It’s your choice! – Or is it really?

Drawing from change blindness research, scientists have come to the conclusion that we perceive the world in much less detail than previously thought (Johansson, Hall, & Sikström, 2008). Rather than monitoring all of the visual details that surround us, we seem to focus our attention only on those features that are currently meaningful or important, ignoring those that are irrelevant to our current needs and goals (O'Regan & Noë, 2001). Thus at any given time, our representation of the world surrounding us is crude and incomplete, making it possible for changes or manipulations to go undetected (Chabris & Simons, 2010).

From Change Blindness to Choice Blindness

Given the difficulty people have in noticing changes to visual stimuli, one may wonder what would happen if these changes concerned the decisions people make. For example, imagine that you are sitting outdoors on a sunny spring day and hear that the person sitting next to you orders black coffee. The waiter comes back with a cappuccino. Do you think you would notice this? Drawing from the findings on change blindness, there is reason to believe that you would not. What, however, if it were you who ordered black coffee and ended up with a cappuccino? Obviously, there is a difference between passively observing the scene and being actively involved in decision making and ordering. In the latter case, it is your intentions and actions that are targeted. This should make a difference – shouldn’t it?

A group of Swedish researchers explored whether people may at times be blind to changes that involve not the visual scene, but their own intentions, actions, and introspections. To address this issue, Johansson, Hall, Sikström, and Olsson (2005) modified the change blindness paradigm to apply it to a decision making task. They showed participants pairs of female faces and asked them to choose which one they found more attractive. After a decision had been made, participants were presented with the selected face and were asked to explain their choice. However, in three out of 15 trials, their choice was manipulated and participants were shown the very face they had not chosen previously (see for a demonstration). Only 26% of the manipulated trials were detected, suggesting that people are often blind to manipulations of their choices. Johansson and colleagues (2008) termed this effectchoice blindness. A critical reader may argue that participants might simply have refrained from revealing that they noticed the manipulation. However, the fact that many participants noticed one of the changes, but not the other two, suggests that this is not the case.

To examine whether choice blindness also occurs in other situations, Hall and colleagues (2010) invited supermarket customers to sample two different kinds of jams and teas. After participants had tasted or smelled both samples, they indicated which one they preferred. Subsequently, they were purportedly given another sample of their preferred choice. On half of the trials however, these were samples of the non-chosen jam or tea (see Again, only about one-third of the participants detected this manipulation. Based on these findings, Hall and colleagues (2010) proposed that choice blindness is a phenomenon that occurs not only for choices involving visual material, but also for choices involvinggustatory and olfactory information. Recently, the phenomenon has also been replicated for choices involving auditory stimuli (Sauerland, Sagana, & Otgaar, 2012). Specifically, participants had to listen to three pairs of voices and decide for each pair which voice they found more sympathetic or more criminal. The voice was then presented again, however, the outcome was manipulated for the second voice pair and participants were presented with the non-chosen voice. Replicating the findings by Hall and colleagues, only 29% of the participants detected this change.

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