scholarly journals Can the Archaeology of Manual Specialization Tell Us Anything About Language Evolution? A Survey of the State of Play

2009 ◽  
Vol 19 (1) ◽  
pp. 97-110 ◽  
Author(s):  
James Steele ◽  
Natalie Uomini

In this review and position paper we explore the neural substrates for manual specialization and their possible connection with language and speech. We focus on two contrasting hypotheses of the origins of language and manual specialization: the language-first scenario and the tool-use-first scenario. Each one makes specific predictions about hand-use in non-human primates, as well as about the necessity of an association between speech adaptations and population-level right-handedness in the archaeological and fossil records. The concept of handedness is reformulated for archaeologists in terms of manual role specialization, using Guiard's model of asymmetric bimanual coordination. This focuses our attention on skilled bimanual tasks in which both upper limbs play complementary roles. We review work eliciting non-human primate hand preferences in co-ordinated bimanual tasks, and relevant archaeological data for estimating the presence or absence of a population-level bias to the right hand as the manipulator in extinct hominin species and in the early prehistory of our own species.

2009 ◽  
Vol 101 (4) ◽  
pp. 1749-1754 ◽  
Author(s):  
Christopher M. Laine ◽  
Kevin M. Spitler ◽  
Clayton P. Mosher ◽  
Katalin M. Gothard

The amygdala plays a crucial role in evaluating the emotional significance of stimuli and in transforming the results of this evaluation into appropriate autonomic responses. Lesion and stimulation studies suggest involvement of the amygdala in the generation of the skin conductance response (SCR), which is an indirect measure of autonomic activity that has been associated with both emotion and attention. It is unclear if this involvement marks an emotional reaction to an external stimulus or sympathetic arousal regardless of its origin. We recorded skin conductance in parallel with single-unit activity from the right amygdala of two rhesus monkeys during a rewarded image viewing task and while the monkeys sat alone in a dimly lit room, drifting in and out of sleep. In both experimental conditions, we found similar SCR-related modulation of activity at the single-unit and neural population level. This suggests that the amygdala contributes to the production or modulation of SCRs regardless of the source of sympathetic arousal.


2021 ◽  
pp. 1-17
Author(s):  
Anna A. Matejko ◽  
Daniel Ansari

Abstract Visuospatial working memory (VSWM) plays an important role in arithmetic problem solving, and the relationship between these two skills is thought to change over development. Even though neuroimaging studies have demonstrated that VSWM and arithmetic both recruit frontoparietal networks, inferences about common neural substrates have largely been made by comparisons across studies. Little work has examined how brain activation for VSWM and arithmetic converge within the same participants and whether there are age-related changes in the overlap of these neural networks. In this study, we examined how brain activity for VSWM and arithmetic overlap in 38 children and 26 adults. Although both children and adults recruited the intraparietal sulcus (IPS) for VSWM and arithmetic, children showed more focal activation within the right IPS, whereas adults recruited the bilateral IPS, superior frontal sulcus/middle frontal gyrus, and right insula. A comparison of the two groups revealed that adults recruited a more left-lateralized network of frontoparietal regions for VSWM and arithmetic compared with children. Together, these findings suggest possible neurocognitive mechanisms underlying the strong relationship between VSWM and arithmetic and provide evidence that the association between VSWM and arithmetic networks changes with age.


2020 ◽  
Vol 30 (7) ◽  
pp. 4076-4091
Author(s):  
Ryu Ohata ◽  
Tomohisa Asai ◽  
Hiroshi Kadota ◽  
Hiroaki Shigemasu ◽  
Kenji Ogawa ◽  
...  

Abstract The sense of agency is defined as the subjective experience that “I” am the one who is causing the action. Theoretical studies postulate that this subjective experience is developed through multistep processes extending from the sensorimotor to the cognitive level. However, it remains unclear how the brain processes such different levels of information and constitutes the neural substrates for the sense of agency. To answer this question, we combined two strategies: an experimental paradigm, in which self-agency gradually evolves according to sensorimotor experience, and a multivoxel pattern analysis. The combined strategies revealed that the sensorimotor, posterior parietal, anterior insula, and higher visual cortices contained information on self-other attribution during movement. In addition, we investigated whether the found regions showed a preference for self-other attribution or for sensorimotor information. As a result, the right supramarginal gyrus, a portion of the inferior parietal lobe (IPL), was found to be the most sensitive to self-other attribution among the found regions, while the bilateral precentral gyri and left IPL dominantly reflected sensorimotor information. Our results demonstrate that multiple brain regions are involved in the development of the sense of agency and that these show specific preferences for different levels of information.


2004 ◽  
Vol 16 (10) ◽  
pp. 1785-1795 ◽  
Author(s):  
Malia F. Mason ◽  
C. Neil Macrae

People are remarkably adroit at understanding other social agents. Quite how these information-processing abilities are realized, however, remains open to debate and empirical scrutiny. In particular, little is known about basic aspects of person perception, such as the operations that support people's ability to categorize (i.e., assign persons to groups) and individuate (i.e., discriminate among group members) others. In an attempt to rectify this situation, the current research focused on the initial perceptual stages of person construal and considered: (i) hemispheric differences in the efficiency of categorization and individuation; and (ii) the neural activity that supports these social-cognitive operations. Noting the greater role played by configural processing in individuation than categorization, it was expected that performance on the former task would be enhanced when stimuli (i.e., faces) were presented to the right rather than to the left cerebral hemisphere. The results of two experiments (Experiment 1—healthy individuals; Experiment 2—split-brain patient) confirmed this prediction. Extending these findings, a final neuroimaging investigation revealed that individuation is accompanied by neural activity in regions of the temporal and prefrontal cortices, especially in the right hemisphere. We consider the implications of these findings for contemporary treatments of person perception.


2019 ◽  
Vol 7 (2) ◽  
pp. e000841
Author(s):  
Garrett Fraess ◽  
Ryan Dickinson ◽  
Brandy Kragness ◽  
Miranda Sadar

A 31-year-old, 5.01 kg, intact male black-capped capuchin (Sapajus apella) was presented for examination after zookeepers noted an enlarged right testicle. Fine-needle aspiration with cytological evaluation identified a seminoma of the right testis. Castration was elected for this non-breeding male, and both testicles were submitted for histopathology. Histopathology confirmed the presence of a seminoma in the right testicle and, incidentally, a mass in the left testis consistent with an interstitial cell tumour was also diagnosed. This report describes the first case of seminoma or interstitial cell neoplasia in a black-capped capuchin, as well as the first case of a non-human primate with synchronous, bilateral testicular neoplasms.


2019 ◽  
Vol 6 (11) ◽  
pp. 190929 ◽  
Author(s):  
J. Daisy Kaplan ◽  
Samantha Y. Goodrich ◽  
Kelly Melillo-Sweeting ◽  
Diana Reiss

Lateralized behaviour is found in humans and a wide variety of other species. At a population level, lateralization of behaviour suggests hemispheric specialization may underlie this behaviour. As in other cetaceans, dolphins exhibit a strong right-side bias in foraging behaviour. Common bottlenose dolphins in The Bahamas use a foraging technique termed ‘crater feeding’, in which they swim slowly along the ocean floor, scanning the substrate using echolocation, and then bury their rostrums into the sand to obtain prey. The bottlenose dolphins off Bimini, The Bahamas, frequently execute a sharp turn before burying their rostrums in the sand. Based on data collected from 2012 to 2018, we report a significant right-side (left turn) bias in these dolphins. Out of 709 turns recorded from at least 27 different individuals, 99.44% ( n = 705) were to the left (right side and right eye down) [ z = 3.275, p = 0.001]. Only one individual turned right (left side and left eye down, 4/4 turns). We hypothesize that this right-side bias may be due in part to the possible laterization of echolocation production mechanisms, the dolphins' use of the right set of phonic lips to produce echolocation clicks, and a right eye (left hemisphere) advantage in visual discrimination and visuospatial processing.


2009 ◽  
Vol 102 (6) ◽  
pp. 3142-3155 ◽  
Author(s):  
Pratik K. Mutha ◽  
Robert L. Sainburg

Previous research has suggested distinct predictive and reactive control mechanisms for bimanual movements compared with unimanual motion. Recent studies have extended these findings by demonstrating that movement corrections during bimanual movements might differ depending on whether or not the task is shared between the arms. We hypothesized that corrective responses during shared bimanual tasks recruit bilateral rapid feedback mechanisms such as reflexes. We tested this hypothesis by perturbing one arm as subjects performed uni- and bimanual movements. Movements were made in a virtual-reality environment in which hand position was displayed as a cursor on a screen. During bimanual motion, we provided cursor feedback either independently for each arm (independent-cursor) or such that one cursor was placed at the average location between the arms (shared-cursor). On random trials, we applied a 40 N force pulse to the right arm 100 ms after movement onset. Our results show that while reflex responses were rapidly elicited in the perturbed arm, electromyographic activity remained close to baseline levels in the unperturbed arm during the independent-cursor trials. In contrast, when the cursor was shared between the arms, reflex responses were reduced in the perturbed arm and were rapidly elicited in the unperturbed arm. Our results thus suggest that when both arms contribute to achieving the task goal, reflex responses are bilaterally elicited in response to unilateral perturbations. These results agree with and extend recent suggestions that bimanual feedback control might be modified depending on task context.


2005 ◽  
Vol 25 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Jacques Vauclair ◽  
Adrien Meguerditchian ◽  
William D. Hopkins

2020 ◽  
Vol 10 (2) ◽  
pp. 188-229
Author(s):  
Gareth Roberts ◽  
Betsy Sneller

Abstract Half a century ago, Uriel Weinreich, William Labov, and Marvin Herzog laid out a programmatic vision for the study of language change. This included establishing five fundamental problems for the field and a radical shift from a focus on idiolects to a focus on population-level change (grounded in their concept of orderly heterogeneity). They also expressed an explicit desire to see an integrated evolutionary study of language change. In spite of this, the newer fields of language evolution and cultural evolution make little contact with the field of sociolinguistics that emerged out of their work. Here we lay out a program, grounded in their five problems, for a more integrated future. We situate each problem in modern sociolinguistics and identify promising points for theoretical exchange, making comparisons with Tinbergen’s four questions, which play a similar role in the evolutionary sciences. Finally, we propose cultural-evolutionary experiments for making empirical progress.


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