Abstract
People can estimate the current position of an occluded moving object. The laboratory version of this task is called ‘motion extrapolation’. Participants typically press a button when they estimate the moving object has arrived at the end of the occluder. The literature is fragmented, and there is no consensus on how people produce accurate responses. This complex topic can be understood by framing four theoretical dichotomies, and considering tentative resolutions. Dichotomy 1: Does mental imagery or visuospatial tracking mediate motion extrapolation? Resolution: A rate control mechanism ‘does the work’ in both accounts, by either updating position of spatial attention, or the position of the imaginary target, at the right speed. Dichotomy 2: Cognitive clocking or visuospatial tracking? Do people obtain a representation of time-to-contact, then count this down, or do they track across the occluder with the spotlight of spatial attention? Resolution: These accounts are not mutually exclusive, while anti-clocking conclusions are premature. Dichotomy 3: One or many rate controllers? People can extrapolation through other ‘spaces’, such as colour space or abstract number space. So, do all forms of extrapolation require a common rate controller, or does each dimension have a separate rate controller? Resolution: Current evidence supports the common rate control model. Dichotomy 4: Common rate controller or a common clock? Resolution: New evidence shows that multidimensional rate control is possible. In summary, diverse motion extrapolation papers from the last 60 years can be organized under the new four dichotomies framework. Recent evidence points to a centralized rate controller for updating all dynamic mental representations.
Meeting abstract presented at VSS 2015