Today I found that a gecko had taken up residence in my garage. It was a markedly melanistic version of the leopard variety. It was also very fast. And it didn’t want to discuss whether or not it was fully documented. As leopard geckos come from Iran and Pakistan, I thought that documentation might be important. For convenience, we can use the initials LG as a name for my visitor.
Whether he, she or it was or was not an illegal alien isn’t the issue that I wish to draw your attention to, however. It is the process of our perception that is interesting. In the case of LG and me, it was a slight movement in my peripheral vision that caused me to turn, dilate my pupils and focus. Two or three seconds later, I said “Oooh!” and it scurried out and disappeared.
This experience fits nicely in with a new paper by Kietzmann et al from the U of Osnabrück on the interplay between overt visual attention and the perceptual outcome (1). So my contralateral visual cortex was booming away with mid-frequency gamma-band activity as LG grabbed my attention, followed by a screeching high-frequency gamma band activity as I put together what it was.
Kietzmann et al’s experiments were of course lab based with fancy eye motion kit set up. Almost 70 subjects were given images to look at. They pressed a button and said what they perceived them to be. Images came in groups of three so that an image could look like one thing. With slight alterations of lines it would look like something else. But in each of these groups of three, there was one image that was neither fish nor fowl, that is, it was ambiguous.
The current big argument out there is does the act of paying attention precede the perception of what your seeing, or do you pay attention after you think you recognize something. Kietzmann et al’s results indicate the former and I am happy to concur wholeheartedly after my unexpected meeting with LG.
My big problem now? Is LG hiding out in my garage or just visiting? If the latter, are my spiders going to get teed-off as they will have competition for the flies and insects that wander to and fro in there when I’m not looking?
