When discussing the processing of information in the human brain, “top-down” and “bottom-up” processing techniques are often analyzed with regard to visual stimuli. Most of the examples used to explain these processes involve optical illusions and visual tricks, because it is relatively easy to manipulate images and see how visual information could be interpreted in multiple ways. However, top-down and bottom-up processing are also very important to speech perception and audial stimuli, especially with regard to complex language cues like those used in sarcasm.

Bottom-up processing can often be thought of as the more “basic” of information pathways – it simply refers to the way the brain takes input from the outside world, by means of sensory perception, and transforms that information into understandable signals for the rest of the brain to interpret (Elbich, 2016). This input comes in many forms, including light energy for vision, chemical energy for taste and olfaction, or waves of energy for hearing. When I listen to someone speak, the bottom-up processing taking place in my brain uses the energy of the sound waves that are converted to action potentials inside my inner ear and sends those signals to other parts of my brain that subsequently analyze them to associate the sounds with meanings (Goldstein, 2011).

This association of sound and meaning leads into the top-down processing pathway, which takes information from previous experiences and uses that information to analyze new input (Elbich, 2016). In optical illusions, this type of processing would help differentiate similar visual stimuli by using the context of surrounding stimuli and remembering previous uses of the stimuli – for example, the lowercase letter L and capital letter I are very similar characters, but by using the context of words most humans have no problem differentiating the two while reading. Speech works in a similar way, because sound syllables are slightly different depending on a person’s tone of voice and inflections, but humans are still able to understand each other because of the language memory we generate throughout our lives.

The use of more complex language, like sarcasm, adds yet another layer to this type of speech processing – in addition to the basic comprehension of sounds and the analysis of syllables to understand words with meanings, sarcasm requires top-down processing of context clues. These clues can come from body language, tone of voice, and previous experience with individuals’ personalities, all of which help to deduce meaning from words. Comprehending sarcasm also requires a general understanding of the connection between certain voice tones and inflections with emotion and humor. For example, I could say “oh, great!” with an upward inflection at the end of the word “great” to convey enthusiasm and surprise, while a more somber or sarcastic “oh, great…” could be used to express frustration or disappointment. Being able to differentiate between these multiple meanings based solely on these cues requires a great deal of top-down processing, as past experiences with sarcastic phrases and tones need to be used to recognize and categorize new stimuli.

As sound information is processed through the ear and analyzed in the brain, both bottom-up and top-down pathways are activated to interpret sounds and words and associate meanings and feelings to them. The use of these pathways is evident when studying sarcastic language, in which the literal meaning of words being spoken may be different from the intended meaning of those words. These cases require context clues and tone to be analyzed in comparison to past experiences to determine intended meanings, which would not be possible without the combination of top-down and bottom-up processing pathways used in the human brain.

References:

Elbich, D. (2016) Lesson 3: Perception. Retrieved from Lecture Notes Website: https://psu.instructure.com/courses/1782691/modules/items/20877302

Goldstein, E. B. (2011). Chapter 2: Cognitive Neuroscience. Cognitive Psychology: Connecting Mind, Research and Everyday Experience (3rd ed.)(pp. 23 – 45). Wadsworth, Cengage Learning.