by Janet Kwazniak
A recent paper looked at when the cause and effect of an event is identified: M. Rolfs, M. Dambacher, and P. Cavanagh; Visual Adaptation of the Perception of Causality; Current Biology, 2013. Here is the abstract:
We easily recover the causal properties of visual events, enabling us to understand and predict changes in the physical world. We see a tennis racket hitting a ball and sense that it caused the ball to fly over the net; we may also have an eerie but equally compelling experience of causality if the streetlights turn on just as we slam our car’s door. Both perceptual and cognitive processes have been proposed to explain these spontaneous inferences, but without decisive evidence one way or the other, the question remains wide open. Here, we address this long-standing debate using visual adaptation—a powerful tool to uncover neural populations that specialize in the analysis of specific visual features. After prolonged viewing of causal collision events called “launches”, subsequently viewed events were judged more often as noncausal. These negative aftereffects of exposure to collisions are spatially localized in retinotopic coordinates, the reference frame shared by the retina and visual cortex. They are not explained by adaptation to other stimulus features and reveal visual routines in retinotopic cortex that detect and adapt to cause and effect in simple collision stimuli.
In other words, this is evidence supporting the idea that at least some types of causality are identify very early in perception, perhaps all. This is not that surprising, perception is for this sort of clarification: identifying objects, movements and producing a meaningful world. It is nice to have the conformation. Very young babies identify causal event (and aminacy and intention) long before they understand all that much about the world. They use these automatic perceptions in order to learn about the world.
What has bothered me is a quote in ScienceDaily by one of the authors. I am unable to read the original paper so I do not know if this is quote is typical of the framework of the paper. It does not seem to be found in the abstract or the paper’s figures which I can access. The underlining is mine.
Rolfs, who conducted much of the research as a post-doctoral fellow in NYU’s Department of Psychology. “This finding ends a long-standing debate over how some visual events are processed: we show that our eyes can quickly make assessments about cause-and-effect — without the help of our cognitive systems.” We frequently make rapid judgments of causality (”The ball knocked the glass off the table”), animacy (”Look out, that thing is alive!”), or intention (”He meant to help her”). These judgments are complex enough that many believe that substantial cognitive reasoning is required — we need our brains to tell us what our eyes have seen. However, some judgments are so rapid and effortless that they “feel” perceptual — we can make them using only our visual systems, with no thinking required. It is not yet clear which judgments require significant cognitive processing and which may be mediated solely by our visual system. In the Current Biology study, the researchers investigated one of these — causality judgments — in an effort to better understand the division of labor between visual and cognitive processes.
I seems to me that it is not possible to draw any sort of firm line between perception and cognition. Perception is sort-of-automatic and cognition ranges from purely automatic to not-so-much so. Whether you include perception in cognition (as I do) or you separate them using some criteria, that criteria cannot be whether the process in automatic or not. The parts of the brain work together, the functions are complex and mixed. Thought is not as it appears – much more is unconscious then we ‘feel’ is.
What we can take home is that the judgment of cause and effect can be done earlier and faster than we had suspected. There is no evidence that it is not modified later as the experimental events were very simple and there would be nothing to correct. Nor is there evidence that a causal judgment could be made later for some events that are too complex for an early, fast determination. We need the rough and ready, early and fast, judgment when it is possible but that is not the whole story. What is the difference in complexity between a judgment about causality and all the other magic of perception: colour consistency is complex, constructing a 3D world is complex – the whole thing is amazingly difficult. Identifying simple causal events may be one of the easier things that perception is involved with. That there is a causal connection when a motion switches the object carrying it seems to require less ‘computation’ then constructing a 3D world. The idea that “no thinking is required” in perception is in danger of taking the meaning out of thinking. If no thinking is involved in perception then, by that logic, we will find that none is required in moving our muscles, and then none is required for memory, none is required for learning and finally that we don’t think at all. This is not a useful path to go down.