication year, focal instrument of the study, sample type, sample age range, characterization of the participants, and procedures and analyses used to provide evidence of validity. The results showed that the studies primarily analyzed patterns of convergence and divergence by correlating the instruments with other tests. Measures of reliability, such as internal consistency and test-retest reliability, were also frequently employed. To provide evidence of relationships between test scores and external criteria, the most common procedures were evaluations of sensitivity and specificity, and comparisons were made between contrasting groups. The statistical analyses frequently used were Receiver Operating Characteristic analysis, Pearson correlation, and Cronbach's alpha. We discuss the necessity of incorporating both classic and modern psychometric procedures and presenting a broader scope of validity evidence, which would represent progress in this field. Finally, we hope our findings will help researchers better plan the validation process for new neuropsychological instruments and batteries.
Abstract in English:The aim of the present study was to review the tasks that have been used to assess the functioning of the episodic buffer in Baddeley's multicomponent model of working memory. A systematic review of studies published from January 2000 to February 2013 was conducted. The search term "episodic buffer" was used in the Web of Knowledge, PsycINFO, PubMed, Embase, and BVS-Psi databases. The selected articles consisted of empirical studies that used tasks to assess the episodic buffer. Theoretical and review papers and studies with animals were excluded. The final sample comprised 36 papers. The tasks were categorized as experimental tasks or standardized tests. The experimental tasks were grouped by modality (unimodal or crossmodal) and described according to four criteria: task to be performed, type of stimulus used, secondary task employed, if any, and retention interval. The standardized tests included classical measures of working memory. Some tasks were found not to meet experimental criteria that were needed to evaluate the episodic buffer. Moreover, some of the standardized tests did not provide theoretical arguments or empirical evidence that the episodic buffer is recruited to perform them. The results are discussed in the context of the multicomponent model of working memory.
Abstract in English:The present study was based on the hypothesis that a limited amount of information can be simultaneously processed in working memory. The main objective was to determine the capacity of working memory under experiment conditions and express it in terms of bits of information. The bit values of the selected objects used in the experiment were determined using Shannon's formula. The objects were presented to the participants as a set of charts. Each chart presented a four-element object with a particular bit value. The elements constituted commonly known signs, with no difficulty in perception. The efficiency of object recollection from working memory decreased as the bit value of the object increased. In each of the experiments, the bit value of the recollected information oscillated between 26.7 and 31.9. The present results did not confirm sex differences in working memory function.
Abstract in English:Different emotional reactions can be induced by the presentation of visual stimuli with affective content. Emotional stimuli are processed and linked with cognitive functions, such as attention, memory, and anxiety, and have implications in the mental health field. Previous studies have reported that positive and negative emotions tend to change cognitive processes in individuals, ultimately resulting in better and worse performance, respectively. Many studies have emphasized the crucial role of affect in directing attention to relevant stimuli, enhancing learning and memory, facilitating decision making, selecting goals, and conflict resolution. The aim of the present study was to investigate the influence of pleasant visual stimuli on memory, focused attention, and anxiety and further understand the effects of emotional induction. The study investigated the effects of presenting a pleasant visual stimulus in a 1.5 min video to a sample of 145 college students on focused attention, working memory (Personnel Selection Testing, memory subtest), and anxiety (State-Trait Anxiety Inventory). Nonsignificant differences were observed in focused attention, working memory, and anxiety state. Statistically significant differences were found in trait anxiety and the comparison between men and women with regard to memory and anxiety. The positive stimulus was not sufficient to alter cognition or emotion in our research participants. Emotion was found to not be the only factor that influences memory, and other factors appear to be important, such as prior knowledge and cognitive, social, and physiological factors, including personal history, the environment, and culture.
Abstract in English:The present study investigated whether overtraining of the conditional discriminations that are the prerequisites of equivalence class formation strengthens the relations among stimuli in an equivalence class. Two groups of college students formed equivalence classes that consisted of faces that expressed emotions (A) and arbitrary stimuli (B, C, D, and E). The overtraining group had twice as many training trials as the regular training group. For participants who formed equivalence classes, relational strength was evaluated by the generalization of expressed emotions from the A to the D stimuli, which was measured using a semantic differential. An untrained control group showed semantic differential scores that were positive for happy faces, negative for angry faces, and neutral for the D stimuli. For the experimental groups, the D stimuli, when included in equivalence classes, produced scores that were similar to those produced by the equivalent faces. The overtraining group, however, had average values closer to the values of the faces than the regular training group. These results indicate that the amount of training is an experimental parameter that influences the strength of relations between stimuli that are found to be equivalent in matching-to-sample tests.
Abstract in English:Reading and writing are functionally independent operants, in which the acquisition of one does not necessarily result in the acquisition of the other. However, when the main components of these behaviors become members of equivalence classes, the abilities become interdependent. Several studies have taught matching printed words to dictated words and matching pictures to dictated words, producing the emergence of equivalence classes and the emergence of reading and spelling, although reading scores were systematically higher than spelling scores. The present study taught spelling skills and sought to determine whether it affects reading skills. Four students learned to spell 30 Portuguese words using a computer-based constructed response matching-to-sample task. Simultaneously with presentation of the sample (i.e., a picture and its corresponding printed word or a dictated word), the computer screen showed a pool of 14 letters. The task was to select the letters in the correct order to spell a word that corresponded to the sample. Differential consequences followed correct and incorrect responses. Spelling and reading improved for all of the participants. Spelling performance was as accurate as reading performance for three of the four participants. These results replicate previous data that showed the effectiveness of the constructed response matching-to-sample task in teaching spelling and promoting the emergence of reading.
Abstract in English:We have shown before that grasping movements from a given starting position to a given object differ substantially when performed as a typical laboratory task (L) and when they are embedded in an everyday-like context (E). The present study investigates whether this context-dependence is related to the subjects' motivation focus. We manipulated subjects' motivation focus and observed significant effects of Context on performance, as in previous work, but also significant effects of Motivation and Context x Motivation on performance. The interaction term could not be interpreted as generally higher or lower motivation sensitivity in L than in E, and therefore it doesn't support the hypothesis that context-dependence of grasping can be reduced to motivation-dependence. We conclude that some brain areas contribute differently to L and to E, thus producing context-dependence, and that those areas are differently sensitive to motivation.
Abstract in English:The ability to process environmental cues and make advantageous choices has been fundamental during human evolution. Discounting future rewards is a capacity of our evolved mind and could be useful for understanding career decisions. This paper investigated the relationship between real-life plans, career choices, and income indicators based on an evolutionary approach of future discounting. Study 1 analyzed the plans of 200 senior high school students, and Study 2 analyzed a database of 46,649 applicants to a Brazilian public university. The results demonstrated that lower income subjects made career decisions with quicker returns and smaller investments. They included a job in immediate plans more frequently than higher income students who planned to go to a university. Analyzing the applicants' choices, higher income subjects sought courses with greater entrance difficulty. We suggest that individuals adjust career plans and choices according to their socioeconomic conditions and assume different discounting rates by considering risks of failure and future gains.
Abstract in English:The reinforcement omission effect (ROE), reflected by response rates that are higher after reinforcement omission than after reinforcement delivery, has been attributed to both motivational and attentional consequences of the surprising reinforcement omission. These processes depend on the operation of separate amygdala areas and their connections with other brain systems. The interaction between the amygdala and orbitofrontal cortex has been suggested to be important in the modulation of motivational processes. The present study sought to verify whether the mechanisms involved in the ROE depend on the integrity of the orbitofrontal cortex. Prior to acquisition training, rats received bilateral excitotoxic lesions of the orbitofrontal cortex or sham lesions. Following postoperative recovery, the rats were trained on a fixed-interval 12 s limited-hold 6 s signaled schedule of reinforcement. After the acquisition of stable performance, the training was changed from a 100% to 50% schedule of reinforcement. The results showed that rats in both groups exhibited the ROE, with no differences in performance between groups following nonreinforcement. These data do not support the hypothesis that the orbitofrontal cortex is included in the neural substrates related to ROE modulation. The results also showed no difference in response rates between groups in the periods that preceded and followed nonreinforcement. These findings confirm previous studies that showed that the ROE is not related to the facilitation of behavior induced by nonreinforcement.
Abstract in English:A tryptophan diet reduces aggressive behavior in different species, although some controversial findings have been reported. We studied 65 male mice divided into four groups according to increasing dosages of tryptophan (10, 20, 30, and 100 mg/kg) and a control group (vehicle). The first four groups ingested 10, 20, 30, and 100 mg/kg tryptophan together with cellulose vehicle and water by gavage before the behavioral tests that sought to record aggressive behavior. The control group received only the vehicle at the same time that the other groups received the tryptophan solutions. The results showed that low concentrations (10 and 20 mg/kg) of tryptophan decreased (p < .04) the frequency of attack bites and lateral threats (i.e., aggressive components; p < .02) after an encounter with a male intruder without altering locomotor activity. In conclusion, the low concentrations of tryptophan diminished aggressive behavior against a male intruder.
Abstract in English:Simvastatin is one of many hydroxymethylglutaryl-coenzyme-A reductase inhibitors that are prescribed to lower cholesterol. Some emerging evidence indicates that classical music can serve as an effective adjuvant in rats treated with simvastatin. Moreover, simvastatin and classical music have been shown to influence some cognitive functions. To further understand the mechanisms of action, we exposed rats to classical music for 1 month, and then treated them orally with simvastatin. The behavioral experiments suggested that exposure to subchronic simvastatin (1 or 10 mg/kg/day) reduced anxiety levels in the elevated plus-maze and open-field test in rats exposed to Mozart music. The recognition object test results indicated that simvastatin altered non-spatial working memory only at the 1 mg/kg/day dose and improved both short- and long-term object recognition. No significant differences were found between Mozart music and silence in the object recognition test, suggesting that music did not significant affect learning and memory in adult rats. We hypothesize that the anxiolytic, but not object-recognition memory, effects of simvastatin and classical music occur through similar mechanisms, providing an important foundation for future preclinical and clinical research.