08:30 - 10:00
Tue-A7-Talk IV-
Tue-Talk IV-
Room: A7
Chair/s:
Belkis Ezgi Arikan, Dimitris Voudouris
Touch is one of the most critical senses, as it provides information about the state of our own body and of the external world. For instance, tactile input from different surfaces influences how humans interact with these surfaces. Meanwhile, tactile sampling and processing is also influenced by our movements. In the real world, touch can be directed to different textures, surfaces and objects, with different goals in mind (from contacting a texture to exploring a surface to changing an object’s position). The proposed symposium will discuss recent findings on the interplay between touch and movement in naturalistic settings. More specifically, we will address how tactile processing is
modulated by various tactile inputs, during motion, and under different tasks. Dione Mariama will talk about how humans explore natural textures and how mechanoreceptive afferents transform physical inputs into the perception of touch. Luigi Tamè will present evidence that distortions in the perceived distances between tactile stimuli on the hand can also be observed in early somatosensory and motor areas. Focusing on natural object manipulation, Benoit Delhaye will then address how tactile interactions between fingertips and objects provide grasp stability. Alessandro Moscatelli will talk about everyday interactions between hand movements and touch, and how optimal integration
models can predict tactile illusions of motion. Finally, Ezgi Arikan will discuss the role of approach-avoidance goals on tactile sensitivity when moving towards and away from objects in a virtual reality environment.
Back
Reconstructing neural representations of tactile space in the sensorimotor areas
Tue-A7-Talk IV-02
Presented by: Luigi Tamè
Luigi Tamè
University of kent
Psychophysical experiments have demonstrated large and highly systematic perceptual distortions of tactile space. Several behavioural studies have investigated such distorted representations, however, the neural bases of such distortions are unknow. Here I will present a study in which we examined the neural basis of tactile distance perception by analysing activity patterns induced by tactile stimulation of nine points on a 3 x 3 square grid on the hand dorsum. I will describe empirical evidence showing that the primary somatosensory and motor cortices, rather than higher-level brain areas, are critical to estimating distances between tactile stimuli on the hand dorsum. By combining functional magnetic resonance, Procrustes alignment, and multidimensional scaling, we reconstructed the shape of skin space in the brain. Strikingly, the shape of the skin that we reconstructed from neural data matches the distortions we found at the behavioural level, providing strong evidence that early sensorimotor areas are critical for the construction of tactile space.
Keywords: Shape of the skin, Tactile distance perception, Somatosensory and motor cortices, Body distortions, fMRI
Back