Distribuição da atenção visual dentro de áreas indicadas: evidência baseada em julgamentos de ordem temporal

Three experiments were performed to investigate the distribution of attention across the visual field and the possibility of attentional resources to be more concentrated inside an abrupt onset frame (cue). The participants performed a temporal order judgment task of two letters presented in sequence; one letter presented inside and the other outside the frame. The results showed that the information presented inside the frame had its perceptual latency shortened in relation to the information presented outside the frame in experimental conditions where the frame orientation, the distance between the two letters and the cue onset time were manipulated. The advantage of the information presented inside the frame was attributed to the displacement of attention to the area delimited by the frame. The results contribute to the understanding of visual perception, showing that attentional resources may be redistributed inside the borders of a geometric figure.Três experimentos foram realizados para investigar a distribuição da atenção pelo campo visual e a possibilidade dos recursos de atenção serem mais concentrados no interior de uma moldura (dica) de início abrupto. Os participantes realizaram uma tarefa de julgamento de ordem temporal de duas letras apresentadas em seqüência; uma letra apresentada dentro e a outra fora da moldura. Os resultados mostraram que a informação apresentada dentro da moldura teve a sua latência perceptual encurtada em relação à informação apresentada fora da moldura em condições experimentais onde a orientação da moldura, a distância entre as duas letras e o tempo de exposição da moldura foram manipulados. Esta vantagem para a informação apresentada dentro da moldura foi atribuída ao deslocamento da atenção para a área delimitada pela moldura. Os resultados contribuem para o entendimento da percepção visual, mostrando que recursos de atenção podem ser redistribuídos dentro das bordas de uma figura geométrica.Co-ordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Substâncias administradas para a indução da Doença de Alzheimer em ratos

Estimates of the progressive expansion of Alzheimer's disease (AD) worldwide indicate the need for constant studies on this pathology, still without cure. Studies have investigated AD in non-human animal models using substances that induced AD. The present study aimed to review the literature on the substances and procedures used in laboratory to reproduce AD in rats. We selected 44 of 111 studies analyzed, keeping only papers that induced AD by chemical substances. The identified substances were aluminum, beta-amyloid, colchicine, d-galactose, scopolamine, streptozocin and homocysteine. It was verified that of the 44 articles, the most used substance was beta-amyloid, the main biomarker of AD. Although different studies have replicated results that simulate the occurrence of AD in rats and the treatments performed with rats in the laboratory appear promising, no cure has yet been found.Las estimaciones sobre la expansión de los casos de la enfermedad de Alzheimer (EA) en el mundo indican la necesidad de constantes estudios sobre esta patología aún sin cura. Los estudios han investigado la EA en modelos animales no humanos utilizando sustancias químicas que inducen a la EA. El presente estudio tuvo como objetivo realizar una revisión de la literatura sobre las sustancias usadas en laboratorio para reproducir la EA en ratas. Se seleccionaron 44 de 111 estudios analizados, manteniendo sólo los artículos que indujeron a EA por sustancias químicas. Las sustancias identificadas fueron el aluminio, la beta-amiloide, la colchicina, la d-galactosa, la escopolamina, la estreptozocina y la homocisteína. Se comprobó que de los 44 artículos, la sustancia más utilizada fue la beta-amiloide, principal biomarcador de la EA. Aunque diferentes estudios han replicado resultados que simulan la ocurrencia de EA en ratas y los tratamientos realizados con ratas en laboratorio parecen prometedores, no se ha encontrado ninguna cura.As estimativas sobre a expansão dos casos da Doença de Alzheimer (DA) no mundo indicam a necessidade de constantes estudos sobre essa patologia ainda sem cura. Os estudos têm investigado a DA em modelos animais não-humanos utilizando substâncias químicas que induzem à DA. O presente estudo teve por objetivo realizar uma revisão da literatura sobre as substâncias usadas em laboratório para reproduzir a DA em ratos. Foram selecionados 44 de 111 estudos analisados, mantendo apenas os artigos que induziram a DA por substâncias químicas. As substâncias identificadas foram o alumínio, a beta-amiloide, a colchicina, a d-galactose, a escopolamina, a estreptozocina e a homocisteína. Verificou-se que dos 44 artigos, a substância mais utilizada foi a beta-amiloide, principal biomarcador da DA. Embora diferentes estudos tenham replicado resultados que simulam a ocorrência de DA em ratos e os tratamentos realizados com ratos em laboratório pareçam promissores, nenhuma cura foi encontrada ainda

Stimulus affective valence reverses spatial compatibility effect

In spatial compatibility tasks, the Reaction Time to right-side stimuli is shorter for right key responses (compatible condition) than for left key responses (incompatible condition) and vice-versa for left-side stimuli. Similar results have been found when the stimulus location is not relevant for response selection, such as in the Simon task. The Simon effect is the difference between the reaction times for non-corresponding and corresponding conditions. The Simon effect and its variants may be modulated by using emotional stimuli. However, until now, no work has studied how the affective valence of a stimulus influences spatial compatibility effects along the horizontal dimension. The present study investigated this issue by using small lateralized figures of soccer team players as stimuli. In the experiment, a compatible or incompatible response was chosen according to the team shirt. In one block, for the Favorite team, the volunteers had to press the key on the same side as the stimulus hemifield but the opposite-side key for the Rival team. In the other block, a reverse code had to be used. Fourteen right-handed volunteers were tested. Mean reaction times were subjected to analysis of variance with the following variables: Preference (Favorite/Rival), Hemifield (Left/Right), and Response Key (Left/Right). A three-way interaction was found (F1,13 = 6.60, p = .023), showing that the spatial compatibility effects depended on Preference. The Favorite team player elicited the usual spatial compatibility pattern, but for the Rival team player, the reverse effect was found, with incompatible responses being faster than compatible responses. We propose that this modulation may result from approach/avoidance reactions to the Favorite and Rival teams, respectively. Moreover, we suggest as a corollary that the classic spatial compatibility task is a powerful tool for investigating approach/avoidance effects.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNPq(FAPERJ) Fundacao de Amparo a Pesquisa do Estado do Rio de JaneiroCNPq - PIBIC-UFFUFF - PROP

The distribution of visual attention: evidence based on temporal order judgment (TOJ) task.

Nós realizamos três experimentos para estudar a distribuição da atenção pelo campo visual e a possibilidade dos recursos atentivos serem mais concentrados no interior de uma área delimitada por uma figura geométrica de aparecimento abrupto. Os participantes realizaram uma tarefa de julgamento de ordem temporal (JOT), na qual julgaram a ordem de duas letras apresentadas em seqüência. Uma letra foi apresentada dentro e a outra fora de uma moldura, que não foi relacionada com a tarefa. A percepção de ordem temporal foi influenciada pela moldura nos três experimentos. A variação da distância entre as duas letras e o tempo de exposição da moldura foram manipulados, alterando o julgamento dos participantes. Os resultados demonstraram uma variação na concentração dos recursos atentivos em função da distância entre as duas letras e em função do tempo de exposição da moldura. Os resultados sugerem que a forma de uma figura geométrica pode produzir uma reorganização dos recursos atentivos, que parecem estar mais concentrados dentro do que fora das suas bordas.We conducted three experiments to examine the distribution of visual attention and the possibility of the attentional resources to be concentrated along an area delimited by a frame of abrupt onset. The participants performed a temporal order judgment (TOJ) task, in which judged the order of two letters presented in sequence. One letter was showed inside and other outside a frame that was not related to the task. Perception of temporal order was influenced by the frame in all experimental conditions. The judgement of participants was affected by the distance between the two letters and the cue lead time. The findings suggest that the form of a geometric figure can reallocate the resources of attention that should be more concentrated inside than outside of its borders

The distribution of visual attention on non-adjacent areas of the visual field

A atenção visual é um conjunto de processos que permite processar preferencialmente uma informação visual em um dado momento. Muitos modelos de atenção visual propõem que a atenção pode ser destinada e focalizada a uma única localização no espaço por vez quando dicas espaciais são usadas para orientar esse deslocamento. Porém, diferentes estudos têm encontrado evidências de que em circunstâncias apropriadas, a atenção pode ser destinada a áreas não adjacentes do campo visual. O objetivo deste estudo foi investigar a distribuição da atenção por estas áreas quando o tamanho e a localização de dicas espaciais periféricas foram manipulados. Os resultados sugerem que a atenção visual pode ser destinada a mais de uma localização ao mesmo tempo como um gradiente com picos de processamento, mas que o tamanho das áreas indicadas não deve ser determinante para isso ocorrer. Os resultados indicam também que a habilidade para dividir a atenção pode depender da localização em que os eventos ocorrem em relação aos lados do campo visual. Eventos que ocorrem em lados opostos têm uma chance maior de serem beneficiados por focos independentes de atenção, enquanto eventos que ocorrem do mesmo lado do campo visual parecem ter mais chance de serem processados por um foco único de atenção, mas essa diferença parece ser relativa do que absoluta. Este estudo traz também contribuições para o entendimento do processo de focalização quando diferentes tarefas são solicitadas, revelando que o ajuste da atenção ao tamanho de uma área indicada é mais facilmente verificado em tarefas que requerem a detecção rápida de um alvo do que quando julgamentos de ordem temporal são solicitados.Visual attention is a set of processes which permits a preferential processing of visual information in a given moment. Several models of visual attention propose that attention might be allocated and focused in only one location by time when spatial cues are used to orient this displacement. However, different studies have been finding evidences that in appropriate circumstances, attention can be deployed to non-adjacent areas of the visual field. The main objective of the present study was to investigate the distribution of attention on these areas when the size and the localization of peripheral spatial cues were manipulated. The results suggest that visual attention can be deployed to more than one location simultaneously as a gradient with peaks in processing quality. The results also indicate that the ability to divide attention might depend on the localization in which the events occur in relation to each hemifield. Events that occur in different hemifields have more chance to take advantage of independent focus of attention while events that happen on the same hemifield have more chance to be processed by a single attentional focus but that this difference seems to be relative than absolute. This study have also contributions for the understanding of the focalization process when different tasks are requested revealing that the adjustment of the attentional focus to the size of a cued area is more easily verified in tasks that require fast detection of an target than when temporal order judgments are requested

Aff_Faces

Conde et al (2011) reported a modulation of the spatial compatibility effect by the affective valence of soccer team figures. For Favorite team, it was faster to respond by pressing the key located on the stimulus side than the opposite key (ipsi- and contralateral keys, respectively). For Rival team, this pattern was reversed. These findings were interpreted as being due to approach and avoidance reactions which facilitate both the ipsilateral response to a positive stimulus and the contralateral response to a negative one and vice-versa. This hypothesis was challenged by arguing that there is no spatial compatibility effect when a mixed-rule task was used and that approach/avoidance reactions are not elicited when a keyboard was employed to execute the responses. Alternatively, it was proposed that Conde et al. (2011) results were due to task-set effects. Here, emotional faces (Happy, Angry and Fearful) faces were used to test the generality of effects elicited by affective stimuli and to disentangle task-set and approach/avoidance reactions hypotheses. We found that there is no task-set effect when the Happiness-Anger pair was used. Moreover, for the Happiness/Fear pair, there was an interaction between valence and spatial compatibility within a block of trials. These results suggest that: (i) the interaction between valence and spatial compatibility in the Affective SC task modulates the spatial compatibility effect; (ii) this modulation elicits a task-set effect that varies according to the pair of affective stimuli and (iv) the task-set effect may be due to an automatic orientation of the visual attention to the positive stimulus which facilitates the ipsilateral response conjoined with an inhibition of the ipsilateral response to the aversive stimulus, simulating a reversed compatibility effect to the negative stimulus

Aff_Faces

Conde et al (2011) reported a modulation of the spatial compatibility effect by the affective valence of soccer team figures. For Favorite team, it was faster to respond by pressing the key located on the stimulus side than the opposite key (ipsi- and contralateral keys, respectively). For Rival team, this pattern was reversed. These findings were interpreted as being due to approach and avoidance reactions which facilitate both the ipsilateral response to a positive stimulus and the contralateral response to a negative one and vice-versa. This hypothesis was challenged by arguing that there is no spatial compatibility effect when a mixed-rule task was used and that approach/avoidance reactions are not elicited when a keyboard was employed to execute the responses. Alternatively, it was proposed that Conde et al. (2011) results were due to task-set effects. Here, emotional faces (Happy, Angry and Fearful) faces were used to test the generality of effects elicited by affective stimuli and to disentangle task-set and approach/avoidance reactions hypotheses. We found that there is no task-set effect when the Happiness-Anger pair was used. Moreover, for the Happiness/Fear pair, there was an interaction between valence and spatial compatibility within a block of trials. These results suggest that: (i) the interaction between valence and spatial compatibility in the Affective SC task modulates the spatial compatibility effect; (ii) this modulation elicits a task-set effect that varies according to the pair of affective stimuli and (iv) the task-set effect may be due to an automatic orientation of the visual attention to the positive stimulus which facilitates the ipsilateral response conjoined with an inhibition of the ipsilateral response to the aversive stimulus, simulating a reversed compatibility effect to the negative stimulus

Influence of happy and fearful faces on spatial compatibility effects

There is a theoretical debate about the mechanisms involved in the influence of the affective valence on the compatible (ipsilateral) and the incompatible (contralateral) responses. Conde et al. (2011) suggested that the modulation of the spatial compatibility effect by the stimulus affective valence resulted from approach and avoidance reactions towards positive and negative valence stimuli, respectively. The Favorite team would yield approach reactions and the Rival team, avoidance reactions, which reversed the spatial compatibility effect for the aversive stimuli (Rival team) while preserving the compatibility effect for the positive stimuli (Favorite team). As an alternative, Proctor (2013) proposed that Conde et al.’s (2011) findings were a combined effect of an interaction of stimuli affective valence and opposed mapping rules between blocks of trials. Following this proposition, any effect in the Affective SC task when blocks of trials are compared must be considered a mapping rule (task-set) effect. Yamaguchi et al. (2017) used flowers and spiders as affective stimuli in two tasks with lateralized responses on a keyboard and found a mapping-rule effect, too. Here, innate affective stimuli (Happy and Fearful faces) were used to study the influence of intervening variables such as task-set effect, emotional valence and/or behavioral tendencies (Approach/Avoidance responses to affective stimuli) on the spatial compatibility effect. Our results were similar to those found in other experiments that employed the Affective SC tasks (Conde et al., 2011, 2014a,b; Cavallet et al., 2016; Yamaguchi et al., 2017). There was an interaction between Valence and Compatibility. For the positive valence stimulus (Happy face), responding by pressing the ipsilateral key (compatible response) was faster than with the contralateral key (incompatible response). In contrast, for the negative valence stimulus (Fearful face), compatible response was slower than the incompatible one. Moreover, ipsilateral (compatible) response to Fearful face was slower than contralateral (incompatible) response to Happy face. These results were also analyzed by employing the Proctor (2013) modified procedure which Congruence and Valence were used as independent variables. Responses in Congruent set (Happy-compatible/Fearful incompatible) were faster than in Incongruent one (Happy-incompatible/Fearful-compatible). Moreover, there was an interaction between Congruence and Valence and the ipsilateral (compatible) response to Fearful face is slower than the contralateral (incompatible) responses to Happy face. This difference occurs inside the Incongruent set showing that there is a modulation of compatibility effect by affective valence that cannot be attributed to different mapping-rules. These results lead us to propose that the onset of a positive peripheral stimulus will elicit an automatic orientation of attention to its position facilitating the response with the ipsilateral key and inhibiting one with the contralateral key. For an aversive stimulus, this facilitation would be followed by an inhibition of the ipsilateral response. In consequence, under Congruent set, there will be facilitations of the ipsilateral (compatible) response to Happy face and contralateral (incompatible) response to Fearful face. In contrast, under Incongruent set, there will be inhibitions of the contralateral response to Happy Face and of the ipsilateral response to Fearful face. Similar effects caused by facilitation of compatible responses to positive stimuli and inhibition of compatible responses to negative stimuli (and vice-versa) may occur along the sagittal (near/far) and vertical dimensions which are currently used in Approach/Avoidance tasks

Grey and white matter volumes either in treatment-naïve or hormone-treated transgender women: a voxel-based morphometry study

Abstract Many previous magnetic resonance imaging (MRI) studies have documented sex differences in brain morphology, but the patterns of sexual brain differences in transgender women – male sex assigned at birth – with a diagnosis of gender dysphoria (TW) have been rarely investigated to date. We acquired T1-weighted MRI data for the following four (n = 80) groups: treatment-naïve TW (TNTW), TW treated with cross-sex hormones for at least one year (TTW), cisgender men, and cisgender women (cisgender individuals as controls). Differences in whole-brain and regional white matter volume and grey matter volume (GMV) were assessed using voxel-based morphometry. We found lower global brain volumes and regional GMVs in a large portion of the posterior-superior frontal cortex in the cisgender women group than in the TTW and cisgender men groups. Additionally, both transgender groups exhibited lower bilateral insular GMVs than the cisgender women group. Our results highlight differences in the insula in both transgender groups; such differences may be characteristic of TW. Furthermore, these alterations in the insula could be related to the neural network of body perception and reflect the distress that accompanies gender dysphoria