Allan Pablo Lameira

Hand posture effects on handedness recognition as revealed by the simon effect.

We investigated the influence of hand posture in handedness recognition, while varying the spatial correspondence between stimulus and response in a modified Simon task. Drawings of the left and right hands were displayed either in a back or palm view while participants discriminated stimulus handedness by pressing either a left or right key with their hands resting either in a prone or supine posture. As a control, subjects performed a regular Simon task using simple geometric shapes as stimuli. Results showed that when hands were in a prone posture, the spatially corresponding trials (i.e., stimulus and response located on the same side) were faster than the non-corresponding trials (i.e., stimulus and response on opposite sides). In contrast, for the supine posture, there was no difference between corresponding and non-corresponding trials. Control experiments with the regular Simon task showed that the posture of the responding hand had no influence on performance. When the stimulus is the drawing of a hand, however, the posture of the responding hand affects the spatial correspondence effect because response location is coded based on multiple reference points, including the body of the hand.

A compatibilidade estímulo-resposta como modelo para o estudo do comportamento motor

When a visual stimulus is randomly displayed either to the left or to the right of the fixation point, manual response is faster when both the response key and the stimulus are located at the same side (compatible condition) than at opposite sides (incompatible condition). In a spatial compatibility task, a difference of 30-40 ms is found between the manual reaction times (MRT) of compatible and incompatible conditions. In the Simon effect, though the criterion to response selection is primarily stimulus shape (or color), the stimulus position also influences the MRT, either increasing it in the compatible condition or delaying it in the incompatible condition. The Simon effect can be inverted if the subject has recently performed incompatible tasks, showing that short-term memory processes elicited by the incompatible associations can modulate stimulus-response relationships based on long-term memory.

Postura da mão e imagética motora: um estudo sobre reconhecimento de partes do corpo

OBJECTIVE: Recognition of body parts activates specific somatosensory representations in a way that is similar to motor imagery. These representations are implicitly activated to compare the body with the stimulus. In the present study, we investigate the influence of proprioceptive information relating to body posture on the recognition of body parts (hands). It proposes that this task could be used for rehabilitation of neurological patients. METHODS: Ten right-handed volunteers participated in this experiment. The task was to recognize the handedness of drawings of a hand that were presented in different perspectives and several orientations. For drawings of a right hand, the volunteers pressed the right key, and for drawings of a left hand, they pressed the left key. The volunteers underwent two sessions: one with their hands in a prone posture and the other with their hands in a supine posture. RESULTS: The manual reaction time was longer for perspectives and orientations for which the real movement was difficult to achieve. This showed that, during the task, motor representations were activated to compare the body with the stimulus. Furthermore, the subjects posture had an influence in relation to specific perspectives and orientations. CONCLUSIONS: These results showed that motor representations are activated to compare the body with the stimulus, and that the position of the hand influences this resonance between the stimulus and the body part.

Memória de longo prazo modulada pela memória de curto prazo

Quando um estimulo ocorre aleatoriamente a esquerda ou a direita, a resposta e mais rapida quando estimulo e resposta estao no mesmo lado (condicao compativel) do que em lados opostos (condicao incompativel). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estimulo, a posicao deste influencia o Tempo de Reacao Manual (TRM). O efeito Simon corresponde a diferenca entre as medias dos TRMs nas duas condicoes (incompativel e compativel). Neste trabalho, estudamos como uma tarefa previa de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntarios realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compativel (14 voluntarios), encontramos um efeito Simon de 24 ms. No incompativel (14 voluntarios), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulacao da memoria de longo prazo por uma tarefa envolvendo a memoria de curto prazo.Cuando un estimulo ocurre aleatoriamente a la izquierda o a la derecha, la respuesta es mas rapida cuando el estimulo y la respuesta estan del mismo lado (condicion compatible), de que cuando estan en lados opuestos (condicion incompatible). En la prueba de Simon, el color o la forma del estimulo determina la respuesta, pero este es mas rapido cuando hay una correlacion espacial entre el estimulo y la respuesta. En este trabajo, estudiamos la modulacion del efecto Simon por la tarea de la compatibilidad espacial en la cual uno dedo indice respondio. Veintiocho voluntarios realizaron la prueba de compatibilidad (14 la compatible y 14 la incompatible). Despues el voluntario realizo la prueba de Simon. En el grupo compatible, encontramos efecto de Simon de 21 ms. Sin embargo, en el grupo incompatibles, ocurrio un efecto de Simon inverso de -16 ms. Estos resultados demuestran una modulacion de la memoria a largo plazo por la memoria a corto plazo.

Hemispheric specialization for processing soccer related pictures: The role of supporter fanaticism.

The response-hemispheric congruence predicts that manual reaction times (MRTs) are faster when responses to the positive stimulus are done with the right hand and to the negative stimulus with the left hand than the opposite arrangement. This effect has been attributed to the hemispheric specialization for emotional processing, in which the left and the right hemispheres are related, respectively, to positive and negative emotions, eliciting a congruence effect when the affective stimulus valence and the responding hand coincide within the same hemisphere. Here, we investigated if this congruence effect can be detected when stimuli represent the favorite and rival soccer teams and whether the results depend on supporter emotional attachment. Volunteers were divided into high and low fanaticism groups according to the Football Supporter Fanaticism Scale. A significant interaction between fanaticism and stimuli field revealed that only the lower fanaticism group exhibited the usual left visual field advantage. There was also a congruence effect for the lower fanaticism group, in which congruent responses were faster than incongruent ones. However, for the higher fanaticism group there were no significant differences for the 2 congruency conditions. Results were discussed as evidence for distinct brain asymmetry patterns among football supporters depending on the level of fanaticism.

Long term memory modulated by short term memory

Quando um estimulo ocorre aleatoriamente a esquerda ou a direita, a resposta e mais rapida quando estimulo e resposta estao no mesmo lado (condicao compativel) do que em lados opostos (condicao incompativel). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estimulo, a posicao deste influencia o Tempo de Reacao Manual (TRM). O efeito Simon corresponde a diferenca entre as medias dos TRMs nas duas condicoes (incompativel e compativel). Neste trabalho, estudamos como uma tarefa previa de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntarios realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compativel (14 voluntarios), encontramos um efeito Simon de 24 ms. No incompativel (14 voluntarios), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulacao da memoria de longo prazo por uma tarefa envolvendo a memoria de curto prazo.Cuando un estimulo ocurre aleatoriamente a la izquierda o a la derecha, la respuesta es mas rapida cuando el estimulo y la respuesta estan del mismo lado (condicion compatible), de que cuando estan en lados opuestos (condicion incompatible). En la prueba de Simon, el color o la forma del estimulo determina la respuesta, pero este es mas rapido cuando hay una correlacion espacial entre el estimulo y la respuesta. En este trabajo, estudiamos la modulacion del efecto Simon por la tarea de la compatibilidad espacial en la cual uno dedo indice respondio. Veintiocho voluntarios realizaron la prueba de compatibilidad (14 la compatible y 14 la incompatible). Despues el voluntario realizo la prueba de Simon. En el grupo compatible, encontramos efecto de Simon de 21 ms. Sin embargo, en el grupo incompatibles, ocurrio un efecto de Simon inverso de -16 ms. Estos resultados demuestran una modulacion de la memoria a largo plazo por la memoria a corto plazo.

Memoria a largo plazo modulada por la memoria a corto plazo

Quando um estimulo ocorre aleatoriamente a esquerda ou a direita, a resposta e mais rapida quando estimulo e resposta estao no mesmo lado (condicao compativel) do que em lados opostos (condicao incompativel). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estimulo, a posicao deste influencia o Tempo de Reacao Manual (TRM). O efeito Simon corresponde a diferenca entre as medias dos TRMs nas duas condicoes (incompativel e compativel). Neste trabalho, estudamos como uma tarefa previa de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntarios realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compativel (14 voluntarios), encontramos um efeito Simon de 24 ms. No incompativel (14 voluntarios), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulacao da memoria de longo prazo por uma tarefa envolvendo a memoria de curto prazo.Cuando un estimulo ocurre aleatoriamente a la izquierda o a la derecha, la respuesta es mas rapida cuando el estimulo y la respuesta estan del mismo lado (condicion compatible), de que cuando estan en lados opuestos (condicion incompatible). En la prueba de Simon, el color o la forma del estimulo determina la respuesta, pero este es mas rapido cuando hay una correlacion espacial entre el estimulo y la respuesta. En este trabajo, estudiamos la modulacion del efecto Simon por la tarea de la compatibilidad espacial en la cual uno dedo indice respondio. Veintiocho voluntarios realizaron la prueba de compatibilidad (14 la compatible y 14 la incompatible). Despues el voluntario realizo la prueba de Simon. En el grupo compatible, encontramos efecto de Simon de 21 ms. Sin embargo, en el grupo incompatibles, ocurrio un efecto de Simon inverso de -16 ms. Estos resultados demuestran una modulacion de la memoria a largo plazo por la memoria a corto plazo.