Abstract
It is widely perceived that there is a problem in giving a naturalistic account of mental representation that deals adequately with the issue of meaning, interpretation, or significance (semantic content). It is suggested here that this problem may arise partly from the conflation of two vernacular senses of representation: representation-as-origin and representation-as-input. The flash of a neon sign may in one sense represent a popular drink, but to function as a representation it must provide an input to a ‘consumer’ in the street. The arguments presented draw on two principles – the neuron doctrine and the need for a venue for ‘presentation’ or ‘reception’ of a representation at a specified site, consistent with the locality principle. It is also argued that domains of representation cannot be defined by signal traffic, since they can be expected to include ‘null’ elements based on non-firing cells. In this analysis, mental representations-as-origin are distributed patterns of cell firing. Each firing cell is given semantic value in its own right – some form of atomic propositional significance – since different axonal branches may contribute to integration with different populations of signals at different downstream sites. Representations-as-input are patterns of local co-arrival of signals in the form of synaptic potentials in dendrites. Meaning then draws on the relationships between active and null inputs, forming ‘scenarios’ comprising a molecular combination of ‘premises’ from which a new output with atomic propositional significance is generated. In both types of representation, meaning, interpretation or significance pivots on events in an individual cell. (This analysis only applies to ‘occurrent’ representations based on current neural activity.) The concept of representations-as-input emphasizes the need for an internal ‘consumer’ of a representation and the dependence of meaning on the co-relationships involved in an input interaction between signals and consumer. The acceptance of this necessity provides a basis for resolving the problem that representations appear both as distributed (representation-as-origin) and as local (representation-as-input). The key implications are that representations in the brain are massively multiple both in series and in parallel, and that individual cells play specific semantic roles. These roles are discussed in relation to traditional concepts of ‘gnostic’ cell types.
Highlights
Concepts of mental representation are widely invoked in neurobiology, linguistics, artificial intelligence, and philosophy
As Seager and Bourget (2007) note: “there is no acknowledged theory of mental representation.”. This appears to be partly because people differ in terms of the explanatory work they want such a theory to do (Stich, 1992). It reflects an impasse in reaching a consensus on how mental representations could fit into a naturalistic account of the brain; what sort of substrate, or causal nexus could support a mental representation, and how? I shall argue that these are interdependent questions and that a careful assessment of the logical constraints on substrate, in terms of physical dynamics and their location, may clarify the ways in which mental representation may be a useful concept, as well as vice versa
The gap between work on post-synaptic integration (e.g., Branco and Häusser, 2011; Smith et al, 2013; Ishikawa et al, 2015) and psychology may still be harder to bridge but the possibility of grounding in plausible input mechanisms should be an acid test of all models of mental representation
Summary
Concepts of mental representation are widely invoked in neurobiology, linguistics, artificial intelligence, and philosophy. From the outset I wish to emphasize that the problem I address relates only to what may be called ‘occurrent’ or ‘active’ representations in which signals are sent and received on specific occasions There is another use of the term that might be called a ‘dispositional representation’ – an acquired pattern of cellular connectivity underlying memory, knowledge, or concept acquisition, that disposes the brain to generate occurrent representations in response to stimuli (Simmons and Barsalou, 2003). The more basic problem is defining the type, or level, of biophysical location that could support a fitting causal role, and with appropriate information capacity (‘bandwidth’) There are those who would argue that we have a rough answer: that representations can be equated with patterns of neural activity, or firing. The gap between work on post-synaptic integration (e.g., Branco and Häusser, 2011; Smith et al, 2013; Ishikawa et al, 2015) and psychology may still be harder to bridge but the possibility of grounding in plausible input mechanisms should be an acid test of all models of mental representation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
