Excerpt: For half a century, threshold has been known to be important in the activities of nerve cell and synapse, but little is known of the general properties that so ubiquitous a feature must impose on the system’s behaviour in the large. Beurle1, in his investigations of the transmission of waves of activity over a conducting not, noticed that a net with threshold would have a marked tendency to be unstable, but his assumptions were complex, and the origin of the instability is not easily identified. Here we propose to show that an instability, similar to his, can readily be traced from a simpler origin.

Intuition suggests that perception follows sensation and therefore bodily feelings originate in the body. However, recent evidence goes against this logic: interoceptive experience may largely reflect limbic predictions about the expected state of the body that are constrained by ascending visceral sensations. In this Opinion article, we introduce the Embodied Predictive Interoception Coding model, which integrates an anatomical model of corticocortical connections with Bayesian active inference principles, to propose that agranular visceromotor cortices contribute to interoception by issuing interoceptive predictions. We then discuss how disruptions in interoceptive predictions could function as a common vulnerability for mental and physical illness.

Biology gives us numerous examples of self-assertional systems whose essence does not precede their existence but is rather revealed through it. Immune system is one of them. The fact of behaving in order not only to satisfy external constraints as a pre-fixed set of possible environments and objectives, but also to satisfy internal “viability” constraints justifies a sharper focus. Adaptability, creativity and memory are certainly interesting “side-effects” of such a tendency for self-consistency. However in this paper, we adopted a largely pragmatic attitude attempting to find the best hybridizing between the biological lessons and the engineering needs. The great difficulty, also shared by neural net and GA users, remains the precise localisation of the frontier where the biological reality must give way to a directed design.

Quote: At least in the MTL [medial temporal lobe], thought can override the reality of the sensory input.

Cognitive scientists have much to learn from Merleau-Ponty. This paper explicates two central, but rarely discussed, notions in Merleau-Ponty’s Phenomenology of Perception: the intentional arc and the tendency to achieve a maximum grip. The intentional arc names the tight connection between body and world, viz. that, as the active body acquires skills, those skills are “stored,” not as representations in the mind, but as dispositions to respond to the solicitations of situations in the world. Maximum grip names the body’s tendency to refine its discriminations and to respond to solicitations in such a way as to bring the current situation closer to the optimal gestalt that the skilled agent has learned to expect. Neither of these “body-functions” requires that the body have any particular size or shape. However, if one tries to implement Merleau-Ponty’s understanding of skill acquisition in a neural network, one finds that, in order to learn to generalize input/output pairs to new situations the way human beings do, a network needs to share crucial aspects of the human body-structure.

Review of “Die Welt der ungewohnten Dimensionen” by Arnold Hildesheimer.

A free-energy principle has been proposed recently that accounts for action, perception and learning. This review looks at some key brain theories in the biological (for example, neural Darwinism) and physical (for example, information theory and optimal control theory) sciences from the free-energy perspective. Crucially, one key theme runs through each of these theories – optimization. Furthermore, if we look closely at what is optimized, the same quantity keeps emerging, namely value (expected reward, expected utility) or its complement, surprise (prediction error, expected cost). This is the quantity that is optimized under the free-energy principle, which suggests that several global brain theories might be unified within a free-energy framework.

In the 20th century we thought the brain extracted knowledge from sensations. The 21st century witnessed a ‘strange inversion’, in which the brain became an organ of inference, actively constructing explanations for what’s going on ‘out there’, beyond its sensory epithelia. One paper played a key role in this paradigm shift.

This paper tries to generate communication, planning and collaboration from perception and imagination