As parents in modern western societies face increasing pressures that strain their ability to provide quality childcare, it is important to consider the neural and hormonal bases of sensitive and ...nurturing parenting. The topic has been explored systematically in non-human animals, and these studies have yielded a rich source of hypotheses for human studies. Considerable evidence links oxytocin (OT) with sensitive caregiving in both men and women, and with stimulatory infant contact in men and affectionate infant contact in women. Testosterone, on the other hand, decreases in men who become involved fathers, and testosterone may interfere with aspects of paternal care. In neuroimaging studies, exposing parents to child stimuli activates neural systems involved in understanding others' facial expressions (the putative mirror neuron system), others' feelings (anterior insula and thalamocingulate regions) and others' thoughts (dorsomedial prefrontal cortex), as well as reward systems involved in approach-related motivation (ventral tegmental area, substantia nigra, ventral striatum and medial orbitofrontal cortex), and systems involved with emotion regulation (lateral prefrontal cortex). There is some evidence that this activity can be attenuated in mothers who do not breastfeed, and mothers with post-partum depression, perhaps due in part to lower levels of OT exposure. On the other hand, there is evidence suggesting that high levels of oxytocin (OT) may enhance activation in some of these systems. For example, OT may stimulate dopamine release in the ventral striatum, rendering child stimuli more rewarding. A few recent studies have gone beyond merely describing neural correlates to establishing the functional significance of activation patterns by linking them with observed maternal behavior outside the scanner. The results of these studies suggest that there may be an optimal range of activation within certain neural systems, neither too high nor too low, that supports appropriate parenting. There is also mounting evidence that the very structure of the human brain is altered by the cognitive challenges inherent in learning how to parent. Given that human mothers typically receive help with childrearing, it will be important to begin studying the neural and hormonal bases of alloparental care, with a particular emphasis on fathers due to their increasing involvement in childcare in modern western societies.
► Oxytocin, vasopressin, prolactin and testosterone affect parental behavior in rodents, primates and humans. ► There is widespread overlap between parental brain systems and the neural systems involved in social cognition. ► Effective parenting may involve maintaining physiological responses within a range that is neither too low nor too high. ► There is a need for more studies on the neural bases of human allomaternalcare.
Parents know the transformative nature of having and caring for a child. Among many mammals, giving birth leads from an aversion to infant stimuli to irresistible attraction. Here, we review the ...biological mechanisms governing this shift in parental motivation in mammals. Estrogen and progesterone prepare the uterus for embryo implantation and placental development. Prolactin stimulates milk production, whereas oxytocin initiates labor and triggers milk ejection during nursing. These same molecules, interacting with dopamine, also activate specific neural pathways to motivate parents to nurture, bond with, and protect their offspring. Parenting in turn shapes the neural development of the infant social brain. Recent work suggests that many of the principles governing parental behavior and its effect on infant development are conserved from rodent to humans.
Highlights • Comparative neuroimaging can identify unique features of the human brain. • Comparisons with chimpanzees are crucial for learning about human brain evolution. • Human brains are special ...in terms of size, cortical organization, and connectivity. • Human brains are special in terms of development and aging.
As parents in modern western societies face increasing pressures that strain their ability to provide quality childcare, it is important to consider the neural and hormonal bases of sensitive and ...nurturing parenting. The topic has been explored systematically in non-human animals, and these studies have yielded a rich source of hypotheses for human studies. Considerable evidence links oxytocin (OT) with sensitive caregiving in both men and women, and with stimulatory infant contact in men and affectionate infant contact in women. Testosterone, on the other hand, decreases in men who become involved fathers, and testosterone may interfere with aspects of paternal care. In neuroimaging studies, exposing parents to child stimuli activates neural systems involved in understanding others' facial expressions (the putative mirror neuron system), others' feelings (anterior insula and thalamocingulate regions) and others' thoughts (dorsomedial prefrontal cortex), as well as reward systems involved in approach-related motivation (ventral tegmental area, substantia nigra, ventral striatum and medial orbitofrontal cortex), and systems involved with emotion regulation (lateral prefrontal cortex). There is some evidence that this activity can be attenuated in mothers who do not breastfeed, and mothers with post-partum depression, perhaps due in part to lower levels of OT exposure. On the other hand, there is evidence suggesting that high levels of oxytocin (OT) may enhance activation in some of these systems. For example, OT may stimulate dopamine release in the ventral striatum, rendering child stimuli more rewarding. A few recent studies have gone beyond merely describing neural correlates to establishing the functional significance of activation patterns by linking them with observed maternal behavior outside the scanner. The results of these studies suggest that there may be an optimal range of activation within certain neural systems, neither too high nor too low, that supports appropriate parenting. There is also mounting evidence that the very structure of the human brain is altered by the cognitive challenges inherent in learning how to parent. Given that human mothers typically receive help with childrearing, it will be important to begin studying the neural and hormonal bases of alloparental care, with a particular emphasis on fathers due to their increasing involvement in childcare in modern western societies.
Given that we live in highly complex social environments, many of our most important decisions are made in the context of social interactions. Simple but sophisticated tasks from a branch of ...experimental economics known as game theory have been used to study social decision-making in the laboratory setting, and a variety of neuroscience methods have been used to probe the underlying neural systems. This approach is informing our knowledge of the neural mechanisms that support decisions about trust, reciprocity, altruism, fairness, revenge, social punishment, social norm conformity, social learning, and competition. Neural systems involved in reward and reinforcement, pain and punishment, mentalizing, delaying gratification, and emotion regulation are commonly recruited for social decisions. This review also highlights the role of the prefrontal cortex in prudent social decision-making, at least when social environments are relatively stable. In addition, recent progress has been made in understanding the neural bases of individual variation in social decision-making.
Highlights • Comparisons between human and non-human primate brains can identify human brain specializations that support language. • Non-human primate brains have homologues of Broca's and ...Wernicke's areas, as well as connections between them. • Wernicke's and Broca's areas have wider minicolumns in human brains than do their homologues in non-human primate brains. • Humans have certain leftward asymmetries in Broca's area and Wernicke's area that are not found in ape brains. • The arcuate fasciculus pathway is involved in language and has markedly expanded in human evolution.
Diffusion Tensor Imaging (DTI) tractography has been used to detect leftward asymmetries in the arcuate fasciculus, a pathway that links temporal and inferior frontal language cortices. In this ...study, we more specifically define this asymmetry with respect to both anatomy and function. Twenty right-handed male subjects were scanned with DTI, and the arcuate fasciculus was reconstructed using deterministic tractography. The arcuate was divided into 2 segments with different hypothesized functions, one terminating in the posterior superior temporal gyrus (STG) and another terminating in the middle temporal gyrus (MTG). Tractography results were compared with peak activation coordinates from prior functional neuroimaging studies of phonology, lexical–semantic processing, and prosodic processing to assign putative functions to these pathways. STG terminations were strongly left lateralized and overlapped with phonological activations in the left but not the right hemisphere, suggesting that only the left hemisphere phonological cortex is directly connected with the frontal lobe via the arcuate fasciculus. MTG terminations were also strongly left lateralized, overlapping with left lateralized lexical–semantic activations. Smaller right hemisphere MTG terminations overlapped with right lateralized prosodic activations. We combine our findings with a recent model of brain language processing to explain 6 aphasia syndromes.
Humans have the largest cerebral cortex among primates. The question of whether association cortex, particularly prefrontal cortex (PFC), is disproportionately larger in humans compared with nonhuman ...primates is controversial: Some studies report that human PFC is relatively larger, whereas others report a more uniform PFC scaling. We address this controversy using MRI-derived cortical surfaces of many individual humans, chimpanzees, and macaques. We present two parcellation-based PFC delineations based on cytoarchitecture and function and show that a previously used morphological surrogate (cortex anterior to the genu of the corpus callosum) substantially underestimates PFC extent, especially in humans. We find that the proportion of cortical gray matter occupied by PFC in humans is up to 1.9-fold greater than in macaques and 1.2-fold greater than in chimpanzees. The disparity is even more prominent for the proportion of subcortical white matter underlying the PFC, which is 2.4-fold greater in humans than in macaques and 1.7-fold greater than in chimpanzees.
The evolution of neurocranial morphology in
Homo sapiens
is characterized by bulging of the parietal region, a feature unique to our species. In modern humans, expansion of the parietal surface ...occurs during the first year of life, in a morphogenetic stage which is absent in chimpanzees and Neandertals. A similar variation in brain shape among living adult humans is associated with expansion of the precuneus. Using MRI-derived structural brain templates, we compare medial brain morphology between humans and chimpanzees through shape analysis and geometrical modeling. We find that the main spatial difference is a prominent expansion of the precuneus in our species, providing further evidence of evolutionary changes associated with this area. The precuneus is a major hub of brain organization, a central node of the default-mode network, and plays an essential role in visuospatial integration. Together, the comparative neuroanatomical and paleontological evidence suggest that precuneus expansion is a neurological specialization of
H. sapiens
that evolved in the last 150,000 years that may be associated with recent human cognitive specializations.
The neural correlates of grandmaternal caregiving Rilling, James K; Gonzalez, Amber; Lee, Minwoo
Proceedings of the Royal Society. B, Biological sciences,
11/2021, Letnik:
288, Številka:
1963
Journal Article
Recenzirano
Odprti dostop
In many societies, grandmothers are important caregivers, and grandmaternal investment is often associated with improved grandchild well-being. Here, we present, to our knowledge, the first study to ...examine grandmaternal brain function. We recruited 50 grandmothers with at least one biological grandchild between 3 and 12 years old. Brain function was measured with functional magnetic resonance imaging as grandmothers viewed pictures of their grandchild, an unknown child, the same-sex parent of the grandchild, and an unknown adult. Grandmothers also completed questionnaires to measure their degree of involvement with and attachment to their grandchild. After controlling for age and familiarity of stimuli, viewing grandchild pictures activated areas involved with emotional empathy (insula and secondary somatosensory cortex) and movement (motor cortex and supplementary motor area). Grandmothers who more strongly activated areas involved with cognitive empathy (temporo-parietal junction and dorsomedial prefrontal cortex) when viewing pictures of the grandchild desired greater involvement in caring for the grandchild. Finally, compared with results from an earlier study of fathers, grandmothers more strongly activated regions involved with emotional empathy (dorsal anterior cingulate cortex, insula and secondary somatosensory cortex), and motivation (nucleus accumbens, ventral pallidum and caudate nucleus). All in all, our findings suggest that emotional empathy may be a key component of grandmaternal responses to their grandchildren.
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