What is the Bandwidth of Perceptual Experience?

Although our subjective impression is of a richly detailed visual world, numerous empirical results suggest that the amount of visual information observers can perceive and remember at any given moment is limited. How can our subjective impressions be reconciled with these objective observations? Here, we answer this question by arguing that, although we see more than the handful of objects, claimed by prominent models of visual attention and working memory, we still see far less than we think we do. Taken together, we argue that these considerations resolve the apparent conflict between our subjective impressions and empirical data on visual capacity, while also illuminating the nature of the representations underlying perceptual experience. Numerous empirical results highlight the limits of visual perception, attention, and working memory. However, it intuitively feels as though we have a rich perceptual experience, leading many to claim that conscious perception overflows these limited cognitive mechanisms.A relatively new field of study (visual ensembles and summary statistics) provides empirical support for the notion that perception is not limited and that observers have access to information across the entire visual world.Ensemble statistics, and scene processing in general, also appear to be supported by neural structures that are distinct from those supporting object perception. These distinct mechanisms can work partially in parallel, providing observers with a broad perceptual experience.Moreover, new demonstrations show that perception is not as rich as is intuitively believed. Thus, ensemble statistics appear to capture the entirety of perceptual experience.National Institutes of Health (U.S.). Ruth L. Kirschstein National Research Service Award (F32EY024483)National Institutes of Health (U.S.) (Grant EY13455

The Turing test as interactive proof

In 1950, Alan Turing proposed his eponymous test based on indistinguishability of verbal behavior as a replacement for the question "Can machines think?" Since then, two mutually contradictory but well-founded attitudes towards the Turing Test have arisen in the philosophical literature. On the one hand is the attitude that has become philosophical conventional wisdom, viz., that the Turing Test is hopelessly flawed as a sufficient condition for intelligence, while on the other hand is the overwhelming sense that were a machine to pass a real live full-fledged Turing Test, it would be a sign of nothing but our orneriness to deny it the attribution of intelligence. The arguments against the sufficiency of the Turing Test for determining intelligence rely on showing that some extra conditions are logically necessary for intelligence beyond the behavioral properties exhibited by an agent under a Turing Test. Therefore, it cannot follow logically from passing a Turing Test that the agent is intelligent. I argue that these extra conditions can be revealed by the Turing Test, so long as we allow a very slight weakening of the criterion from one of logical proof to one of statistical proof under weak realizability assumptions. The argument depends on the notion of interactive proof developed in theoretical computer science, along with some simple physical facts that constrain the information capacity of agents. Crucially, the weakening is so slight as to make no conceivable difference from a practical standpoint. Thus, the Gordian knot between the two opposing views of the sufficiency of the Turing Test can be cut.Engineering and Applied Science

How our belief in qualia evolved, and why we care so much : a reply to David H. Baßler

David Baßler’s commentary identifies five unasked questions in my work, and provides excellent answers to them. His explanation of the gradual evolution of higher-order intentionality via a Bayesian account leads to an explanation of the persistence of our deluded belief in qualia

The Disunity of Consciousness

It is commonplace for both philosophers and cognitive scientists to express their allegiance to the "unity of consciousness". This is the claim that a subject’s phenomenal consciousness, at any one moment in time, is a single thing. This view has had a major influence on computational theories of consciousness. In particular, what we call single-track theories dominate the literature, theories which contend that our conscious experience is the result of a single consciousness-making process or mechanism in the brain. We argue that the orthodox view is quite wrong: phenomenal experience is not a unity, in the sense of being a single thing at each instant. It is a multiplicity, an aggregate of phenomenal elements, each of which is the product of a distinct consciousness-making mechanism in the brain. Consequently, cognitive science is in need of a multi-track theory of consciousness; a computational model that acknowledges both the manifold nature of experience, and its distributed neural basis

Haig’s ‘strange inversion of reasoning’ (Dennett) and Making sense: information interpreted as meaning (Haig)

David Haig (this issue) propounds and illustrates the unity of a radically revised set of definitions of the family of terms at the heart of philosophy of cognitive science and mind: information, meaning, interpretation, text, choice, possibility, cause. This biological re-grounding of much-debated concepts yields a bounty of insights into the nature of meaning and life. An interpreter is a mechanism that uses information in choice. The capabilities of the interpreter couple an entropy of inputs (uncertainty) to an entropy of outputs is dispelled by observation (input of information). The second entropy is dispelled (output of decision). I propose that an interpreter’s response to inputs meaning of the information for the interpreter. In this conceptual framework, the mechanisms of interpreters provide the much-debated link between Shannon information and semantics

Embodied cognitive ecosophy: the relationship of mind, body, meaning and ecology

The concept of embodied cognition has had a major impact in a number of disciplines. The extent of its consequences on general knowledge and epistemology are still being explored. Embodied cognition in human geography has its own traditions and discourses but these have become somewhat isolated in the discipline itself. This paper argues that findings in other disciplines are of value in reconceptualising embodied cognition in human geography and this is explored by reconsidering the concept of ecosophy. Criticisms of ecosophy as a theory are considered and recent work in embodied cognition is applied to consider how such criticisms might be addressed. An updated conceptualisation is proposed, the embodied cognitive ecosophy, and three characteristics arising from this criticism and synthesis are presented with a view to inform future discussions of ecosophy and emotional geography

Our vulnerable high streets – death by permitted development?

Ben Clifford, Adam Dennett, Bin Chi and Daniel Slade outline some of the key findings of research on the likely impacts of the latest expansion of permitted development rights

Response to De Caro, Lavazza, Lemos, and Pereboom

Author's reply to De Caro's, Lavazza's, Lemos', and Pereboom's comments on D.C. Dennett, Reflection on Sam Harris' "Free Will