This is the fifth of a deeper look into ten philosophical positions. This one is on convergence realism within the category of epistemology. A full article is available on Substack, with supporting information on a recent post here on Philosophics Blog.
Below is a ~5-minute short podcast.
Language works, but not uniformly.
Its effectiveness declines as the conceptual complexity, abstraction, contestability, contextual dependence, and institutional burden of what it is asked to communicate increase. We routinely mistake grammatical fluency for semantic precision and social agreement for shared reference.
I describe this through an Effectiveness–Complexity Gradient:
Invariants are comparatively stable terms with constrained error ranges.
Contestables remain usable but acquire their force within normative or institutional frameworks.
Fluids drift across contexts and disciplines, preserving family resemblance without reliable closure.
Ineffables mark domains where propositional language collapses into metaphor, gesture, paradox, or silence.
These are not ontological species. They are diagnostic regions along a gradient. The important feature is not the label but the rate at which apparent linguistic effectiveness decays as conceptual load increases.
This is the fourth of a deeper look into ten philosophical positions. This one is on convergence realism within the category of epistemology. A full article is available on Substack, with supporting information on a recent post here on Philosophics Blog.
Below is a ~5-minute short podcast.
I don’t regard the self as a persistent entity travelling through time while accumulating experiences like stamps in a metaphysical passport.
The first-person “I” is an indexical compression. It marks the presently organised locus of perspective, salience, memory-access, and action. It is indispensable, but indispensability does not establish an inner owner to which the index refers.
The diachronic self is a broader compression: a narrative, biological, documentary, interpersonal, and institutional device for tracking selected continuities across time. Memory contributes to this, but memory is lossy, reconstructive, and uneven. The person remembered is not transported intact into the act of remembering.
This is the second of a deeper look into ten philosophical positions. This one is on mediated encounter realism (ontology) within the category of metaphysics and ontology. A full article is available on Substack, with supporting information on a recent post here on Philosophics Blog.
This is the first of a deeper look into my position of diagnostic anti-foundationalism within the category of philosophical method for metaphilosophy. A full article is available on Substack, with supporting information on a recent post here on Philosophics Blog.
The question is reasonable, although belief may already be doing more work than I would permit it under cross-examination. My writing is generally diagnostic rather than doctrinal. I am more interested in identifying the architectural assumptions beneath a dispute than in selecting a furnished room within it. Where philosophy offers a contest between established positions, I often suspect that the arena itself has been badly designed.
Still, repeated diagnoses eventually disclose a pattern. Certain commitments recur: suspicion of substance, resistance to metaphysical inflation, distrust of linguistic confidence, rejection of moral realism, scepticism toward persistent personal identity, and an insistence that mediation does not entail fabrication.
What follows is therefore neither a creed nor a completed system. It is a provisional map of where I presently stand.
The labels are intended as coordinates, not allegiances. Where no established term quite fits, I have used my own. This is partly unavoidable and partly evidence for the very linguistic difficulty I spend so much time diagnosing.
This content, including video and podcast summary, are of a longer Substack article on my philosophical positions with descriptions.
I keep an eye on the metrics of my various social media outlets, but I don’t always click in. Today, I did, and I noticed a female-dominant listenership.
This is surprising for two reasons.
Most interactions I get are from males – at least people with traditionally male names.
Until now, the split has been reversed.
I am not going to make any assumptions based on these data, but I was, as I said, surprised.
Add to this the age chart, and it shows that the majority of these listeners were between 35 and 44, a majority of whom were female. This is the outlier spike. Other than this, listeners skew toward older males, especially between 45 and 59. This makes intuitive sense to me, given my age, content and interests.
This was an unplanned post. I just wanted to share my surprise. More on unicorns and perspectival realism to follow presently. Please stand by.
NB: Don’t blame me for the cover image. This is Midjourney’s idea of a male and female engaging in a tug-of-war. Are those outfits standard fare? I’m not so sure about the rope physics either. 🧐
I wrote about this content in 2019, but I wanted to revisit it for a video as well as create a podcast audio version.
Video: YouTube version of this page content
Podcast: Audio rendition of this page content
In today’s segment, I am going to share my perspectives on the truth about truth. To start, I’ll let the audience know that I do not believe in the notion of truth. I feel the term is ill-defined especially in the realm of metaphysics and morality. I feel that when most people employ the word ‘truth’, what they mean to say is ‘fact.’ That a fire engine is red, for example, may be a fact, if indeed the fire engine happens to be red, but it is not true. This is a misapplication of the term. If you employ truth as a direct synonym for fact, then this is not what’s being discussed here, and perhaps your time might be better spent watching some content by the Critical Drinker.
My argument is that truth is not objective. Rather it is subjective and perspectival. I concede that there may be some objective truth out there somewhere, but it is not and will not ever be accessible to us because of limitations in our sense-perception faculties and cognitive limitations. Per Aristotle, we only have five senses with which we can connect to the world, and these senses are limited. If there is anything out there that would require another sense receptor—a sense receptor not available to us—, we would never be able to sense it, to even know of its existence. Perhaps the universe emits 100 sense signals, but we are only capable of receiving and translating five. We’d be oblivious to 95 per cent of reality.
I am not making any claims that this is the case, but human cognition is so limited, that we can’t even conceive of what another sense might be. If you can, please leave a comment.
To be clear, I am not talking about senses we know other species possess. Bats may have echolocation, and sharks may have electroreception. Some animals may have greater sensory acuity—superior vision and auditory senses, olfactory and gustatory, tactile, or whatever. Some can see into infrared or ultraviolet light spectra. Technology that includes biomimicry provides humans with microscopes for the microworld and telescopes for the macroworld. We have x-rays and sonar and radar, radios and televisions that extend our senses, but these provide no new sensory receptors.
Like the story of the blind people and the elephant, we are left grasping at parts. But even if we are able to step back to view the whole elephant, to hear the elephant, to touch and smell or even taste the elephant, if there is more to the elephant, we cannot know it. The same goes for ourselves.
I know that some people might inject gods or psychic or paranormal energy into this void, and sure, feel free, but I am looking beyond these pedestrian concepts. What else might there be?
But let’s depart this train and head in a different direction. I want us to focus on the senses we do have. For the typical human, sight is our primary arbiter of reality, at least as defined idiomatically. We tend to believe what we see, and what we see, we assume as real—even if we are later mistaken. I guess that wasn’t a unicorn or a pink elephant. I must have been hallucinating or dreaming. I could have sworn that was Auntie Em.
There are several competing theories around truth, but I’ll focus on the Correspondence theory, which is simply put, the notion that, proxying reality for truth, human perception corresponds with the real world. And a pragmatist might argue that’s close enough for the government.
Keep in mind that historically humans have contorted themselves into making calculations. Remember how long people had been tying themselves into knots to show planetary motion in a geocentric system creating epicycles and retrograde motion to map understanding to a perceived reality.
One might even argue that we’ve progressed. It wasn’t true or accurate then, but now it is. And perhaps it is. Let’s look at some illustrations.
NB: Due to an editorial mishap, this paragraph was dropped in the podcast, hence dropped from the video, which shared the podcast audio source. As such, this image was also not used in the video. This is unfortunate, as it was meant to introduce those with limited maths knowledge to the asymptotic curve, as described. Apologies, and I hope this serves to orient any travellers who may have lost their way at this point.
In this first illustration, we see Truth (or relative truthiness) on the Y-axis and Time on the X-Axis. On the top, we see a threshold representing Reality. In the plane, I’ve rendered an asymptotic curve, where over time, we get closer and closer to the Truth. But we never quite get there. More on this later.
The next illustration will help to demonstrate what’s happening.
Notice there is a gap between the curve and the Reality cap. For one thing, we don’t really know where we are relative to Reality. In the case of the geocentric system, we might have been at the leftmost space. Once we determined that the system is actually solar-centric, we might have moved right on the curve to close the gap. We might be tempted to defend that we’ve finally reached the truth, but we’d have been equally willing to make the same defence from the geocentric position, so we need to be mindful of the past.
Perhaps, this last example was too obvious. We feel comfortable staking a truth claim—or at least a claim of fact. So let’s look at another example.
Let’s re-use the same axes—Truth and Time—, but rather than an asymptotic curve, let’s presume something more polynomial in nature—or not particularly cyclic. Rather than retrograde motion in planets, let’s visit the supposed progress of Newtonian over Einsteinian physics.
This takes a bit more setup but bear with me. In this case, I have taken liberties and illustrated the Einsteinian physics gap to capture an inferior vantage on reality over Newtonian physics. Granted, I need to rely on a bit of suspension of disbelief, but in the bigger picture, I am trying to convey a scenario where some new paradigm puts the prior knowledge in perspective.
In this instance, both Newtonian and Einsteinian flavours of physics are based on a materialistic, particles-based model, which is where the modern physics consensus resides. But, let’s say that consensus changes in such a way that it is determined that something else underlies reality, say consciousness per Analytic Idealism as proposed by Bernardo Kastrup or per Integrated Information Theory (IIT) as advanced by Donald Hoffman and others. As with retrograde motion, we might end up finding that we were barking up the wrong tree. This might be a bit different because the particles are a directly perceived manifestation of the underlying consciousness, but I wanted to create a scenario where knowledge thought to have advanced actually regressed, but this wasn’t revealed until a new perspective was available.
Yet again, an important aspect of note is that we don’t actually know the distance between our perceptions and real Reality.
This last illustration builds upon the first asymptotic chart but has an in-built error margin meant to reflect language insufficiencies. There is some concept that people feel they grasp, but the consensus is not as unified as the group thinks.
I’ll share two examples, the first being the concept of justice. To me, Justice is what I deem a weasel word. It’s a word we commonly use, but it means different things to different people. To me, it’s a euphemism for vengeance by proxy, but for others, it transcends that and mirrors some impartial dispensation of just desert—some good old-fashioned law and order.
[Justice is] a euphemism for vengeance by proxy
Without getting stuck down some rabbit hole, my point is that if we aggregate these beliefs, the asymptotic curve represents an average consensus vantage rather than something as obvious as 2 plus 2 equals 4. On this note, allow me to clear the air.
Some viewers might be clamouring to say, “but 2 plus 2 equals four is true.” But this is tautologically true, which is to say that it’s true by definition. It’s a similar tautology to saying that it’s true that snow is white, or coal is black. We’ve already defined snow, white, coal, and black, so these may be facts, but they are true by definition.
Revisiting the chart, notice that there are two curves in the space. In this case, I illustrate competing truth claims from the perspective of an omniscient narrator. The case is whether the earth is an oblate spheroid or is flat. I am going to go out on a limb and assert the earth is spherical, as represented by the top blue curve—and we have some margin of error as to what that might mean. The bottom red curve depicts the perceived truth of the flat earthers, who also have some room for semantic error.
Given that I am presuming that I am in the right adopting the majority position—please be right—, the blue curve is closer to Reality than the red curve. Of course, in the event that the earth is really flat, then it proves my point that we don’t know where we are relative to truth, so we assume that the state of knowledge at any given time is what’s real.
Again, forgive my fanciful examples. Please don’t tell me that this spheroid versus planer earth is tautological too because you’d be correct, but I am already aware. They are just nonsensical illustrations. Nonetheless, I hope they’ve served to express a point.
I could have as well created curves that depicted two cohorts’ beliefs on the efficacy of tarot or astrology in predicting the future. I am sure that it might render somewhat like the last chart, but I’d also presume that both curves would have very low truth values as seen from an objective observer. Secretly, I hope tarot wins the truth battle.
Before I end our time together, I’d like to convey that for an Analytic Idealist, these charts might be more acceptable at face value. For a Realist, Naïve or otherwise, they may argue that this curve is not asymptotic and may in fact reach some tangency. I don’t happen to believe this is the case or I wouldn’t have spent my time assembling and presenting this. Time will tell. Or will it?
The theme of this Institute of Art and Ideas video is ‘Should we move away from postmodernism?‘
Podcast: Audio rendition of this page content
EDIT: Find my version of this content on YouTube:
Video: Postmodern Defence
At the start, I feel as usual, that the definition of postmodernism is nebulous, and the fora agree, methinks. Toward the end, Hilary Lawson concedes that key actors tied to the early postmodern movement denied being postmoderns, singling out Foucault and Derrida. More on this. Keep reading.
Julian Baggini, the bloke sat on the left and whose positions I am only getting familiar with, starts off the clip. He makes some points, some of which I agree with and others not so much.
He makes a play at claiming that there is some objective truth to be attained, following on with the statement that without this notion, it’s anything goes. I disagree with both of these assertions. Then he cites Thomas Nagel’s The View from Nowhere, wherein he posits that subjectivity and objectivity are extrema on a spectrum and that experience is somewhere in between. This conforms to my beliefs, but there are two provisos. First, the extremum of objective truth is unattainable, objectively speaking. Moreover, as I’ve written before, we have no way of adjudicating whether a given observation is truer than another. It seems that he leaves it that we don’t need to know the absolute truth to know “true enough”, but I think this is both a copout and wrong—but not too wrong for pragmatism to operate.
For example—not mentioned in the clip—, I can imagine that physicists feel that Einsteinian motion physics is truer than Newtonian physics, especially as we need to take measurements nearer to the speed of light. In my thinking, this might provide a better approximation of our notion of the world, but I can also conceive of an Ideal, non-materialistic perspective where both of these are rubbish from the perspective of truth. I feel that people tend to conflate truth with utility.
Julian makes an interesting point about semantics with the claim that “some people” define certain things in such a way as to not possibly be attainable and then claim victory. But what are his three examples? Free will, the self, and objectivity. If you’ve been following me, you’ll know that I might be in his crosshairs because I tend to be in the camp that sees these concepts as sketchy. And to be fair, his claim of defining something in a manner to keep a concept out of bounds is the other side of the same coin as defining something in such a way as to get it into bounds.
The self is different to free will insomuch as it’s a construction. As with any construction, it can exist, but it’s a fiction.
I’ve spoken at length about my position on free will, but I am fairly agnostic and don’t particularly care either way. I feel that the causa sui argument as it applies to human agency is more important in the end. The self is different to free will insomuch as it’s a construction. As with any construction, it can exist, but it’s a fiction. Without interacting with Julian or reading his published works on the self, if there are any, I don’t know how he defines it. And here we are discussing objectivity.
Given Nagel’s objective-subjective polarity, it seems they want to paint postmodernism as claiming that everything is subjective and that science (and religion) hold claims to objectivity. Hilary Lawson, the geezer on the right takes a position between extremes, but he denounces Julian’s claim about objective truth, noting that many people (especially of religious persuasions) make claims on Truth that are diametrically opposed, ostensibly labelling the same object simultaneously black and white. And the object for all intents and purposes is red.
I’ve gotten out of order, but Julie Bindel makes some good points on Feminism and suggests that the philosophical feminists—may I call them pheminists? No? OK then—such as Judith Butler have set women’s rights back by claiming that the category of ‘woman’ is invalid. Minni Salami defended Judith by noting that Butler has helped constructively in some ways and, citing Simone de Beauvoir, that woman is a category established by men to create The Other Sex. Still, Julie—not incorrectly—states that without a category, women (or whatever collective term one decides is representative) cannot be afforded legal protections—because law, as facile as it is, is all about categories and classes.
Hilary reenters the fray and states that it is not acceptable for one person to claim that their lived experience is all that is needed just because that is their truth. To be fair, this feels like a bit of a strawman argument. Perhaps I need to get out more, but I am not familiar with anyone credible making this claim.
I enjoyed watching this clip and processing the information. I hope you do as well. If you have any comments, I’d love to read them.
This is my take on the fifth chapter of The Matter with Things. I suggest reviewing the previous chapters before you delve into this one, but I won’t stop you from jumping queue.
Podcast: Audio rendition of this page content
Intro
Chapter five of The Matter with Things is titled Apprehension, following the previous chapters, Attention, Perception, and Judgment. From the start, let’s clarify that apprehension is not meant in the manner of being nervous or apprehensive. It’s meant to pair with comprehension. More on this presently.
Whilst the previous chapters have been heavily focused on the importance of the right hemisphere, this chapter is focused on the left, which may be given the chance to redeem itself. Not surprisingly perhaps, given the relative function of the right hemisphere versus the left, this chapter is much shorter than prior chapters.
Content
This chapter opens by asking what happens to a person who experiences left hemisphere damage. But let’s return to the chapter title. Apprehension is retaken etymologically and means to hold onto or to grasp. This is the function of the left hemisphere. The right hemisphere is about comprehension. The root ‘prehension’ is Latin for hold; the added ap prefix suggests holding on, whilst the com prefix suggests holding together.
Whilst conceptualising and abstract language is a right hemisphere function, spoken words are a left-brain function. It turns out that so is pointing and other gesticulation, reminding me of some ethnic stereotypes of people who speak with their hands. We need to keep in mind that the right hemisphere controls the left part of the body whilst the left hemisphere controls the right. What this means is that the right hand, being guided by the left hemisphere is marching to a different drummer.
Also, keep in mind from the previous chapters that the right hemisphere is holistic whilst the left is atomistic. Where right hemisphere damage is evident, a person has difficulty viewing the parts of a whole, whilst if the damage is on the left, a person has difficulty constructing a whole from its constituent parts. Namely, it may recognise that a body is constructed from an inventory of pieces—head and shoulders, knees, and toes—, but it can’t seem to grasp the cohesive orchestrated picture.
Apart from body continuity, when the left hemisphere is damaged, it might know all of the steps of a given process—McGilchrist shares the example of a person trying to light a smoking pipe—, but there may be difficulty in some of the instrumentation along the way. He cites an example by Czech neurologist, Arnold Pick, which I share here intact:
The patient is given a pipe and brings it correctly to his mouth, then expertly reaches for the tobacco pouch and takes a match from the box but when asked to light it, sticks the head of the match into the mouthpiece and puts the other end in his mouth as if to smoke it. Then he takes it out of his mouth, draws it out of the mouthpiece and sticks the other end of the match in the mouthpiece of the pipe, pulls it out again, holds it for a while in his hand apparently thinking, and then puts it away.
a person when encountering a pencil would feel compelled to grab it and start writing nothing in particular
To underscore the apprehension, where there is damage evident in the right hemisphere, the right hand (under control of the left hemisphere) may just grasp at things for no reason, perhaps reaching arbitrarily out to doorknobs. In one case, a person when encountering a pencil would feel compelled to grab it and start writing nothing in particular. In each case, the right hemisphere was not available to contextualise the experience. This right hemisphere is opening and exploratory whilst the left is closing and instrumental. It seems one might tend to meander without the left to provide a certain will and direction.
McGilchrist makes some correlations between humans and other great apes, but I’ll just mention this in passing.
I am going to pause to editorialise on McGilchrist’s next claim. He argues that Saussure’s claim that language signs are arbitrary is false and gives some examples—sun, bread, and spaghetti—but I am not ready to accept this stance. For now, I am remaining in the camp with Saussure and Wittgenstein that language is both arbitrary and self-referential. Getting down off my soapbox.
Recall again that whilst the right hemisphere takes the world as presented, the left hemisphere can only re-present. This is why language symbols are handled by the left hemisphere. Coming back to Saussure, the right-brain experiences a ‘cat’ whilst the left-brain names that object a ‘cat’ and classifies it as a mammal, feline, quadruped, and whatever else.
The right hemisphere is about metaphor, prosody, and pragmatics whilst the left hemisphere, though not exclusively, is about syntax and semantics.
The right hemisphere is about metaphor, prosody, and pragmatics whilst the left hemisphere, though not exclusively, is about syntax and semantics. The left hemisphere is about symbols. As such, lipreading and interpreting sign language are both left-brain activities.
An interesting conveyance is a case study of a person with left hemisphere damage reading a book who recites the elephant in place of the written word India, so making an association by not recognising the word itself. And there may be a naming problem, so if there was a problem related to an ankle, they would point to an ankle but substitute the name of the part.
Finally, to reiterate the holistic versus atomistic divide, some people with left hemisphere damage can articulate the parts of the body or a bicycle, but when queried can’t relate that the mouth is beneath the nose or some such.
Perspective
To summarise, McGilchrist leaves with a comment, “The fabric of reality typically goes for the most part unaltered when the left hemisphere is suppressed.”
As I’ve been editorialising a bit throughout, I don’t have much to add at this point. Aside from my Saussure nit, I am still very interested in the concept that the right hemisphere constructs reality. I feel that I interpret this construction differently to Iain.
I believe that we agree that there is a world out there, and we interpret this world by interacting with it. Where I feel we differ is that he feels there is a world of objects that we interact with and perceive whilst I believe that we construct this world of objects by means of constructing the underlying material, from particles to fields. I think he’ll discuss this more in later chapters and I could be off base. Time will tell.
Having put Apprehension to bed, next up is a chapter on Emotional Support and Intelligence. I hope you’ll join me.
What are your thoughts? What did you think of this chapter? Were there any surprises? Anything of particular interest?
In this segment, I continue the journey through Iain McGilchrist’s masterwork, The Matter with Things by summarising chapter three, Perception, a followup to the previous chapters, respectively titled Some Preliminaries and Attention. I strongly recommend that you listen to these in turn, but feel free to play the rebel and cut queue. No one will even notice but you, and if you don’t tell, neither shall I. Come join me.
Podcast: Audio rendition of this page content
Intro
Chapter two of The Matter with Things is titled Perception. Following the previous chapter, Attention, it’s about how we perceive what we attend to. Without attention, there is no perception, but perception is not always correspondent with the so-called reality “out there”.
Content
From the start, McGilchrist wants to assess which hemisphere is more veridical. Spoiler Alert: It’s the right half. But you already knew that because you’ve been keeping pace. And you also know that I feel he is leaving an option on the table, that neither is veridical to the actual terrain; rather, one just better maps the map. But the question essentially resolves to the same place, not as much verity as trust.
Sensory perception occurs in both hemispheres, but it is better in the right hemisphere than the left, as the left has been somewhat relegated to re-presentation over time—the same hemisphere that is better suited for codifying and mapping using symbolic language—something reserved for the brains of primates—which gives us a virtually inexhaustible way of mapping the world.
Perception is holistic, something better handled by the right hemisphere, being as the left hemisphere is more about focus and specificity. On balance, the right hemisphere is the arbiter of performance delegation, whether to perform a task or delegate it to the left hemisphere. About three-quarters of perception functions are right hemisphere processes.
McGilchrist is partial to the position advanced by Merleau-Ponty, that is “perception as a reciprocal encounter.” Perception is not a passive act. It is an interactive intercourse with the environment. What and how we perceive is affected by our experience and the situation.
Visual Perception
Perception involves all the available senses—and by definition none of those otherwise unavailable. He starts with vision. The right hemisphere does a lot of heavy lifting here. It handles size, shape and pattern recognition, contour, shadows, distance and depth, for example, three-dimensional space, and motion and time as well as the ability to recognise objects from unusual angles or from incomplete information, which I tend to think of as playing some Gestalt role. The right also handles colour perception, though the left maintains the colour name mapping.
The left hemisphere is slightly faster at detection, but if what is detected has any signal degradation, the right hemisphere tends to be more accurate. And since the left hemisphere is, what I’ll call lazy, it may tire quickly and space out, so the right hemisphere may have to intervene, if even a bit more slowly. Paradoxically, if the left hemisphere is given more time, its recognition error rate increases. Incidentally, one reason the right hemisphere may respond more slowly is that it is deliberating to attempt to deliver the correct response whilst the left tosses out its first best guess and declares victory. Nailed it!
Nailed It!
Recall from the last chapter that the left hemisphere is also a master of denial, so it is unapologetic when it guesses wrong. I imagine it signalling ‘that’s not a bus’ just as it hits you and then insists that it never was a bus; that injury must have been caused by something else. Perhaps it was an untoward wrecking ball.
Without delving into details here, McGilchrist points out that much early research might be invalid because it employed cathode ray tubes—CRTs—whose mechanisms present biased information to the visual field, thereby invalidating conclusions.
the left hemisphere is better at recognising tools—hammers and spanners—, but not musical instruments, which it perceives more as living entities
An interesting area for me is that the left hemisphere is better at recognising tools—hammers and spanners—, but not musical instruments, which it perceives more as living entities. And this is an apt segue to auditory perception.
Auditory Perception.
Whereas the left hemisphere is better at symbolic language processing and “the processing of meaningless noises, such as clicks”, the right hemisphere pretty much handles the rest, from pitch, inflexion, tone, phrasing, metre and complex rhythm, and melody. The left keeps tabs on basic rhythmic patterns. It is assumed that rhyming relies on both hemispheres working in concert.
For most people, music processing is a right hemisphere event, but this is not true for professional musicians, who utilise both hemispheres, likely owing to the musical language translation processing unnecessary for the casual listener.
Olfactory Perception
Interestingly, the acuity of the nose is orders of magnitude superior to that of the eyes and ears. Olfactory recognition and discrimination have a right hemisphere preference, but emotional reactions to scent may be stronger in the left hemisphere.
Gustatory Perception
“Apart from five very basic tastes – salt, sweet, sour, bitter and umami – which come from the tongue, all flavours come from the olfactory sense.” In general, gustatory perception is a right hemisphere function. However, there is an exception for professional wine tasters, who like professional musicians need to map experiences to words associated to rating and naming.
Tactile Perception
Remembering that the right hemisphere controls the left half of the body, whilst the left hemisphere controls the right, the sense of touch is superior in the left hand. Feelings of warmth, and temperature discriminations in general, are associated with right hemisphere activation. Interoception, the ability to perceive the internal workings of the body, is another right hemisphere process.
Local versus Global Perception
Recall that the right hemisphere captures the world holistically whilst the left hemisphere has a laser focus. This equates respectively to global and local perception. As it happens, the right can do both, but the left is limited to local. This means that if the left hemisphere is damaged, the right can pick up the slack, but if the right hemisphere is damaged, the left cannot compensate for the lost holistic perspective. In practice, the right runs the show and delegates to the left when it deems it to be appropriate for the circumstance. For some reason, normal adolescents have a bias toward local perception over global.
Pathologies of Perception
This leads us to abnormalities, such as Alzheimer’s disease. Deterioration of right hemisphere function leads to a sense of disorganisation and loss of sensation. This hemisphere is also responsible for constructing a sense of self and self-awareness. McGilchrist calls out that the term self has multiple meanings. Much of the notion of self is associated with the medial prefrontal cortex in both hemispheres, but the objectified self and the self as an expression of will (in the respect Schopenhauer spoke of) are left brain aspects.
Perception of a contiguous self over time is a right hemisphere function, the loss of which is not uncommon in cases of schizophrenia.
In discussing visual hallucinations and distortions, almost ninety per cent of these have been attributable to right hemisphere anomalies. McGilchrist shares examples over several pages, but I’ll summarise by description alone of what can be categorised under the umbrella term of metamorphopsia. These might lead to object impermanence, or viewing things as too large or too small, too close or too distant, skewed, or the wrong shape altogether. In some cases, only half of an object, including self-perception, was outsized. This might occur on a macro level or a micro level, which is to say that it may be entire objects or bodies or just faces, or just familiar faces or just eyes or just one eye. This might occur on a macro level or a micro level, which is to say that it may be entire objects or bodies or just faces, or just familiar faces or just eyes or just one eye.
Some of these cases involved motion, for example, the sense that some object is receding away from the observer as the observer draws nearer to it.
After a journey through Charles Dodgson, AKA Lewis Carroll, and Alice in Wonderland, provides a plethora of examples in prose of some of these visual effects.
From visual hallucinations, we wonder through hallucinations of the other senses, though the data points on these are much sparser, but the left hemisphere does seem to be the culprit of most auditory hallucinations.
Perspective
To summarise, I am again left to feel that the left hemisphere is a deadbeat hanger-on. It’s there in a pinch, but it’s an unreliable narrator and worker that falls asleep at the wheel. Psychology does have a position on what a normal person should see and hear and taste and touch, but normal doesn’t mean real.
I was hoping to see some information and perspective on synaesthesia, a condition where people perceive experiences through sense-perception organs different to normal. These people see music and hear smells or taste colours and so on. We consider this to be anomalous, but does it provide a fitness benefit, and are these people ahead of “normal” people or are they carrying excess baggage that creates a burden, even if the condition is otherwise benign.
Now that we’ve covered attention and perception, we’ll be covering judgment in the next chapter. I hope you’ll join me.
What are your thoughts? What did you think of this chapter? Have you experienced or know of anyone who has experienced any of these so-called anomalies. Are you familiar with any of the effects mentioned in Alice in Wonderland? Leave comments below.