Why We See What We Want to See

The neuropsychology of motivated perception.

Posted Jul 09, 2019

CC0/Unsplash
Source: CC0/Unsplash

Obi-Wan Kenobi once advised Luke Skywalker to not trust his eyes, because “your eyes can deceive you.” Most of us can recall an instance from our own non-Jedi lives when these words rang true. Think of a time when your eyes saw what they wished to see: a person you were thinking about on a busy street, a heart-shaped pebble you were looking for on the beach.

This phenomenon, called motivated perception, has been explored in psychological research for decades. Indeed, the world as we conceive it in our awareness is not exactly an accurate representation of what it truly is. Our perception is often biased, selective, and malleable.

Even our desires can affect what we see by impacting the way we process visual information. For example, when presented with an ambiguous figure that could be interpreted either as the letter B or the number 13, participants in one study were more likely to report seeing that which aligned with desirable outcomes over less desirable ones (in this case, drinking orange juice if they saw a letter, or drinking a foul-smelling smoothie if they saw a number).

In an earlier study from 1954, when students from rival universities watched the same football game, controversy and disagreement ensued, since the students reported seeing more fouls committed by the other team. 

Why are we prone to seeing what we want to see? Recent research published in Nature Human Behavior demonstrates how our motivations and desires can give rise to two biases: a perceptual bias (when our motivations have a top-down influence on our perceptions) and a response bias (when we report seeing what we wish to see). The study, led by researchers from Stanford University, explores how these biases affect our perceptions. It proposes underlying neurocomputational mechanisms that guide these judgments. 

The study

While in an fMRI scanner, participants performed a visual categorization task. They were presented with composite images that depicted a mixture of a face (male/female) and a scene (indoor/outdoor) in varying proportions. Participants had four seconds to decide whether the image had “more face” or “more scene,” earning money for each correct categorization. The researchers then manipulated the participants’ motivation to see one type of image over another (for example, a face over a scene) by informing them that they could win (or lose) extra money if the next image they saw turned out to be of a particular category (a face). 

The results showed that the participants tended to demonstrate biases in their perceptual judgments that aligned with their motivations and wishes. Namely, they tended to label the ambiguous images as displaying the category associated with the reward (face). This occurred even when their perceptions were incorrect, leading to monetary losses. Thus, the wish to see a certain image affected the participants’ judgment, reflecting both a perceptual as well as a response bias—they not only tended to report seeing what they had wished to see, but they were also more likely to actually see what they wished to see. 

How do we make perceptual judgments?

How did the participants of the study decide whether they were looking at a face or at a scene? It all begins in the eyes. The information travels from the eyes to the primary visual cortex in the occipital lobe of the brain.

One theory (two-streams hypothesis) suggests that information is further processed in two visual streams: the ventral stream, which is thought to be responsible for encoding what we are looking at; and the dorsal stream, which identifies where within our environment the visual event occurs.

In the ventral stream, there are specific areas containing neurons that are more selective for perceiving faces, and neurons that are more specialized in scenes. A perceptual judgment can then be made by comparing the activity of the neurons in face-selective or scene-selective regions: The region that shows more activity should “win,” and the category represented by these neurons should be selected.

What the results of the present study suggest is that the neurons in these regions can also be influenced by attentional and reward systems. In fact, researchers were able to investigate the corresponding neural mechanisms of the two biases and explore how the participants’ motivation to see one category (face) over the other (scene) influenced their perceptual judgments.

As such, greater motivational biases were linked to more neural activity in ventral visual areas of the brain, while activity in the nucleus accumbent—a central region of the brain’s reward system—correlated with participants’ response biases.

Our desires and goals have an undisputable influence on our lives. As research is demonstrating, these influences taint not only our cognition, emotions, and behavior, but also—quite literally—how we see the world.

According to lead author Yuan Chang Leong, their latest study has two important implications. The first one has to do with our representation of the world. “In most cases, we would like to have an objective view of reality in order to make accurate judgments based on objective evidence. If we are aware of how desires color our perception, we can take steps towards mentally correcting for the bias,” says Leong.

The second implication concerns the way we relate to others—in particular, those who don’t share our desires and beliefs: “Knowing that others could truly be seeing things differently from us, and neither of us is necessarily closer to objective reality, we would be better able to empathize with how they act and feel.” An insight—summoned from experiments in neuroscience and psychology—that would have likely aligned with Jedi wisdom

Facebook image: Pereslavtseva Katerina/Shutterstock

References

Leong, Y.C., Hughes, B.L., Wang, Y. & Zaki, J. (2019). Neurocomputational mechanisms underlying motivated seeing. Nature Human Behaviour https://doi.org/10.1038/s41562-019-0637-z 

Kanwisher, N., McDermott, J., & Chun, M. M. (1997). The fusiform face area: a module in human extrastriate cortex specialized for face perception. Journal of Neuroscience, 17(11), 4302-4311.

Epstein, R., & Kanwisher, N. (1998). A cortical representation of the local visual environment. Nature, 392(6676), 598.

Balcetis, E., & Dunning, D. (2006). See what you want to see: motivational influences on visual perception. Journal of Personality and Social Psychology, 91(4), 612.

Hastorf, A. H., & Cantril, H. (1954). They saw a game; a case study. The Journal of Abnormal and Social Psychology, 49(1), 129.

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