Towards a unified theory of the reference frame of the ventriloquism aftereffect

Abstract

Background: Ventriloquism aftereffect (VAE), observed as a shift in the perceived locations of sounds after audiovisual stimulation, requires reference frame (RF) alignment since hearing and vision encode space in different RFs (head-centered, HC, vs. eye-centered, EC). Experimental studies examining the RF of VAE found inconsistent results: a mixture of HC and EC RFs was observed for VAE induced in the central region, while a predominantly HC RF was observed in the periphery. Here, a computational model examines these inconsistencies, as well as a newly observed EC adaptation induced by AV-aligned audiovisual stimuli. Methods: The model has two versions, each containing two additively combined components: a saccade-related component characterizing the adaptation in auditory-saccade responses, and auditory space representation adapted by ventriloquism signals either in the HC RF (HC version) or in a combination of HC and EC RFs (HEC version). Results: The HEC model performed better than the HC model in the main simulation considering all the data, while the HC model was more appropriate when only the AV-aligned adaptation data were simulated. Conclusion: Visual signals in a uniform mixed HC+EC RF are likely used to calibrate the auditory spatial representation, even after the EC-referenced auditory-saccade adaptation is accounted for.

Diplopod types in the Hungarian Natural History Museum, II. (Arthropoda: Myriapoda: Diplopoda)

“…Loksa, 1967 Type material -several males and females, Spain: Canary Islands, Tenerife, Anaga-Gebirge, Pico del Ingles, 8-13 April 1965; Montes de las Mercedes,[8][9][10][11][12][13] …”