Does a landmark near a head direction neuron's preferred firing direction exert more stimulus control than one farther away?

Citation

Zinyuk LE & Dudchenko P (2005) Does a landmark near a head direction neuron's preferred firing direction exert more stimulus control than one farther away?. http://www.psychology.stir.ac.uk/staff/staff-profiles/?a=27307

Abstract
Recent data have suggested that location in which a hippocampal place cell fires is more controlled by proximal, as opposed to distal, landmarks. In this study we sought to test a related issue in head direction (HD) neurons: are HD cells more influenced by visual landmarks that the animal faces when the cell is active? We recorded from HD neurons in the anterior thalamus as rats explored a cylindrical apparatus equipped with two cue cards. After a baseline recording with the cue cards in their normal position, the rat was removed from the apparatus and the cards were rotated by different amounts. We hypothesised that if a HD cell followed the nearest cue card (in a directional sense), the shift in its preferred firing direction should approximate the shift in the position of that cue card. Our results suggest that this was not the case. Rather, HD cells appeared to be controlled by both landmarks regardless of their initial firing direction.