37 research outputs found
Effects of Picture Size Reduction and Blurring on Emotional Engagement
The activity of basic motivational systems is reflected in emotional responses to arousing stimuli, such as natural pictures. The manipulation of picture properties such as size or detail allows for investigation into the extent to which separate emotional reactions are similarly modulated by perceptual changes, or, rather, may subserve different functions. Pursuing this line of research, the present study examined the effects of two types of perceptual degradation, namely picture size reduction and blurring, on emotional responses. Both manipulations reduced picture relevance and dampened affective modulation of skin conductance, possibly because of a reduced action preparation in response to degraded or remote pictures. However, the affective modulation of the startle reflex did not vary with picture degradation, suggesting that the identification of these degraded affective cues activated the neural circuits mediating appetitive or defensive motivation
Does Presentation Format Influence Visual Size Discrimination in Tufted Capuchin Monkeys (Sapajus spp.)?
Most experimental paradigms to study visual cognition in humans and non-human species are based on discrimination tasks involving the choice between two or more visual stimuli. To this end, different types of stimuli and procedures for stimuli presentation are used, which highlights the necessity to compare data obtained with different methods. The present study assessed whether, and to what extent, capuchin monkeys\u27 ability to solve a size discrimination problem is influenced by the type of procedure used to present the problem. Capuchins\u27 ability to generalise knowledge across different tasks was also evaluated. We trained eight adult tufted capuchin monkeys to select the larger of two stimuli of the same shape and different sizes by using pairs of food items (Experiment 1), computer images (Experiment 1) and objects (Experiment 2). Our results indicated that monkeys achieved the learning criterion faster with food stimuli compared to both images and objects. They also required consistently fewer trials with objects than with images. Moreover, female capuchins had higher levels of acquisition accuracy with food stimuli than with images. Finally, capuchins did not immediately transfer the solution of the problem acquired in one task condition to the other conditions. Overall, these findings suggest that - even in relatively simple visual discrimination problems where a single perceptual dimension (i.e., size) has to be judged - learning speed strongly depends on the mode of presentation
First valence, then arousal: the temporal dynamics of brain electric activity evoked by emotional stimuli
The temporal dynamics of the neural activity that implements the dimensions valence and arousal during processing of emotional stimuli were studied in two multi-channel ERP experiments that used visually presented emotional words (experiment 1) and emotional pictures (experiment 2) as stimulus material. Thirty-two healthy subjects participated (mean age 26.8 +/- 6.4 years, 24 women). The stimuli in both experiments were selected on the basis of verbal reports in such a way that we were able to map the temporal dynamics of one dimension while controlling for the other one. Words (pictures) were centrally presented for 450 (600) ms with interstimulus intervals of 1,550 (1,400) ms. ERP microstate analysis of the entire epochs of stimulus presentations parsed the data into sequential steps of information processing. The results revealed that in several microstates of both experiments, processing of pleasant and unpleasant valence (experiment 1, microstate #3: 118-162 ms, #6: 218-238 ms, #7: 238-266 ms, #8: 266-294 ms; experiment 2, microstate #5: 142-178 ms, #6: 178-226 ms, #7: 226-246 ms, #9: 262-302 ms, #10: 302-330 ms) as well as of low and high arousal (experiment 1, microstate #8: 266-294 ms, #9: 294-346 ms; experiment 2, microstate #10: 302-330 ms, #15: 562-600 ms) involved different neural assemblies. The results revealed also that in both experiments, information about valence was extracted before information about arousal. The last microstate of valence extraction was identical with the first microstate of arousal extraction
Autosomal recessive nondystrophic myotonia report of a case with unusual clinical course: relato de um caso com aspectos clĂnicos atĂpicos
We describe the case of a girl with a probable autosomal recessive form of nondystrophic hereditary myotonia whose clinical findings are more compatible with the dominant ones mainly myotonia congenita of Thomsen or myotonia fluctuans. Besides the clinical aspects of the atypical form presented by our patient, the efficacy of the more available drugs employed for the treatment of myotonia congenita is briefly discussed
Effect of clonidine on the human acoustic startle reflex
The present study investigated in healthy human volunteers whether clonidine reduced the amplitude of the acoustic startle reflex and whether this effect, if found, was due to an accelerated rate of habituation. Subjects were presented with startle-eliciting noise-bursts after intravenous (iv) infusion of clonidine (1.5 microgram/kg) and saline on separate days. Clonidine significantly reduced the amplitude of the acoustic startle reflex (as indexed by the eyeblink component) relative to the saline treated condition. This effect was neither due to an accelerated rate of habituation of the startle reflex nor to the sedative effect of clonidine. These findings complement an earlier report (Morgan et al. 1993) that yohimbine augments the amplitude of the startle reflex in man. Taken together, the two reports indicate a new model for the clinical investigation of central alpha2 adrenoceptor function in humans
Detecção de doenças sexualmente transmissĂveis em ambientes clĂnicos e nĂŁo clĂnicos na Cidade de Salvador, Bahia, Brasil Screening of sexually transmitted diseases in clinical and non-clinical settings in Salvador, Bahia, Brazil
O objetivo deste trabalho foi avaliar (1) a aceitação de rastreamento para DST em ambientes nĂŁo clĂnicos por indivĂduos assintomáticos, (2) os fatores de risco e prevalĂŞncia de DST em ambientes nĂŁo clĂnicos e clĂnicos e (3) o rastreamento nĂŁo clĂnico de populações assintomáticas como um mĂ©todo viável para controle das DST. Recrutamos 139 participantes masculinos e 486 femininos entre 18 e 30 anos em clĂnica de planejamento familiar, escolas e comunidades de baixa renda. Inquirimos os recrutados sobre sintomas de DST e comportamentos de risco para DST/HIV e os testamos para gonorrĂ©ia, clamĂdia, sĂfilis e HIV. Exceto pelo HIV, as mulheres recrutadas diretamente da comunidade apresentavam maior prevalĂŞncia de DST do que as que procuravam a clĂnica. O rastreamento das DST em ambientes nĂŁo clĂnicos no Brasil Ă© aceitável e vantajoso para jovens em comunidades de baixa renda. Participantes infectados provavelmente nunca teriam procurado assistĂŞncia, sido testados ou tratados. Medidas para o controle das DST podem ser implementadas em qualquer lugar onde se alcancem as populações de risco e transformadas em rotina nos serviços de saĂşde, mesmo entre indivĂduos com problemas nĂŁo relacionados com DST.<br>The objectives were to study: (1) acceptance of STD screening in non-clinical settings for asymptomatic individuals; (2) risk factors and STD prevalence among individuals in non-clinical and clinical settings; and (3) non-clinical screening of asymptomatic populations as a feasible method for STD control. We recruited 139 males and 486 females between 18 and 30 years of age from a family planning clinic, schools, and community centers in low-income neighborhoods. We asked about STD symptoms and STD/HIV risk behaviors and tested the individuals for gonorrhea, Chlamydia, syphilis, and HIV. Except for HIV, women recruited directly from the community had higher STD rates than those who came in for care at the clinic. Screening in non-clinical settings in Brazil is feasible and has a high yield among young adults in low-income communities. Infected participants would likely never have otherwise sought care or been tested or treated. STD control efforts could be implemented in any site that can reach populations at risk and become a routine procedure in health care settings where people report for problems unrelated to STDs