Scielo RSS <![CDATA[Psychology & Neuroscience]]> vol. 7 num. 2 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b><i>Psychology & Neuroscience</i> indicators in 2013</b>: <b>evidence of growth and internationalization</b>]]> <![CDATA[<b>Self-face perception</b>: <b>Individual differences and discrepancies associated with mental self-face representation, attractiveness and self-esteem</b>]]> Self-face perception plays an important role in self-consciousness and personal identity as well as in social exchanges and well-being. Despite its significance, little is known about how individuals represent their faces internally. This study explored mechanisms of self-face perception in three experiments. First, participants chose from two images (self-face image vs. self-image with manipulated facial features) which one was their veridical image and which one they liked most. Afterwards, participants could (digitally) manipulate their facial features to increase their attractiveness (either to themselves or to an imagined other/s). Results showed that self-face recognition was better when veridical faces were paired with 'clones' with larger facial features or when all facial features were enlarged concurrently. Moreover, up to half of the participants preferred smaller noses and larger eyes and manipulated their self-images accordingly. State (but not trait) self-esteem was inversely correlated with eye, mouth and nose size manipulations made to increase one's attractiveness. The results indicate that a certain tolerance for error in self-face recognition might be required to maintain a consistent facial identity during one's lifespan. The discovered preference for neotenous features and discrepancies between one's perceived and one's veridical face and their link to state self-esteem are discussed. <![CDATA[<b>Recognition of facial emotional expressions and its correlation with cognitive abilities in children with Down syndrome</b>]]> Down syndrome (DS) is one of the most common chromosomal abnormalities. Delays in cognitive development are found in the first years of life. As years pass, it may turn into intellectual deficiencies that unfold into several aspects, including difficulty recognizing emotional facial expressions. The present study investigated the recognition of six universal facial emotional expressions in a population of children aged 6-11 years who were divided into two groups: DS group and typically developing children (TDC) group. We used the Perception Test of Facial Emotional Expressions (Teste de Percepção de Emoções Faciais; TEPEF) and Wechsler Intelligence Scale for Children (WISC-III) and found that children with DS presented alterations in the recognition of expressions of disgust, surprise, and fear, whereas the recognition of happiness, sadness, and anger was maintained at a level comparable to the TDC group. Participants with DS presented significant positive correlations between sadness and Picture completion, Mazes, Arithmetic, Vocabulary, Digits, Verbal IQ, Verbal Comprehension Index, and Working Memory Index. All other facial expressions showed significant negative correlations with the Intelligence Quotient and WISC-III factorial index subtests. Absence of correlations was found among the TEPEF's six facial expressions and Information, Coding, Symbols, and Working Memory Index. The contribution of this study is related to understanding the characteristics of the recognition of facial emotions in children with DS, an important component of social relationships with their peers, schools, and families. <![CDATA[<b>Effects of affective valence on a mixed Spatial Correspondence Task</b>: <b>a reply to Proctor (2013)</b>]]> The present study investigated the influence of emotional valence on the spatial stimulus-key location correspondence effect in three experiments using the Affective Spatial Correspondence task (AffSCt). We initially reanalyzed the results of Conde et al. (2011) according to the model proposed by Proctor (2013). In that study, compatible and incompatible responses were chosen according to the participants' team preference. In one block, the volunteers had to press a key on the same side for the Favorite team and on the opposite side for the Rival team. In another block, a reverse code was used. We found that responses were faster for the Favorite-compatible/Rival-incompatible condition (614 ms) compared with the Favorite-incompatible/Rival-compatible condition (691 ms). The same experimental arrangement was replicated in another Brazilian city, and similar results were found. Additionally, we employed non-affective "fake" soccer teams as a control condition, and no mapping-rule effect was observed. Finally, a final experiment that used the same design but different non-affective stimuli (yellow and blue bars) was performed to provide further evidence that the valence effect in the present experimental paradigm only occurs with affective stimuli. As expected, non-affective stimuli did not produce an overall advantage for any mapping rules, corroborating earlier findings with similar mixed designs. The results confirmed the previous findings and validity of the AffSCt as a methodology to investigate the effects of emotional valence on stimulus-response correspondence. However, we are unable to provide a conclusive explanation to support the several hypotheses proposed previously in our paper and by Proctor (2013). <![CDATA[<b>Effect of disparity on the perception of motion-defined contours</b>]]> We present three experiments that explored the effect of binocular disparity on the perception of contours defined by motion in a Spatiotemporal Boundary Formation. Depending on the disparity, the stimulus is perceived as an object that moves behind a holed surface (occluded configuration) or as a luminous transparency that moves over a surface that contains dots (occluding configuration). In all of the experiments, we used a Vernier task to assess the strength of contour perception. In the first experiment, we measured acuity as a function of disparity for a range of speeds and dot densities. The results showed that, despite the difference in the percepts, acuity was similar in both situations, replicating the dependence on speed and dot density demonstrated in previous studies. In the second experiment, the results showed that the dynamics of contour integration were identical for both occluded and occluding configurations. In the third experiment, we tested whether the mechanism of contour integration works independently from the interpretation of the scene. In this experiment, we inverted the disparity during stimulus presentation so that the stimulus switched between occluded and occluding configurations. The results showed that the switch of the depth order increased the threshold to the value obtained with a shorter presentation time. This might be produced by a resetting of the integration process driven by the change of depth order. The results are discussed within a conceptual model that places the process of contour integration in the context of the perception of objects in a Spatiotemporal Boundary Formation. <![CDATA[<b>Early postnatal protein malnutrition impairs recognition memory in rats<i> (Rattus norvegicus)</i></b>]]> The initial period of postnatal life is critical for brain development in both rodents and humans. Protein malnutrition imposed during this period produces irreversible consequences that include structural, neurochemical, and functional changes in the central nervous system, leading to long-term alterations in behavioral and cognitive parameters, such as memory. In this work, previously malnourished rats were evaluated in recognition memory procedures. Male Wistar rats (n = 132) were given isocaloric diets that contained 6% (malnourished) or 16% (control) protein until 49 days of life. A nutritional recovery period with standard lab chow was imposed from 50 to 70 days of age when the experiments began. Four different procedures of recognition memory were conducted. The analysis showed that malnourished rats had lower body weight compared with control rats from the first week of life until the end of the experiments (p < .05). In the memory procedures, malnourished rats had lower recognition indices compared with controls (p < .05). Well-nourished rats had a tendency to direct their exploration toward novelty, whereas malnourished rats explored the objects in the same proportion, demonstrating that they did not recognize the novelty. Protein malnutrition imposed early in life is suggested to affect hippocampal formation, the development of which is concentrated during this developmental period, and thus impair memory consolidation. <![CDATA[<b>Neonatal lipopolysaccharide exposure induces sexually dimorphic sickness behavior in adult rats</b>]]> The aim of the present study was to evaluate whether neonatal exposure to lipopolysaccharide (LPS; 50 µg/kg, i.p., on postnatal day 2) induces depressive- and/or anxiety-like effects and sexually dimorphic responses in rats challenged with LPS (100 µg/kg, i.p.) in adulthood. The results revealed that males presented a less depressive state in the forced swim test and exhibited no changes in general motor activity in the open field test. Females exhibited an increase in sickness behavior, revealing different behavioral strategies in response to a bacterial disease. The male rats also exhibited higher cell proliferation, reflected by bone marrow and peripheral blood counts, and female rats exhibited a decrease in corticosterone levels. No changes were observed in the elevated plus maze or peripheral cytokine levels (interleukin-1β and tumor necrosis factor-α). Neonatal exposure to LPS induced sexually dimorphic behavioral, neuroendocrine, and immune effects after an LPS challenge in adulthood, differentially affecting male and female susceptibility to disease later in life. <![CDATA[<b>Effect of postnatal intermittent hypoxia on locomotor activity and neuronal development in rats tested in early adulthood</b>]]> The present study evaluated the effects of postnatal intermittent hypoxia on locomotor activity and neuronal cell survival in early adulthood rats. During a critical period of brain development on postnatal day (PD) 7-11, male rat pups were exposed to intermittent hypoxia and randomly assigned to three experimental groups: (1) intermittent hypoxia, (2) normoxia, and (3) control (unhandled). One and a half months later on PD56, a behavioral test was conducted, and cell survival was estimated in the hilus, dental gyrus, and CA1 and CA3 subfields of the hippocampus, nucleus accumbens shell and core, dorsal and ventral striatum, and prefrontal cortex. Our results showed that intermittent hypoxia produced hyperactivity that correlated well with psychomotor agitation observed in patients with schizophrenia. Moreover, post-hypoxic rats exhibited a reduction of the number of neurons in the hilar region of the hippocampus and dorsal striatum, structures that have been neuropathologically associated with schizophrenia.These findings suggest that intermittent hypoxia can modify the pattern of locomotor activity and selectively affect neurons in rats tested in early adulthood. <![CDATA[<b>Evidence of criterion validity for the Benton Visual Retention Test</b>: <b>comparison between older adults with and without a possible diagnosis of Alzheimer's disease</b>]]> The present study sought to provide evidence of criterion validity for the Benton Visual Retention Test by making comparisons between older adults with and without a possible diagnosis of Alzheimer's disease. The control group was composed of 50 older adults, and the clinical group was composed by 16 subjects. Descriptive and inferential statistics were performed, including χ² test, F and Wald statistics, t-test, analyses of covariance with α = .05, and effect size calculations. We used a sociodemographic data form, the Geriatric Depression Scale-15, and Mini Mental State Examination. Despite the small clinical sample size, the results pointed to evidence of validity for the Benton Visual Retention Test for Administration A (Memory) and Administration C (Copy). The clinical group had significantly poorer performance on most scores. These results also indicate important deficits in other neuropsychological functions in Alzheimer's disease. <![CDATA[<b>Evaluation of body representation in children with hemiplegic cerebral palsy</b>: <b>toward the development of a neuropsychological test battery</b>]]> Clinical observations indicate that many children with hemiplegic cerebral palsy (HCP) exhibit a lack of use or disregard of the affected upper limb. The aim of the present study was to develop, adapt, and verify the psychometric properties of a neuropsychological battery to assess body perception and representation disturbances in children with HCP. Three groups of children participated in this study, who took part in different phases of the validation process: one group of typically developing children (TD; n = 30; aged 4-6 years) and two groups of HCP children (HCP1: n = 12, aged 5-10 years; HCP2: n = 49, aged 5-13 years). Because no cognitive-neuropsychological model of body representation has been specifically developed for children, the tasks were designed based on a cognitive-neuropsychological model developed for adults. The chosen model comprises three levels of body representation: body schema, body structural description, and body image. The following steps were adopted in developing the instrument: development and choice of the tasks, selection and preparation of stimuli, adequacy and improvement of the instrument, semantic analysis of items, internal consistency, and feasibility and acceptability of application for TD and HCP children. The final set of tasks and items was chosen to balance the levels of difficulty and internal consistency. We concluded that the final battery was adequate and can be used to assess body representation disturbances in children with HCP. <![CDATA[<b>Impaired acuity of the approximate number system in 22q11.2 microdeletion syndrome</b>]]> A magnitude comparison deficit has been frequently observed in velocardiofacial syndrome (Del22q11.2). We hypothesized that this deficit extends to impairments in the acuity of the approximate number system (ANS). Three groups of children aged 8-14 years were investigated: Del22q11.2 children (n = 12), low cognitive ability children (LCA; n = 12), and matched typically developing children (TD; n = 28). All children were assessed with a simple reaction time task and symbolic and nonsymbolic number comparison tasks. To estimate the acuity of the ANS, the Weber fraction (w) was calculated from the nonsymbolic comparison task. The Del22q11.2 group exhibited a significantly higher w compared with the other groups. Importantly, no significant differences were found in w between the TD and LCA groups. The performance pattern of the Del22q11.2 group was similar to the TD group in the symbolic comparison task, and both of these groups had better performance than the LCA group. The impairment of ANS acuity observed in individuals with Del22q11.2 cannot be explained by deficits in general processing speed because no significant group differences were found in the simple reaction time task. These results suggest that lower acuity of the ANS should be added to the behavioral phenotype of Del22q11.2. The absence of impaired ANS acuity in the LCA group is consistent with the hypothesis that number sense is a relatively specific and autonomous domain. Investigations of low ANS acuity in mathematics learning difficulties and Del22q11.2 should be intensified. <![CDATA[<b>A possible correlation between vestibular stimulation and auditory comprehension in children with attention-deficit/hyperactivity disorder</b>]]> Twenty children, aged 10 to 12 years with attention-deficit/hyperactivity disorder (ADHD), were selected to study the effect of vestibular stimulation on auditory perception and sensitivity using the Integrated Visual and Auditory Continuous Performance Test (IVA CPT; a neuropsychological test that is applied in occupational therapy clinics). The present study examined children based on the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision. After obtaining guardian and parental consent, the children were enrolled in the study and randomly matched according to age across intervention and control groups. The IVA CPT was applied as a pre-test. The children in the intervention group then received vestibular stimulation during therapy sessions twice per week for 10 weeks. The IVA CPT assessment (post-test) was then applied in both groups. The mean pre- and post-test scores were compared across groups. The statistical analyses revealed a significant difference in improvement in auditory comprehension. In conclusion, the present findings suggest that vestibular training is a reliable and powerful treatment option for ADHD, especially when combined with other training. Stimulating the sense of balance highlights the important interaction between inhibition and cognition. <![CDATA[<b>Case study</b>: <b>saturday cognitive habilitation program for children with prenatal alcohol exposure</b>]]> This case study describes the outcomes of a Saturday community intervention program for children suspected of or affected by prenatal exposure to alcohol who exhibited learning deficits. Five children participated in the program and received individualized interventions designed to address learning and academic deficits in either reading or mathematics. Often children affected by prenatal alcohol exposure exhibit deficits with executive processes, including metacognitive functioning, that interfere with learning. Instruction to improve metacognitive skills was incorporated into the intervention programs. The metacognitive training was adapted from the Math Interactive Learning Experience (MILE) and targeted the children's skills to plan, organize, shift, and evaluate problem solving strategies. Standardized tests of nonverbal reasoning and academic achievement were administered before and after the children received interventions to measure progress. The results indicated that four of the five children who participated in the program showed clinically significant gains with scores increasing from the borderline or low average to the average range on measures of nonverbal reasoning, reading comprehension, or mathematics reasoning. One child showed no gains on measures of nonverbal reasoning and reading. A variety of factors including age, cognitive profile, session attendance, and access to special education and other intervention services may have influenced the child's progress. Overall, the case reviews suggest that the interventions show promise to remediate learning problems of children affected by prenatal alcohol exposure in a community setting. <![CDATA[<b>An ethical discussion of the use of transcranial direct current stimulation for cognitive enhancement in healthy individuals</b>: <b>a fictional case study</b>]]> Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique. Because of its low cost, ease of use, safety, and portability, tDCS has been increasingly investigated for therapeutic purposes in neuropsychiatric disorders and in experimental neuropsychological studies with healthy volunteers. These experiments on healthy cognition have shown significant effects on working memory, decision-making, and language. Such promising results have fomented reflections on studying tDCS to enhance or modify normal cognitive function, a concept described by some as "cosmetic" neurology. As the field evolves, discussing whether the use of tDCS in these situations is appropriate is important, including how bioethical principles may help resolve these challenges. In this article, we present some examples of the effects of tDCS on cognition in healthy participants as a starting point for this ethical debate. We envision a futuristic "Brain Boosting" tDCS clinic that specializes in cosmetic neurology and cognitive enhancement. Using the typical cases of a fictitious Dr. Icarus as a discussion starting point, we raise some issues that are both humorous and provocative about the use of tDCS in healthy people. The importance of this work is to ask relatively new questions regarding cosmetic neurology in the field of neuromodulation and discuss the related ethical conflicts. <![CDATA[<b>On the current neuroenhancement use of transcranial direct current stimulation by healthy individuals - a non-fictional snap-shot</b>: <b>commentary on Lapenta et al. 2014</b>]]> This commentary examines the pros and cons of the fictitious enhancement scenarios used in Lapenta et al. 2014. Then it gives a non-fictional impression of the current self-enhancement use of transcranial direct current stimulation (tDCS) by healthy individuals and discusses the ethical issues involved. <![CDATA[<b>Electrophysiological investigation of the functional overlap between semantic and equivalence relations</b>]]> Recent research using the event-related potential (ERP) technique has shown that equivalence relations have properties similar to genuine semantic relations. This study aimed to advance electrophysiological investigations of the functional overlap between semantic and equivalence relations. The N400 component, an index of semantic processing, was used to measure whether semantic relations were experimentally established between arbitrary stimuli. The stimuli became equivalent via a matching-to-sample training designed to maximize the establishment of equivalence relations and the strength of the classes. Non-equivalent pairs of stimuli elicited larger N400 responses than equivalent pairs in electrodes placed over the central and parietal scalp regions, providing additional support for the assumption that stimulus equivalence is an appropriate model of semantic relations. Latency of the N400 component was shorter than in previous studies, probably due to experimental parameters that maximized relational strength. These data raise the possibility that N400 latency may provide a continuous measure of relational strength, thus supplementing the all-or-none character of equivalence tests based on matching to sample. <![CDATA[<b>Blank-comparison matching-to-sample reveals a false positive symmetry test in a capuchin monkey</b>]]> A positive symmetry test result was obtained with a capuchin monkey that had previously exhibited virtually errorless AB and BA arbitrary matching-to-sample (MTS) with different stimuli. The symmetry test (BA) followed the acquisition of a new AB relation. It seemed possible, however, that the positive result could have occurred through the exclusion of previously defined comparison stimuli and not because the new AB and BA relations had the property of symmetry. To assess this possibility, a blank-comparison MTS procedure was implemented that permitted the separate assessment of select and reject (i.e., exclusion) control with both baseline and BA matching relations. In this assessment, the monkey did not exhibit reliable BA matching when exclusion was not possible, thus showing that the symmetry result was a false positive. However, the study demonstrated the feasibility of using a blank comparison MTS procedure with capuchins. The present results may set the stage for more successful methodology for establishing desired forms of relational stimulus control in capuchins and ultimately improving the assessment of relational learning capacity in that species, other nonhuman species, and nonverbal humans. <![CDATA[<b>Exclusion performance in visual simple discrimination in dogs (<i>Canis familiaris</i>)</b>]]> Choices based on exclusion have been investigated in different species because of its emergent nature, leading to evidence of rudimentary symbolic behavior in non-verbal organisms. Simple discrimination procedures provide a simple method to investigate exclusion performance, in which each trial consists of the simultaneous presentation of two stimuli, one with a positive function (S+) and one with a negative function (S-). In exclusion probe trials, an undefined stimulus (UnS) is presented with a familiar S-, and choices based on exclusion may lead to choosing the UnS, excluding the previously known S-. Novelty control trials (S+/UnS) are also conducted to assess the possible preference for the UnS. In this case, if performance is not controlled by novelty, then the subjects must choose the S+ and not the UnS. The present study investigated exclusion performance in visual simple simultaneous discrimination tasks in eight dogs. The results indicated that seven of eight dogs showed evidence of exclusion performance (p < .05). These findings corroborate the literature that shows that dogs are capable of responding by exclusion, suggesting that potentially symbolic behavior may rely on basic behavioral learning and conditioning principles. <![CDATA[<b>Assessing restricted stimulus control in typically developing preschool children and bees (<i>Melipona quadrifasciata</i>)</b>]]> This study established a simple simultaneous discrimination between a pair of two-element compound visual stimuli in children (Experiment 1) and bees (Melipona quadrifasciata, Experiment 2). The contingencies required discriminative control by the compound and the question was whether the accurate stimulus control reached at this level would hold for each individual element of the compound. After baseline reached stability, probe trials assessed stimulus control by each single element of both S+ and S-. Average data showed that children (Exp. 1) tended to show stimulus control by a single element of the S+ compound. In Experiment 2 three of four bees showed stimulus control by both elements of S+ and did not respond or responded only infrequently to the elements of the S-. The children's decline in discrimination accuracy in probe trials, along with its maintenance during the baseline, replicated previous findings showing the development of restricted stimulus control (RSC). The precise stimulus control shown by the bees indicated that all elements correlated with reinforcement acquired stimulus control over their behavior; this confirms the extensive literature on visual discriminative learning in bees, but due to the small number of subjects it is premature to say that bees do not develop RSC. <![CDATA[<b>Modulation of the startle response in verbal aggressors</b>: <b>differences among stimuli with distinct affective social content</b>]]> The emotional response to socially affective stimuli is an important variable to understand aggression. Research is lacking on the psychophysiological basis of verbal aggressiveness that would allow the identification of these emotional responses. The aim of the present study was to investigate modulation of the startle response in verbal aggressors during the presentation of visual stimuli with different affective social content. Acoustic startle probes were administered to 29 verbal aggressors and 28 non-verbal aggressors while viewing slides from the International Affective Picture System, which contains sexual, filial, neutral, unpleasant, and suffering of others pictures. Verbal aggressors showed a low startle response to sexual pictures compared with non-verbal aggressors and a potentiated startle response to neutral pictures compared with unpleasant, filial, and suffering of others pictures. These differences were observed among women. Based on previous studies, the present results may be explained by high testosterone levels, low cortisol levels, and moral disengagement exhibited by verbally aggressive women. <![CDATA[<b>Discrimination of anxiety- versus panic-like behavior in the wall lizard <i>Tropidurus oreadicus</i></b>]]> A behavioral test battery is proposed for wall lizards (Tropidurus oreadicus) that consists of inducing tonic immobility (TI) followed by post-TI behavioral scoring. After the induction of TI, the usual behavioral sequence was flight followed by freezing and tongue-flicking and/or thigmotaxis, with flight being more probable than freezing. These sequences were not observed after restraint in a normal upward position (which induced freezing but not TI) or after handling (which increased the probability of tongue-flicking). Alprazolam and imipramine selectively decreased the duration of TI as well as the following flight and freezing behavior. Tongue-flicking was increased by diazepam and alprazolam, whereas fluoxetine decreased it. Finally, thigmotaxis was reduced by diazepam, alprazolam, and imipramine but increased by fluoxetine. These results suggest that panic and anxiety can be discriminated pharmacologically in wall lizards. <![CDATA[<b>6-Hydroxydopamine lesions in the medial prefrontal cortex of rats exposed to a peak-interval procedure</b>]]> Impaired temporal control is symptomatic of several neurological disorders; recently, it has been implicated in schizophrenia. An animal model of schizophrenia using 6-hydroxydopamine (6-OHDA) infused to the medial pre-frontal cortex (mPFC) was employed to examine its effects on temporal control. Twelve rats were trained on a peak-interval procedure (PIP) until stable patterns of behavior were obtained. Rats infused with 6-OHDA responded less during peak trials and their peak functions were flatter than sham rats. These results are consistent with similar studies with transgenic mice with increased striatal dopamine D2 receptor activity. Lesions in the mPFC decreased motivation to respond in a PIP. These effects may be considered analogous to negative symptoms of schizophrenia.