Decreases in Brain Size and Encephalization in Anatomically Modern Humans

Growth in human brain size and encephalization is well documented throughout much of prehistory and believed to be responsible for increasing cognitive faculties. Over the past 50,000 years, however, both body size and brain mass have decreased but little is known about the scaling relationship between the two. Here, changes to the human brain are examined using matched body remains to determine encephalization levels across an evolutionary timespan. The results find decreases to encephalization levels in modern humans as compared to earlier Holocene <i>H. sapiens</i> and Late Pleistocene anatomically modern <i>Homo</i>. When controlled for lean body mass, encephalization changes are isometric, suggesting that much of the declines in encephalization are driven by recent increases in obesity. A meta-review of genome-wide association studies finds some evidence for selective pressures acting on human cognitive ability, which may be an evolutionary consequence of the more than 5% loss in brain mass over the past 50,000 years.

Regular recreational Cannabis users exhibit altered neural oscillatory dynamics during attention reorientation

Background Cannabis is the most widely used illicit drug in the United States and is often associated with changes in attention function, which may ultimately impact numerous other cognitive faculties (e.g. memory, executive function). Importantly, despite the increasing rates of cannabis use and widespread legalization in the United States, the neural mechanisms underlying attentional dysfunction in chronic users are poorly understood. Methods We used magnetoencephalography (MEG) and a modified Posner cueing task in 21 regular cannabis users and 32 demographically matched non-user controls. MEG data were imaged in the time−frequency domain using a beamformer and peak voxel time series were extracted to quantify the oscillatory dynamics underlying use-related aberrations in attentional reorienting, as well as the impact on spontaneous neural activity immediately preceding stimulus onset. Results Behavioral performance on the task (e.g. reaction time) was similar between regular cannabis users and non-user controls. However, the neural data indicated robust theta-band synchronizations across a distributed network during attentional reorienting, with activity in the bilateral inferior frontal gyri being markedly stronger in users relative to controls (p's < 0.036). Additionally, we observed significantly reduced spontaneous theta activity across this distributed network during the pre-stimulus baseline in cannabis users relative to controls (p's < 0.020). Conclusions Despite similar performance on the task, we observed specific alterations in the neural dynamics serving attentional reorienting in regular cannabis users compared to controls. These data suggest that regular cannabis users may employ compensatory processing in the prefrontal cortices to efficiently reorient their attention relative to non-user controls.

The personal digital twin, ethical considerations

The personal digital twin extends to individual persons, a concept that originated in engineering to twin complex machines with a digital simulation containing a model of its functions to monitor its past and present behaviour, and repair, correct, improve or otherwise ensure its optimal operation. Several independent trends in technological developments are seen to converge towards the elaboration of the digital replication of individual human data and life history, notably in health industries. Among the main ones, we consider the ubiquitous distribution of digital assistants, the rapid progress of machine learning concurrent with the exponential growth of ‘personal’ Big Data and the incipient interest in developing lifelogs. The core hypothesis here is that among the psychological effects of the digital transformation, the externalization of cognitive faculties such as memory, planning and judgement, the decision-making processes located within the human person are also emigrating to digital functions, perhaps as a prelude to a later re-integration within the person via brain–computer interfaces. The paper concludes with ethical considerations about these ongoing developments. This article is part of the theme issue ‘Towards symbiotic autonomous systems’.

What Behavioral Abilities Emerged at Key Milestones in Human Brain Evolution? 13 Hypotheses on the 600-Million-Year Phylogenetic History of Human Intelligence

This paper presents 13 hypotheses regarding the specific behavioral abilities that emerged at key milestones during the 600-million-year phylogenetic history from early bilaterians to extant humans. The behavioral, intellectual, and cognitive faculties of humans are complex and varied: we have abilities as diverse as map-based navigation, theory of mind, counterfactual learning, episodic memory, and language. But these faculties, which emerge from the complex human brain, are likely to have evolved from simpler prototypes in the simpler brains of our ancestors. Understanding the order in which behavioral abilities evolved can shed light on how and why our brains evolved. To propose these hypotheses, I review the available data from comparative psychology and evolutionary neuroscience.

Exploring predictors of translation performance

The study reported on examined the question of whether translators’ cognitive faculties might be able to predict their performance on a translation task. Research on individual cognitive differences in translation has been a new issue in the realm of Translation Studies. However, the majority of previous studies have targeted single cognitive faculties for the purpose of investigation and we therefore know little about how sets of cognitive faculties can affect the process of translation from one language into another. In this study, three individual cognitive differences were targeted: emotional intelligence (EI), tolerance of ambiguity (TA), and working memory (WM). For the purposes of the study, 54 Iranian MA students of Translation Studies were sampled as participants. The participants completed measures of their EI, TA, and WM. In addition, they were requested to translate an excerpt from English (Source Language) into Persian (Target Language). The results of multiple regression analysis indicated that the regression model, incorporating EI, TA, and WM as its predictors, was able to predict a significant amount of variance in participants’ translation performance. Of the three predictors, the contributions of TA and WM to the total variance in the participants’ translation scores were statistically significant, while the contribution of EI to the total variance was not. The findings of the study have some implications for research and practice in the field of Translation Studies.

Revelation and Cognitive Science

Cognitive science tells us that human minds are not equally receptive to any and all sorts of ideas or information. Instead, they can be characterized as having special subsystems that preferentially attend to, and process, some kinds of information over others. Furthermore, as finite information processors, human minds naturally and automatically fill in informational gaps to make coherent meaning from what they experience. In so far as divine revelation is an act of communication, and that the divine communicator knows how human minds are active in any act of communication, it follows that divine revelation will take advantage of human cognitive systems in particular and effective ways. One way in which it would do so is in establishing some general predilections towards humans’ receptivity to the idea that there are divine realities. As cognitive science of religion has shown, humans may find certain aspects of divinity and divine order relatively easy to understand and receive from interaction with the natural world. This general revelation, however, is inchoate and incomplete. Room is left for additional revelation to augment understandings of divine truths. This additional revelation, however, would also be interpreted through ordinary human cognitive faculties, whether its medium is private mystical experiences, reading Scripture, or observing the actions and teachings of Jesus first hand. Drawing upon C. S. Lewis’s treatment of miracles, the chapter considers Jesus’ miracles as instances of divine revelation that can be made more explicable through the lenses of cognitive science.

Differential tracking of linguistic vs. mental state content in naturalistic stimuli by language and Theory of Mind (ToM) brain networks

Language and social cognition, especially the ability to reason about mental states, known as Theory of Mind (ToM), are deeply related in development and everyday use. However, whether these cognitive faculties rely on distinct, overlapping, or the same mechanisms remains debated. Some evidence suggests that, by adulthood, language and ToM draw on largely distinct—though plausibly interacting—cortical networks. However, the broad topography of these networks is similar, and some have emphasized the importance of social content / communicative intent in the linguistic signal for eliciting responses in the language areas. Here, we combine the power of individual-subjects functional localization with the naturalistic-cognition inter-subject correlation approach to illuminate the language-ToM relationship. Using fMRI, we recorded neural activity as participants (n=43) listened to stories and dialogs with mental state content (+linguistic, +ToM), viewed silent animations and live action films with mental state content but no language (-linguistic, +ToM), or listened to an expository text (+linguistic, -ToM). The ToM network robustly tracked stimuli rich in mental state information regardless of whether mental states were conveyed linguistically or non-linguistically, while tracking a +linguistic/-ToM stimulus only weakly. In contrast, the language network tracked linguistic stimuli more strongly than a) non-linguistic stimuli, and than b) the ToM network, and showed reliable tracking even for the linguistic condition devoid of mental state content. These findings suggest that in spite of their indisputably close links, language and ToM dissociate robustly in their neural substrates, and thus plausibly cognitive mechanisms, including during the processing of rich naturalistic materials.

A systematic review of the efficacy of intermittent theta burst stimulation (iTBS) on cognitive enhancement

Intermittent theta-burst stimulation (iTBS) has been used to focally regulate excitability of neural cortex over the past decade – however there is little consensus on the generalizability of effects reported in individual studies. Many studies use small sample sizes (n &lt; 30), and there is a considerable amount of methodological heterogeneity in application of the stimulation itself. This systematic meta-analysis aims to consolidate the extant literature and determine if up-regulatory theta-burst stimulation reliably enhances cognition through measurable behavior. Results show that iTBS – when compared to suitable control conditions — may enhance cognition when outlier studies are removed, and there is a significant amount of heterogeneity across studies. Significant contributors to between-study heterogeneity include location of stimulation and method of navigation to the stimulation site. Surprisingly, the type of cognitive domain investigated was not a significant contributor of heterogeneity. The findings of this meta-analysis demonstrate that standardization of iTBS is urgent and necessary to determine if neuroenhancement of particular cognitive faculties are reliable and robust, and measurable through observable behavior.

“The Boundless Realm Where All Form Lies”. Representing Imagination at the Crossway Between Literary and Neurocognitive Studies

According to ancient texts on poetics, the concept of representation is deeply bound to that of “mimesis;” this last was intended in two main ways: as “imitation” and as “world construction.” In Aristotle's Poetics, mimesis is theorized as the main form of “world simulation,” giving rise to the complex universe of fiction. The concept of simulation plays a pivotal role in the neurocognitive theories on the embodied mind: within this frame, embodied simulation is intended as a functional prelinguistic activation of the human sensorimotor mechanism. This happens not only with regard to intercorporeality and intersubjectivity in the real world but also in relation to the process of imagination giving rise to literary imagery and to the reader's reception of the fictional world, since human beings share a common sensorimotor apparatus. Imagination is a central concept in the recent neurocognitive studies since it plays a core role in human life and in artistic production and reception. Imagination has been considered as a complex emergent cognitive faculty deeply intertwined with perception, memory, and consciousness, shaping human life and transforming the limited horizon of our perceptual affective understanding, being, and acting. Although there is an immense bulk of literature on this topic, imagination is still an elusive concept: its definition and understanding change according to different heuristic frames—mainly the philosophical, aesthetic, poetic, and cognitive ones—giving rise to debates about its modalities and effects, particularly in relation to the construction of aesthetic and symbolic constraints. In this paper, we claim that scientific research may take advantage from the literary representation of the imaginative faculties, which occurs in specific tests characterized by dynamic images and motion. In such meta-representation of the imagination, we witness the phenomenological emergence of endogenous dynamic processes involving a cluster of cognitive faculties, activated by triggering the reader's embodied simulation. One of the main German poets, Johann Wolfgang von Goethe, in the second part of his masterwork Faust II, intuitively represents the very process of the imagination and its responding to embodied simulation with regard both to the author's creative act and to its reception by the reader. At the crossway between literary and neurocognitive, this study aims to highlight the advantage offered to future transdisciplinary inquiries by the literary representation showing features and dynamics of the still mysterious phenomenon of the imagination.