« Home

Home » Psychology » Rose: Consciousness » Student resources » Updates » December 2006 » Chapter 03

Rose: Consciousness

Chapter 03

An interesting meta-scientific position has recently been propounded by Lamme (2006). He suggests that a scientific advance in studying consciousness can only take place if we adopt what he calls the ‘neural stance’, by which he means we should define consciousness in neural terms rather than phenomenological or philosophical. Thus, he adopts a pure form of type identity (Consciousness, section 2.4.1) when he suggests that we equate consciousness with recurrent processing in the brain (for more on this neural type see Chapters 6-11!). This assertion has eliminativist overtones (section 2.4.4) in that it would put aside all attempts to circumscribe and describe the object of our studies in subjective experiential terms. Rather, we should ignore the current confusion over how we can define consciousness — not to mention how to monitor whether it is present on any given occasion (indeed Lamme lists and critiques a plethora of different studies that have tried to do so but have produced inconsistent results). Instead, by making recurrent neural processing the central explanandum we would focus our empirical research and enable real progress to be made. Then, consciousness and subjectivity would be later redefined or reinterpreted as: whatever is happening experientially or cognitively when someone has recurrent processing in their brain. The ideal outcome, that consciousness would be found to map one to one onto the neural state, is unlikely to occur because we have no clear or universally agreed structural map or picture of the mental realm. This indeed is the position of the eliminativists (section 2.4.4.) — although Lamme does not couch his position in those terms. This pragmatic approach might well find favour among many empirical scientists.

On the other hand, why should we select recurrent processing to be the neural type for the putative reduction? This choice must have been derived from previous research and thinking using mental-level definitions and understanding of what ‘consciousness’ is; otherwise, it would become an arbitrary selection. For instance a previous attempt to implement such a method might have been to assert that 40 Hz oscillations just are consciousness. This view has become less popular now than it once was (section 6.4.2.2), so how did Lamme choose a successor neural candidate to replace it, and how would we do so again if recurrent processing turns out to be similarly inadequate for the job? The higher level (intuitive, phenomenal, philosophical) sense of ‘consciousness’ must surely be used to guide our evaluation of the evidence that arises from research under any given hypothesis and thus to provide feedback on its correctness, but also to guide the choice of a new postulate to replace it for subsequent research (section 4.2.5).

Section 3.5.5 Oversimplicity

As part of my critique of over-simplified theories, I included some empirical estimates of the minimum number of cells involved in a representation. Figures from 100,000 to 10 million were cited (Consciousness, p. 72). I now note with amusement another estimate, derived from brain-scanning studies, that ‘at least a million neurons in object-related cortex ... are involved in the representation of a single-object image.’ (Levy et al., 2004, p. 996). This is about 2% of the cells in the relevant cortical area. Across the whole visual cortex the figure is larger: at least 30 million (or as many as ten times that number) are active.

Recommended reading

Brook and Akins (2005) have produced an excellent volume on the project to relate philosophy of mind and neuroscience. Numerous examples are given of the way these approaches can be integrated, and how this work feeds back into the philosophical issues. Further chapters, focussing especially on reduction, can also be found in Schouten and Looren de Jong (2006).

References

Brook, A. and Akins, K. (2005) eds. Cognition and the Brain. The philosophy and neuroscience movement. Cambridge University Press, Cambridge.

Lamme, V.A.F. (2006) Towards a true neural stance on consciousness. Trends in Cognitive Sciences 10, 494-501.

Levy, I., Hasson, U. and Malach, R. (2004) One picture is worth at least a million neurons. Current Biology 14, 996-1001.

Schouten, M. and Looren de Jong, H. (2006) eds. The Matter of the Mind. Philosophical essays on psychology, neuroscience and reduction. Blackwell, Oxford.