A friend brought to my attention an interesting paper by Mark P. Mattson titled “Superior pattern processing is the essence of the evolved human brain“. It discusses the uniquely powerful capabilities of the human brain, and provides a partial theory for why these capabilities evolved.
Here is summary of what I consider to be the paper’s key points:
- Humans have a uniquely powerful brain.
- The human brain has the same structure and components as the brains of other mammals; what distinguishes the human brain is a higher quantity of neurons and synapses that enable superior pattern processing (SPP).
- SPP is sufficient to explain unique human capabilities such as creativity, imagination, language, and magical thinking.
- The human brain began to enlarge about 5-8 million years ago via a self-reinforcing feedback loop created by the synergy of increased brain power in a social species with an upright posture able to forage longer distances.
- Human survival depended on social cooperation which created another self-reinforcing relationship between social interactions and SPP ability, and which led to an extended theory of mind with which humans understand that others have thoughts and emotions very similar to their own.
- SPP led to language emerging about 100,000 years ago, and language is likely a major reason for the current dominance of Homo sapiens.
- The ability to draw came after language about 30,000 years ago and enhanced the ability to communicate important spatial information like maps.
- SPP enabled human imagination and invention which enhanced the success of humans via tool making, but also created a human tendency for magical thinking such as religious beliefs.
- Gods were fabricated as explanations for phenomena that were not understood. As those phenomena were later explained by science those Gods were abandoned. With one exception, there is exceptional resistance to the science of human evolution and magical thinking persists on the origin of humans.
- Psychiatric disorders result from abnormal SPP that blurs the boundaries between reality and imagination.
- Homo sapiens is the only hominid to survive from an original pool of from 8 to 27 species. This suggests that only Homo sapiens evolved superior pattern processing which it used to outcompete its cousins.
So far so good, but then Mattson veers off into what feels like just so stories for his SPP theory:
- Mattson thinks differences in SPP between populations today explains why some groups prosper and others struggle. For example, Africans must have a low SPP because they are poor, and Americans, Europeans, and Asians must have high SPP because they are affluent. Mattson might be right here, but I think it more likely that the self-reinforcing relationship between early access to low-cost energy, wealth creation, and wealth multiplication via growth enabled debt is a more likely explanation.
- Mattson thinks differences in SPP between groups today is likely explained by epigenetics. For (my) example, malnourished mothers may have babies will less powerful brains.
- Mattson concludes with a cheery prediction that humans will continue to evolve SPP which they will use to make better decisions and to invent technologies that eliminate suffering and ensure long-term survival. This sounds to me like a grade 12 valedictorian speech.
- Mattson also concludes that we should educate everyone about how SPP works so that we can once and for all end our silly beliefs in god and the suffering this causes. Here he seems almost as delusional as my earlier hope that awareness of genetic reality deny might help mitigate our impending overshoot collapse.
- Finally he suggests further research into SPP might help us design better AI computers.
Setting aside Mattson’s concluding unicorns and rainbows, I agree with his earlier points. Unfortunately he spends a lot of time discussing the obvious bits and ignores the interesting bits:
- After 8 million years of slowly improving brain power in many hominids species, there was a dramatic jump about 100,000 years ago in one of the species that enabled language and enhanced tools making, and that species used its unique skills to outcompete all the others. That species also simultaneously began to believe in life after death which was later elaborated into religions, something no other species does. Using Mattson’s reasoning, brain power should have simultaneously improved for all hominids with no unusual discontinuity.
- Mattson is mistaken about the adaptive value of religion. He thinks that the magical thinking associated with religion has some adaptive value. I think the evidence is clear that humans apply magical thinking to many aspects of their lives, including religion. The adaptive value of religions is not magical thinking, rather it is that religions serve to define, unite, govern, motivate, and entertain tribes, and (especially in times of scarcity) define outside tribes as enemies. In other words, religions improve survival via enhanced social cooperation.
- Mattson acknowledges that magical thinking about human divinity is a unique and fascinating persistent behavior but does not offer an explanation. I think the explanation is clear. Given the human brain’s tendency for magical thinking we should expect religious beliefs to include every conceivable wacky story, as they do, and we should statistically expect a few of those wacky stories to involve life after death, but they don’t, instead every one of the thousands of human religions has a life after death story which suggests there must be a separate genetic reason for the universal belief in life after death.
- Mattson thinks the primary cause of anxiety disorders and depression is defective SPP resulting in a blurring of reality, self-doubt, and hopelessness. While no doubt true in some cases, Mattson does not consider that a defective ability to deny unpleasant realities can be the cause of mental illness. For example, fully accepting the science of human overshoot, climate change, and net energy decline coupled with an understanding that an individual cannot influence the outcome is a plenty strong reason for depression. In other words, magical thinking likely improves mental health.
All of these interesting bits, and more, are explained by Varki’s Mind Over Reality Transition (MORT) theory.
Following are a few excerpts from Mattson’s paper that highlight ideas I thought were noteworthy, but I recommend you read the entire paper for proper context.
The cognitive repertoire of humans far exceeds that of all other animals, and understanding the neurobiological basis of this superiority is therefore of interest not only to scientists, but also to society. As humans evolved from their anthropoid ancestors, and the size of their cerebral cortex expanded, novel pattern processing capabilities emerged.
The main purposes of the present article are to describe the superior pattern processing (SPP) capabilities of the human brain, to forward the hypothesis that SPP is the neurobiological foundation of human sociocultural evolution, and to describe the roles of aberrant SPP in some major neurological disorders.
The types of pattern processing that appear to occur robustly, if not uniquely in the human brain and are therefore considered as SPP include:
- Creativity and invention, which have resulted in the development of tools, processes and protocols for solving problems and saving time, and the arts (Goel, 2014; Orban and Caruana, 2014; Zaidel, 2014). Examples include all aspects of agriculture, transportation, science, commerce defense/security, and music;
- Spoken and written languages that enable rapid communication of highly specific information about all aspects of the physical universe and human experiences;
- Reasoning and rapid decision-making;
- Imagination and mental time travel which enables the formulation and rehearsal of potential future scenarios; and
- Magical thinking/fantasy, cognitive process that involves beliefs in entities and processes that defy accepted laws of causality including telepathy, spirits, and gods (Einstein and Menzies, 2004).
A major purpose of the present article is to forward the proposal that not only is pattern processing necessary for higher brain functions of humans, but SPP is sufficient to explain many such higher brain functions including creativity, imagination, language, and magical thinking.
The human brain has retained many features of brain structure and cellular organization of the brains of birds and lower mammals, but has greatly elaborated upon them by developing more robust cortical neuronal networks involved in the processing of visual and auditory patterns. As in lower mammals, being aware of one’s position in the environment, and remembering the locations of resources (food, shelter, etc.) and hazards (predators, cliffs, etc.) is of fundamental importance for the survival of humans. However, the encoding of visual inputs into “cognitive maps” of spatial relationships between objects in the environment (spatial pattern separation), and the encoding of auditory inputs, is necessary but not sufficient for the advanced pattern processing abilities of humans including imagination, invention, and pattern transfer (language). The evidence suggests that expansion of the visual cortex, prefrontal cortex, and parietal—temporal—occipital (PTO) association area enabled the SPP that defines the human intellect capacity and all of its manifestations, including consciousness, language and mental fabrication and time travel. The remainder of this article describes some of the salient evidence for SPP as the basis of most, if not all, higher cortical functions in humans.
Thus, findings from neuroscience research has confirmed the general conclusion of Charles Darwin who proposed in The Descent of Man that the minds of humans and related species are fundamentally similar (Darwin, 1871).
Neuroanatomical and neurochemical considerations… section suggest that the superior intellectual capabilities of humans are solely or largely the result of the increase in the number of neurons and synapses that mediate enhanced encoding, integration and inter-individual transfer of patterns. There is little or no uniqueness in the structural or functional properties of the neuronal circuits that mediate intelligence in humans. Moreover, the intellectual capability of any individual requires the integrated function of pattern-processing networks distributed throughout the cerebral cortex, indicating that there is no single brain structure responsible for the mental superiority of humans.
One prominent phenotypic change that is believed to have occurred during the evolutionary transition from the Genus Pan (chimpanzees) to the Genus Homo (approximately 5–8 million years ago), was the acquisition of an upright bipedal endurance/distance runner phenotype (Bramble and Lieberman, 2004; Lieberman and Bramble, 2007; Mattson, 2012). Bipedalism also enabled the evolution of the shoulder in ways that allowed humans to throw objects accurately at a high velocity, greatly improving their ability as hunters (Roach et al., 2013). This was also the period in the evolution of our species when the size of the cerebral cortex increased relatively rapidly, which suggests that the expansion of the territory covered by individuals and groups of humans (enabled by endurance running) played a role in the expansion of the cerebral cortex. Coverage of a larger territory during the great human expansion (Henn et al., 2012) would have provided the opportunity to access more resources (food, water, and shelter), and required a greater pattern processing capacity to remember details of the location and nature of the resources. Importantly, humans evolved the ability to transfer the information acquired and processed in their brains during their journeys to other individuals via gestures, map drawing, and language. Visual and auditory patterns were likely the most commonly processed and transferred because of the ability to readily and accurately reproduce sights and sounds. Accordingly, the regions of the brain that expanded in humans are mostly involved in pattern processing of sights and sounds, and their codification as written and spoken languages. Very interestingly, specialized motor training (sports) enhances language understanding by a mechanism involving recruitment of the left dorsal lateral premotor cortex, suggesting that the language system is functionally connected to motor skill-related areas outside of the core language networks (Beilock et al., 2008). The latter findings suggest that the language SPP capabilities of the human brain co-evolved with development of organized “teamwork,” which may have bolstered functional interactions between brain regions involved in language and those responsible for specialized sensory-motor skills.
Emotions such as fear, anger, pleasure, and love are elevated states of arousal that enhance memory and recall of the events occurring during those emotional states (Bergado et al., 2011; Maren et al., 2013). This is a major, if not singular, function of emotions. Emotions evolved to reinforce memories of patterns of particular significance vis-à-vis survival and reproduction. Remembering the details of the events of an attack by a predator or intra-species rival will increase the probability of avoidance of such potentially deadly encounters in the future. Memories of the pleasurable experience of intercourse with fertile individuals of the opposite sex provides motivation for additional bouts of intercourse, and so increases the probability of passing one’s genes on to future generations.
Humans have evolved as highly social animals (Chang et al., 2013) with close emotional ties to mates, offspring, parents and close friends that enhance their survival and reproductive success (Damasio and Carvalho, 2013). As with other emotions, those associated with social interactions may have evolved to enhance SPP. In this view, there is a self-amplifying reciprocal relationship between social interactions and SPP ability. Thus, advanced PP abilities enable the development of social bonds and networks and, conversely, social interactions stimulate SPP. Success in social interactions requires that one recognize others, remember their past experiences with those individuals, and communicate their intentions. Dunbar’s social brain hypothesis of evolution of the primate brain includes the possible role of emotional attachments to mates and friends in complex social networks in the expansion of the cerebral cortex during anthropoid evolution (Dunbar, 2009; Sutcliffe et al., 2012). Because the memories of specific patterns (faces, places, conversations, etc.) can be reinforced or even embellished by emotions (Holland and Kensinger, 2010), it is reasonable to consider that evolution of the social brain was bolstered by emotional relationships. In addition to their use of complex language (see next Section), humans have added another dimension to social interactions—they are aware that others have thoughts and emotions very similar to their own. Humans therefore not only encode and process patterns representing their own experiences, but also the experiences of their family, friends and workmates. Social interactions require processing of information regarding the histories, behaviors and thoughts of many other individuals. Whether family members, employees or competitors, there are clear advantages to being able to know what others have done in the past, and to predict their future behaviors. Thus, inter-personal SPP is critical for success in most aspects of life, including acquiring and retaining friends, a job and a mate. Emotions reinforce inter-personal SPP, such that interactions involving anger, pleasure, sadness, etc. are retained, recalled and processed more thoroughly than interactions occurring in a neutral emotional context.
Language is the quintessential example of the evolved SPP capabilities of the human brain as it involves (once learned) the instantaneous conversion of sounds to visual symbols, and vice-versa. Language is a complex behavior in which auditory and/or visual patterns learned from other individuals or perceived in the environment are encoded, processed and modified for the purpose of transfer of information to other individuals. Language involves the use of patterns (symbols, words, and sounds) to code for objects and events encountered either via direct experience or communication from other individuals. Language-related SPP can create new patterns (stories, paintings, songs, etc.) of “things” that may (reality) or may not (fiction) exist. Language-mediated encoding and transfer of auditory and visual patterns enabled the rapid evolution of the human brain and is likely a major reason for the current dominance of Homo sapiens. (Aboitiz et al., 2006; Berwick et al., 2013).
While birds and non-human primates exhibit auditory communication, their vocalizations convey general information such as danger, rather than detailed instructions. It has been proposed by Tomasello (2008) that the kinds of gestures used by great apes is an evolutionary precursor of language. Studies of infant humans further support the notion that pointing and gestures are an ontogenic precursor to language (Goldin-Meadow, 2007; Liszkowski et al., 2009). Languages involving complex vocabularies and written symbols and words are believed to have arisen in Homo sapiens beginning approximately 100,000 years ago (Berwick et al., 2013). The rapid evolution of language skills, and the underlying neural circuits that mediate language processes, is fully consistent with its fundamental role in the rapid advancement of human societies. Language provides powerful reproductive and survival advantages. A man who engages a woman in stimulating conversation is more likely to attract her as a mate than is an inarticulate man. An army whose soldiers use detailed maps and advanced communication skills is more likely to win a battle than is an army that charges forward “blindly.”
The importance of imagination and invention for the rapid advancement of the human species cannot be overstated. The invention of tools and technologies have dominated the recent development of civilizations throughout the world. The earliest evidence for the invention of tools by our human ancestors dates to approximately 2.5 million years ago in Ethiopia and Kenya where stones were fashioned into cutting tools (Plummer, 2004). At that time hominid brains were about the same size as those of apes (approximately 500 grams), whereas the brain of modern humans is nearly three times larger.
A fascinating aspect of human SPP is the ability to fabricate mental entities that do not exist in the real world, including magical thinking. Magical thinking can be defined as “beliefs that defy culturally accepted laws of causality. In Western culture magical thinking refers to beliefs in, among other things, clairvoyance, astrology, spirit influences, and telepathy.” (Einstein and Menzies, 2004). Superstitions and rituals are examples of types of magical thinking. The cognitive fabrication of imaginary patterns is prominently illustrated in religious beliefs which have presumably provided an adaptive advantage to many societies. Magical thinking is at the core of all major religions wherein specific life events are believed to be controlled by “God,” and the “believers” behavior is designed to please “God” and avoid “his” wrath (Bloom, 2012). Figure 3 illustrates how a type of SPP, magical thinking, has had a major influence on cultural evolution. A recent functional MRI study suggests that religious belief involves neural networks that process information regarding intent and emotion, abstract semantics and imagery (Kapogiannis et al., 2009a). Transcranial magnetic stimulation focused on the left lateral temporal lobe, but not the right lateral temporal lobe or vertex, reduced magical thinking (Bell et al., 2007) providing further insight into the neural networks involved in magical thinking. Interestingly, structural differences between religious and non-religious subjects have been demonstrated including increased volume of right middle temporal cortex and reduced volumes of left precuneus and orbitofrontal cortex in religious subjects (Kapogiannis et al., 2009b). These findings are consistent with psychological theories of the evolution of religious belief which posit adaptive cognitive functions of such magical thinking (Culotta, 2009).
In general, psychiatric disorders result from an abnormal skewing of SPP in ways that dissolve the neural circuit-based boundaries between reality and imagination, between the realms of possibilities and probabilities. There are likely evolution-based reasons that anxiety and depression, and “paranoia spectrum disorders” are so common. Everyone experiences anxiety transiently in situations that involve real threats to oneself or loved ones; this heightened state of arousal is an adaptive response that provides motivation toward actions that can mitigate the danger. However, individuals with an anxiety disorder react to perceived threats that either do not in fact exist or are highly unlikely to occur. Depression is a state of self-doubt and hopelessness that often follows a period of chronic anxiety or a catastrophic life event. It involves a pervasive distortion of reality and an unrealistic catastrophic view of the future.
If SPP has played a fundamental role in the evolution of the human brain, then this should be evident in both the historical record and trajectories of different human populations throughout the world. The SPP theory predicts that populations that more rapidly develop SPP capabilities will experience accelerated accrual of resources and prosperity. The examples of major SPP abilities acquired during human evolution that were considered above (language, invention, imagination, reasoning, and planning for the future) should have each provided a survival and resource-accumulating advantage. The SPP theory therefore predicts that populations that did not develop each of these SPP capabilities would have been outcompeted by those populations with brains that did acquire, through evolution, those SPP capabilities. This prediction is supported by the fact that all surviving populations of H. sapiens use language, invent tools and exhibit imagination and complex reasoning. Hominin populations lacking, or with relatively poorer, SPP capabilities presumably failed to compete successfully, and so no longer exist.
The SPP theory predicts that variability in SPP capabilities among current human populations will be associated with variations in resources, health and welfare (indicators of fitness) of the different populations. Studies have documented positive associations of brain size with greater intelligence, faster decision making and greater cultural achievements between and within genetically differentiated populations of modern humans (Rushton and Jensen, 2008). This suggests that variability in SPP among existing groups of humans may be sufficiently robust to influence their relative fitness and so the future evolution of the human brain. The differential SPP-mediated development of technologies to improve transportation, manufacturing, scientific discovery and health care have resulted in the advancement of some populations above others. Individuals in populations that have most heavily utilized the SPP capabilities of their brains currently enjoy the greatest levels of prosperity, better health and longer lives. The disparities between and within countries are in some cases quite striking, with African countries exhibiting considerably less propensity for SPP, as reflected in poverty, low levels of education, high infant mortality and short lifespans. In contrast, the United States, and many countries in Europe and Asia are experiencing economic growth that is arguably resulting, in large part, from development of SPP-based technologies, with computer-based systems being a prominent example of a human invention that enables processing of information at rates many orders of magnitude beyond the capability of the human brain. Clearly, humans have recognized the central importance of SPP for their advancement as a species.
Finally, the SPP theory predicts that human evolution will continue to involve expansion of the prefrontal cortex and functionally associated brain regions, with resulting improvements in the brain’s ability to rapidly process information and make (good) decisions. The specific outcomes of advanced SPP for future generations remain to be determined, but may (hopefully) include the invention of technologies that eliminate suffering and help ensure the long-term survival of our species.