The striatum (caudate nucleus, putamen and nucleus accumbens) is the main input structure of the basal ganglia. It receives cortical projections from the vast majority of the cortex, as well as from other subcortical structures such as the thalamus and amygdala. Its role in planning, preparation and execution of voluntary movements is known to be fine-tuned by the interaction between projection neurons and interneurons. Since the 1990s, it has been accepted that the proportion of interneurons increases phylogenetically, being about 5% in rodents and 26% in humans. However, these data have not been confirmed with unbiased techniques, such as stereology. In the present report, we have divided the human striatum into functional territories (associative, sensorimotor and limbic) and we have quantified the numerical density of all striatal neurons (using Nissl staining) in each area. Taking into account our past research on the estimation of striatal interneurons, we have calculated the proportion of interneurons in each territory. This value was on average 17.1% for the whole striatum, although interneurons were more abundant in the associative (21.9%) than in the sensorimotor (12.8%) and limbic (11.1%) aspects. Therefore, we demonstrate with unbiased stereology that the overall proportion of striatal interneurons is slightly lower than that reported in previous studies, and that it varies in the functional territories of this structure.

We contest the claim that musically induced sadness cannot be enjoyable in itself. This possibility is supported by closer attention to a musical experience as well as cases of affective reversal, such as the "hedonic flip" of painful feelings. We propose that the affective reversal of sadness in music is due to the high granularity of musically induced emotion.

La conformación de las estructuras anatómicas es compleja en los 3 planos del espacio. Históricamente, la enseñanza de la anatomía se ha hecho a partir de representaciones bidimensionales, de modelos físicos tridimensionales o de cuerpos reales. Solo recientemente ha sido factible crear modelos anatómicos digitales tridimensionales, que pueden ser explorados en línea a través de Internet. El objetivo del presente trabajo es analizar 2 de las herramientas en línea más conocidas para la visualización anatómica (Anatomography® y BioDigital® Human), y presentar una experiencia docente de uso en el área de neurociencias. Se crearon imágenes de estructuras cerebrales animadas que se usaron en clase posteriormente, y se preguntó a los alumnos sobre su interés y utilidad. Los resultados indicaron que la utilización de este tipo de recursos es interesante por su flexibilidad, atractivo y coste.

In this article we introduce the hypothesis that neuropsychological adolescent maturation, and in particular emotional management, may have opposing explanations depending on the interpretation of the assumed brain architecture, that is, whether a componential computational account (CCA) or a dynamic systems perspective (DSP) is used. According to CCA, cognitive functions are associated with the action of restricted brain regions, and this association is temporally stable; by contrast, DSP argues that cognitive functions are better explained by interactions between several brain areas, whose engagement in specific functions is temporal and context-dependent and based on neural reuse. We outline the main neurobiological facts about adolescent maturation, focusing on the neuroanatomical and neurofunctional processes associated with adolescence. We then explain the importance of emotional management in adolescent maturation. We explain the interplay between emotion and cognition under the scope of CCA and DSP, both at neural and behavioral levels. Finally, we justify why, according to CCA, emotional management is understood as regulation, specifically because the cognitive aspects of the brain are in charge of regulating emotion-related modules. However, the key word in DSP is integration, since neural information from different brain areas is integrated from the beginning of the process. Consequently, although the terms should not be conceptually confused, there is no cognition without emotion, and vice versa. Thus, emotional integration is not an independent process that just happens to the subject, but a crucial part of personal growth. Considering the importance of neuropsychological research in the development of educational and legal policies concerning adolescents, we intend to expose that the holistic view of adolescents is dependent on whether one holds the implicit or explicit interpretation of brain functioning.

In this article, I discuss the importance of multidisciplinary research to tackle the questions that empirical sciences, and in particular neuroscience, ultimately encounter. The last decades have witnessed an enormous progress in brain research, mainly because of the improvement of neuroimaging techniques and neurogenetics, and the development of optogenetics. Furthermore, the US Government and European Union have launched the BRAIN Initiative and Human Brain Project, respectively, to promote a better understanding of brain functioning and its disorders. Unfortunately, their gates appear sealed for disciplines that pursue a deep knowledge of the mind, such as philosophy or psychology. The most probable outcome of this situation is "promissory materialism", as Sir John Eccles warned several decades ago. I review the multidisciplinary approach of Eccles to the study of the brain and mind, especially through his relationship with Mariano Artigas. Finally, I propose that interdisciplinary research may be improved by a more solid understanding of the discipline one wants to dialogue with, and a multidisciplinary training from the beginning of the research career.

A substantial minority of patients with terminal illness hold unrealistically hopeful beliefs about the severity of their disease or the nature of its treatment, considering therapy as curative rather than palliative. We propose that this attitude may be understood as self-deception, following the current psychological theories about this topic. In this article we suggest that the reason these patients deceive themselves is to preserve their belief systems. According to some philosophical accounts, the human belief system (HBS) is constituted as a web with a few stable central nodes - deep-seated beliefs - intimately related with the self. We hypothesize that the mind may possess defensive mechanisms, mostly non-conscious, that reject certain sensory inputs (e.g., a fatal diagnosis) that may undermine deep-seated beliefs. This interpretation is in line with the theory of cognitive dissonance. Following this reasoning, we also propose that HBS-related self-deception would entail a lower cognitive load than that associated with confronting the truth: whereas the latter would engage a myriad of high cognitive functions to re-configure crucial aspects of the self, including the setting of plans, goals, or even a behavioral output, the former would be mostly non-conscious. Overall, we believe that our research supports the hypothesis that in cases of terminal illness, (self-)deceiving requires less effort than accepting the truth.

The notion of habit used in neuroscience is an inheritance from a particular theoretical origin, whose main source is William James. Thus, habits have been characterized as rigid, automatic, unconscious, and opposed to goal-directed actions. This analysis leaves unexplained several aspects of human behavior and cognition where habits are of great importance. We intend to demonstrate the utility that another philosophical conception of habit, the Aristotelian, may have for neuroscientific research. We first summarize the current notion of habit in neuroscience, its philosophical inspiration and the problems that arise from it, mostly centered on the sharp distinction between goal-directed actions and habitual behavior. We then introduce the Aristotelian view and we compare it with that of William James. For Aristotle, a habit is an acquired disposition to perform certain types of action. If this disposition involves an enhanced cognitive control of actions, it can be considered a "habit-as-learning". The current view of habit in neuroscience, which lacks cognitive control and we term "habit-as-routine", is also covered by the Aristotelian conception. He classifies habits into three categories: (1) theoretical, or the retention of learning understood as "knowing that x is so"; (2) behavioral, through which the agent achieves a rational control of emotion-permeated behavior ("knowing how to behave"); and (3) technical or learned skills ("knowing how to make or to do")...

Newell & Shanks (N&S) carry out an extremely sharp and static distinction between conscious and unconscious decisions, ignoring a process that dynamically transfers decisions and actions between the conscious and unconscious domains of the mind: habitual decision making. We propose a new categorisation and discuss the main characteristics of this process from a philosophical and neuroscientific perspective.

Objective Frontostriatal circuitry is critical to learning processes, and its disruption may underlie maladaptive decision making and the generation of psychotic symptoms in schizophrenia. However, there is a paucity of evidence directly examining the role of modulatory neurotransmitters on frontostriatal function in humans. In order to probe the effects of modulation on frontostriatal circuitry during learning and to test whether disruptions in learning processes may be related to the pathogenesis of psychosis, the authors explored the brain representations of reward prediction error and incentive value, two key reinforcement learning parameters, before and after methamphetamine challenge. Method Healthy volunteers (N=18) underwent functional MRI (fMRI) scanning while performing a reward learning task on three occasions: after placebo, after methamphetamine infusion (0.3 mg/kg body weight), and after pretreatment with 400 mg of amisulpride and then methamphetamine infusion. Brain fMRI representations of learning signals, calculated using a reinforcement Q-learning algorithm, were compared across drug conditions. Results In the placebo condition, reward prediction error was coded in the ventral striatum bilaterally and incentive value in the ventromedial prefrontal cortex bilaterally. Reward prediction error and incentive value signals were disrupted by methamphetamine in the left nucleus accumbens and left ventromedial prefrontal cortex, respectively. Psychotic symptoms

ICSBackground: The afferent projections of the striatum (caudate nucleus and putamen) are segregated in three territories: associative, sensorimotor and limbic. Striatal interneurons are in part responsible for the integration of these different types of information. Among them, GABAergic interneurons are the most abundant, and can be sorted in three populations according to their content in the calcium binding proteins calretinin (CR), parvalbumin (PV) and calbindin (CB). Conversely, striatal dopaminergic cells (whose role as interneurons is still unclear) are scarce. This study aims to analyze the interneuron distribution in the striatal functional territories, as well as their organization regarding to the striosomal compartment. Methodology/Principal Findings: We used immunohistochemical methods to visualize CR, PV, CB and tyrosine hydroxylase (TH) positive striatal neurons. The interneuronal distribution was assessed by stereological methods applied to every striatal functional territory. Considering the four cell groups altogether, their density was higher in the associative (2120 +/- 91 cells/mm(3)) than in the sensorimotor (959 +/- 47 cells/mm(3)) or limbic (633 +/- 119 cells/mm(3)) territories. CB- and TH-immunoreactive (-ir) cells were distributed rather homogeneously in the three striatal territories. However, the density of CR and PV interneurons were more abundant in the associative and sensorimotor striatum, respectively. Regarding to their compartmental organiz

Ventricular enlargement is one of the most consistent abnormal structural brain findings in schizophrenia and has been used to infer brain shrinkage. However, whether ventricular enlargement is related to local overlying cortex and/or adjacent subcortical structures or whether it is related to brain volume change globally has not been assessed. We systematically assessed interrelations of ventricular volumes with gray and white matter volumes of 40 Brodmann areas (BAs), the thalamus and its medial dorsal nucleus and pulvinar, the internal capsule, caudate and putamen. We acquired structural MRI ( patients with schizophrenia (n = 64) and healthy controls (n = 56)) and diffusion tensor fractional anisotropy (FA) (untreated schizophrenia n = 19, controls n = 32). Volumes were assessed by manual tracing of central structures and a semi-automated parcellation of BAs. Patients with schizophrenia had increased ventricular size associated with decreased cortical gray matter volumes widely across the brain; a similar but less pronounced pattern was seen in normal controls; local correlations (e.g. temporal horn with temporal lobe volume) were not appreciably higher than non-local correlations (e.g. temporal horn with prefrontal volume). White matter regions adjacent to the ventricles similarly did not reveal strong regional relationships. FA and center of mass of the anterior limb of the internal capsule also appeared differentially influenced by ventricular volume but findings were s