Online research in philosophy

This paper proposes a preliminary infrastructure for future philosophical discourse on the virtual, interactive, visual, top layer of the Internet. The paper begins by introducing thoughts on such words as real, virtual, reality, knowledge, and truth. Next, news summaries are provided illustrating some effects from the “real world” on the virtual part of the Internet, and vice versa. Subsequently, nine major categories of Internet variables are identified. Finally, over one hundred questions about the philosophical nature of the virtual part of the Internet are listed and are organized into fourteen categories.

Currently there is considerable interest in the notion that dorsal and ventral visual systems might differ in their specializations for thought and action. Behavior invariably involves multiple processes such as perception, judgment, and response execution. It is not clear that characteristics of the dorsal and ventral processing streams, as described by Norman, are entirely of a perceptual nature.

Neuropsychological findings used to motivate the “two visual systems” hypothesis have been taken to endanger a pair of widely accepted claims about spatial representation in visual experience. The first is the claim that visual experience represents 3-D space around the perceiver using an egocentric frame of reference. The second is the claim that there is a constitutive link between the spatial contents of visual experience and the perceiver’s bodily actions. In this paper, I carefully assess three main sources of evidence for the two visual systems hypothesis and argue that the best interpretation of the evidence is in fact consistent with both claims. I conclude with some brief remarks on the relation between visual consciousness and rational agency.

It is our contention that the concept of planning in Glover's model is too broadly defined, encompassing both action/goal selection and the programming of the constituent movements required to acquire the goal. We argue that this monolithic view of planning is untenable on neuropsychological, neurophysiological, and behavioural grounds. The evidence demands instead that a distinction be made between action planning and the specification of the initial kinematic parameters, with the former depending on processing in the ventral stream and the latter on processing in the dorsal stream.

Hommel et al. propose that high-level perception and action planning share a common representational domain, which facilitates the control of intentional actions. On the surface, this point of view appears quite different from an alternative account that suggests that “action” and “perception” are functionally and neurologically dissociable processes. But it is difficult to reconcile these apparently different perspectives, because Hommel et al. do not clearly specify what they mean by “perception” and “action planning.” With respect to the visual control of action, a distinction must be made between conscious visual perception and unconscious visuomotor processing. Hommel et al. must also distinguish between the what and how aspects of action planning, that is, planning what to do versus planning how to do it.

Today many philosophers of mind accept that the two cortical streams of visual processing in humans can be distinguished in terms of conscious experience. The ventral stream is thought to produce representations that may become conscious, and the dorsal stream is thought to handle unconscious vision for action. Despite a vast literature on the topic of the two streams, there is currently no account of the way in which the relevant empirical evidence could fit with basic Husserlian phenomenology of vision. Here I offer such an account. In this article, I show how the empirical evidence ought to be understood in a way that is informed by phenomenology. The differences in the two streams are better described as differences in spatial and temporal processing. Rather than simply “unconscious,” the dorsal stream can be better described as making a special contribution to what Husserl identified as the visual horizon.

Recent work in "embodied, embedded" cognitive science links mental contents to large-scale distributed effects: dynamic patterns implicating elements of (what are traditionally seen as) sensing, reasoning and acting. Central to this approach is an idea of biological cognition as profoundly "action-oriented" - geared not to the creation of rich, passive inner models of the world, but to the cheap and efficient production of real-world action in real-world context. A case in point is Hurley's (1998) account of the profound role of motor output in fixing the contents of conscious visual awareness - an account that also emphasizes distributed vehicles and long-range dynamical loops. Such stories can seem dramatically opposed to accounts, such as Milner and Goodale (1995), that stress relatively local mechanisms and that posit firm divisions between processes of visual awareness and of visuomotor action. But such accounts, I argue, can be deeply complimentary and together illustrate an important lesson. The lesson is that cognition may be embodied and action-oriented in two distinct - but complimentary - ways. There is a way of being embodied and action-oriented that implies being closely geared to the fine-grained control of low level effectors (hands, arms, legs and so on). And there is a way of being embodied and action-oriented that implies being closely geared to gross motor intentions, current goals, and schematic motor plans. Human cognition, I suggest, is embodied and action-oriented in both these ways. But the neural systems involved, and the size and scope of the key dynamic loops, may be quite different in each case.

Machine generated contents note: -- 1. Introduction -- Consciousness and Sensorimotor Dynamics: Methodological Issues -- 2. Computational consciousness, D. Ballard -- 3. Explaining what people say about sensory qualia, J. Kevin O'Regan -- 4. Perception, action, and experience: unraveling the golden braid, A. Clark -- The Two-Visual Systems Hypothesis -- 5. Cortical visual systems for perception and action, A.D. Milner and M.A. Goodale -- 6. Hermann Lotze's Theory of 'Local Sign': evidence from pointing responses in an illusory figure, D.R. Melmoth -- Understanding Agency and Object Perception -- 7. Two visual systems and the feeling of presence, M. Matthen -- 8. Spatial coordinates and phenomenology in the two-visual systems model, P. Jacob and F. de Vignemont -- 9. Perceptual experience and the capacity to act, S. Schellenberg -- Perception and Action: Studies in Cognitive Neuroscience -- 10. Why does the perception-action functional dichotomy not match the ventral-dorsal streams in anatomical segregation: optic ataxia and the function of the dorsal stream, Y. Rossetti et al -- 11. Mapping the neglect syndrome onto neurofunctional streams, G. Vallar and F. Mancini -- 12. Motor representations and the perception of space: perceptual judgments of the boundary of action space, Y. Delevoye-Turrell -- The Role of Action and Sensorimotor Knowledge in Sensorimotor Theories of Perception -- 13. Vision without representation, A. Noe -- 14. Sensorimotor knowledge and the contents of experience, J. Kiverstein -- Boundaries of the Agent -- 15. Extended vision, R. A. Wilson.

Deictic coding offers a useful model for understanding the interactions between the dorsal and ventral streams of visual processing in the cerebral cortex. By extending Ballard et al.'s ideas on teleassistance, I show how dedicated low-level visuomotor processes in the dorsal stream might be engaged for the services of high-level cognitive operations in the ventral stream.

David Milner and Melvyn Goodale’s dissociation hypothesis is commonly taken to state that there are two functionally specialized cortical streams of visual processing originating in striate (V1) cortex: a dorsal, action-related “unconscious” stream and a ventral, perception-related “conscious” stream. As Milner and Goodale acknowledge, findings from blindsight studies suggest a more sophisticated picture that replaces the distinction between unconscious vision for action and conscious vision for perception with a tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. The combination excluded by the tripartite division is the possibility of conscious vision for action. But are there good grounds for concluding that there is no conscious vision for action? There is now overwhelming evidence that illusions and perceived size can have a significant effect on action (Bruno & Franz, 2009; Dassonville & Bala, 2004; Franz & Gegenfurtner, 2008; McIntosh & Lashley, 2008). There is also suggestive evidence that any sophisticated visual behavior requires collaboration between the two visual streams at every stage of the process (Schenk & McIntosh, 2010). I nonetheless want to make a case for the tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. My aim here is not to refute the evidence showing that conscious vision can affect action but rather to argue (a) that we cannot gain cognitive access to action-guiding dorsal stream representations, and (b) that these representations do not correlate with phenomenal consciousness. This vindicates the semi-conservative view that the dissociation hypothesis is best understood as a tripartite division.