Nuestros investigadores

Gonzalo Arrondo Ostiz

Mente Cerebro
Instituto Cultura y Sociedad (ICS). Universidad de Navarra
Líneas de investigación
Toma de decisiones y función dopaminérgica, Aprendizaje y procesos de recompensa, Epistemología de la psiquiatría, Funciones ejecutivas en trastornos neurodegenerativos, Buenas prácticas en investigación
Índice H
10, (Google Scholar, 29/06/2017)
8, (WoS, 21/06/2017)
8, (Scopus, 21/06/2017)

Publicaciones científicas más recientes (desde 2010)

Autores: Garofalo, S., ; Justicia, A., ; Arrondo Ostiz, Gonzalo; et al.
ISSN 1664-2295  Vol. 8  2017  págs. 156
Psychotic symptoms frequently occur in Parkinson's disease (PD), but their pathophysiology is poorly understood. According to the National Institute of Health RDoc programme, the pathophysiological basis of neuropsychiatric symptoms may be better understood in terms of dysfunction of underlying domains of neurocognition in a trans-diagnostic fashion. Abnormal cortico-striatal reward processing has been proposed as a key domain contributing to the pathogenesis of psychotic symptoms in schizophrenia. This theory has received empirical support in the study of schizophrenia spectrum disorders and preclinical models of psychosis, but has not been tested in the psychosis associated with PD. We, therefore, investigated brain responses associated with reward expectation and prediction error signaling during reinforcement learning in PD-associated psychosis. An instrumental learning task with monetary gains and losses was conducted during an fMRI study in PD patients with (n¿=¿12), or without (n¿=¿17), a history of psychotic symptoms, along with a sample of healthy controls (n¿=¿24). We conducted region of interest analyses in the ventral striatum (VS), ventromedial prefrontal and posterior cingulate cortices, and whole-brain analyses. There was reduced activation in PD patients with a history of psychosis, compared to those without, in the posterior cingulate cortex and the VS during reward anticipation (p¿<¿0.05 small volume corrected). The results suggest that cortical and striatal
Autores: Ruiz-Goikoetxea, M., ; Cortese, S., ; Aznárez Sanado, Maite; et al.
Revista: BMJ OPEN
ISSN 2044-6055  Vol. 7  Nº 9  2017  págs. e018027
Attention-deficit hyperactivity disorder (ADHD) has been related to increased rates of unintentional injuries. However, the magnitude of the effect and to which extent variables such as sex, age or comorbidity can influence this relationship is unknown. Additionally, and importantly, it is unclear if, and to which degree, ADHD medications can decrease the number of unintentional injuries. Due to the amount of economic and social resources invested in the treatment of injuries, filling these gaps in the literature is highly relevant from a public health standpoint. Here, we present a protocol for a systematic review and meta-analysis to estimate the relationship between ADHD and unintentional injuries and assess the impact of pharmacological treatment for ADHD METHODS AND ANALYSIS: We will combine results from 114 bibliographic databases for studies relating ADHD and risk of injuries. Bibliographic searches and data extraction will be carried out independently by two researchers. The studies' risk of bias will be assessed using the Newcastle-Ottawa Scale. Articles reporting ORs or HRs of suffering an injury in ADHD compared with controls (or enough data to calculate them) will be combined using Robust Variance Estimation, a method that permits to include multiple non-independent outcomes in the analysis. All analyses will be carried out in Stata. Age, sex and comorbid conduct disorders will be considered as potential causes of variance and their effect analysed through meta-re
Autores: Segarra, N., ; Metastasio, A., ; Ziauddeen, H., ; et al.
ISSN 1740-634X  Vol. 41  Nº 8  2016  págs. 2001 - 2010
Alterations in reward processes may underlie motivational and anhedonic symptoms in depression and schizophrenia. However it remains unclear whether these alterations are disorder-specific or shared, and whether they clearly relate to symptom generation or not. We studied brain responses to unexpected rewards during a simulated slot-machine game in 24 patients with depression, 21 patients with schizophrenia, and 21 healthy controls using functional magnetic resonance imaging. We investigated relationships between brain activation, task-related motivation, and questionnaire rated anhedonia. There was reduced activation in the orbitofrontal cortex, ventral striatum, inferior temporal gyrus, and occipital cortex in both depression and schizophrenia in comparison with healthy participants during receipt of unexpected reward. In the medial prefrontal cortex both patient groups showed reduced activation, with activation significantly more abnormal in schizophrenia than depression. Anterior cingulate and medial frontal cortical activation predicted task-related motivation, which in turn predicted anhedonia severity in schizophrenia. Our findings provide evidence for overlapping hypofunction in ventral striatal and orbitofrontal regions in depression and schizophrenia during unexpected reward receipt, and for a relationship between unexpected reward processing in the medial prefrontal cortex and the generation of motivational states.
Autores: Arrondo Ostiz, Gonzalo; Segarra, Nuria; Metastasio, Antonio; et al.
ISSN 1664-1078  Vol. 6  2015  págs. 1280
In the research domain framework (RDoC), dysfunctional reward expectation has been proposed to be a cross-diagnostic domain in psychiatry, which may contribute to symptoms common to various neuropsychiatric conditions, such as anhedonia or apathy/avolition. We used a modified version of the Monetary Incentive Delay (MID) paradigm to obtain functional MRI images from 22 patients with schizophrenia, 24 with depression and 21 controls. Anhedonia and other symptoms of depression, and overall positive and negative symptomatology were also measured. We hypothesized that the two clinical groups would have a reduced activity in the ventral striatum when anticipating reward (compared to anticipation of a neutral outcome) and that striatal activation would correlate with clinical measures of motivational problems and anhedonia. Results were consistent with the first hypothesis: two clusters in both the left and right ventral striatum were found to differ between the groups in reward anticipation. Post-hoc analysis showed that this was due to higher activation in the controls compared to the schizophrenia and the depression groups in the right ventral striatum, with activation differences between depression and controls also seen in the left ventral striatum. No differences were found between the two patient groups, and there were no areas of abnormal cortical activation in either group that survived correction for multiple comparisons. Reduced ventral striatal activity was related to greater anhedonia and overall depressive symptoms in the schizophrenia group, but not in the participants with depression. Findings are discussed in relation to previous literature but overall are supporting evidence of reward system dysfunction across the neuropsychiatric continuum, even if the specific clinical relevance is still not fully understood. We also discuss how the RDoC approach may help to solve some of the replication problems in psychiatric fMRI research.
Autores: Arrondo Ostiz, Gonzalo; Aznárez Sanado, Maite; Fernández Seara, María Asunción; et al.
ISSN 0924-977X  Vol. 25  Nº 6  2015  págs. 817 - 827
Studies on animals and humans have demonstrated the importance of dopamine in modulating decision-making processes. In this work, we have tested dopaminergic modulation of economic decision-making and its neural correlates by administering either placebo or metoclopramide, a dopamine D2-receptor antagonist, to healthy subjects, during a functional MRI study. The decision-making task combined probability and time delay with a fixed monetary reward. For individual behavioral characterization, we used the Probability Time Trade-off (PTT) economic model, which integrates the traditional trade-offs of reward magnitude-time and reward magnitude-probability into a single measurement, thereby quantifying the subjective value of a delayed and probabilistic outcome. A regression analysis between BOLD signal and the PTT model index permitted to identify the neural substrate encoding the subjective reward-value. Behaviorally, medication reduced the rate of temporal discounting over probability, reflected in medicated subjects being more prone to postpone the reward in order to increase the outcome probability. In addition, medicated subjects showed less activity during the task in the postcentral gyrus as well as frontomedian areas, whereas there were no differences in the ventromedial orbitofrontal cortex (VMOFC) between groups when coding the subjective value. The present study demonstrates by means of behavior and imaging that dopamine modulation alters the probability-time trade-off in human economic decision-making.
Autores: Arrondo Ostiz, Gonzalo; Murray, G. K., ; Hill, E., ; et al.
ISSN 0007-1250  Vol. 207  Nº 1  2015  págs. 79 - 80
Depression and borderline personality disorder (BPD) are both thought to be accompanied by alterations in the subjective experience of environmental rewards. We evaluated responses to sweet, bitter and neutral tastes (juice, quinine and water) in 29 women with depression, 17 women with BPD and 27 female healthy controls (HC). BPD patients gave lower pleasantness and higher disgust ratings for quinine and juice compared to controls; depression patients did not differ significantly from controls. Juice disgust ratings were related to self-disgust in BPD, suggesting close links between abnormal sensory processing and self-identity in BPD.
Autores: Luis García, Elkin Oswaldo; Arrondo Ostiz, Gonzalo; Vidorreta Díaz de Cerio, Marta; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 10  Nº 7  2015  págs. e0131536
BACKGROUND: Imaging studies help to understand the evolution of key cognitive processes related to aging, such as working memory (WM). This study aimed to test three hypotheses in older adults. First, that the brain activation pattern associated to WM processes in elderly during successful low load tasks is located in posterior sensory and associative areas; second, that the prefrontal and parietal cortex and basal ganglia should be more active during high-demand tasks; third, that cerebellar activations are related to high-demand cognitive tasks and have a specific lateralization depending on the condition. METHODS: We used a neuropsychological assessment with functional magnetic resonance imaging and a core N-back paradigm design that was maintained across the combination of four conditions of stimuli and two memory loads in a sample of twenty elderly subjects. RESULTS: During low-loads, activations were located in the visual ventral network. In high loads, there was an involvement of the basal ganglia and cerebellum in addition to the frontal and parietal cortices. Moreover, we detected an executive control role of the cerebellum in a relatively symmetric fronto-parietal network. Nevertheless, this network showed a predominantly left lateralization in parietal regions associated presumably with an overuse of verbal storage strategies. The differential activations between conditions were stimuli-dependent and were located in sensory areas. CONCLUSION: Successful WM processes in the elderly population are accompanied by an activation pattern that involves cerebellar regions working together with a fronto-parietal network.
Autores: Martínez Villar, Martín; Villagra Poviña, Federico; Loayza Paredes, Francis Roderich; et al.
ISSN 0278-0062  Vol. 33  Nº 5  2014  págs. 1044 - 1053
Repetitive and alternating lower limb movements are a specific component of human gait. Due to technical challenges, the neural mechanisms underlying such movements have not been previously studied with functional magnetic resonance imaging. In this study, we present a novel treadmill device employed to investigate the kinematics and the brain activation patterns involved in alternating and repetitive movements of the lower limbs. Once inside the scanner, 19 healthy subjects were guided by two visual cues and instructed to perform a motor task which involved repetitive and alternating movements of both lower limbs while selecting their individual comfortable amplitude on the treadmill. The device facilitated the performance of coordinated stepping while registering the concurrent lower-limb displacements, which allowed us to quantify some movement primary kinematic features such as amplitude and frequency. During stepping, significant blood oxygen level dependent signal increases were observed bilaterally in primary and secondary sensorimotor cortex, the supplementary motor area, premotor cortex, prefrontal cortex, superior and inferior parietal lobules, putamen and cerebellum, regions that are known to be involved in lower limb motor control. Brain activations related to individual adjustments during motor performance were identified in a right lateralized network including striatal, extrastriatal, and fronto-parietal areas.
Autores: Goñi Cortés, Joaquín; Sporns, O., ; Cheng, H., ; et al.
ISSN 1053-8119  Vol. 83  2013  págs. 646 - 657
High-resolution isotropic three-dimensional reconstructions of human brain gray and white matter structures can be characterized to quantify aspects of their shape, volume and topological complexity. In particular, methods based on fractal analysis have been applied in neuroimaging studies to quantify the structural complexity of the brain in both healthy and impaired conditions. The usefulness of such measures for characterizing individual differences in brain structure critically depends on their within-subject reproducibility in order to allow the robust detection of between-subject differences. This study analyzes key analytic parameters of three fractal-based methods that rely on the box-counting algorithm with the aim to maximize within-subject reproducibility of the fractal characterizations of different brain objects, including the pial surface, the cortical ribbon volume, the white matter volume and the gray matter/white matter boundary. Two separate datasets originating from different imaging centers were analyzed, comprising 50 subjects with three and 24 subjects with four successive scanning sessions per subject, respectively. The reproducibility of fractal measures was statistically assessed by computing their intra-class correlations. Results reveal differences between different fractal estimators and allow the identification of several parameters that are critical for high reproducibility. Highest reproducibility with intra-class correlations in the range of 0.9-0.95 is achieved with the correlation dimension. Further analyses of the fractal dimensions of parcellated cortical and subcortical gray matter regions suggest robustly estimated and region-specific patterns of individual variability. These results are valuable for defining appropriate parameter configurations when studying changes in fractal descriptors of human brain structure, for instance in studies of neurological diseases that do not allow repeated measurements or for disease-course longitudinal studies.
Autores: Goñi Cortés, Joaquín; Cervantes Ibáñez, Sebastián; Arrondo Ostiz, Gonzalo; et al.
ISSN 1387-2877  Vol. 33  Nº 4  2013  págs. 1009 - 1019
The aim of our study was to elucidate whether specific patterns of gray matter loss were associated with apolipoprotein E epsilon 4 (APOE epsilon 4) and microtubule-associated protein tau (MAPT)-H1) genetic variants in subjects with mild cognitive impairment (MCI) at a baseline visit. Gray matter voxel-based morphometry analysis of T1 magnetic resonance imaging scans were performed in 65 amnestic-MCI subjects. MCI APOE epsilon 4 carriers compared with non-carriers showed increased brain atrophy in right hippocampus and rostral amygdala, superior and middle temporal gyrus, and right parietal operculum, including inferior frontal gyrus, inferior parietal, and supramarginal gyrus. MAPT-H1/H1 MCI carriers showed an increased bilateral atrophy in superior frontal gyri (including frontal eye fields and left prefrontal cortex) and precentral gyrus but also unilateral left atrophy in the inferior temporal gyrus and calcarine gyrus. In addition, MCI subjects carrying both APOE epsilon 4 and MAPT-H1/H1 variants showed gray matter loss in the supplementary motor area and right pre- and postcentral gyri. The effect of APOE epsilon 4 on gray matter loss in right hippocampus suggests that, at least in some AD sub-types, the neuronal vulnerability could be increased in the right hemisphere. The pattern of frontal gray matter loss observed among MCI MAPT H1/H1 carriers has also been found in other tauopathies, suggesting that MCI may share etiological factors with other tauopathies. Frontal and parietal cortex vulnerability was found when adding MAPT H1/H1 and APOE epsilon 4 effects, suggesting a synergistic effect of these variants. These results could be due to changes in APOE epsilon 4 and MAPT expression.
Autores: Goñi Cortés, Joaquín; Aznárez Sanado, Maite; Arrondo Ostiz, Gonzalo; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 6   Nº 3  2011  págs. e17408
Decision making can be regarded as the outcome of cognitive processes leading to the selection of a course of action among several alternatives. Borrowing a central measurement from information theory, Shannon entropy, we quantified the uncertainties produced by decisions of participants within an economic decision task under different configurations of reward probability and time. These descriptors were used to obtain blood oxygen level-dependent (BOLD) signal correlates of uncertainty and two clusters codifying the Shannon entropy of task configurations were identified: a large cluster including parts of the right middle cingulate cortex (MCC) and left and right pre-supplementary motor areas (pre-SMA) and a small cluster at the left anterior thalamus. Subsequent functional connectivity analyses using the psycho-physiological interactions model identified areas involved in the functional integration of uncertainty. Results indicate that clusters mostly located at frontal and temporal cortices experienced an increased connectivity with the right MCC and left and right pre-SMA as the uncertainty was higher. Furthermore, pre-SMA was also functionally connected to a rich set of areas, most of them associative areas located at occipital and parietal lobes. This study provides a map of the human brain segregation and integration (i.e., neural substrate and functional connectivity respectively) of the uncertainty associated to an economic decision making paradigm.
Autores: Goñi Cortés, Joaquín; Arrondo Ostiz, Gonzalo; Sepulcre Bernad, Jorge; et al.
Revista: Cognitive Processing - Heidelberg
ISSN 1612-4782  Vol. 12  Nº 2  2011  págs. 183 - 186
Semantic memory is the subsystem of human memory that stores knowledge of concepts or meanings, as opposed to life-specific experiences. How humans organize semantic information remains poorly understood. In an effort to better understand this issue, we conducted a verbal fluency experiment on 200 participants with the aim of inferring and representing the conceptual storage structure of the natural category of animals as a network. This was done by formulating a statistical framework for co-occurring concepts that aims to infer significant concept-concept associations and represent them as a graph. The resulting network was analyzed and enriched by means of a missing links recovery criterion based on modularity. Both network models were compared to a thresholded co-occurrence approach. They were evaluated using a random subset of verbal fluency tests and comparing the network outcomes (linked pairs are clustering transitions and disconnected pairs are switching transitions) to the outcomes of two expert human raters. Results show that the network models proposed in this study overcome a thresholded co-occurrence approach, and their outcomes are in high agreement with human evaluations. Finally, the interplay between conceptual structure and retrieval mechanisms is discussed.
Autores: Arrondo Ostiz, Gonzalo; Alegre Esteban, Manuel; Villoslada Díaz, Pablo
ISSN 2041-8000  Vol. 1  2010  págs. 1 - 8
Memantine, an uncompetitive, low-affinity N-methyl-D-aspartate (NMDA) receptor antagonist, is an approved compound for use inmoderate to severe Alzheimer¿s disease. Its pharmacological features allow it to block excessive neuronal activation produced by glutamate,while permitting normal activation of the NMDA receptor channel. A review of the trials that have evaluated the use of the compound invascular dementia, Alzheimer¿s disease, or both shows that it is well tolerated and has mild but statistically significant positive effects oncognition and other domains of patients with advanced Alzheimer¿s disease. Recently, a double-blind, placebo-controlled trial in patients withmultiple sclerosis reported neurological worsening in several patients similar to the typical pseudoexacerbations of this disease. Also, the useof memantine in patients with Lewy body disease produces adverse effects. Although the mechanisms of such side-effects are unknown, wesuggest that they could be due to the impairment of synaptic transmission in the demyelinated pathways.
Autores: Sepulcre Bernad, Jorge; Peraita, Herminia; Goñi Cortés, Joaquín; et al.
ISSN 1380-3395  Vol. 33  Nº 2  2010  págs. 169-175
The aim of the study was to analyze lexical access strategies in patients with multiple sclerosis (MS) and their changes over time. We studied lexical access strategies during semantic and phonemic verbal fluency tests and also confrontation naming in a 2-year prospective cohort of 45 MS patients and 20 healthy controls. At baseline, switching lexical access strategy (both in semantic and in phonemic verbal fluency tests) and confrontation naming were significantly impaired in MS patients compared with controls. After 2 years follow-up, switching score decreased, and cluster size increased over time in semantic verbal fluency tasks, suggesting a failure in the retrieval of lexical information rather than an impairment of the lexical pool. In conclusion, these findings underline the significant presence of lexical access problems in patients with MS and could point out their key role in the alterations of high-level communications abilities in MS.
Autores: Goñi Cortés, Joaquín; Martincorena, I., ; Corominas-Murtra, B.; et al.
Revista: International Journal of Bifurcation and Chaos
ISSN 0218-1274  Vol. 20  Nº 3  2010  págs. 913 - 922
Semantic memory is the subsystem of human memory that stores knowledge of concepts or meanings, as opposed to life specific experiences. The organization of concepts within semantic memory can be understood as a semantic network, where the concepts (nodes) are associated (linked) to others depending on perceptions, similarities, etc. Lexical access is the complementary part of this system and allows the retrieval of such organized knowledge. While conceptual information is stored under certain underlying organization (and thus gives rise to a specific topology), it is crucial to have an accurate access to any of the information units, e. g. the concepts, for efficiently retrieving semantic information for real-time need. An example of an information retrieval process occurs in verbal fluency tasks, and it is known to involve two different mechanisms: "clustering", or generating words within a subcategory, and, when a subcategory is exhausted, "switching" to a new subcategory. We extended this approach to random-walking on a network (clustering) in combination to jumping (switching) to any node with certain probability and derived its analytical expression based on Markov chains. Results show that this dual mechanism contributes to optimize the exploration of different network models in terms of the mean first passage time. Additionally, this cognitive inspired dual mechanism opens a new framework to better understand and evaluate exploration, propagation and transport phenomena in other complex systems where switching-like phenomena are feasible.
Autores: Güell Pelayo, Francisco Juan; Arrondo Ostiz, Gonzalo; de Castro Manglano, María Pilar; et al.
Libro:  Psychiatry and neuroscience update: A translational approach
Vol. II  2017  págs. 105 - 116
In psychiatry, as in any other medical specialty, the clinician collects information from the patient¿s anamnesis, clinical observation, and diagnostic tests; evaluates these data; and makes a diagnosis. The most common manuals used to assess a patient¿s mental disease according to his or her symptoms are the Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Classification of Diseases (ICD). This chapter focuses on the dialogue that philosophy and psychiatry have held for decades to achieve a better understanding of dissociative identity disorder (DID). The outcome of this dialogue is the expression of the diagnostic criteria for DID, as well as other dissociative disorders, in the medical manuals. Thus, we first analyze the evolution of DID across the different versions of ICD and DSM. We then show that the characterization of DID and other dissociative disorders is a lively debate that is far from being settled. We demonstrate that the core of this debate is the understanding of person after John Locke¿s philosophy: a person is defined by the apparent expression of consciousness and memories. This leads to what we have termed a primary conceptual dissociation: the mental qualities of the person are dissociated from the body. We propose an alternative account based on the dynamic nature of identity and the understanding of person as a mind¿body unity. We hope that our proposal, which results from the interdisciplinary dialogue between psychiat