SLEEP STAGES and the so-called “COGNITIVE MAP”
(note: This post appears to be about just “sleep” but it is mainly concerned with how we integrate “space” and “time” into “maps” and so situate our “Selves”…and nightlong alternation between Slow Wave Sleep and Dream Sleep is key )
This recent article from Scientific American is a great review of the epistemological difficulties entailed in the study of our “minding brain’s” map making and how that model of the brain needs to be updated.
Decoding Space and Time in the Brain
It begins this way: “…henceforth, space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union between the two will preserve an independent reality.”
They go on, “This now iconic quote spoken by Hermann Minkowski in 1906 captured the spirit of Albert Einstein’s recently published special theory of relativity. Einstein, in a stroke of mathematical genius, had shown that both space and time as independent mathematical constructs were mere illusions in the equations of relativity, conceding instead to a 4-dimensional construct which Minkowski adroitly termed space-time.
While most people are familiar with the ensuing influence Einstein’s ideas had on both the academic and public conception of the physical universe, few people are aware a similar revolution against space and time is underway in the fields of experimental psychology and neuroscience.”
We have recently posted on a few “erudite” but fatally flawed publications on the nature of “dreams” and their integration into the Role of Sleep in Making our Way through our lives when we are Awake (we might call it the ‘DayJob” rather than the “”Night Job”
Unfortunately, we see here, again in a popular article, the customary narrative of how and why we cycle through sleep stages.
However, the account that is still so rampant in our popular culture and in our Paparazzi driven media, does not point to the direct linkages which we suspect must exist between Slow Wave Sleep and REM sleep and its dreams.
We recently posted on this superficial and narrow view of dreams just a couple of weeks ago. That post was about more “junk science” from #Aeon
HOW SEX RULES OUR DREAMS? IS FREUD BACK?
An entertaining and nice BEDTIME STORY
Today, we have realized how much crucial “consolidation’ occurs during Slow Wave Sleep, enabling the hippocampal repository of ‘episodically” described moments and experience to be somehow transferred or shared with cortical processes for use in the our next day’s and subsequent days’ experience and our management of our responses to the events that follow.
There’s a fine review of Sleep Consolidation and the exquisite coordinations between parts of the brain going as we sleep available here:
About Sleep’s Role in Memory
Just how this ongoing synergy between hippocampus and cortical areas goes on is not yet discussed in any clear manner by neuroscience…although there is increasing aware of the characteristic charting of waves frequency and amplitudes that is associated with that correspondence, much of which arises during the nonREM Slow Wave Sleep periods of our nights.
Once of the prevalent ways of speaking, we have had since Tolman introduced his “cognitive map” notion in the 1940s as a counter to simplistic behaviorist narratives of the mind…is the treatment of the ‘minding brain” as one which somehow relies on maps that are formed over the course of experience to guide us in our lives…or “navigating” through, not just mazes and geography but the other aspects of life.
As we have noted here on numerous occasions, the problem with the map narrative is that it is not sufficiently understood by those who speak in terms of the concept. It is universally acknowledged that maps are not the actual territory, but then it is presumed that line between the objective world and the linguistic world is found in structure and that some dedicative rendering provides the isomorphism.
The tendency to think that a ‘map”, any map, is actually some kind of “picture” of a “territory” is quite insufficient, and, as we see it, mostly misguided.
The cognitive map concept suffers from the same problems as the concept of ‘maps” in general Most of us know by now the famous quote by Korzybski, a polymath of the beginning of the last century, “The Map is NOT the Territory”
“Two important characteristics of maps should be noticed. A map is not the territory it represents, but, if correct, it has a similar structure to the territory, which accounts for its usefulness”
But here we have to differ. The ‘map” any map is not truly founded on creating an isomorphism between points in space or any territory and some equivalent drops of pigment on a canvas somewhere in our brain, or, more recently the ‘hippocampus
This is obvious but it is usually forgotten by those who speak in the ‘lingo” of the map. More recently (see below) investigations into the nature of the hippocampus have begun to focus on this aspect of any ‘map” rather than its composite via some sort of little “memory” chunks to resemble a territory or space in which we find ourselves.
This kind of ‘Map” that somehow mirrors “all’ of our Reality would be an incredibly complex and vast map. The question of “storage” of all this information naturally comes up to those who have happened to think this way.
Recently, even the Mosers, have succumbed to this logical mis-step, based on the assumed relation between “territory” and “map” and found themselves ruminating about the ‘storage” for such an infinite collection of mapped detail.
“Probing the brain’s extensive capacity for storing memories
The brain creates and stores memories in small networks of brain cells, with the memories of events and places stored in a structure called the hippocampus.
Researchers have long wondered if there is an upper limit to our capacity to store memories. Nor do they fully understand how we are able to remember so many events without mixing up events that are very similar.
“This indicates that the brain has an enormous capacity for storage. The ability to create a unique memory or map for every locale explains how we manage to distinguish between very similar memories and how the brain prevents us from mixing up events.”
This issue of “storage”is a gross mis-step, and one to which the unfortunate language of neuroscience predisposes those who speak of “maps”
As we see it, the problem is not one of ‘storage” but of having available a ‘gas station” at which to stop and just pick up and put together the maps you need for that particular trip. Or if you’re not driving but walking the streets to get another sort of mapping. The brain must do this on the fly in response to salient cues derived from the events of that moment in time and ‘what is’ doing” and “where it’s going”.
For example, we have such maps as roadmaps, or subway maps, or pedestrian street maps, or airplane flying maps, and so on. These are based on the “mode of movement” and the possibilities and limitations of how the “vehicle” or movements themselves.
Moreover, when we, or anyone, as we used to do in the good old days, takes a trip, they must decide which of many maps that are available they wish to use on that given occasion.
Similarly as with the drivers of those days, any talk of a “cognitive map cannot be limited to a depiction of an entire vast “reality” in which the user might find themselves. On the contrary, what the brain must do…as any smart travel must do is constantly make choices of just which map and what sort of map is to be relevant on a given occasion.
In the quest to try to understand the hippocampus, for example, this issue has arisen time and again where the hippocampus was found to have ‘place cells” and the researchers were off and running in speaking of the map and of something called “allocentric” space…..so that for them the “outside world” or ‘space” in which the animal was navigating was “represented” in some simplistic fashion in a pictorially based hippocampus
These issues were addressed by John O’Keefe and his colleagues in the 1970s through a series of studies that cumulated in an elegant theory proposed in the aptly titled book The Hippocampus as a Cognitive Map (1976).
Strikingly, the locations in which place cells fire appears fixed over repeated exposure to an environment, anchoring themselves to environmental landmarks. O’Keefe and Nadel believed that these place cells form the neurological basis of a cognitive map – a map defined by the interrelations of the different elements that compose an environment.
Does hippocampal activity embody the cognitive map? One should expect the neural instantiation of Tolman’s cognitive map to contain units (neurons) that are fully allocentric, that is, identify places in the environment independent of the subject’s perspective (egocentric direction) and ongoing behavior.
We excerpt a few points from a recent neuroscience study below, which expands on the concept we use to speak of the hippocampus in greater detail than most, tells us: Eventually, as they go through seeking to point to “place cell’s as points on the map, then “time cells” (see below) and then have to rely on ‘grid cells” (see below). the realization arises that a map is not a picture of a space. but is emergent from the movements and possibilities of the ‘user” of the map as he navigates
Complementary Roles of Hippocampus and Medial Entorhinal Cortex in Episodic Laboratory of Neurophysiology of Memory,
“Furthermore, one should expect that the neural ensemble composed of these units would be holistic; that is, all the neuronal representations should be tied to one another and change together between environments. And, if the map is to suit the purpose Tolman proposed in guiding behavior according to expectancies, the map should signal the locations of current goals.
Initially, hippocampal place cells seemed to satisfy key criteria for elements of Tolman’s cognitive map. The first complete study characterized place cells as signaling an animal’s location in the environment independent of egocentric direction and ongoing behavior, as would be expected of the units in an allocentric representation
An expansive literature followed on the initial observations, and many interpreted the results as support for the claim that the neural substrate for the cognitive map lies in the circuitry of the hippocampus
As they say, “In sum, place cells do identify where the animal is when important things happen. But place cells do not carry a reliable allocentric signal, and populations of place cells do not operate as a holistic representation of space or anticipate the locations of goals. Therefore, hippocampal neurons do not have the requisite properties to support Tolman’s cognitive map.
By contrast, the findings indicate that hippocampal neurons represent events in the places where they occur, consistent with current views of hippocampal involvement in episodic memory .
The recent discovery of spatial firing patterns in the cortex immediately adjacent to the hippocampus has refocused the search for the cognitive map to a zone within the medial entorhinal area
A majority of the data describes the spatial firing patterns of principal neurons in the medial entorhinal cortex, and more specifically how a proportion of these neurons, the so-called “grid cells,” exhibit an intriguing and unique spatial firing pattern with several interesting properties.
First, the relative angles and densities of peaks within grids of neighboring cells remain invariant both across environments and in response to changes in local cues Second, while grid fields of medial entorhinal neurons remain stable in response to modest environmental manipulation, hippocampal CA3 neurons change their rate of firing (“rate remapping,”
The regularity observed in the firing patterns of grid cells does not appear to be derived from environmental features, or any type of sensory information.
Rather, they appear to code a spatial structure that is generated internally within the brain and use it to scaffold the external environment, much in the same manner that Kant had anticipated.
Interestingly, grid cells have been identified primarily within an area of the brain called the entorhinal cortex, one of the primary neural inputs to the hippocampus, suggesting that grid cells provide a source of the spatial framework upon which cognitive maps of environments are formed.
One of our tenets here is that the ostensible involvement of our hippocampus in two seemingly distinct functions, episodic memory and navigation in space, is really very tragically flawed. First, we believe that there have to be principles by means of which these two activities are seen as dependent on similar functionality in the hippocampal area. Secondly, these two aspects are both evidenced right there in the same tissue for more than mere coincidence because we believe that both of those functions of the hippocampus must come into play in the course of either one of them being the apparent focus function.
One of the key aspects of the use of any map is what we are told when we visit any mall and try to find our way. The informational map says, “You are Here Now”…without that we do not have any way of using that map. That too is a key aspect of any ‘cognitive map’ use….the awareness of the “now” in terms of its integration into the map. That is where the map use starts.
In a more recent very interesting review by the Mosers , called “Mapping Your Every Move” ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4087187/) they try to work their way out of the vocabulary “muddle” which they inherited via inheritance ofancient notions of “memory” and “maps” and they state:
“We were surprised to find that cells that have no role in our sense of location actually send signals to place cells, because until now, the specific kinds of brain cells found to be involved in navigation—place cells, head direction cells, and grid cells—all have specific jobs. What is the role of the cells that are not actually part of the sense of direction? They send signals to place cells, but what do they actually do? This remains a mystery.”
“We also wonder,” they tell us, “how the cells in the hippocampus are able to sort out the various signals they receive. Do they “listen” to all of the cells equally effectively all the time, or are there some cells that get more time than others to “talk” to place cells?””
The rather sloppily defined so called “episodic memories” of which so much is made in psychology talk are not more pictures or representations of the past events…just as the map of the hippocampus is not a picture either. In fact these “episodic memories’ are inferred because the person is asked about them and then they must speak and recall what and where they were at that “TIME”.
In fact, there was a failure by researchers until relatively recently to appreciate that rodents and other mammals might even have the equivalent of ‘episodic memory” function in areas of their hippocampus because the poor creatures could not be asked questions and then have to report on those.
Unsurprisingly all sorts of recent research points to the importance of the lateralized specialization of the hippocampus, where the left side tends to be more involved with performance in response to the demands for ‘episodic memory” and indeed in a variety of other types of language use, while the right side is more devoted to the navigation in space.
However, what is also found is that these two sides, two facets of the hippocampus must work together….just as the corpus collosum integrates left and right in general for our brains..so the two sides of the hippocampus both must come into play ..either when traveling in space or via episodic memory, traveling in time.
Any one who has ever tried to travel and avoid getting lost, whether with a map or a GPS or by their own devices, realizes that moving through space is a product of both the allowing oneself to be guided by rules of a GPS or map and simply following those AND additionally the use of landmarks or aspects that are recalled from ones experience. We don’t do one or the other. IF we do we find ourselves in the typical GPS predicament where we don’t verify via integration of our current spatial frame with our previous temporal frame, whether or not the instructions make sense.
This critical interplay between the lateralized aspects of the Hippocampus is discussed in more detail here, one side being prominent in sequential organization that is describable via the flow of time, and the other side being prominent in spatial organization that is describable via movements in space, with both working together….
Lateralized human hippocampal activity predicts navigation based on sequence or place memory
“The hippocampus is crucial for both spatial navigation and episodic memory,” they say, “suggesting that it provides a common function to both. Here we adapt a spatial paradigm, developed for rodents, for use with functional MRI in humans to show that activation of the right hippocampus predicts the use of an allocentric spatial representation, and activation of the left hippocampus predicts the use of a sequential egocentric representation.
Both representations can be identified in hippocampal activity before their effect on behavior at subsequent choice-points.
Our findings support the idea of lateralized hippocampal involvement during spatial navigation. The right hippocampus is involved in allocentric or map-based navigation, whereas the left hippocampus is involved in the sequential organization of successive choices. Both representations are active in parallel during the training phase of the task. Overall, we suggest that involvement of the left human hippocampus in remembering narrative prose, learning novel sequences, and in supporting sequential egocentric representations in our study, could reflect a more general role in associative processing of sequential elements of an episode.
Our results suggest that, rather than providing a single common function, the two hippocampi provide complementary representations for navigation, concerning places on the right and temporal sequences on the left, both of which likely contribute to different aspects of episodic memory.”
We should note that, to the extent, that there is any occasion to talk about “the self” by current consciousness devotees, they should consider that the team work between the hippocampus and the cortex and the founding of that teamwork on the integration of left and right sides, verbal movement through time and physical movement through space, both must come into play…and form the basis of any ‘self concept” before it is further shaped and massaged by other aspects of our brain.
As the Scientific American article says, ” Researchers found that the hippocampus is crucial for encoding the order of visual stimuli – whether pictures on a computer screen or landmarks in an environment – and that it expresses unique patterns of activity during overlapping segments of routes through an environment.
The latter finding is particularly important, as it counters a purely place cell model of hippocampal function during navigation.
In such a model it would be expected that hippocampal activity is consistent during overlapping route segments, as a person’s physical location is the same through these portions of an environment.
“Time has proven to be a much more elusive concept for both psychology and neuroscience”, they write. “Despite numerous decades of research, the majority of what we know about time representation in the brain comes from two lines of research: how overlapping events are parsed into discrete episodes and the sequential ordering of those events into a temporal framework
This suggests that the hippocampus is involved in representing more than simply the spatial layout of an environment.
A key breakthrough in identifying which types additional information the hippocampus processes was provided by Howard Eichenbaum and his colleagues at Boston University. In a 2011 paper, the authors proposed a new type of neuron population within the hippocampus which they labeled as ‘time cells’.
Through a series of studies with rats, it was found that time cell activity could uniquely code successive events and were able to disambiguate overlapping sequences in temporally organized episodes.
As we believe here that final integration depends as well on the mathematical sense that we have, and many of our other species have as well and which is centered in the parietal cortex (but that will have to await another post)
It is there however that vast amounts of information from all areas of the brain are integrated and decisions made in regard to any such “maps” that we may have and how they might relate to “where we are” in our experiences during the events of daily life.”
The Mosers ( “Mapping Your Every Move”) are now shifting focus to this more sophisticated analysis,
‘ It is easy to forget,”they say, “as we move effortlessly from home to job, or from job to supermarket to home, the enormous number of processes and steps that make up our ability to navigate. We are now working our way through different aspects of the brain’s navigational system to better understand how all these pieces fit together.
At the moment we are studying what we have dubbed speed cells—cells that react exclusively to the speed of an animal’s movement—and how these types of cells factor in to the navigational equation.
We’re also looking at decision-making. As an animal moves through a labyrinth, it must choose which way to go or what turn to make next. The neurons involved in this decision-making can be found in the prefrontal cortex, which connects to the hippocampus via a small nucleus in the thalamus.”
Our belief here s that there is a direct and highly active connecting path between the posterior parietal cortex, where just about every mathematical related function of our brains is centered and evident, via the retrosplenial cortex right down to that area where the still mysterious “grid cells” are located, the entorhinal cortex, which is constantly the means and mode of interface between the hippocampus and the prefrontal cortex. That deeper aspect of brain coordination will , we believe, to rooted in the math genius of the parietal cortex to integrate a wide range of inputs and allow “decisions to be made”.
For those who wish to inquire into this aspect here is a good review of the role of the Parietal Cortex as it relates to this type of decision making ( and note that the Parietal is surely where mathematics gets its life and expression in our brains)
Navigating actions through the rodent parietal cortex
These decisions will not be made and could not possibly be made on point to point analysis of vast arrays of information and ‘matching’ of past with present, but have to be processed in a way that is characterized by enhanced speed and efficiency (that allow survival and adaptation” as the availability of any algorithm is to plodding through calculations and data points.
This means that there is a whole lot of ‘putting things together” in useful ways based on the user’s capabilities and destinations that takes place. It is therefore not sufficient when we speak about sleep and its consolidation, for instance, to just leave it at that, and consider the Slow Wave Sleep to be sufficient conceptually to get our ‘map” or “maps’ in order.
As the Mosers have recently acknowledged,
“We now know that this coding system works like your own air traffic controller—monitoring every movement you make, knowing every step you ever made, and creating links to every event and experience you have had. Essentially, while your brain is making mental maps to help you navigate, it is also overlaying memories—experiences, smells—onto those maps.
They say, “This ability of the brain to overlay recollections creates a cognitive map—a multilayered collection of memories—rather than a mere cartographic map. It also means that learning how the brain computes navigation is a step toward understanding how networks are built up in the cerebral cortex, the part of the brain that is responsible for imagination, reasoning, and planning—thought processes that make us human. ”
What must happen then for the person sleeping is that the organization of that ‘map library”, let’s call it, in terms of events in their lives…must then be enacted in such a way that the work of that night proves useful to finding one’s way in the world the next day.
The conclusion (from Scientific American)here is one the share whole heartedly”
“If our experience of time and space share similar neural correlates, it begets a fundamental question: are space and time truly distinct in the mind, or are they the product of a generalized neurocognitive system that allows us to understand the world?
While Kant had much more to say about space than time, contemporary cognitive neuroscientists have begun composing theories to address this question.
One proposal by Demis Hassabis and Eleanor Maguire suggests that the primary function of the hippocampus isn’t to think about past and future, or to move about through space per se.
Rather, through cooperation in a larger network spread throughout the brain, the hippocampus allows us to construct a representation of the world in a spatiotemporal context that affords the ability to simulate past experiences in order to make predictions about the future, and to ultimately use this information to direct action in the present.”
They conclude, “Specifically, it suggests that the hippocampus is able to tune its activity to both spatial and temporal aspects of an experience, depending on what type of information needs to be encoded or recalled”
Our view of this “movement’ is that it requires essentially moving through two spaces at once and the integration of those ‘movements”: The movement of our bodies through the three dimensional space of geometry and our placement with its three dimensions and, as well, the one dimensional space normally labelled “time” and our movement through that space via the language we use.
The REM sleep and its progressively increasing dreaming that occurs after the progressively increasing Slow Wave Consolidation events of the night must be giving us not only chunks of ‘map” in some generic and vague sense of the word, but “maps based on different episodes in our lives” and useful for different purposes in our lives that might just happen.
And indeed these various guides for behaving must all be indexed and related to each other so that wherever we “are” or “wherever we might be headed” the next day we will be able to call up and use the right one for that mode of movement and that purpose.
Thus what we experience as the dreams of the REM state are the combination and permutation and the “trying on for size” of the work done earlier in the night via the consolidation of the hippocampal content into the cortex.
Do they represent fantasied “wish fulfillments”? Perhaps. But more likely they represent the anticipatory schema by means of which the hippocampus always works, day or night. Do they predict the future? Not exactly, but in some way they do..because they determine what manner of map we just might be using , and how it is put together…so they do predict how we are likely to try to make our way in the world when we are awake….either tomorrow or in the future.
For now, that’s a nice part of the story of our nights and dreams that we must appreciate….and indeed that is how evolution must have worked its magic hand to allow all that to happen at night.
We should not close our eyes to all the rest that transpires between Slow Wave Sleep and our Dreams. There are countless maps, in fact an infinite number of them that are made possible by these processes that occur during sleep.
We may never use many of them or most of them. Perhaps sometimes we do, however, have to dig down and find re awaken those “maps” for ourselves. That may be how some mysticism works by encouraging us to lend credence to those dreams. and that is surely how much psychotherapy seeks to bring us ‘back in touch” with our dreams…since they just might be the maps we forget to use.
And they might lead us the those “roads less traveled” if we conjure up those maps to guide us if we realize that our journey is very much based on which maps we bring with us…and which bring us.
What we believe is that, while it makes good sense to finally provide a narrative of how our bodies in a three dimensional geometric space move around and find their way to new places and experiences, it also makes sense to speak of our “Selves’ are traveling in one dimension, that of verbally mediated (integration of past moments) and how that Self can find its way in that one dimension related to time to new experiences.
Just as we noted occurs whenever we “go” somewhere on whichever roads we travel, there is an essential back and forth that must occur between the past “episodic” elements ordered in time and the present spatial plans and movements oriented in space.
This recent publication deals with \interactions between the prefrontal cortex and the hippocampus as they play a critical role in the modulation of goal-directed self-action and the strengthening of episodic memories
A Prefrontal-Hippocampal Comparator for Goal-Directed Behavior: The Intentional Self and Episodic Memory
These authors write “Action plans are essential for successful goal-directed behavior, and are elaborated by the prefrontal cortex. When an action plan is initiated, the prefrontal cortex transmits an efference copy (or corollary discharge) to the hippocampus where it is stored as a working memory for the action plan (which includes the expected outcomes of the action plan).
The hippocampus then serves as a response intention-response outcome working memory comparator.
Hippocampal comparator function is enabled by the hippocampal theta rhythm allowing the hippocampus to compare expected action outcomes to actual action outcomes. If the expected and actual outcomes match, the hippocampus transmits a signal to prefrontal cortex which strengthens or consolidates the action plan.
If a mismatch occurs, the hippocampus transmits an error signal to the prefrontal cortex which facilitates a reformulation of the action plan, fostering behavioral flexibility and memory updating.
The corollary discharge provides the self-referential component to the episodic memory, affording the personal and subjective experience of what behavior was carried out, when it was carried out, and in what context (where) it occurred.”
However as we noted above, the exquisite “mathematical sense of the parietal cortex” must play a role here as it does in most of our actions, although mathematics is not fully appreciated as being at the core of our Selves and of our Brain Function.
It’s our central mathematical sense and capacity that allows such an “integration” and in the course of that integration we find ourselves experiencing a Self as an index of that integration and not located within either time or space data points.
Thus in “Navigating actions through the rodent parietal cortex (see the link above)
they write, “parietal neurons encoded route progress irrespective of spatial position or direction of motion, and the fact that they did so equally well in darkness or light implied a possible function in path integration.
Based on the finding that PPC firing fields, unlike hippocampal place cells, scaled flexibly to match maze segments when they were lengthened or shortened, it was concluded that PPC cells were more tightly linked to the reference frame of the animals’ route than a world-based spatial reference frame
Many of the basic questions relating to cognitive motor functions, though, are not necessarily specific to one species or another—such as the time course over which a movement plan evolves relative to action initiation, the cortical representation of movement goals, or the computational contribution of common anatomical pathways.
Evolutionary date implies s that place cells and grid cells date back at least 65–100 million years to the common ancestor of placental mammals and it is quite likely that such spatial circuitry arose long before in even simpler, more ancient organisms.
The same principle applies to the parieto-frontal pathway, which is another common feature of all mammalian nervous systems.
As opposed to generating spatial maps, it enables the synthesis of efficient movements and meaningful interactions with objects within those spatial maps, computing behavioral solutions to everyday problems which terrestrial vertebrates have encountered for countless millennia.”
In the end, it is not some indefinable, dualistically problematic, Self, however, which magically travels and puts together various decisions and game plans for moving through space and/or time…but it is the need to conduct those movements by an organism’s brain which requires it to experiences its moments of life via a ‘Self”.
The “reality” of the Self leads to much, far too much, endless quibbling about issues that only beg of our understanding of that notion, many of them dependent on ‘locating” a “Self” as an entity, or, as we prefer to say, “entitizing it” as existing in either/or both space and time.
That is how we put ‘space and time” together to function as organisms That is how the ‘self” can be considered quite “REAL” but not situated in either space or time. In fact our “self” and our “self talk” are ordered very much as are the natural numbers in one dimension as we know it is the “measure” of time just as much as our geometric “maps” of our movements and their possibilities is a measure of “space”
If, however, we consider what we believe to be the “reality” status of the “center of gravity” when we discuss natural law via Newtonian theory, we realize that this concept of “self” not outside of space and time but being a manifestation of our computation of space and time, is as “real” as anything of which we can speak, as it allows us to engage in the vary acts of speaking that describe how movement occurs in space and change arises over time.
As Anais Non wrote, “Dreams pass into the reality of action. From the actions stems the dream again; and this interdependence produces the highest form of living.” –