Optimal Foraging at the Salad Bar: the perceptual language of food, rocks, sunsets, and skydiving


Nathan Daley MD MPH

Evan, one of my patients, recently experienced unintentional hypnosis as we discussed nutrition. I explained to him the physiological effects of high glycemic foods and related these effects to experiences (or symptoms) of fatigue, impaired focus, and being overweight. Next time we met, he explained that suddenly, after that visit, he had absolutely no preference for starchy or sweet foods. In fact, these foods actually made him slightly nauseated. Subsequently, he no longer ate them.

Just after that appointment I had a very short (too short) break to grab some lunch. I literally ran across the street from my office to the local eatery. I ordered the salad bar to go with the plan to eat it as I prepared for my next appointment. It was around noon, and I was in a hurry, so inevitably the place was busy, including the salad bar.

As I waited for access to the first items on the salad bar, it seemed like the customers in front of me were taking an unusually long time to decide if they wanted to add each particular item to their plate. It was a large salad bar and selecting among the many possible items could, indeed, be an agonizing process. I watched the slow motion drama unfold, item by item, inch by inch, until I was one body away from engaging the bar. The man in front of me had just gained access and seemed particularly distressed. Apparently he had made a wrong choice and desired to return an item to the bar, but realized that such an action might appear unsanitary. He took the item off his plate and placed it on his tray instead. I too have faced this conflict, usually after noticing swollen raisins among my olives. The sight of those wrinkled bodies bloated with olive juice leaves me uneasy. I always quarantine them quickly, so their putridness does not contaminate my entire salad. As I finished empathizing with the man in front of me, I noticed that another man had piled his plate full of only three items (literally forming a huge pile). He chose sliced cucumbers, cherry tomatoes, and hard boiled eggs.

Still, as I waited and watched, everyone seemed to be taking a great deal of time to decide upon the items. The process appeared to be one of standing in front of the most proximate items and letting the hand sort of hover over and around them and their individual tongs. Some sort of contemplation or cognition was obviously occurring in this lingering moment of relative inaction. Then, and usually suddenly, the hand would take action and move quite rapidly and confidently in grabbing the tongs and begin loading items onto the plate. However, another lingering moment of contemplation of cognition seemed to occur near the termination of this action, apparently in a process of deciding how much of the item should be loaded on to the plate. On more than one occasion, the thinking appeared to be “that is enough… well perhaps not, just one more will do it… yes, that is good.”

There was no discussion among the customers at the salad bar about which items should be chosen. No one discussed the various nutritional density, oxygen radical absorbance capacity, or freshness of the vegetables. No one discussed or seemed to apply optimal foraging theory’s metric of contrasting an items energy yield (upon ingestion) to its energy investment (in its acquisition). Really, there was no speaking at all. What was going on, I wondered.

This was not the first time I’ve thought about how we choose to ingest specific foods from a wide selection of potential foods. I know how it works for me, but I began to wonder if I could reasonably conclude, based on my observations, that these other customers were experiencing the same phenomena as I.

Experiencing is a key word here. It emphasizes the reciprocal process of selecting foods where one is acted upon as much as one acts upon. When I meet a potential food, I engage in a non-conceptual and unspoken dialogue with it. I sensuously connect with it, perceiving it with the whole of my senses. I move my eyes over its surfaces and shift my head to reveal new surfaces, manifesting its dimensional existence. Presumably drawing on a previous relationship with its kindred, I visually feel the texture of its surface, the crunch of its body, and the aroma and flavor of its substance. This kaleidoscope of sensation combines with the smells, sounds, and sights of the restaurant and those of the day unfolding outside to generate a gestalt offering to my body. My baseline hunger might then increase like an emptiness or openness in my abdomen while my senses seem to resonate and become enhanced in the presence of this gestalt. My energy and mood seem augmented, my mouth salivates, and my hand moves to receive the centerpiece of this offering, the food which will become part of my body. I am spoken to, in the language of sensation, through a dialogue of perception. The food speaks and the dialogue results in either an offer/accept or no offer/accept relationship. There is no separate offer and acceptance but a simple congruence, a mutual way of being. Then, as I’m loading up my plate, there seems to be a point at which that resonance and congruence deteriorates into dissonance and incongruence. I then move on, hovering around the next item, sensing, perceiving, and feeling.

The experience of the whole process resembles the experience of intuition and, perhaps, they are one and the same. It is a simple somatic judgment of rightness, in the sense of mutual or multi-factorial alignment. It is, actually, the same way I end up orienting myself in a chair or adopting and changing my posture while standing. It is the same way I “decide” to warm up with a coat. It is a process of somatic cognition, the indivisible interaction of organism and environment. It is the inter-becoming of organism and environment, coupled in a continuously dynamic regeneration. It is the ecological alignment of interactants. This process requires no concept of “mind” for explanation, just the living, active, perceiving body. Yet this is not the common concept of the mechanical body, as that concept must be possessed by a mind or spirit. Instead, it is a concept of body as a sentient being in motion (animate), defined by and manifested through interaction. A physical being, yes, but not mechanical. This is to experience the self as fully body, to be embodied.

I suspect most or all of those other customers at the salad bar where making their choices in a similar manner, regardless of the fact that they might explicitly articulate that process differently than I have. The question is, does this perceptual dialogue contain content beyond its phenomenal experience? James Gibson, the father of ecological psychology, would answer “yes.” In his view, perception is the active revelation of “affordances”, or the qualities of a perceived entity which provision for the perceiver’s needs. Affordances are dynamic and relative to both the perceived and the perceiver. For example, the phenomena we call stick can, in one moment, afford for the need to dig while, a moment later, afford for the need to defend. Such affordances are typically not interpreted by the perceiver, though they may be, but are the substance of the perceptive dialogue itself. In running across a boulder field, one selects each foot strike based upon how well each rock affords for stable footing, given the immediate context of relative motion, through a fluid process of perception. Rarely does the placement of a foot strike result from a conscious assessment of the relative circumstances. Affordances are relative not just to the perceiver in isolation, but to the perceiver in the context of the whole perceptual field. Affordances, therefore, are also relative to other affordances. For example, a leaf may afford for the collection of water as long as water affords for collection.

In my opinion, affordances can be simplified as the dynamic interactivity of perceptual phenomena. In the case of the stick, it may afford linear rigidness and sharpness that will penetrate and displace soft mud or dirt as it is pushed and twisted downward. In the case of the creek and the rock, the creek affords wetness while the rock affords firmness to the perceiver’s body in the context of gravity.

If affordances relate perceptual phenomena in terms of interactivity, then affordances are meaningful only because the perceived phenomena have meaning. Yet affordances are revealed through the perception of these phenomena, not through the conscious interpretation, conceptualization, or relational analysis of the phenomena. Meaning is pre-conceptual, active, and embodied. Anything that appears to have meaning does so only through referencing phenomenal perceptual experience (phenomenal, perceptual, and experience may all be redundant, but they are used together here to emphasize individual pre-conceptual experience). This is contrary, then to the common understanding that meaning is given to phenomena. For example, we typically say that words and concepts have meaning as if their meaning is intrinsic, and we might be eager to say that perceptual phenomena become meaningful not when we perceive them but when we interpret them, give them meaning, using these words and concepts. The phenomena of wetness, one might say, becomes meaningful at the moment we refer to the concept of wetness by way of the word “wetness.” Yet I believe this is completely upside down. The perceptual experience of the phenomena we call wetness is, itself, the meaning of the concept of wetness we reference with the word “wetness.” Other’s (see David Abram’s The Spell of the Sensuous) have traced the evolution of words from their origins in the oral and onomatopoeic imitation of the phenomena to which they refer, to their alpha-phonetic and textual existence today. These sounds, the words they became, and the concepts which they express today, refer to raw perceptual phenomena, and this phenomena is their meaning. A sentence has no meaning until it is read and related to perceptual experience by the reader. In the same way, the phenomena to be perceived has no meaning until it is perceived by the perceiver.

The proverbial example of trying to describe a sunset to a blind man might help to illustrate this position. A man who has never perceived the world visually will never know the meaning of “sunset” despite any attempt to provide the meaning through concepts and words. One could argue that “sunset” literally means that “the sun falls below the horizon” and that telling the blind man this will, thus, give him the literal meaning of the word. Yet this is more of a definition of the word “sunset” or the relating of one word to other words. We can define it using other words, but these words are no less understood by way of perceptual experience. In relating “sunset” to “sun” and “horizon”, the blind man still does not possess the meaning of “sunset” nor “sun” nor “horizon” because he has never perceived these phenomena. Perception is the generation of meaning.

When we say, “words cannot describe” we don’t actually mean that there are no words for the phenomena we wish to describe but that the available words are insufficient as the phenomena perceived is quite different in some way than our previous perceptual experiences that have established the meaning of the available words.

Years ago I went skydiving and, besides the wind, I did not really know what I was experiencing. Sure, I could use words that might be accurate like land, sky, depth, elevation, acceleration, etc., but these words, for me, do no mean what I was perceiving, holistically, while hanging outside of an airplane, crouching on its small wheel well, surrounded by the widened angle of land and sky, wind screaming over my ears, and then plunging into thin air, flipping and spinning through a blur of colors until finally recovering that view of the horizon, wind still screaming over my ears. The perceptual experience was so novel that the phenomena of skydiving remained quite meaningless. It was not frightening, just new and stimulating. I had no perceptual memory from which meaning could manifest and, to this day, the meaning of that perceptual experience is nothing other than skydiving and it affords to me nothing other than novel stimulation. I do not feel that I can convey the experience, the meaning, through any available words to someone who has never skydived.

Metaphorically, then, one could say that affordances are the sentences of perceptual dialogues in which perceptual phenomena are the words. In affordances, the individual meaning of perceptual phenomena are related to manifest an understanding of interactivity. If you encounter a creek while out walking and need to cross it, the rock in the middle may invite you by affordance, through your exchange of perceptual words, to step upon it and leap off of it.

So what affordances and meanings may be present in the salad bar? One might first think of micronutrients, macronutrients, calories, polyphenols and various phytonutrients, and etc., but these are not perceptually available qualities. These concepts are objective analytes. For those that understand them and have related them to food items, however, they nonetheless factor into the perceptual dialogue (more on this later), but they are not universal to all people who eat. Instead, the food items in the salad bar may universally afford eating, nourishment, satiation, and energy (in the subjective sense). They may also afford nausea, illness, discomfort, and fatigue. These food items communicate these affordances through their various combinations of meaningful crunchiness, coolness, bitterness, pungence, and sweetness as well as various aromas, colors, and sounds that occur upon biting into them. Unique combinations of these qualities comprise the multi-sensory perceptual phenomena that we refer to as broccoli, for instance.

Why might one person reveal different affordances than another person, given similar perceptual phenomena? For example, why is broccoli appetizing to one person and aversive to another, despite both people perceiving the same green, branching, bushy, crunchy and slightly bitter phenomena?

The answer is hugely complex and, of course, relative to the individual perceiving the qualities. The simple answer is, a food’s affordances have been constructed or developed along with the perceiving individual. An individual’s development certainly includes one’s perceptual life history, but also much more. A person, and any other organism, develops through constructive interactionism within a developmental system. Whoa! What does that mean? Well, it means the meaning of perceptual phenomena is constructed , like perception itself, under the distributed influence of the entire system within which we are embedded. Meaning is local to the individual within a scale-free or holistic context. Much of this system is inherited. Nucleic acids, epigenetic regulation (methylation, acetylation, etc.) of nucleic acids, mitochondrial nucleic acid expression, cytoplasmic structures and organelles, energy substrates, phospholipid membrane, proteins, the intra-maternal (in utero) environment, the extra-maternal environment (natural and built, local and global), the cosmic environment, maternal ecology, and the socio-cultural system are all dynamic yet all “inherited” by every individual. This is the evolving developmental system within which each one of us interactively and continuously self-constructs (self-organizes). The very slow dynamic rate (rate of change) of the genome, cellular constituents, biospheric environment, and cosmic environment mesh with the more intermediate dynamic rate of the socio-cultural, built, and local natural environment as well as the more rapid dynamic rate of maternal ecology and physiology, epigenetic regulation and (once born) individual ecology to influence perception and perceptual meaning. In short, affordances are locally and continuously developed through an organism’s perceptual engagement (ecology) within an evolving developmental system.

In regard to the subject of food, we refer to affordances as food preferences or aversions.  The development of food preferences or aversions originates in the variable and dynamic genetic expression of differentiated (i.e. specialized) cells which produce the human biochemistry that interacts with the food biochemistry (manifesting as perceptual and physiological interactions), a biochemical concordance that has resulted from human organism-food organism co-evolution.  These specialized cells begin differentiation within the context of intrauterine environment already rich in perceptible tastes and smells as well as the subsequent maternal physiological responses from her ingestion of the foods which are tasteable and smellable.  The maternal physiological response transmits to the developing embryo simultaneously with the stimuli of taste and smell.  The ability of the embryo to perceive develops through the action of perceiving in the context of perceptible phenomena in the way of co-emergence or mutual and reciprocal development and, in this case, cellular differentiation.  The development of perception is contingent upon an environment with perceptible phenomena, and interaction between perceiver and perceived.   This perceptual development never ends, it is never complete, but continues as long as perception continues.   Maternal diet continues to be an influence during nursing and experiences of food throughout post-infant phases of life then carry on this development.  The acts of relating these experiences to past experiences (something we call interpretation) continue to develop, alter, or adjust the affordances available through specific foods.   One can “learn” to like a food (hot peppers or coffee for example) and one can “learn” to dislike a food (the aversion that occurs after becoming ill from a favorite food, for example) as their affordances are altered through individual development within a complex, developmental system.  Like all affordances, the developmental past of food preferences are collapsed into the immediate individual context.   The perception of thirst, after being active on a hot sunny day, is to perceptually re-experience thirst and the refreshment and hydration afforded by a cold beverage.

For those individuals engaged in the conceptualization of food biochemistry (macro and micronutrients, etc.) and the related physiology or pathophysiology (blood glucose, insulin, leptin, etc.), this conceptualization is yet another process of relating food items to perceptual memory and, thus, manifest their affordances. The abstractions of food that we call molecules are meaningful because we have experienced the phenomena of shape, and the related abstraction of life that we call biochemical physiology is meaningful because we have experienced the phenomena of fit (as in shapes fit into complementary spaces) and the phenomena of shape-fit interactionism (as in combining lock and key affords change). We then connect these abstractions to abstractions of the organism such as disease or vitality and, to make disease or vitality meaningful, we then connect them to experiences of disease or vitality such as, for example, fatigue and nausea or energy and happiness. Thus to understand food biochemistry, to give it meaning, we connect the perceptual phenomena that is a food, to abstractions of food, to abstractions of physiology, to abstractions of organisms to, finally, perceptual memory. Thus remains the essential generative source of affordances (food preferences in this case), the coupling of perceptual phenomena and perceptual memory.

So we can now circle back to where we started, with Evan’s unintentional hypnosis. My attaching the experiential words fatigue, impaired focus, and weight gain to high glycemic foods was an act of connecting Evan’s perceptual memory (experiences of being fatigued, etc.) to those foods, thus revealing new affordances in Evan’s perception of high glycemic foods. In essence, for Evan, those foods now afforded for not being well or, in fact, for actually being ill. This is how hypnosis works, giving new affordance (i.e. perceived interactivity) to interactive phenomena. As an ongoing developmental process, it is never complete and never static. The results from hypnotherapy are ephemeral and must be continuously reinforced, that is redeveloped.

In summary, the selection of items to ingest occurs through a process of perception, which itself is inextricably rooted in development process of any one individual, an ongoing process through which the evolutionary past and individual life history collapse into the immediate present. Selecting foods from a spectrum of options is far from a calculative intellectual process, far from a genetic program, and far from a cultural program, all common assumptions. Tim Ingold, the “Galileo of modern anthropology”, suggests that foraging in hunter gatherers occurs in the wild just as it occurs at the salad bar. The difference is in the developmental system that determines the available affordances that are perceived. We “civilized moderns” are “wild” and “primitive” as we forage within our indigenous habitat; a habitat rich in patches of edibles we call restaurants, grocery stores, and salad bars. We forage perceptually and, in doing so, manifest the affordances and meaning of food. We develop these affordances and meanings not in isolation or independently, but through our active-perceptive existence in a fluid developmental system, a system where there is no central control but pervasive influence, a system of influence that permeates our being. The dichotomies of gene-environment, nature-nurture, mind-body, and biology-culture all dissolve, right there at the salad bar, in the perceptual process of filling one’s plate. The essence of being alive often lies in the ordinary activities of everyday life where seemingly small matters manifest only through the full content of one’s being.

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About Nathan Daley

"The needs of the person are those of the planet, and the needs of the planet are those of the person. There is only one health, without which there is infinite disease."
This entry was posted in affordances, anthropology, Co-Evoluation or Holistic Evolution, developmental systems, Ecological Medicine, ecological psychology, Ecology, food preferences and aversions, Health, hypnosis and hypnotherapy, language, Life, meaning, Mind, Nutrition and Diet, optimal foraging theory, perception, Philosophy, primitive and modern, Ways of Knowing, Wisdom and tagged , . Bookmark the permalink.

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