Human Perception: Making Sense of the World

Learn how human perception, the process by which the brain interprets and organizes the chaos that bombards our senses, is formed and how it affects our memories.


| January 2015



Human Perception

According to neuroscientists, everything we perceive is a construction of the brain, thus, human perception is largely a linguistic and cultural process that assigns meaning to the millions of sensations we encounter daily.

Photo by Fotolia/kengmerry

Listening, Thinking, Being (Penn State University Press, 2014), turns everything you knew, or thought you knew about language and communication, listening and speaking, inside out. It’s not about how to be a good listener or the ten barriers to good listening; it’s about how listening brings humans into being. The following excerpt from Chapter 2, “Vibrating Worlds and Listening Bodies,” explains how sensation is organized and filtered during the process of human perception.

We encounter, in each nanosecond of our lives, billions of sensations, some of which we are aware and many, many more of which we are not. The vast majority of these sensations are ignored by our conscious mind, while those that we recognize and name become perceptions—categorized sensations of which we are consciously aware. Consider a conversation between two people in a crowded café. The air is filled with a cacophony of sound that includes the murmuring of voices, the clanking of spoons, the hiss of the various coffee-making machines, the faint strains of Muzak, and the ring of the cash register. Similarly, the air is also thick with the sharp aroma of coffee as well as of cologne and baked goods, and is also perhaps peppered with a sharp waft of perspiration or the faint odors of sour milk and ammonia. At the same time, thousands of colors, shapes, and patterns surround the pair in the short and middle distance—even when each looks steadily at the other’s face, their peripheral vision observes movement, color, size, shape.

Though neither person may be aware of it, the skin and bones of both their bodies receive thousands of simultaneous touches—the smooth warmth of the coffee mug beneath the fingers, the hard wood of the chair on the sit bones, the soft rubber of the mat under their feet, and the cool metal of the table under their wrists. They might even feel a mordant burn in the solar plexus when a tricked-out muscle car passes by outside, subwoofers roaring. And at the same time, there may be a sharp tang of Sumatra dark roast on one’s tongue, balanced by a sweet burst of cranberry and orange from a morning muffin. All of which is not to even mention the thunderstorm of thoughts in both their heads—everything from worries and plans to memories and dreams tumbling around like clothes in a big round laundromat dryer. And all of this is happening together, at the same time, while one friend tells the other about the disturbing dream he had last night.

So in order to listen, one must zero in and pay attention to the speaker and his or her words, and thereby ignore the zillions of other sensations competing for awareness. The better one can do this, consciously, the better one’s focus, concentration, and presence. The American epidemic of ADD (attention deficit disorder) is a disturbance of conscious focus that makes concentration tremendously difficult for some people. And while most of us can choose (to greater or lesser degrees) where we place our attention, our brains are in fact doing this unconsciously all day long. According to neuroscientists, the brain receives vastly more sensory information per second than it can process, so it has to filter things out and organize the remaining sensations into patterns and categories. This filtering and classifying process is what we call perception, and it illustrates the difference between sensation and perception. Since the eighteenth century or so, some Western philosophers, such as Immanuel Kant, Henri Bergson, and William James, have surmised that objects presumably “out there” in the “real world” are not entirely “out there,” and that, in fact, the human mind is partly responsible for constructing our perceptions. Kant’s legendary dictum that without concepts (“thoughts”) our perceptions (“content”) are empty and without perceptions (“intentions”) our thoughts are blind basically means that sensations need to be processed by the mind before they can be considered perceptions. Similarly, William James observed how “[t]he baby, assailed by eyes, ears, nose, skin, and entrails at once, feels it all as one great blooming, buzzing confusion.”

During the second half of the twentieth century, neuroscientists and cognitive scientists began to identify the actual physical processes that transform sensations into perceptions. According to this new scientific paradigm, everything we perceive, including “external reality,” “is a construction of the brain. Our senses are confronted by a chaotic, constantly changing world that has no labels, and the brain must make sense of that chaos. It is the brain’s correlations of sensory information that create the knowledge we have about our surroundings, such as the sounds of words and music, the images we see in paintings and photographs, the colors we perceive.” Thus, perception is a process of distilling sensations into culturally distinct patterns—what transforms that blooming buzz into more or less organized perceptions is largely a linguistic and cultural process that describes, names, and gives meaning to those zillions of sensations. The neuroscientist Israel Rosenfield describes how “there are no colors in nature, only electromagnetic radiation of varying wavelengths (the visible spectrum is between 390 and 750 nanometers). If we were aware of our ‘real’ visual worlds we would see constantly changing images of dirty gray, making it difficult for us to recognize forms . . . colors themselves are not in our surroundings.”

While color recognition may be a universal human perception, the kinds and numbers of categories named for color in a given language can differ greatly from culture to culture. A few cultures have no semantic category for color, and of those that do, the number of basic colors can range from eleven (as in English), to a two-color system (containing black and white or warm and cool) and combinations in between. Consider: I just this moment glance out the window and am caught by a bloom of red and dying leaves, the wind animating the branches of the giant maple in my neighbor’s yard. Then a flash of yellow as a neighbor’s child pedals by on her bike on the sidewalk in the rain. This brief experience is not a transcription of visual sensory input, but is instead a kind of linguistic tableau filled with culturally imbued words, meanings, and categories—it is as much a description of me (my nationality, age, race, gender, social class, etc.) and my language and culture as it is of the scene itself.

benhop
8/13/2016 6:33:32 PM

What?...no mention of the fundamental survival need to differentiate between hot and cold, black and white, wet and dry, large and small, fast and slow, etc.--AND the need (urge?) to QUANTIFY and MEASURE and COMPARE and COMMUNICATE about these differences AND the urge, eventually, to develop measurement UNITS and utilize NUMBERS, AND then to analyze the data with some kind of LOGIC, sll of which gives us, for better or worse, modern SCIENCE . . . ? On the basis of this excerpt, I would say that this book seeks to substitute masses of data for true insight--social "science" at its worst. Will I choose to read more? No way.