Signaled two-way avoidance learning using electrical stimulation of the inferior colliculus as negative reinforcement: effects of visual and auditory cues as warning stimuli

The inferior colliculus is a primary relay for the processing of auditory information in the brainstem. The inferior colliculus is also part of the so-called brain aversion system as animals learn to switch off the electrical stimulation of this structure. The purpose of the present study was to determine whether associative learning occurs between aversion induced by electrical stimulation of the inferior colliculus and visual and auditory warning stimuli. Rats implanted with electrodes into the central nucleus of the inferior colliculus were placed inside an open-field and thresholds for the escape response to electrical stimulation of the inferior colliculus were determined. The rats were then placed inside a shuttle-box and submitted to a two-way avoidance paradigm. Electrical stimulation of the inferior colliculus at the escape threshold (98.12 ± 6.15 (A, peak-to-peak) was used as negative reinforcement and light or tone as the warning stimulus. Each session consisted of 50 trials and was divided into two segments of 25 trials in order to determine the learning rate of the animals during the sessions. The rats learned to avoid the inferior colliculus stimulation when light was used as the warning stimulus (13.25 ± 0.60 s and 8.63 ± 0.93 s for latencies and 12.5 ± 2.04 and 19.62 ± 1.65 for frequencies in the first and second halves of the sessions, respectively, P<0.01 in both cases). No significant changes in latencies (14.75 ± 1.63 and 12.75 ± 1.44 s) or frequencies of responses (8.75 ± 1.20 and 11.25 ± 1.13) were seen when tone was used as the warning stimulus (P>0.05 in both cases). Taken together, the present results suggest that rats learn to avoid the inferior colliculus stimulation when light is used as the warning stimulus. However, this learning process does not occur when the neutral stimulus used is an acoustic one. Electrical stimulation of the inferior colliculus may disturb the signal transmission of the stimulus to be conditioned from the inferior colliculus to higher brain structures such as amygdala

Facilitatory effects of an auditory warning stimulus in a visual location identification task and a visual shape identification task

The occurrence of a weak auditory warning stimulus increases the speed of the response to a subsequent visual target stimulus that must be identified. This facilitatory effect has been attributed to the temporal expectancy automatically induced by the warning stimulus. It has not been determined whether this results from a modulation of the stimulus identification process, the response selection process or both. The present study examined these possibilities. A group of 12 young adults performed a reaction time location identification task and another group of 12 young adults performed a reaction time shape identification task. A visual target stimulus was presented 1850 to 2350 ms plus a fixed interval (50, 100, 200, 400, 800, or 1600 ms, depending on the block) after the appearance of a fixation point, on its left or right side, above or below a virtual horizontal line passing through it. In half of the trials, a weak auditory warning stimulus (S1) appeared 50, 100, 200, 400, 800, or 1600 ms (according to the block) before the target stimulus (S2). Twelve trials were run for each condition. The S1 produced a facilitatory effect for the 200, 400, 800, and 1600 ms stimulus onset asynchronies (SOA) in the case of the side stimulus-response (S-R) corresponding condition, and for the 100 and 400 ms SOA in the case of the side S-R non-corresponding condition. Since these two conditions differ mainly by their response selection requirements, it is reasonable to conclude that automatic temporal expectancy influences the response selection process.

Analysis of exploratory eye movements in patients with schizophrenia during visual scanning of projective tests' figures

OBJECTIVE: Compare pattern of exploratory eye movements during visual scanning of the Rorschach and TAT test cards in people with schizophrenia and controls. METHOD: 10 participants with schizophrenia and 10 controls matched by age, schooling and intellectual level participated in the study. Severity of symptoms was evaluated with the Positive and Negative Syndrome Scale. Test cards were divided into three groups: TAT cards with scenes content, TAT cards with interaction content (TAT-faces), and Rorschach cards with abstract images. Eye movements were analyzed for: total number, duration and location of fixation; and length of saccadic movements. RESULTS: Different pattern of eye movement was found, with schizophrenia participants showing lower number of fixations but longer fixation duration in Rorschach cards and TAT-faces. The biggest difference was observed in Rorschach, followed by TAT-faces and TAT-scene cards. CONCLUSIONS: Results suggest alteration in visual exploration mechanisms possibly related to integration of abstract visual information.

Uma experiência didática de corrosão usando colorimetria visual

In this paper, a simple and rapid method of evaluating galvanized steel sheet corrosion in a CuSO4 solution, as an experimentation proposal for corrosion teaching. Galvanized steel corrosion is present in tanks and tubing by leading of natural or industrial waters which contain soluble copper compounds. This was the rationale for choosing the Cu2+ ions solution as an oxidizing agent. The method principle is based on visual colorimetry because the used oxidant has an intense blue color. Thus, a change in its concentration as a result of the corrosive process can be followed by a color intensity change in the solution thereby allowing evaluation of the corrosion rate.

Inhibition of return, gap effect and saccadic reaction time to a visual target

Simple manual reaction time (MRT) to a visual target (S2) is shortened when a non-informative cue (S1) is flashed at the S2 location shortly before the onset of S2 (early facilitation). Afterwards, MRT to S2 appearing at the S1 location is lengthened (inhibition of return - IOR). Similar results have been obtained for saccadic reaction time (SRT). Moreover, when there is a temporal gap between offset of the fixation point (FP) and onset of a target (gap paradigm), SRT is shorter than SRT in an overlap paradigm (FP remains on). In the present study, we determined SRT to S2 (10º) after presenting S1 at the same eccentricity (10º) or at a parafoveal position (2º) in the same or in the opposite hemifield. In addition, we employed both gap and overlap paradigms. Twelve subjects were asked not to respond to S1 (2º or 10º) to the right or to the left of FP, but to respond by making a saccadic movement in response to S2. We obtained the following results: 1) a 40-ms gap effect, 2) an interaction between gap effect and IOR, 3) a 39-ms delay (IOR) when S2 appeared at the cued (S1) position, and 4) a smaller (17 ms) but significant inhibition when S1 occurred at 2º in the ipsilateral hemifield. Thus, a parafoveal (2º) S1 elicits an inhibition of SRT towards ipsilateral peripheral targets. Since an inhibition of the ipsilateral hemifield by a 1º eccentric cue has been reported to occur when manual responses are employed, we suggest that the postulated functional link between covert and overt orienting of attention is also valid for parafoveal cues.

Relative contribution of expectancy and immediate arousal to the facilitatory effect of an auditory accessory stimulus

An auditory stimulus speeds up a digital response to a subsequent visual stimulus. This facilitatory effect has been related to the expectancy and the immediate arousal that would be caused by the accessory stimulus. The present study examined the relative contribution of these two influences. In a first and a third experiment a simple reaction time task was used. In a second and fourth experiment a go/no-go reaction time task was used. In each of these experiments, the accessory stimulus preceded the target stimulus by 200 ms for one group of male and female volunteers (G Fix). For another group of similar volunteers (G Var) the accessory stimulus preceded the target stimulus by 200 ms in 25% of the trials, by 1000 ms in 25% of the trials and was not followed by the target stimulus in 50% of the trials (Experiments 1a and 1b) or preceded the target stimulus by 200 ms in 6% of the trials and by 1000 ms in 94% of the trials (Experiments 2a and 2b). There was a facilitatory effect of the accessory stimulus for G Fix in the four experiments. There was also a facilitatory effect of the accessory stimulus at the 200-ms stimulus onset asynchrony for G Var in Experiments 1a and 1b but not in Experiments 2a and 2b. The facilitatory effects observed were larger in the go/no-go task than in the simple task. Taken together, these results suggest that expectancy is much more important than immediate arousal for the improvement of performance caused by an accessory stimulus.

Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.)

Reproductive fish behavior is affected by male-female interactions that stimulate physiological responses such as hormonal release and gonad development. During male-female interactions, visual and chemical communication can modulate fish reproduction. The aim of the present study was to test the effect of visual and chemical male-female interaction on the gonad development and reproductive behavior of the cichlid fish Nile tilapia, Oreochromis niloticus (L.). Fifty-six pairs were studied after being maintained for 5 days under one of the four conditions (N = 14 for each condition): 1) visual contact (V); 2) chemical contact (Ch); 3) chemical and visual contact (Ch+V); 4) no sensory contact (Iso) - males and females isolated. We compared the reproductive behavior (nesting, courtship and spawning) and gonadosomatic index (GSI) of pairs of fish under all four conditions. Visual communication enhanced the frequency of courtship in males (mean ± SEM; V: 24.79 ± 3.30, Ch+V: 20.74 ± 3.09, Ch: 0.1 ± 0.07, Iso: 4.68 ± 1.26 events/30 min; P < 0.05, two-way ANOVA with LSD post hoc test), induced spawning in females (3 spawning in V and also 3 in Ch+V condition), and increased GSI in males (mean ± SEM; V: 1.39 ± 0.08, Ch+V: 1.21 ± 0.08, Ch: 1.04 ± 0.07, Iso: 0.82 ± 0.07%; P < 0.05, two-way ANOVA with LSD post hoc test). Chemical communication did not affect the reproductive behavior of pairs nor did it enhance the effects of visual contact. Therefore, male-female visual communication is an effective cue, which stimulates reproduction among pairs of Nile tilapia.

Interaction between affordance and handedness recognition: a chronometric study

The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject's hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation.

Análise da correlação entre a escala visual-análoga e o Tinnitus Handicap Inventory na avaliação de pacientes com zumbido

Um dos tópicos mais questionado nos estudos clínicos sobre zumbido é o método de mensuração do mesmo. As Escalas Visual-Análogas (EVAs) e o Tinnitus Handicap Inventory (THI) são freqüentemente utilizados para este fim. OBJETIVO: Verificar a correlação entre os escores da EVA e do THI em pacientes com zumbido neurossensorial através de um estudo prospectivo. MATERIAL E MÉTODO: 43 pacientes com zumbido neurossensorial quantificaram o zumbido pelos dois métodos, sendo os escores comparados através do Coeficiente de Relação de Spearman. RESULTADOS: Foi observada correlação entre os escores da EVA e do THI. CONCLUSÃO: Em pacientes com zumbido neurossensorial existe correlação entre os escores da EVA e do THI.

Avaliação visual da qualidade da estrutura do solo em sistemas de uso das terras

Sistemas sustentáveis de produção agropecuária demandam solos com boa estrutura, por isso, são necessários métodos eficientes para avaliação dessa estrutura. Objetivou-se, com este estudo, aplicar a metodologia de avaliação visual da estrutura do solo, em áreas previamente cobertas por Floresta com Araucária, em longo período de uso após o desmatamento. Selecionaram-se áreas sob três tipos de usos: floresta nativa, pastagem e cultivo agrícola, considerados como tratamento, sendo realizadas dez amostragens por tipo de uso. Nas amostras coletadas, procedeu-se à avaliação da qualidade da estrutura do solo, seguida da análise estatística dos dados, por meio da análise de variância e do teste de separação de médias. Observaram-se diferenças significativas nos valores médios de escore entre as áreas avaliadas. Os solos da área com floresta apresentaram Qe (Qualidade visual) médio = 1.68, estatisticamente semelhante ao dos solos sob pastagem (Qe médio = 2.25) e inferior ao dos solos cultivados, Qe médio = 2.40. Os valores de Qe obtidos por avaliação visual da qualidade da estrutura do solo mostraram-se eficientes para identificar diferenças entre os sistemas de uso do solo.

Access to information: assessment of the use of automated interaction technologies in call centers

With the purpose of at lowering costs and reendering the demanded information available to users with no access to the internet, service companies have adopted automated interaction technologies in their call centers, which may or may not meet the expectations of users. Based on different areas of knowledge (man-machine interaction, consumer behavior and use of IT) 13 propositions are raised and a research is carried out in three parts: focus group, field study with users and interviews with experts. Eleven automated service characteristics which support the explanation for user satisfaction are listed, a preferences model is proposed and evidence in favor or against each of the 13 propositions is brought in. With balance scorecard concepts, a managerial assessment model is proposed for the use of automated call center technology. In future works, the propositions may become verifiable hypotheses through conclusive empirical research.

Interaction between information systems and work in the Brazilian banking sector

This article presents the results of a research to understand the conditions of interaction between work and three specific information systems (ISs) used in the Brazilian banking sector. We sought to understand how systems are redesigned in work practices, and how work is modified by the insertion of new systems. Data gathering included 46 semi-structured interviews, together with an analysis of system-related documents. We tried to identify what is behind the practices that modify the ISs and work. The data analysis revealed an operating structure: a combination of different practices ensuring that the interaction between agents and systems will take place. We discovered a structure of reciprocal conversion caused by the increased technical skills of the agent and the humanization of the systems. It is through ongoing adjustment between work and ISs that technology is tailored to the context and people become more prepared to handle with technology.

VISUAL ART AND REGULATORY FIT MESSAGES ON CONSUMER EVALUATIONS

ABSTRACT In this study, we demonstrate that the art infusion effect, in which the presence of visual art causes a positive impact on consumers' perceptions of products and advertising messages, might have a moderation effect on regulatory fit and non-fit messages. We investigate the impact of visual art on advertisement evaluations in regulatory (non-) fit conditions. Regulatory focus theory suggests that consumers rely on their motivational focus (prevention vs. promotion) for their evaluations and decisions. Usually, consumers prefer products that fit with their personal motivational focus. In the present study, the results of three experiments indicate that using visual art with a promotion or prevention fit message is recommended, while non-art images increase message persuasiveness when non-fit messages are presented. Therefore, not all information compatible with the consumer's motivational focus are best evaluated. When non-art images are presented, non-fit messages might be more persuasive.

Antropologia visual, práticas antigas e novas perspectivas de investigação

A antropologia visual nasceu em meados do século XIX com a "era da reprodutibilidade técnica" e da expansão industrial. Como se reformula hoje, na era da globalização e da transformação digital, essa disciplina ou convergência disciplinar? Voltada inicialmente para a documentação e preservação de práticas culturais ameaçadas, a antropologia de urgência, como se transformou ao longo do tempo em formas narrativas visuais, sonoras, audiovisuais e, mais recentemente, digitais? Orientada em primeiros passos para alimentar e enriquecer as coleções dos museus, como passa hoje por meio de múltiplas formas e suportes para o espaço público à procura de novos espectadores/atores (ou públicos)? Inicialmente instrumentação que pareceria garantir a objetividade, atribuindo-se-lhe o estatuto de tecnologia de pesquisa ou mesmo de auxiliar de pesquisa, como se confrontou com novos paradigmas epistemológicos ou se antecipou a eles? Voltada sobretudo para o registo das técnicas materiais e rituais e depois para as palavras e as sonoridades, como se orienta hoje no âmbito de novos objetos de estudo como a antropologia da arte, a antropologia do design, a cultura visual em contextos de processos acelerados de transformação social e cultural? Acrescentamos ainda mais duas perguntas às inquietações que nos fazem refletir sobre essa temática: como se repensa atualmente a antropologia visual no âmbito da antropologia? O que fazer com a antropologia visual hoje? Procuraremos traçar algumas formas de práticas antigas que adquirem nova e maior pertinência na era atual (trabalho com os arquivos, a memória, a relação entre o passado e o projeto, os objetos, a cultura material) e perspectivar novas oportunidades, novas práticas, novos objetos de estudo.

Validade da aferição da acuidade visual realizada pelo professor em escolares de 1ª à 4ª série de primeiro grau de uma escola pública do município de São Paulo, Brasil

Trata-se de avaliação da medida da acuidade visual pelo professor, comparativamente àquela efetuada pelo médico-oftalmologista, utilizando-se ambos da tabela optométrica de Snellen. Éste estudo foi realizado em decorrência do Plano de Oftalmologia Sanitária Escolar (POSE), em desenvolvimento no Estado de São Paulo, que atinge escolares de 1ª série, classe especial e pré-primário das escolas estaduais de 1º grau, onde a atuação dos professores constitui fator básico da programação, principalmente no seu aspecto educativo e na verificação da acuidade visual. Foram testados 1.352 escolares de 1ª a 4ª série de 1º grau de um estabelecimento de ensino do município de São Paulo (SP) em 1975. Encontrou-se uma concordância de resultados em 80,86% dos casos. Com a diferença de 2 linhas entre os resultados do professor e do médico, constataram-se 122 casos (9,02%) e, com a diferença de 3 linhas, 54 casos (3,99%). À medida em que se consideravam diferenças maiores, decrescia progressivamente o número de casos discordantes encontrados. Observou-se que, à medida em que aumentava a desigualdade de aferição entre o professor e o oftalmologista, isto se verificava em ambos os olhos, o que evidencia uma dificuldade de interpretação daquelas crianças para responder o teste. Considerou-se altamente válida a aplicação do teste de acuidade visual pelo professor devidamente treinado, com a finalidade de triagem a nível de escola, como um dos aspectos para identificar alunos necessitados de exame médico-oftalmológico.