VII. Our Earthuman Ascent: A Major Evolutionary Transition in Individuality
3. A Complementary Brain and Thought Process
While Emergent Bicameral Brain above reported a consistent presence of bilateral faculties across evolutionary animal lineages, this section records their developmental fulfillment in human beings with distinctive left and right hemisphere qualities. While long intimated, scientific proof began in the 1960s by way of the CalTech neuroscientist Roger Sperry. Into the 2010s, after decades of clinical and neuroimaging studies, an actual double, reciprocal asymmetry has been well quantified, as these citations convey. In general, the left side focuses on finer, discrete objects out of context, with the right half complement connecting the dots within a holistic field of view.
Speech Prosody 2018. sp9.home.amu.edu.pl. A website for the 9th international conference on this linguistic field which broadly is about, along with syntax and grammar, the rhythmic visual signs and bodily gestures which are vital for clear dialogue communication. It was held in Poznan, Poland in June. The opening keynote is The Future of Prosody by Dafydd Gibbon, reviewed herein. By August, most presentations are available in full from this site such as Investigating Prosody in Music and Speech and How Parents Motivate their Children through Prosody.
The biennial meeting of the Speech Prosody Special Interest Group of the International Speech Communication Association is the only recurring conference focused on prosody as an organizing principle for the social, psychological, linguistic, and technological aspects of spoken language. Past conferences have been attended by 300-400 experts from a range of disciplines including linguistics, acoustics, speech synthesis and recognition, cognitive psychology, neuroscience, speech therapy, language teaching, computer science, electrical engineering, speech and hearing science and psychology. Speech Prosody 2018 will be held at Adam Mickiewicz University, Poznań, whose tradition reaches back to the 17th century.
Albouy, Philippe, et al. Distinct Sensitivity to Spectrotemporal Modulation Supports Brain Asymmetry for Speech and Melody. Science. 367/1043, 2020. In a paper that merited an issue highlight, McGill University, Laval University and Aix Marseille University neuropsychologists including Robert Zatorre describe sophisticated experiments which reveal how our cerebral faculty proceeds to comport discrete wordy (digital) discourse to the left hemisphere, and continuous, meaningful (analog) content to the right side. Once again, these complementary modes are found to distinguish a whole, script + song = knowledge, microcosmic brain.
Does brain asymmetry for speech and music emerge from acoustical cues or from domain-specific neural networks? We filtered temporal or spectral modulations in sung speech stimuli for which verbal and melodic content was crossed and balanced. Functional magnetic resonance imaging data showed that the neural decoding of speech and melodies depends on activity patterns in left and right auditory regions, respectively. This asymmetry is supported by specific sensitivity to spectrotemporal modulation rates within each region. Our results suggest a match between acoustical properties of communicative signals and neural specializations adapted to that purpose. (Abstract excerpt)
Aziz-Zadeh, Lisa, et al. Exploring the Neural Correlates of Visual Creativity. Social Cognitive and Affective Neuroscience. 8/4, 2013. In this Oxford Academic journal, University of Southern California researchers use neuroimaging to reveal that while spatial tasks tend to a right side mode, the left detailed side also gets involved so to fully perceive an image. These results help evince that rather than isolate hemispheres, a whole brain complementarity is actually in play by which to achieve integral comprehension.
Although creativity has been called the most important of all human resources, its neural basis is still unclear. In the current study, we used fMRI to measure neural activity in participants solving a visuospatial creativity problem that involves divergent thinking and has been considered a canonical right hemisphere task. As hypothesized, both the visual creativity task and the control task as compared to rest activated a variety of areas including the posterior parietal cortex bilaterally and motor regions. However, directly comparing the two tasks indicated that the creative task more strongly activated left hemisphere regions including the posterior parietal cortex, the premotor cortex, dorsolateral prefrontal cortex (DLPFC) and the medial PFC. These results demonstrate that even in a task that is specialized to the right hemisphere, robust parallel activity in the left hemisphere supports creative processing. (Abstract)
Banich, Marie. Cognitive Neuroscience and Neuropsychology. Boston: Houghton Mifflin, 2004. A good introduction to the field with a strong chapter on Hemispheric Specialization.
Bassett, Danielle, et al. Task-Based Core-Periphery Organization of Human Brain Dynamics. PLoS Computational Biology. 9/9, 2013. UC Santa Barbara, Oxford University, and University of North Carolina researchers including Mason Porter advance the case for two distinct phases and roles of neural net processing. These involve reciprocal interactions between a constrained, finely focused region and an outlying area open to wider interpretations. The entry draws on earlier work in Core-Periphery Structure in Networks by Porter’s team (search Rombach). The insights are also availed in Functional Dynamics of the Language System by Lucy Chai, et al (herein 2016), see also Pun Processing from a Psycholinguistic Perspective (Tara McHugh) for another view. A prime benefit is a “fix and flex” complementarity as the brain’s way to viably think and act. One might add that such novel findings could inform social behaviors - a post-election United States map actually had interior conservative red states and blue “coastal liberals.”
As a person learns a new skill, distinct synapses, brain regions, and circuits are engaged and change over time. In this paper, we develop methods to examine patterns of correlated activity across a large set of brain regions. Using recently developed algorithms to detect time-evolving communities, we find that the complex reconfiguration patterns of the brain's putative functional modules that control learning can be described parsimoniously by the combined presence of a relatively stiff temporal core that is composed primarily of sensorimotor and visual regions whose connectivity changes little in time and a flexible temporal periphery that is composed primarily of multimodal association regions whose connectivity changes frequently. The core of dynamically stiff regions exhibits dense connectivity, which is consistent with notions of core-periphery organization established previously in social networks. Our results demonstrate that core-periphery organization provides an insightful way to understand how putative functional modules are linked. (Abstract)
Behrmann, Marlene and David Plaut. A Vision of Graded Hemispheric Specialization. Annals of the New York Academy of Sciences. Online July, 2015. Carnegie Mellon University psychologists propose a more distributed view of how our complementary brain asymmetry forms by degrees over a life span. But again the prime aspect of left side “word” detail, and right “face” image are seen as the main characteristic.
Understanding the process by which the cerebral hemispheres reach their mature functional organization remains challenging. We propose a theoretical account in which, in the domain of vision, faces and words come to be represented adjacent to retinotopic cortex by virtue of the need to discriminate among homogeneous exemplars. Orthographic representations are further constrained to be proximal to typically left-lateralized language-related information to minimize connectivity length between visual and language areas. As reading is acquired, orthography comes to rely more heavily on the left fusiform region to bridge vision and language. Consequently, due to competition from emerging word representations, face representations that were initially bilateral become lateralized to the right fusiform region. We then summarize empirical evidence from a variety of studies across different populations (children, adolescents, and adults) that supports the claims that hemispheric lateralization is graded rather than binary and that this graded organization emerges dynamically over the course of development. (Abstract)
Bennett, Fionn. Music and Language in Ancient Verse: The Dynamics of an Antagonistic Concord. Humanities. Online January, 2016. As the extended Abstract explains, a Centre Interdisciplinaire de Recherche sur les Langues et la Pensée, Reims, France scholar discerns an original complementary synthesis between melodic conveyance and glyphic inscriptions. These dual archetypal modes of rhythm and speech, prosody and content, actually occur in a close, sympathetic unity. For recent proof, see for example Hemispheric Asymmetry of Endogenous Neural Oscillations in Young Children by Elaine Thompson, et al, from coauthor Nina Kraus’ auditory neuroscience laboratory at Northwestern University (Nature Scientific Reports 6/19737, 2016). From another corner, a vital cerebral reciprocity is again evident, which is now so fractured in a patriarchal cacophony.
In antiquity, the relationship between “music”, “poetry”, and “language” was very different from the way they relate to each other today, for back then each of these mediums was endowed with a distinct, independent signifying code expressing a semiosis all its own. However, these separate “semiospheres” nonetheless never ceased growing towards and into one another. This is so because music and “melic” poetry were believed to have the capacity to denote something ordinary language could not denote but could not do without, namely “etymonic truth”. As a result, the users of ordinary language were obsessed with divining the “hyponoia” poets encoded in music and chant. Above all, they wanted this hyponoia to constitute the signifié of their language. For this reason, the meaning expressed in language was subject to a process in which it was constantly being “deported” from its ordinary acceptations and transported towards meanings encoded in music. However, this “deterritorialization” of ordinary meaning never resulted in a full “reterritorialization” upon the terrain of the truth encoded in music. Musicians and poets would not tolerate it. As far as they were concerned, music and poetry would cease being “truthful” if the semiosis they conveyed and the semiosis conveyed by language were interchangeable. For, again, as a signifying code, prosaic language was sui generis incapable of representing the truth. Hence, the relationship between these three codes consisted of a sort of intersemiotic dynamic equilibrium in which language was continuously evolving towards a non-linguistic expression of meaning which conferred truth upon it and what it means. And yet the music and poetry which were the source of that truth deliberately kept language from consummating the aspiration of accosting the truth they encoded. This paper explores the mechanics of this intersemiotic dynamic equilibrium.
Bilalic, Merim, et al. It Takes Two-Skilled Recognition of Objects Engages Lateral Areas in Both Hemispheres. PLoS One. 6/1, 2011. University of Tubingen, Wursburg, and Aachen neuroscientists study whether the brains of proficient game players, such as chess masters, function better than novices. Indeed they do, for they make dynamic, complementary use of both left fine object focus, and right holistic, survey. A report on this work “Proof That Chess Experts' Brains Work Differently” appeared in the New York Times for January 24, 2011.
The question remains why the right temporo-lateral brain areas are associated with skilled object recognition. One possible explanation would be the holistic processing of stimuli which is generally more related to the right hemisphere than to the left one. Right hemisphere, for example, processes more global aspects of a visual stimulus, while left hemisphere is better in processing local aspects. The skilled recognition of chess objects and their function, however, also involved the left hemisphere. Although there were some differences between the activation levels in right and left hemispheres among experts, the activations in both hemispheres were clearly above the baseline. It is thus possible that in experts both hemispheres may work together to enable automatic and parallel processing and thus superior domain specific object recognition. (7)
Blackman, Lisa. Immaterial Bodies: Affect, Embodiment, Mediation. London: Sage Publications, 2012. An academic work in association with Theory, Culture & Society journal by a Reader in Media and Communications at Goldsmiths University of London. It concludes with a remarkable chapter “Neuroscience: The Bicameral Mind and the Double Brain” that joins Julian Jaynes insights (1976) with those of Iain McGilchrist (2009) to to make even more import of our individual and collective hemispheric endowments. Human and humankind are truly of dual, archetypal minds, an attribute we need much to understand for it can explain everything, for better or worse. In regard, an original right side sensory mode of organic relational, passion/emotion, “female and nonwhite,” shifts in history to a later left stress of motor activity, separateness, rationalities, “male and white.” So we arrive today, at earth’s finite closure, beset by these parallel, double universes in much conflict and need of a bicameral complementary sanity.
Blakeslee, Sandra. Humanity? Maybe It’s in the Wiring. New York Times. December 9, 2003. A report on the finding of specialized neurons in the brain called spindle cells whose circuitry appears vital for social emotions. What is notable is that the right hemisphere has one-third more of these cells than the left, a ratio that holds from human to chimpanzee. This evidence supports the right brain as the locale of moral, emotional and empathic sensibilities, often considered as more feminine in kind.
Bourne, Victoria. Lateralised Processing of Positive Facial Emotion: Sex Differences in Strength of Hemispheric Dominance. Neuropsychologia. 43/6, 2005. With regard to this task, men tend to use the right hemisphere while women draw on both sides of the brain. These findings are taken to imply that males are field-independent, females more field (context) dependent.
The results suggest that females are more bilaterally distributed and hence have greater access to mechanisms located in each hemisphere. (953)
Brosnan, Mark, et al. Gestalt Processing in Autism. Journal of Child Psychology and Psychiatry. 45/3, 2004. Autistic children are said to lack a capacity for ‘gestalt grouping,’ distinguished here from overall global images. Dots are perceived but connections elude. Inter-element relationships, an ability to interact socially, is a consequent deficit. And while reading this article, one could not help think that our national mindset seems autistic as we descent into cognitive, rhetorical, and military chaos. As often cited after 9/11, we are unable to connect the dots and pieces into any meaningful pattern or salutary vision.
There is a large body of literature that suggests the right hemisphere primarily subserves the processing underpinning gestalt and global analysis, while the left primarily subserves local analysis. (466)