Haptic Invariance: from Mechanics, Perception, and Neural Coding to Interface Design

Afternoon Workshop (Concerto, 14:00-17:00)

The brain has the capacity to maintain perceptual constancy of the object attributes (e.g. color, shape, texture, loudness etc.) we experience, despite changes in sensing conditions and in our optic and acoustic environments. The problem would seem at least as important in haptics, where sensory surfaces undergo complex movements in space and establish a greater variety of contact condition. Moreover any sensory system with the ability to move faces the problem of accounting for changes in proximal stimulation that are due to self-generated movement, and those that are due to external modifications of the world. To optimize survival and goal attainment, our somatosensory system has developed invariance in response at multiple levels, via mechanical, perceptual and computational invariants. The proposed workshop will explore haptic invariance at each of these levels with the goal of identifying the essential features for robust haptic interfaces and perceptual synthesis. The first talk will tackle the problem of invariance in haptic perception and interface design (Hayward). The following talk will present work characterizing mechanical invariants for perceptual constancy of asperities (Bochereau). The third talk will focus on the surprising lack of invariance for position in external space for a range of different object properties such as shape, compliance and length (Hartcher-O'Brien). The fourth talk will focus on the differences across visual and haptic perceptual constancy and identify differences in computational mechanisms that shed light on the complexity facing the somatosensory system (Moscatelli). The fifth talk will provide insights into the neural coding strategies that enable the perceptual and sensory invariance in surface property perception (Bensmaia). The insights provided by the workshop into the workings of our somatosensory system in the face of changes in sensing conditions will provide invaluable information to anyone interested in human-machine interface design based on haptics and other modalities.


The workshop is focused on stimulating discussion and changes in assumptions of a broad haptics audience. The focus of the workshop is the problem of invariance at the signal, coding and perceptual level which has implications for perception, neuroscience and interface design researchers alike.

Tentative Program

14:00 Static, kinematic, dynamic, and generic invariants in touch
Vincent Hayward, ISIR UPMC
14:30 Mechanical basis to perceptual invariants between amplitude and duration in asperity exploration
Serena Bochereau, ISIR UPMC
15:00 Objects feel different in the two hemispaces, but not in the hemispheres
Jessica Hartcher-O'Brien, ISIR UPMC
15:30 Break
16:00 Invariants and priors in tactile perception of object motion
Alessandro Moscatelli, University of Bielefeld
16:30 Texture invariance and its neural basis
Hannes Saal, University of Chicago


Jessica, Hartcher-O'Brien, Dr.   ISIR, UPMC, Paris France

Jess Hartcher-O'Brien studied auditory system suppression mechanisms in human perception of room acoustics with Dr. Jorg Buchholz and Prof. Simon Carlile at UWS Sydney and Prof. Torsten Dau, DTU Denmark. Realizing that studying acoustics in isolation was not going to provide the answer to how the brain experiences and maintains a coherent representation of the world, she went on to explore perceptual and computational mechanisms underlying multisensory integration working with Prof. Spence at the University of Oxford and Prof. Ernst at the Max Planck Institute for biological cybernetics. She identified coding strategies used by the brain to integrate information across the senses and across time. She was awarded a personal fellowship to investigate the possibility of perceptual invariances as the key to our ability to externalise local patterns of sensory input in collaboration with Dr. Malika Auvray and Prof. Hayward. She is currently working on haptic perception and sensory augmentation at the UPMC Paris and behavioural identification of the auditory temporal impulse response function in collaboration with Dr. Carmel Levitan and Dr. Chris Cantor.