Investigating neural representations: the tale of place cells

Abstract

While neuroscientists often characterize brain activity as representational, many philosophers have construed these accounts as just theorists' glosses on the mechanism. Moreover, philosophical discussions commonly focus on finished accounts of explanation, not research in progress. I adopt a different perspective, considering how characterizations of neural activity as representational contributes to the development of mechanistic accounts, guiding the questions neuroscientists ask as they work from an initial proposal to a more detailed understanding of a mechanism. I develop one illustrative example involving research on the information processing mechanisms mammals employ in navigating their environments. This research was galvanized by the discovery in the 1970s of place cells in the hippocampus. This discovery prompted research about how place representations are constructed in the relevant hippocampal neurons and how they figure in navigation. It also led to the discovery of a host of other types of neurons-grid cells, head--direction cells, boundary cells-that interact with place cells in the mechanism underlying spatial navigation. As I will try to make clear, the research is explicitly devoted to identifying representations and determining how they are constructed and used in an information processing mechanism. Construals of neural activity as representations are not mere glosses but are characterizations to which neuroscientists are committed in the development of their explanatory accounts.

Content Pragmatism Defended

“…The fact, repeatedly appealed to by Bechtel (2016), that cognitive scientists are interested in finding out what neural states represent is perfectly in line with what the content pragmatist holds. It is indeed a central step in trying to individuate the computational mechanisms that explain successful cognitive behaviour.…”

“…The research efforts are designed to answer these questions and it would be difficult to understand why the researchers pursue these projects if their goal was not to identify representations and determine what they represent. (Bechtel 2016(Bechtel , p. 1289 Bechtel then describes in great detail the process of discovery and theoretical development that have marked scientific work on place, grid, and head-direction cells in the past four decades. He uses this careful reconstruction of progress in this area, what motivated it and what it was directed at explaining, to argue that a commitment to the reality of representations was essential for that scientific project.…”

“…In the last few years, Egan's attempt at building a fourth alternative has come under attack by Neander, 2 Ramsey,3 and Bechtel (2016). My aim in this paper is to defend content pragmatism from recent objections, showing that it is a valid alternative to the traditional positions.…”

From symbols to icons: the return of resemblance in the cognitive neuroscience revolution

“…First, as noted above, claims about detection are often heuristically essential in constructing and evaluating theories about the broader internal models (i.e. iconic representations) that underpin intelligence (Bechtel 2014;Kiefer and Hohwy 2017). Indication relations are thus often crucial components of the explananda that iconic representations are posited to explain.…”

Es pot naturalitzar la intencionalitat?

“…De nou, en totes aquestes explicacions els biòlegs atribueixen un gran nombre de representacions cerebrals. Això no només és imprescindible per a entendre com certs organismes són capaços de realitzar tasques molt complexes, sinó que també és crucial per a guiar la investigació científica i establir noves preguntes i projectes de recerca (Bechtel 2016). Finalment, cal mencionar que la noció de representació no és només important perquè moltes explicacions científiques i no científiques l'usen.…”