"The Easy Way Out"

“and once again I’m thinking about, taking the easy way out. . . . ” - Westlife

Common sense tells us that we highly depend on information coming through our eyes in order to perceive the distance of an object, agree? Like anything, however, we rely on more than just optical information when judging distances. For example, research has proved that wearing heavy backpacks made people estimate farther distances than those who were not wearing backpacks (Proffitt, Stefanucci, Banton & Epstein, 2003, as cited in Goldstein, 2007, p. 254). The mere thinking of the effort they had to exert to reach a certain distance was enough for them to perceive the place as far or near. The same was true when participants were asked to actually throw heavy and light balls to targets that were 4 to 10 meters away (Witt, Proffitt & Epstein, 2004, as cited in Goldstein, 2007, p. 254). As expected, those who threw heavy balls had larger distance estimations. When binocular cues (ability to see the object) were removed, participants used familiar size to end up with a similar finding (McIntosh & Lashley, 2008). How, then, do we make sense of these findings?

On one hand, we might conclude that humans are naturally programmed to take the easy way out, that there’s no escaping our “lazy bones”. Then again, perceiving distances in relation to our energy expenditure may just be our body’s way of adapting. In fact, perceiving distances based on expected effort exerted is just one “nonoptical” variable.

Imagine you were trying to “accidentally” hold the hand of your crush or significant other in the mall. As a right-handed person, you find it difficult to smoothly lock your left hand with his (her) right hand. You then try situating yourself to his (her) left side, walking a little faster so your can be in line with him (her). But, something unexpected happens. As you sway your right arm in synchronization with his (her) left arm, he (she) all of a sudden inserts his (her) left hand in his (her) pocket as he (she) was striding, leaving you with a failed plan. What does holding hands have to do with the other factors? Well, another important factor includes reachability and an object’s orientation when perceiving distance. Linkenauger, Witt, Stefanucci, Bakdash & Proffitt (2009) discovered that orienting a tool’s handle to make it more difficult to grasp caused their participants to find the tool less reachable. Consequently, these participants perceived the tool as situated farther away compared to when the handle’s orientation made grasping easier. Emphasizing your right-handedness in my story reflects an interesting finding from this study, as it was discovered that perceived reachability was only present in right-handed people. Regardless of the handle orientation of the tools, the left-handed participants saw tools from the same apparent distance and did not affect their perceived ability to reach for the tool. A possible explanation for this discrepancy was that left-handed people are more ambidextrous than right-handed people. This means that unlike right-handed people who almost always intend to use their right hand to reach for objects, left-handed people perceive to reach and grasp the tools with either hand (Linkenauger et al, 2009). While right-handed people are thinking of the ease of grasping the tool with respect to their dominant hand, left-handed people are thinking of which had to use to grasp the tool. Going back to our story, it wouldn’t have been necessary for you to transfer to your love’s left side if you were left-handed. Either way, you’d find either of his (her) hands reachable and close to you. When it comes to adapting to unexpected events, uncomfortable grasps and awkward orientations, left-handed people win. Not fair, you say? Look at it this way, left-handed people have to learn living in a world structured for right-handed people. As a right-handed person myself, I think we should cut them some slack.

Let’s consider another scenario. Imagine you are a morbidly obese man (woman) who came across this physically attractive person. Being twice the size of any person walking by him (her) that afternoon, you are assured that he (she) will see you (a.k.a. you are a “target” in his vision). You desperately think of ways to hide away the infinite flabs and folds in your arms, legs, chin and mid-section but you don’t know what to do. Higashiyama & Adachi (2006) may have the not-so-perfect solution for you. They discovered that viewing targets from between legs with the participant’s head bent forward caused them to perceive a decrease in size and increased viewing distance. This underconstancy of size was due to the unusual orientation of the participant’s body. We are, after all, conditioned to a proprioceptive “upright” body state; only then are we able to accurately judge and object’s size and perceived distance. Maybe you can think of ways to make him (her) look at you from between his (her) legs. This may come as another challenge but at least you have an option.

After discussing unusual orientations, nonoptic variables and distance perception, I hope that one thing is clear: the visual system utilizes more than optical variables to perceive the size and distance of an object, especially when viewing conditions or orientations are unfavorable to a person. You don’t always have to go through the road less taken. In terms of perceiving objects, the easy way out is our best option.

References:

Goldstein, E. B. (2007). Sensation and Perception (7^th Eds.). Belmont, CA: Wadsworth.

Higashiyama , A. & Adachi, K. (2006). Perceived size and perceived distance of targets viewed from between the legs: Evidence for proprioceptive theory, Vision Research, 46, 3961–3976. doi:10.1016/j.visres.2006.04.002

Linkenauger, S., Witt, J., Stefanucci, J., Bakdash, J. & Proffitt, D. (2009). The Effects of Handedness and Reachability on Perceived Distance, Journal of Experimental Psychology, 35, 1649–1660. doi: 10.1037/a0016875

McIntosh, R. & Lashley, G. (2008). Matching boxes: Familiar size influences action programming, Neuropsychologia, 46, 2441-2444. doi:10.1016/j.neuropsychologia.2008.03.003

Proffitt, D., Stefanucci, J., Banton, T., & Epstien, W. (2003). The role of effort in perceiving distance. Psychological Science, 14, 106-112.

Witt, J., Proffitt, D., & Epstein, W. (2004). Perceiving distance: A role of effort and intent. Perception, 33, 577-590.