Grief’s impact on sensorimotor expectations: an account of non-veridical bereavement experiences

The philosophy of grief has directed little attention to bereavement’s impact on perceptual experience. However, misperceptions, hallucinations and other anomalous experiences are strikingly common following the death of a loved one. Such experiences range from misperceiving a stranger to be the deceased, to phantom sights, sounds and smells, to nebulous quasi-sensory experiences of the loved one’s presence. This paper draws upon the enactive sensorimotor theory of perception to offer a phenomenologically sensitive and empirically informed account of these experiences. It argues that they can be understood as deriving from disruption to both sensorimotor expectations and perceived opportunities for action, stemming from the upheaval of bereavement. Different facets of the enactive sensorimotor approach can help to explain different types of post-bereavement perceptual experience. Post-bereavement misperceptions can be accounted for through the way that alterations to sensorimotor expectations can result in atypical ‘amodal completion’, while bereavement hallucinations can be understood as ‘appearances’ that fail to form part of the usual patterns of sensorimotor contingency. Quasi-sensory experiences of the presence of the deceased can be understood as resulting from changes to perceived affordances. This paper aims to demonstrate the explanatory value of key aspects of the sensorimotor approach by highlighting how they can help to explain the phenomenology of post-bereavement experiences. However, it also illuminates certain areas in which the sensorimotor approach ought to be supplemented, especially if it is to account for tight connections between perception, affect, and intersubjectivity that are salient in grief.

A Formal Account of Structuring Motor Actions With Sensory Prediction for a Naive Agent

For naive robots to become truly autonomous, they need a means of developing their perceptive capabilities instead of relying on hand crafted models. The sensorimotor contingency theory asserts that such a way resides in learning invariants of the sensorimotor flow. We propose a formal framework inspired by this theory for the description of sensorimotor experiences of a naive agent, extending previous related works. We then use said formalism to conduct a theoretical study where we isolate sufficient conditions for the determination of a sensory prediction function. Furthermore, we also show that algebraic structure found in this prediction can be taken as a proxy for structure on the motor displacements, allowing for the discovery of the combinatorial structure of said displacements. Both these claims are further illustrated in simulations where a toy naive agent determines the sensory predictions of its spatial displacements from its uninterpreted sensory flow, which it then uses to infer the combinatorics of said displacements.

A critical approach to sensorimotor contingency theory: brain as agent and conscious mind as a guide of action

I present and consider critically O'Regan and Noë's sensorimotor contingency theory, proposed as an alternative to solve the explanatory gap problem. I start with the criticism that these authors address the current conception of representation, according to which conscious experiences are representations of the external world produced by the brain. Afterward, I summarize the way the sensorimotor contingency theory addresses the problem of the explanatory gap, explaining the existence, form, and content of visual consciousness in terms of an "exploratory activity" mediated by sensorimotor contingency laws. Finally, in agreement with criticisms addressed to O'Regan and Noë's solution, I propose a way to face the problem of the explanatory gap, which, recognizing the relevance of the body and the external environment to the existence, form and content of visual consciousness, but privileging the role of the brain as an organ of visual consciousness, and as an agent who uses visual consciousness as a guide to initiate and maintain embodied and situated adaptive actions in the world.

Detection of sensorimotor contingencies in infants before the age of one year: a comprehensive review

In order to benefit from the exploration of their body and their physical and social environment, infants need to detect sensorimotor contingencies linking their actions to sensory feedback. This ability, which seems to be present in babies from birth and even in utero, has been widely used by researchers in their study of early development. However, a careful look at the literature, particularly recent literature, suggests that babies may not be uniformly sensitive to all sensorimotor contingencies. This literature review examines in detail the mechanism of sensorimotor contingency detection in infants before the age of one year. Four aspects of sensorimotor contingency detection are considered: characteristics of action and feedback, contingency parameters, exposure conditions, and inter-individual differences. For each topic we highlight what favours and what hinders the detection of sensorimotor contingencies in infants. Our review also demonstrates the limitations of our knowledge about sensorimotor contingency detection. We advocate the importance of making progress in this field at a time when sensorimotor contingency detection is of major interest in developmental robotics and artificial intelligence.

Bodily Action and Distal Attribution in Sensory Substitution

According to proponents of the sensorimotor contingency theory of perception, active control of camera movement is necessary for the emergence of distal attribution in tactile-visual sensory substitution (TVSS) because it enables the subject to acquire knowledge of the way stimulation in the substituting modality varies as a function of self-initiated, bodily action. This chapter, by contrast, approaches distal attribution as a solution to a causal inference problem faced by the subject’s perceptual systems. Given all of the endogenous and exogenous evidence available to those systems, what is the most probable source of stimulation in the substituting modality? From this perspective, active control over the camera’s movements matters for rather different reasons. Most importantly, it generates proprioceptive and efference-copy based information about the camera’s body-relative position necessary to make use of the spatial cues present in the stimulation that the subject receives for purposes of egocentric object localization.

Task-dependent representations of stimulus and choice in mouse parietal cortex

The posterior parietal cortex (PPC) has been implicated in perceptual decisions, but whether its role is specific to sensory processing or sensorimotor transformation is not well understood. To distinguish these possibilities, we trained mice of either sex to perform a visual discrimination task and imaged the activity of PPC populations during both engaged behavior and passive viewing. Unlike neurons in primary visual cortex (V1), which responded robustly to stimuli in both conditions, most neurons in PPC responded exclusively during task engagement. However, PPC responses were heterogeneous, with a smaller subset of neurons exhibiting stimulus-driven, contrast-dependent responses in both conditions. Neurons in PPC also exhibit stronger modulation by noise correlations relative to V1, as illustrated by a generalized linear model that takes into account both task variables and between-neuron correlations. To test whether PPC responses primarily encoded the stimulus or the learned sensorimotor contingency, we imaged the same neurons before and after re-training mice on a reversed task contingency. Unlike V1 neurons, most PPC neurons exhibited a dramatic shift in selectivity after re-training and reflected the new sensorimotor contingency, while a smaller subset of neurons preserved their stimulus selectivity. Mouse PPC is therefore strongly task-dependent, contains heterogeneous populations sensitive to stimulus and choice, and may play an important role in the flexible transformation of sensory inputs into motor commands.Significance StatementPerceptual decision making involves both processing of sensory information and mapping that information onto appropriate motor commands via learned sensorimotor associations. While visual cortex (V1) is known to be critical for sensory processing, it is unclear what circuits are involved in the process of sensorimotor transformation. While the mouse posterior parietal cortex (PPC) has been implicated in visual decisions, its specific role has been controversial. By imaging population activity while manipulating task engagement and sensorimotor contingencies, we demonstrate that PPC, unlike V1, is highly task-dependent, heterogeneous, and sensitive to the learned task demands. Our results suggest that PPC is more than a visual area, and may instead be involved in the flexible mapping of visual information onto appropriate motor actions.

Acquisition of a space representation by a naive agent from sensorimotor invariance and proprioceptive compensation

In this article, we present a simple agent which learns an internal representation of space without a priori knowledge of its environment, body, or sensors. The learned environment is seen as an internal space representation. This representation is isomorphic to the group of transformations applied to the environment. The model solves certain theoretical and practical issues encountered in previous work in sensorimotor contingency theory. Considering the mathematical description of the internal representation, analysis of its properties and simulations, we prove that this internal representation is equivalent to knowledge of space.