Retrospective Analysis of Causal Perception


  • Daniel Bermúdez University of Vienna


The human brain distinguishes between two types of causality: inferential causality and perceptual causality. The first kind refers to rational procedures. In contrast, the perception of causality seemingly relies on a perceptual module devoted exclusively to recognizing direct causes and effects in the environment. From this perspective, humans perceive causality as they perceive colors, sizes, shapes, orientations, etc. Nevertheless, the assumption that the perception of causality does not require intricate inferences has not been sufficiently demonstrated. Numerous researchers had focused on investigating the psychophysical conditions required for perceiving causality, e.g., Michotte's [1] temporal-spatial parameters required to perceive causality. The principal aim of my master thesis is to prove one hypothesis that might explain the psychophysics and plausible modularity of perceptual causality. This is because the perception of causality depends on a retrospective process in the brain. Two other subsequent hypotheses will be tested as well: 1) the retrospective process is based on a specific module, 2) the perception of causality is independent of other visual properties such as shapes, sizes, colors, etc. 

Three visual launching-effect [2] experiments are being implemented to prove these hypotheses, which are recorded with EEG equipment as well. The first one consists of a classical launching effect in real motion. The participants have to rate how strong was the influence of the launcher on the target's movement. In a second experiment, two screens are shown to the participants creating an apparent motion illusion. In the third, the target moves in a real motion sequence, either vertically or horizontally. The participants have the additional task of choosing the direction (horizontal or vertical) of the target's movement. The third experiment follows the previous scheme, but six variables are modified: the target's speed and size, the launcher's size and direction, the collision temporary delay, launcher-target spatial gap. The participants have the same tasks as in the second experiment.

In the apparent motion experiments, the participants do not know the target's direction of movement. Thus, only after the impact, the visual system reconstructs the preceding directions. If the perceptions about the target's movements coincide with the target movement presented, it is presumable the retrospective reconstruction. Comparing the event-related potentials among the apparent motion and the real motion experiments, it will be possible to localize temporarily and spatially the perception of causality [3], and the influence of other visual properties. 


[1] A. Michotte, The Perception of Causality, Adfo Books, 1963.

[2] T. Hubbard, Launching, Entraining, and Representational Momentum: Evidence Consistent with an Impetus Heuristic in Perception of Causality, Springer Science + Business, 2012.

[3] S. Blackmore, "A psychological theory of the out-of-body experience," Journal of Parapsychology, vol. 48, 1984.