Visual Perception: Top down processing affected by Mood and emotions?

Is Visual Perception purely a top down process or do other factors alter our visual perception? Top down processing depends on a person’s prior knowledge or expectations. Bottom down processing begins with stimulation of the receptors. As someone living with mild depression, I know that emotions and mood can alter our perception. I believe our mood can alter how we see the world and what we get out of it. An experiment done in 2011 by Jacob Jolif and Maaike Meurs, University of Groningen, tested if how we feel changes how we perceive the world.

In top down processing perception is determined by three sources. These three sources are: stimulation of receptors (bottom-up processing), context in which the object appears, and knowledge or expectations of the perceiver. The idea that perception depends on knowledge was proposed in a theory back in the 19th century by physicist and physiologist Hermann von Helmholtz. Helmholtz’s Theory of Unconscious inference states that some of our perceptions are the result of unconscious assumptions that we make about the environment. What affect does mood and emotions further have on our perception?

The experiment conducted by Jolij and Meurs tested 43 students and analyzed the results. The task of each participant was to identify weather a happy face, sad face, or no face was seen after each trial. The trial was tested in 3 different scenarios to measure how mood affected the results. Each participant has 15 minutes of songs that made them feel happy and minutes that made them feel sad. Each scenario lasted 10 minutes at most and the music played through out. The participants all took the Self-Assessment Manakin in the beginning before either scenario was tested.

The experiment not only tested if mood affected visual stimulus but it also demonstrated how closely music and mood are interrelated. We all have experienced a song bringing a smile to our faces or possibly bringing on tears that we were not expecting. Participants of this experiment reported a significantly more positive mood with positive music, as compared to with no music and a more negative mood after listening to negative music.

The results of the experiment regarding visual perception show an elevation in detecting the correct face when music was present versus no music. During Happy music the participants were more accurate when it was a happy face and during sad music were more accurate when it was a sad face. The experiment proves the theory it was testing, that perception can be altered by your mood or emotions. It altered certain participant’s perception in such a way that they reported seeing happy or sad faces when no faces were present. The one aspect the experiment failed to acknowledge is the likelihood principle. The likelihood principle state that we perceive the object that is most likely to have caused the pattern of stimuli we have received. It’s likely that the participants saw faces correlating to the music they were listing due to the likelihood principle.

What part of the perception equation does mood and emotions affect? Could it be feedback signals are affected by emotions or mood? Feedback signals are associated with a person’s knowledge and expectations and are transmitted from higher levels of the brain then the receptors. It is certain that perception is more than top or bottom down processing.

References

Goldstein, E.B., (2001).Cognitive Psychology: Connecting Mind, research, and Everyday Experience, Canada, Linda Schreiber-Ganster

Jolij, J. & Meurs, M. (2011). Music Alters Visual Perception. Retrieved from http://www.plosone.org/article/Authors/info:doi/10.1371/journal.pone.0018861