Aggressive behavior is instinctively driven behavior that helps animals to survive and reproduce and is closely related to multiple behavioral and physiological processes. The dorsal raphe nucleus (DRN) is an evolutionarily conserved midbrain structure that regulates aggressive behavior by integrating diverse brain inputs. The DRN consists predominantly of serotonergic (5‐HT:5‐hydroxytryptamine) neurons and decreased 5‐HT activity was classically thought to increase aggression. However, recent studies challenge this 5‐HT deficiency model, revealing a more complex role for the DRN 5‐HT (...) system in aggression. Furthermore, emerging evidence has shown that non‐5‐HT populations in the DRN and specific neural circuits contribute to the escalation of aggressive behavior. This review argues that the DRN serves as a multifaceted modulator of aggression, acting not only via 5‐HT but also via other neurotransmitters and neural pathways, as well as different subsets of 5‐HT neurons. In addition, we discuss the contribution of DRN neurons in the behavioral and physiological aspects implicated in aggressive behavior, such as arousal, reward, and impulsivity, to further our understanding of DRN‐mediated aggression modulation. (shrink)

Aggleton & Brown propose that familiarity-based recognition depends on a perirhinal-medial dorsal thalamic system. However, connections between these structures are sparse or absent. In contrast, the perirhinal cortex is connected to midline/intralaminar nuclei. In a human, a lesion in this thalamic domain, sparing the medial dorsal nucleus, impaired familiarity-based recognition while sparing recollective-based recognition. It is thus more likely that the intralaminar/midline nuclei are involved in recognition.

The isocortex is a distinctive feature of mammalian brains, which has no clear counterpart in the cerebral hemispheres of other amniotes. This paper speculates on the evolutionary processes giving rise to the isocortex. As a first step, we intend to identify what structure may be ancestral to the isocortex in the reptilian brain. Then, it is necessary to account for the transformations (developmental, connectional, and functional) of this ancestral structure, which resulted in the origin of the isocortex. One long-held perspective (...) argues that part of the isocortex derives from the ventral pallium of reptiles, whereas another view proposes that the isocortex originated mostly from the dorsal pallium. We consider that, at this point, evidence tends to favor correspondence of the isocortex with the dorsal cortex of reptiles. In any case, the isocortex may have originated partly as a consequence of an overall “dorsalizing” effect (that is, an expansion of the territories expressing dorsal-specific genes) during pallial development. Furthermore, expansion of the dorsal pallium may have been driven by selective pressures favoring the development of associative networks between the dorsal cortex, the olfactory cortex, and the hippocampus, which participated in spatial or episodic memory in the early mammals. In this context, sensory projections that in reptiles end in the ventral pallium, are observed to terminate in the isocortex (dorsal pallium) of mammals, perhaps owing to their participation in these associative networks. Key Words: basolateral amygdala; claustrum; Emx-1; endopiriform nucleus; dorsal cortex; dorsal ventricular ridge; hippocampus; homology; olfactory cortex; Pax-6; ventral pallium. (shrink)

This review considers a number of recent theories on the neural basis of consciousness, with particular attention to the theories of Bogen, Crick, Llinás, Newman, and Changeux. These theories allot different roles to various key brain areas, in particular the reticular and intralaminar nuclei of the thalamus and the cortex. Crick's hypothesis is that awareness is a function of reverberating corticothalamic loops and that the spotlight ofintramodalattention is controlled by the reticular nucleus of the thalamus. He also proposed different (...) mechanisms for attention and intention . The current review presents a new hypothesis, based on elements from these hypotheses, includingintermodalattention and olfaction and pain, which may pose problems for Crick's original theory. This work reviews the possible role in awareness and intermodal attention and intention of the cholinergic system in the basal forebrain and the tegmentum; the reticular, the intralaminar, and the dorsomedial thalamic nuclei; the raphe and locus coeruleus; the reticular formation; the ventral striatum and extended amygdala; insula cortex, and other selected cortical areas. Both clinical and basic research data are covered. The conclusion is reached that the brain may work by largely nonlinear parallel processing and much intramodal shifts of attention may be effected by intracortical, or multiple corticothalamic mechanisms . But this is constrained by the functional anatomy of the circuits concerned and waking “awareness” is modulated by the many “nonspecific” systems . But the principal agents for intermodal attention shifts, the “searchlight,” may be two key nuclei of the cholinergic system in the mesencephalon. Clinical loss of consciousness results from damage to these nuclei but not from damage to the cholinergic nucleus basalis of the basal forebrain. (shrink)

Increasingly, functional and evolutionary research has highlighted the important contribution emotion processing makes to complex human social cognition. As such, it may be asked whether neural structures involved in emotion processing, commonly referred to as limbic structures, have been impacted in human brain evolution. To address this question, we performed an extensive evolutionary analysis of multiple limbic structures using modern phylogenetic tools. For this analysis, we combined new volumetric data for the hominoid (human and ape) amygdala and 4 amygdaloid nuclei, (...) hippocampus, and striatum, collected using stereological methods in complete histological series, with previously published datasets on the amygdala, orbital and medial frontal cortex, and insula, as well as a non-limbic structure, the dorsal frontal cortex, for contrast. We performed a parallel analysis using large published datasets including many anthropoid species (human, ape, and monkey), but fewer hominoids, for the amygdala and 2 amygdaloid subdivisions, hippocampus, schizocortex, striatum, and septal nuclei. To address evolutionary change, we compared observed human values to values predicted from regressions run through a) nonhuman hominoids and b) nonhuman anthropoids, assessing phylogenetic influence using phylogenetic generalized least squares regression.Compared with other hominoids, the volumes of the hippocampus, the lateral nucleus of the amygdala, and the orbital frontal cortex were, respectively, 50%, 37%, and 11% greater in humans than predicted for an ape of human hemisphere volume, while the medial and dorsal frontal cortex were, respectively, 26% and 29% significantly smaller. Compared with other anthropoids, only human values for the striatum fell significantly below predicted values. Overall, the data present support for the idea that regions involved in emotion processing are not necessarily conserved or regressive, but may even be enhanced in recent human evolution. (shrink)

Current theories suggest that the brain is the sole source of mental illness. However, affective disorders, and major depressive disorder (MDD) in particular, may be better conceptualized as brain-body disorders that involve peripheral systems as well. This perspective emphasizes the embodied, multifaceted physiology of well-being, and suggests that afferent signals from the body may contribute to cognitive and emotional states. In this review, we focus on evidence from preclinical and clinical studies suggesting that afferent thermosensory signals contribute to well-being and (...) depression. Although thermoregulatory systems have traditionally been conceptualized as serving primarily homeostatic functions, increasing evidence suggests neural pathways responsible for regulating body temperature may be linked more closely with emotional states than previously recognized, an affective warmth hypothesis. Human studies indicate that increasing physical warmth activates brain circuits associated with cognitive and affective functions, promotes interpersonal warmth and prosocial behavior, and has antidepressant effects. Consistent with these effects, preclinical studies in rodents demonstrate that physical warmth activates brain serotonergic neurons implicated in antidepressant-like effects. Together, these studies suggest that (1) thermosensory pathways interact with brain systems that control affective function, (2) these pathways are dysregulated in affective disorders, and (3) activating warm thermosensory pathways promotes a sense of well-being and has therapeutic potential in the treatment of affective disorders. (shrink)

Originally published in 1879, and reprinted numerous times, this book presents the complete English text of Thomas More's Utopia, together with a glossary and detailed textual notes. An introduction and biography of More are also included. This book will be of value to anyone with an interest in More's writings and political philosophy in general.

On new world order, internationalism, politics, and economic integration.

Although developmental dyslexia (DD) is frequently associate to a phonological deficit, the underlying neurobiological cause remain undetermined. One prominent hypothesis suggests a specific deficit in magnocellular-dorsal (M-D) pathway. Here we investigated the visual M-D and parvocellular-ventral (P-V) pathway in dyslexic and in chronological age and IQ-matched normally reading children by measuring dynamic (frequency doubling illusion) and static stimuli sensibility, respectively. A specific deficit in M-D task was found. Importantly, the M-D deficit was selectively shown in poor phonological decoders. M-D (...) deficit appears to be frequent because 75% of poor pseudo-word readers were at least 1 SD below the mean of the controls. Finally, a replication study by using a new group of poor phonological decoders and reading level controls suggests a possible role of M-D deficit in DD. These results showed that a M-D deficit might impair the sub-lexical mechanisms that are critical for reading development. The possible link between these findings and the oscillatory “temporal sampling” framework is discussed. (shrink)

Dorsal closure (DC), the closure of a hole in the dorsal epidermis of Drosophila embryos by the joining of opposing epithelial cell sheets, has been used as a model process to study the molecular and cellular mechanisms underlying epithelial spreading and wound healing. Recent studies have provided novel insights into how different tissues function cooperatively in this process. Specifically, they demonstrate a critical function of the epidermis surrounding the hole in modulating the behavior of the amnioserosa cells inside. (...) These findings shed light not only on the mechanisms by which the behavior of different tissues is coordinated during DC, but also on the general mechanisms by which tissues interact to trigger global morphogenesis, an essential but yet poorly explored aspect of embryogenesis. (shrink)

The dorsal turn -- Facades of the other : Heidegger, Althusser, Levinas -- No one home : Homer, Joyce, Broch -- A line drawn in the ocean : Exodus, Freud, Rimbaud -- Friendship in torsion : Schmitt, Derrida -- Revolutions in the darkroom : Balázs, Benjamin, Sade -- The controversy of dissidence : Nietzsche.

The origin of the isocortex may be seen as a series of gradual changes (each one with an adaptive value) from a reptilian-like cerebral cortex, as proposed by Aboitiz et al., or as a new dorsal pallium derivative in mammals which undergoes a surface expansion concomitant with the expansion of the dorsal tier of the dorsal thalamus.

The first Ukrainian translation of J. Thomasius’ work “Nucleus disputationis de plagio literario maxime theoreticus, thesibus paucis & brevibus comprehensus”.

Today many philosophers of mind accept that the two cortical streams of visual processing in humans can be distinguished in terms of conscious experience. The ventral stream is thought to produce representations that may become conscious, and the dorsal stream is thought to handle unconscious vision for action. Despite a vast literature on the topic of the two streams, there is currently no account of the way in which the relevant empirical evidence could fit with basic Husserlian phenomenology of (...) vision. Here I offer such an account. In this article, I show how the empirical evidence ought to be understood in a way that is informed by phenomenology. The differences in the two streams are better described as differences in spatial and temporal processing. Rather than simply “unconscious,” the dorsal stream can be better described as making a special contribution to what Husserl identified as the visual horizon. (shrink)

Patients with apraxia perform poorly when demonstrating how an object is used, particularly when pantomiming the action. However, these patients are able to accurately identify, and to pick up and move objects, demonstrating intact ventral and dorsal stream visuomotor processing. Appropriate object manipulation for skilled use is thought to rely on integration of known and visible object properties associated with ‘ventro-dorsal’ stream neural processes. In apraxia, it has been suggested that stored object knowledge from the ventral stream may (...) be less readily available to incorporate into the action plan, leading to an over-reliance on the objects’ visual affordances in object-directed motor behaviour. The current study examined grasping performance in left hemisphere stroke patients with (N = 3) and without (N = 9) apraxia, and in age-matched healthy control participants (N = 14), where participants repeatedly grasped novel cylindrical objects of varying weight distribution. Across two conditions, object weight distribution was indicated by either a memory-associated cue (object colour) or visual-spatial cue (visible dot over the weighted end). Participants were required to incorporate object-weight associations to effectively grasp and balance each object. Control groups appropriately adjusted their grasp according to each object’s weight distribution across each condition, whereas throughout the task two of the three apraxic patients performed poorly on both the memory-associated and visual-spatial cue conditions. A third apraxic patient seemed to compensate for these difficulties but still performed differently to control groups. Patients with apraxia performed normally on the neutral control condition when grasping the evenly weighted version. The pattern of behaviour in apraxic patients suggests impaired integration of visible and known object properties attributed to the ventro-dorsal stream: in learning to grasp the weighted object accurately, apraxic patients applied neither pure knowledge-based information (the memory-associated condition) nor higher-level information given in the visual-spatial cue condition. Disruption to ventro-dorsal stream predicts that apraxic patients will have difficulty learning to manipulate new objects on the basis of information other than low-level visual cues such as shape and size. (shrink)

Perception, as Gibson described it – picking up information that specifies the real local situation – includes not only perceiving affordances and controlling small movements, but also seeing the large-scale environmental layout and the position/movement of the “ecological self.” If the dorsal cortical system is also responsible for that very significant achievement, its activity must be at least partly conscious.

In his paper, “The Dorsal Stream and the Visual Horizon,” Michael Madary argues that “dorsal stream processing plays a main role in the spatiotemporal limits of visual perception, in what Husserl identified as the visual horizon” (Madary 2011, p. 424). Madary regards himself as thereby providing a theoretical framework “sensitive to basic Husserlian phenomenology” (Madary 2011). In particular, Madary draws connections between perceptual anticipations and the experience of the indeterminate spatial margins, on the one hand, and the Husserlian (...) spatiotemporal visual horizons, on the other. I argue that Madary’s arguments, for a Husserlian view of the two visual systems, are not convincing. When the notion of visual horizon is adequately understood as a constitutive notion, there will be reason to regard the connections between dorsal processing and the Husserlian spatiotemporal horizons as tenuous at best. (shrink)

Everyday life suggests that picture seeing is sometimes infused by an emotional charge. However, nobody has addressed the importance of explaining this emotional charge in picture perception. Even our best model of picture perception, the dorsal/ventral account of picture perception, which integrates the most important empirical results coming from our best model on vision in neuroscience, the two visual systems model, lacks a reference to this emotional charge. The aim of the present paper is to offer an account of (...) picture perception that is able to regain and explain this neglected emotional charge. My claim is that, as for face-to-face perception, during picture perception, we are not only in a visual perceptual state, but also in an emotional state, which is directly connected to our visual perceptual state. I also show that it is possible to offer this integration while remaining in the philosophical/empirical framework of the dorsal/ventral account of picture perception, whose explanatory power is confirmed and improved. (shrink)

AimVisual functions of the dorsal stream are considered vulnerable in children with early brain damage. Considering the recognition of objects in suboptimal representations a dorsal stream dysfunction, we examined whether children with early brain damage and impaired object recognition had either general or selective dorsal stream dysfunctions.MethodIn a group of children with early brain damage we evaluated the dorsal stream functioning. To determine whether these patients had an increased risk of a dorsal stream dysfunction we (...) compared the percentage of patients with impaired object recognition, assessed with the L94, with the estimated base rate. Then we evaluated the performance levels on motion perception, visual attention and visuomotor tasks in patients with and without object recognition abnormalities. A general dorsal stream dysfunction was considered present if a patient showed at least one abnormally low score in two out of three additional dorsal stream functions.ResultsSix of the eighteen patients with object recognition problems scored abnormally low on at least two additional dorsal stream functions. This was significantly higher than the base rate. The difference of 24.1% between the patients with and without object recognition problems was not significant. Of the patients with object recognition problems 72.2% had at least 1 dorsal weakness, whereas this was only the case in 27.3% of patients without object recognition problems. Compared to patients with normal object recognition, patients with object recognition problems scored significantly more abnormally low on motion perception and visual attention but did not differ on visuomotor skills.ConclusionChildren with object recognition problems seem at risk for other dorsal stream dysfunctions, but dysfunctions might be rather specific than general. Multiple functions/aspects should be evaluated in neuropsychological assessment of children at risk. (shrink)

There is a paucity of treatment options for cognitively normal individuals with drug resistant genetic generalized epilepsy. Centromedian nucleus of the thalamus deep brain stimulation may be a viable treatment for GGE. Here, we present the case of a 27-year-old cognitively normal woman with drug resistant GGE, with childhood onset. Seizure semiology are absence seizures and generalized onset tonic clonic seizures. At baseline she had 4–8 GTC seizures per month and weekly absence seizures despite three antiseizure medications and vagus (...) nerve stimulation. A multidisciplinary committee recommended off-label use of CM DBS in this patient. Over 12-months of CM DBS she had two GTC seizure days, which were in the setting of medication withdrawal and illness, and no GTC seizures in the last 6 months. There was no significant change in the burden of absence seizures. Presently, just two studies clearly document CM DBS in cognitively normal individuals with GGE or idiopathic generalized epilepsy [in contrast to studies of cognitively impaired individuals with developmental and epileptic encephalopathies ]. Our results suggest that CM DBS can be an effective treatment for cognitively normal individuals with GGE and underscore the need for prospective studies of CM DBS. (shrink)

The Role of Dorsal Premotor Cortex in Resolving Abstract Motor Rules provides alternative hypotheses about the cognitive functions affected by the application of repetitive transcranial magnetic stimulation. Their model simulated the effect of stimulation of the left dorsal premotor cortex right as participants provide a Models were used to demonstrate that the increased variability in observed response times can result from interference in replanning during the process of responding to the uninstructed stimulus.

Deep Brain Stimulation (DBS) is an effective treatment for advanced Parkinson’s disease. However, identifying stimulation parameters, such as contact and current amplitudes, is time-consuming based on trial and error. Directional leads add more stimulation options and render this process more challenging with a higher workload for neurologists and more discomfort for patients. In this study, a sweet spot-guided algorithm was developed that automatically suggested stimulation parameters. These suggestions were retrospectively compared to clinical monopolar reviews. A cohort of 24 Parkinson’s disease (...) patients underwent bilateral DBS implantation in the subthalamic nucleus at our center. First, the DBS’ leads were reconstructed with the open-source toolbox Lead-DBS. Second, a sweet spot for rigidity reduction was set as the desired stimulation target for programming. This sweet spot and estimations of the volume of tissue activated were used to suggest (i) the best lead level, (ii) the best contact, and (iii) the effect thresholds for full therapeutic effect for each contact. To assess these sweet spot-guided suggestions, the clinical monopolar reviews were considered as ground truth. In addition, the sweet spot-guided suggestions for best lead level and best contact were compared against reconstruction-guided suggestions, which considered the lead location with respect to the subthalamic nucleus. Finally, a graphical user interface was developed as an add-on to Lead-DBS and is publicly available. With the interface, suggestions for all contacts of a lead can be generated in a few seconds. The accuracy for suggesting the best out of four lead levels was 56%. These sweet spot-guided suggestions were not significantly better than reconstruction-guided suggestions (p = 0.3). The accuracy for suggesting the best out of eight contacts was 41%. These sweet spot-guided suggestions were significantly better than reconstruction-guided suggestions (p < 0.001). The sweet spot-guided suggestions of each contact’s effect threshold had a mean error of 1.2 mA. On an individual lead level, the suggestions can vary more with mean errors ranging from 0.3 to 4.8 mA. Further analysis is warranted to improve the sweet spot-guided suggestions and to account for more symptoms and stimulation-induced side effects. (shrink)

It is necessary to distinguish among representations caused directly by perception, representations of past perceptions in long-term memory, the representations underlying linguis- tic utterances, and the surface phonological and grammatical structures of sentences. The target article dealt essentially with predicate-argument structure at the first of these levels of representation. Discussion of the commentaries mainly involves distinguishing among various applications of the term “predicate”; clarifying the assumed relationship between classical FOPL and language; clarifying the status of unique individuals as conceived by (...) humans; and addressing the issues of motion-perception, binding between object-percepts and predicate-percepts, and target-driven versus stimulus-driven attention. (shrink)

Dr Seuren's study deals with the problem of presenting an adequate model of grammatical description. The model he proposes conforms in its main outlines to the transformational generative grammar established by Chomsky, but differs in important respects. These mainly affect that part of Chomsky's syntactic component known as the 'base', which generates basic or 'deep' structures. In the model of the base proposed here two main constituents are distinguished for every deep structure representation of a sentence, vis-a-vis the operators and (...) the nucleus. The deep structure of a sentence is thus seen to be very similar to the logical structure of a proposition. The arguments given in support of this analysis are based on mainly on considerations of simplicity and semantic adequacy. (shrink)

Where the isocortex comes from is an important question, but even more important is understanding what it leads to – that is, what advantage is afforded by its peculiar organization in layers of distinct neuronal types. A computational hypothesis accounts for granulation and for the differentiation between supra- and infragranular pyramidal layers, as quantitatively advantageous to support fine topography in sensory maps.

The origin of mitosis and the nuclear envelope were the pivotal processes in the evolutionary origin of the nucleus; they probably occurred in a wall‐less mutant bacterium that evolved a cytoskeleton and phagocytosis about 1500 million years ago. Principles of intracellular coevolution clarify their origin, as well as that of nucleosomes, spliceosomes, and the evolution of genome size.

Deep brain stimulation of the subthalamic nucleus is a clinically effective tool for treating medically refractory Parkinson’s disease, but its neural mechanisms remain debated. Previous work has demonstrated that STN DBS results in evoked potentials in the primary motor cortex, suggesting that modulation of cortical physiology may be involved in its therapeutic effects. Due to technical challenges presented by high-amplitude DBS artifacts, these EPs are often measured in response to low-frequency stimulation, which is generally ineffective at PD symptom management. (...) This study aims to characterize STN-to-cortex EPs seen during clinically relevant high-frequency STN DBS for PD. Intraoperatively, we applied STN DBS to 6 PD patients while recording electrocorticography from an electrode strip over the ipsilateral central sulcus. Using recently published techniques, we removed large stimulation artifacts to enable quantification of STN-to-cortex EPs. Two cortical EPs were observed – one synchronized with DBS onset and persisting during ongoing stimulation, and one immediately following DBS offset, here termed the “start” and the “end” EPs respectively. The start EP is, to our knowledge, the first long-latency cortical EP reported during ongoing high-frequency DBS. The start and end EPs differ in magnitude and latency, and the end, but not the start, EP magnitude has a significant relationship to ongoing high gamma power during the EP. These contrasts may suggest mechanistic or circuit differences in EP production during the two time periods. This represents a potential framework for relating DBS clinical efficacy to the effects of a variety of stimulation parameters on EPs. (shrink)

Fertilization triggers cytoplasmic movements in the frog egg that lead in mysterious ways to the stabilization of β‐catenin on the dorsal side of the embryo. The novel Huluwa (Hwa) transmembrane protein, identified in China, is translated specifically in the dorsal side, acting as an egg cytoplasmic determinant essential for β‐catenin stabilization. The Wnt signaling pathway requires macropinocytosis and the sequestration inside multivesicular bodies (MVBs, the precursors of endolysosomes) of Axin1 and Glycogen Synthase Kinase 3 (GSK3) that normally destroy (...) β‐catenin. In Xenopus, the Wnt‐like activity of GSK3 inhibitors and of Hwa mRNA can be blocked by brief treatment with inhibitors of membrane trafficking or lysosomes at the 32‐cell stage. In dorsal blastomeres, lysosomal cathepsin is activated and intriguing MVBs surrounded by electron dense vesicles are formed at the 64‐cell stage. We conclude that membrane trafficking and lysosomal activity are critically important for the earliest asymmetries in vertebrate embryonic development. (shrink)

Experimental data suggest that the division between the visual ventral and dorsal pathways may indeed indicate that static and dynamical information is processed separately. Contrary to Hurford, it is suggested that the ventral pathway primarily generates representations of objects, whereas the dorsal pathway produces representations of events. The semantic object/event distinction may relate to the morpho-syntactic noun/verb distinction.

Support for the proposed dorsal-ventral distinction for the somatosensory system is not yet convincing, nor is the anatomical segregation of its pathways as clearly defined as the visual pathways. Consideration of alternative organizational principles might reveal critical differences across sensory processing systems. The role of attention and manipulations that modulate functional systems might also be worth considering.

The author argues that the theory of a dorsal/ventral stream for visual processing can be used to reconcile the constructivist and direct perception theories. My commentary discusses neurophysiological and psychophysical studies that run counter to the view. In addition, the central issue of debate between the constructionist and direct perception approaches regarding what is visual information is discussed.