|
Possible low- and high-level mechanisms for the perception of biological motion| old_uid | 2214 |
|---|
| title | Possible low- and high-level mechanisms for the perception of biological motion |
|---|
| start_date | 2007/02/09 |
|---|
| schedule | 14h-16h |
|---|
| online | no |
|---|
| summary | The perception of movements of people around us is one of the most important behavioral tasks that we have to carry out in our everyday life. It is thus not surprising that humans exhibit a high degree of sensitivity in perceiving the actions of con-specifics. In this talk I will deal with possible low- and high-level mechanisms for the visual perception of biological motion. The talk will be divided into two parts.
In the first part I will deal with the problem on how the visual system can robustly generalize from normal stimuli to impoverished point-light stimuli. I will present experimental and theoretical results suggesting that this generalization might be accomplished by an extraction of simple mid-level optic flow features within coarse
spatial arrangement, potentially exploiting relatively simple neural circuits. In particular, our data suggest that recognition of biological motion might be accomplished by detecting mid-level optic flow features with relatively coarse spatial localization. The computationally challenging reconstruction of precise position information from degraded stimuli might not be required.
In the second part of the talk I will present experimental data about the possible influence of the observer's motor programs on the visual perception of similar actions. In our experimental design, the visual recognition of gait patterns from point-light stimuli was assessed before and after nonvisual motor training. During this training, subjects were blindfolded and learned a novel coordinated upper-body movement based only on verbal and haptic feedback. The learned
movement matched one of the visual test patterns. Despite the absence of visual stimulation during training, we observed a selective improvement of the visual recognition performance for the learned movement. Furthermore, visual recognition performance after training correlated strongly with the accuracy of the execution of the learned motor pattern. These results prove, for the first time, that motor learning has a direct and highly selective influence on visual action recognition that is not mediated by visual learning. |
|---|
| responsibles | Romand |
|---|
| |
|