Place cognition as an example of situated cognition:a study with evolved agents

摘要

The discovery of 'place cells' in the hippocampus of the ratwas a seminal finding in the cognitive neuroscience ofspace processing (O'Keefe and Dostrovsky 1971). Placecells are pyramidal neurons in CAI field of the dorsalhippocampus whose firing strongly depends on the rat'slocation in a given environment. The discharge pattern ofthese cells is associated to a well-defined area of theenvironment where the unit maximally fires, the so-called`place field'. In O'Keefe's words, a place cell is "a cellwhich constructs the notion of a place in an environment byconnecting together several multi-sensory inputs each ofwhich can be perceived when the animal is in a particularplace in the environment" (1979, p. 425). Complementaryto the information about position is the information aboutdirection, provided by head direction cells, neurons that fireonly when animals have their head in a certain direction.Recently, a new class of cells has been discovered whosefiring depends on animal's position. These are the grid cells(Fyhn et al. 2004) in dorsocaudal medial entorhinal cortex(dMEC), which are activated when the animal occupies a vertex of a regular grid that spans the entire surface of theenvironment.