Active touch sensing

Abstract

Active sensing systems are purposive and information-seeking sensory systems. Active sensing usually entails sensor movement, but more fundamentally, it involves control of the sensor apparatus, in whatever manner best suits the task, so as to maximize information gain. In animals, active sensing is perhaps most evident in the modality of touch. In this theme issue, we look at active touch across a broad range of species from insects, terrestrial and marine mammals, through to humans. In addition to analysing natural touch, we also consider how engineering is beginning to exploit physical analogues of these biological systems so as to endow robots with rich tactile sensing capabilities. The different contributions show not only the varieties of active touch-antennae, whiskers and fingertips-but also their commonalities. They explore how active touch sensing has evolved in different animal lineages, how it serves to provide rapid and reliable cues for controlling ongoing behaviour, and even how it can disintegrate when our brains begin to fail. They demonstrate that research on active touch offers a means both to understand this essential and primary sensory modality, and to investigate how animals, including man, combine movement with sensing so as to make sense of, and act effectively in, the world.

Tactile perception and working memory in rats and humans

“…S1 confirms that rats remained in the nose poke to attend to both stimuli and the go cue, excluding the possibility that they adhered to some stereotyped timing routine (15). In well-trained rats, the self-generated motion known as "whisking" was suppressed throughout the trial (Movie S2), indicating that the sensorimotor system entered a "receptive sensing" mode of operation (16,17). Experiments with human subjects (Fig.…”

“…There are several distinctions in experimental design. In our task, rather than applying stimuli to the fingertip, we selected the whisker sensory system due to its behavioral importance in rats (16,17,(28)(29)(30)(31)(32)(33)(34). Another distinction is the structure of the vibration.…”

Active Bayesian Perception for Simultaneous Object Localization and Identification

“…Our senses are not merely passive receivers of information, but actively select and refine sensations according to our present goals and perceptions [5]. Our bodies are not external from the world, but direct actions within it to access the information that we need [2,15]. Thus, sensation, perception and action cannot be considered simply as a forward process, but instead form a closed 'active perception' loop with a task-dependent motor control strategy.…”

Active sensorimotor control for tactile exploration

“…or passive when the sensory data does not affect the motion of the sensor relative to the stimulus [1,2]. The ability 153 to control sensor movements using active perception based on previous sensory data, for example to explore areas of 154 apparent interest, gives an improvement to the perceptual performance, such as the decision speed and perceptual 155 accuracy.…”