1-10 of 179 Results


Behavioral, Cognitive, and Neural Mechanisms of Human Social Interaction  

Antonia F. de C. Hamilton

Social interaction is a fundamental part of what makes humans human and draws on a wide range of neural and cognitive mechanisms. This review summarizes research in terms of four suggested brain networks. First, the social perception network responds selectively to viewing and interpreting other people’s faces and bodies. Second, the theory of mind network is engaged when people think about other people’s beliefs and knowledge states. Third, the mirror neuron network has a role in understanding and imitating actions. Fourth, the emotion network shows some selective responses to emotional facial expressions and when people empathize with other’s pain. The role of these four networks in dynamic social interactions and real-world communication is also considered.


Jean-René Cruchet (1875–1959)  

Olivier Walusinski

Jean-René Cruchet (1875–1959) was a French physician from Bordeaux, where he practiced for the entirety of his career. His notoriety resulted from his publication of the first cases of the encephalitis lethargica epidemic in World War I soldiers in 1917, a few days before Constantin von Economo reported his cases. Cruchet developed an interest in abnormal movements, notably tics and dystonia, for which he primarily saw a psychological cause, to be treated rigorously with good habits and repressive precepts. He wrote prolifically about his areas of interest, also focusing on parkinsonian syndromes and the treatment of hysterics, notably soldiers with camptocormia. One of the first physicians to also be an aviator, Cruchet was a pioneer in the study of autonomic modifications caused by flying and pressure variations, which he referred to as aviator’s disease. As a personality with an outsized ego, he imagined that he would remain as famous after his death as Jean-Martin Charcot or Louis Pasteur.


Transcriptional Regulation Underlying Long-Term Sensitization in Aplysia  

Robert J. Calin-Jageman, Theresa Wilsterman, and Irina E. Calin-Jageman

The induction of a long-term memory requires both transcriptional change and neural plasticity. Many of the links between transcription and memory have been revealed through the study of long-term sensitization in the Aplysia genus of marine mollusks. Sensitization is a conserved, non-associative form of pain memory in which a painful stimulus produces an increase in arousal and defensive behavior. The neural circuits that help encode sensitization memory are well characterized, and sensitization can be simulated in neuronal cell cultures. One feature of sensitization in Aplysia is that only some training protocols initiate transcription and produce long-term memory; others produce only short-term memories. This occurs because the induction of long-term sensitization requires the activation of two signal-transduction pathways that regulate transcription: (a) a fast but transient activation of the cAMP/PKA pathway that activates the transcription factor CREB1 and (b) a delayed activation of the ERK isoform of MAPK that deactivates the transcriptional repressor CREB2. The effectiveness of different training protocols is based on the synchronization of these pathways. The cAMP/PKA and MAPK pathways are complex, involving extracellular and trans-synaptic signaling, feedback loops, and crosstalk. It has proven possible to model transcriptional activation with enough fidelity to generate in silico predictions for optimized learning, which has been validated in cell cultures and intact animals. Training protocols that successfully activate CREB1 while deactivating CREB2 produce a complex transcriptional cascade that helps encode long-term sensitization memory. The transcriptional cascade involves a focused wave of immediate-early transcriptional activations. This includes the activation of additional transcription factors, such as C/EBP, as well as effectors such as uch, sensorin, and tolloid/BMP-1. These early transcriptional changes close feedback loops that help extend and stabilize the early wave of transcriptional changes, triggering a broader late wave of transcriptional changes likely to alter neural signaling, increase protein production, transport mRNAs, and induce meta-plasticity. A small set of transcripts participate in both the early and late waves, and several of these (CREB1, synataxin, eIF4) play essential roles in completing the induction of long-term sensitization. Most transcriptional changes fade as sensitization memory is forgotten, but some changes persist beyond forgetting, including a long-lasting up-regulation of an inhibitory peptide transmitter that could foster forgetting. The maintenance of long-term sensitization may involve self-sustaining transcriptional feedback loops. In particular, CREB1 binds to its own promoter, producing a long-lasting increase in CREB1 mRNA, protein, and gene activation that is essential for sustaining cellular correlates of sensitization for at least 1 day after induction. Many aspects of the induction, stabilization, and maintenance of sensitization memory in Aplysia are conserved, suggesting that it will continue to be a fruitful, simpler system for understanding the physical basis of lasting memory.


Crossmodal Plasticity, Sensory Experience, and Cognition  

Valeria Vinogradova and Velia Cardin

Crossmodal plasticity occurs when sensory regions of the brain adapt to process sensory inputs from different modalities. This is seen in cases of congenital and early deafness and blindness, where, in the absence of their typical inputs, auditory and visual cortices respond to other sensory information. Crossmodal plasticity in deaf and blind individuals impacts several cognitive processes, including working memory, attention, switching, numerical cognition, and language. Crossmodal plasticity in cognitive domains demonstrates that brain function and cognition are shaped by the interplay between structural connectivity, computational capacities, and early sensory experience.


Jean-Martin Charcot (1825–1893)  

Olivier Walusinski

Jean-Martin Charcot (1825–1893), son of a Parisian craftsman, went on to a brilliant university career and worked his way to the top of the hospital hierarchy. Becoming a resident in 1858 at the women’s nursing home and asylum at La Salpêtrière Hospital, he returned there in 1868 as chief physician. Observing more than 2,000 elderly women, he first worked as a geriatrician–internist, leading him to describe thyroid pathology, cruoric pulmonary embolism, and so forth. To deal with the numerous nervous system pathologies, he applied the anatomoclinical method with the addition of microscopy. In less than around 10 years, his perspicacious clinical eye enabled him to describe Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis, and tabetic arthropathy and to identify medullary localizations, for example. Already aware of functional neurological disorders, at that time referred to as hysteria and frequent to this day, Charcot used hypnosis to try to decipher the pathophysiology. His thinking gradually evolved from looking for lesions to recognizing triggering psychological trauma. This prolonged search, misinterpreted for years, opened the way to fine, precise clinical semiology, specific to neurology and psychosomatic medicine. Charcot knew how to surround himself with a cohort of brilliant clinicians, who often became as famous as he was, notably Pierre Marie (1853–1940), Georges Gilles de la Tourette (1857–1904), Joseph Babiński (1857–1932), and Pierre Janet (1859–1947). This cohort and the breadth of Charcot’s innovative work define what is now classically called the “Salpêtrière School.”


Diagnosis and Treatment of Gambling Addiction  

Gemma Mestre-Bach and Marc N. Potenza

Gambling disorder (GD) is a relatively rare psychiatric concern that may carry substantial individual, familial, and societal harms. GD often presents complex challenges, with high prevalence in adolescents and young adults. GD often co-occurs with other psychiatric disorders, complicating treatment. GD has multiple biopsychosocial contributions, with genetic, environmental, and psychological factors implicated. Advances in neuroimaging and neurochemistry offer insights into the neurobiology of GD. GD diagnostic criteria have evolved, although identification often remains challenging given shame, stigma, ambivalence regarding treatment and limited screening. Because many people with GD do not receive treatment, identification (screening and treatment outreach) and therapeutic (behavioral, neuromodulatory, and pharmacological) approaches warrant increased consideration and development..


The Natural Scene Network  

Diane Beck and Dirk B. Walther

Interest in the neural representations of scenes centered first on the idea that the primate visual system evolved in the context of natural scene statistics, but with the advent of functional magnetic resonance imaging, interest turned to scenes as a category of visual representation distinct from that of objects, faces, or bodies. Research comparing such categories revealed a scene network comprised of the parahippocampal place area, the medial place area, and the occipital place area. The network has been linked to a variety of functions, including navigation, categorization, and contextual processing. Moreover, much is known about both the visual representations of scenes within the network as well as its role in and connections to the brain’s semantic system. To fully understand the scene network, however, more work is needed to both break it down into its constituent parts and integrate what is known into a coherent system or systems.


Neural Processing of Speech Using Intracranial Electroencephalography: Sound Representations in the Auditory Cortex  

Liberty S. Hamilton

When people listen to speech and other natural sounds, their brains must take in a noisy acoustic signal and transform it into a robust mapping that eventually helps them communicate and understand the world around them. People hear what was said, who said it, and how they said it, and each of these aspects is encoded in brain activity across different auditory regions. Intracranial recordings in patients with epilepsy, also called electrocorticography or stereoelectroencephalography, have provided a unique window into understanding these processes at a high spatiotemporal resolution. These intracranial recordings are typically performed during clinical treatment for drug-resistant epilepsy or to monitor brain function during neurosurgery. The access to direct recordings of activity in the human brain is a benefit of this method, but it comes with important caveats. Research using intracranial recordings has uncovered how the brain represents acoustic information, including frequency, spectrotemporal modulations, and pitch, and how that information progresses to more complex representations, including phonological information, relative pitch, and prosody. In addition, intracranial recordings have been used to uncover the role of attention and context on top-down modification of perceptual information in the brain. Finally, research has shown both overlapping and distinct brain responses for speech and other natural sounds such as music.


Understanding How Humans Learn and Adapt to Changing Environments  

Daphne Bavelier and Aaron Cochrane

Compared to other animals or to artificial agents, humans are unique in the extent of their abilities to learn and adapt to changing environments. When focusing on skill learning and model-based approaches, learning can be conceived as a progression of increasing, then decreasing, dimensions of representing knowledge. First, initial learning demands exploration of the learning space and the identification of the relevant dimensions for the novel task at hand. Second, intermediate learning requires a refinement of these relevant dimensions of knowledge and behavior to continue improving performance while increasing efficiency. Such improvements utilize chunking or other forms of dimensionality reduction to diminish task complexity. Finally, late learning ensures automatization of behavior through habit formation and expertise development, thereby reducing the need to effortfully control behavior. While automatization greatly increases efficiency, there is also a trade-off with the ability to generalize, with late learning tending to be highly specific to the learned features and contexts. In each of these phases a variety of interacting factors are relevant: Declarative instructions, prior knowledge, attentional deployment, and cognitive fitness have unique roles to play. Neural contributions to processes involved also shift from earlier to later points in learning as effortfulness initially increases and then gives way to automaticity. Interestingly, video games excel at providing uniquely supportive environments to guide the learner through each of these learning stages. This fact makes video games a useful tool for both studying learning, due to their engaging nature and dynamic range of complexity, as well as engendering learning in domains such as education or cognitive training.


Functional Specialization Across the Visual Cortex  

Erez Freud, Tzvi Ganel, and Galia Avidan

Vision is the most important sensory modality for humans, serving a range of fundamental daily behaviors from recognizing objects, people, places, and actions to navigation and visually guided interactions with objects and other individuals. One of the most prominent accounts of cortical functional specialization implies that the visual cortex is segregated into two pathways. The ventral pathway originates from the early visual cortex in the occipital lobe and projects to the inferior surface of the temporal cortex, and it mediates vision for perception. The dorsal pathway extends from the occipital lobe to the posterior portion of the parietal cortex, and it mediates vision for action. This key characterization of the visual system is supported by classic neuropsychological, behavioral, and neuroimaging evidence. Recent research offers new insights on the developmental trajectory of this dissociation as well as evidence for interactions between the two pathways. Importantly, an emerging hypothesis points to the existence of a third visual pathway located on the lateral surface of the ventral pathway and its potential roles in action recognition and social cognition.