Search

Bilingualism has been shown to contribute to increased resilience against cognitive aging. One of the key brain structures linked to memory and dementia symptom onset, the hippocampus, has been observed to adapt in response to bilingual experience – at least in healthy individuals. However, in the context of neurodegenerative pathology, it is yet unclear what role previous bilingual experience might have in terms of sustaining integrity of this structure or related behavioral correlates. The present study adds to the limited cohort of research on the effects of bilingualism on neurocognitive outcomes in Mild Cognitive Impairment (MCI) using structural brain data. We investigate whether bilingual language experience (operationalized as language entropy) results in graded neurocognitive adaptations within a cohort of bilinguals diagnosed with MCI. Results reveal a non-linear effect of bilingual language entropy on hippocampal volume, although they do not predict episodic memory performance, nor age of MCI diagnosis.

Background: Malfunctioning of the default mode network (DMN) has been consistently related to mild cognitive impairment (MCI) and Alzheimer’s disease (AD). However, evidence on differences in this network between MCI converters (MCI-c) and non-converters (MCI-nc), which could mark progression to AD, is still inconsistent. Objective: To multimodally investigate the DMN in the AD continuum. Methods: We measured gray matter (GM) volume, white matter (WM) integrity, and functional connectivity (FC) at rest in healthy elderly controls, MCI-c, MCI-nc, and AD patients, matched on sociodemographic variables. Results: Significant differences between AD patients and controls were found in the structure of most of the regions of the DMN. MCI-c only differed from MCI-nc in GM volume of the left parahippocampus and bilateral hippocampi and middle frontal gyri, as well as in WM integrity of the parahippocampal cingulum connecting the left hippocampus and precuneus. We found significant correlations between integrity in some of those regions and global neuropsychological status, as well as an excellent discrimination ability between converters and non-converters for the sum of GM volume of left parahippocampus, bilateral hippocampi, and middle frontal gyri, and WM integrity of left parahippocampal cingulum. However, we found no significant differences in FC. Conclusion: These results further support the relationship between abnormalities in the DMN and AD, and suggest that structural measures could be more accurate than resting-state estimates as markers of conversion from MCI to AD.

The foreign language effect shows that emotional reactivity is reduced when we use a second language instead of our native one to address different situations. The present study aims to test whether the use of cognitive reappraisal could be influenced by the participant’s language (native/foreign). For this purpose, a sample of 60 participants with subclinical phobia to cockroaches was exposed to several phobic and neutral pictures while they used cognitive reappraisal in their native or in a foreign language. Physiological measures (pupil dilation and electrodermal activity) and self-reports of affective valence and arousal were collected. Results show an overall effectiveness of the strategy of reappraisal in both languages. Additionally, the use of a foreign language depicts a decrease in the affective negativity of the threat stimuli in terms of valence. The ratings of arousal also show a general higher arousal as an effect of the use of a foreign language. The present results suggest that using a foreign language could be advantageous to reduce negative emotionality by reappraisal. However, it could be a barrier for reappraising non-unpleasant pictures. Further studies should explore the foreign language effect in psychotherapy to open new ways of approaching different disorders.

Altres ajuts: The study was funded by the grant COPERNICO from the Spanish Ministry of Health/National Drugs Plan, and by the Norte Portugal Regional Operational Programme (NORTE 2020) under the Portugal 2020 Partnership Agreement (NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000023). VC was supported by the grant PID2019-105077RJ-I00/AEI/10.13039/501100011033. AVG was supported by a Medical Research Future Fund fellowship (MRF1141214). ABL has received research support from the Universitat Jaume I (UJI-B2020-23). MPP was supported by the Spanish Ministry of Universities, with funds from the European Union - NextGenerationEU (MAZ/2021/11). Cocaine use disorder (CUD) and gambling disorder (GD) share clinical features and neural alterations, including emotion regulation deficits and dysfunctional activation in related networks. However, they also exhibit differential aspects, such as the neuroadaptive effects of long-term drug consumption in CUD as compared to GD. Neuroimaging research aimed at disentangling their shared and specific alterations can contribute to improve understanding of both disorders. We compared CUD (N = 15), GD (N = 16) and healthy comparison (HC; N = 17) groups using a network-based approach for studying temporally coherent functional networks during functional magnetic resonance imaging (fMRI) of an emotion regulation task. We focused our analysis in limbic, ventral frontostriatal, dorsal attentional (DAN) and executive networks (FPN), given their involvement in emotion regulation and their alteration in CUD and GD. Correlations with measures of emotional experience and impulsivity (UPPS-P) were also performed. The limbic network was significantly decreased during emotional processing both for CUD and GD individuals compared to the HC group. Furthermore, GD participants compared to HC showed an increased activation in the ventral frontostriatal network during emotion regulation. Finally, networks' activation patterns were modulated by impulsivity traits. Functional network analyses revealed both overlapping and unique effects of stimulant and gambling addictions on neural networks underpinning emotion regulation.

Individual differences in pitch discrimination have been associated with the volume of both the bilateral Heschl’s gyrus and the right inferior frontal gyrus (IFG). However, most of these studies used samples composed of individuals with different amounts of musical training. Here, we investigated the relationship between pitch discrimination and individual differences in the gray matter (GM) volume of these brain structures in 32 adult musicians, 28 adult non-musicians, and 32 children without musical training. The results showed that (i) the individuals without musical training (whether children or adults) who were better at pitch discrimination had greater volume of auditory regions, whereas (ii) musicians with better pitch discrimination had greater volume of the IFG. These results suggest that the relationship between pitch discrimination and the volume of auditory regions is innately established early in life, and that musical training modulates the volume of the IFG, probably improving audio-motor connectivity. This is the first study to detect a relationship between pitch discrimination ability and GM volume before beginning any musical training in children and adults. This work was supported by grants from the Spanish Ministry of Economy and Competitiveness (PSI-2016-78805-R and PID2019-108198GB) to C.Á. Authors M-Á. P-G and A.M-P were supported by a postdoctoral graduate program grant (Jaume I University). Author M.H was supported by Ramón y Cajal Research Program of the Spanish Ministry of Science, Innovation, and Universities (RYC-2016-19477). Authors J.A-V and E.V-R were supported by a predoctoral graduate program grant (National FPU). Author V.C was supported by a postdoctoral grant (Juan de la Cierva).

Background and purpose Previous investigations show that bilinguals exhibit the first symptoms of dementia 4-5 years later than monolinguals. Therefore, bilingualism has been proposed as a cognitive reserve mechanism. Recent studies have advanced towards an understanding of the brain mechanisms underlying bilingualism's protection against dementia, but none of them deals with white matter (WM) diffusion. Methods In this study, the topic was investigated by measuring WM integrity in a sample of 35 bilinguals and 53 passive bilinguals with mild cognitive impairment. Results No significant differences were found between the groups in cognitive level, education, age or sex. However, bilinguals showed higher mean diffusivity in the fornix, but higher fractional anisotropy, lower mean diffusivity, axial diffusivity and radial diffusivity in the parahippocampal cingulum, and lower radial diffusivity in the right uncinate fasciculus. Significant correlations were also found between WM integrity in the left parahippocampal cingulum and the Boston Naming Test in passive bilinguals. Conclusions These results suggest that bilingualism contributes to a differential pattern of WM disintegration due to mild cognitive impairment in fibers related to bilingualism and memory.

Previous investigations have used global graph theory measures in order to disentangle the complexity of the neural reorganizations occurring in cocaine use disorder (CUD). However, how these global topological alterations map into individual brain network areas remains unknown. In this study, we used resting state functional magnetic resonance imaging (fMRI) data to investigate node-level topological dysfunctions in CUD. The sample was composed of 32 individuals with CUD and 32 healthy controls, matched in age, years of education and intellectual functioning. Graph theory measures of optimal connectivity distance, node strength, nodal efficiency and clustering coefficient were estimated in each participant using voxel-wise functional connectivity connectomes. CUD individuals as compared with healthy controls showed higher optimal connectivity distances in ventral striatum, insula, cerebellum, temporal cortex, lateral orbitofrontal cortex, middle frontal cortex and left hippocampus. Furthermore, clinical measures quantifying severity of dependence were positively related with optimal connectivity distances in the right rolandic operculum and the right lateral orbitofrontal cortex, whereas length of abstinence was negatively associated with optimal connectivity distances in the right temporal pole and the left insula. Our results reveal a topological distancing of cognitive and affective related areas in addiction, suggesting an overall reduction in the communication capacity of these regions. Funding for open access charge: CRUE-Universitat Jaume I This research was supported by grant 040/2011 from Spanish National Drug Strategy, Ministerio de Sanidad y Consumo to ABL. JAV was supported by a predoctoral graduate programme grant (National FPU). MPG and AMP were supported by a postdoctoral graduate programme grant (postdoc-UJI). VC was supported by grant PID2019-105077RJ-I00 from Ministerio de Ciencia, Innovación y Universidades.

Alzheimer's disease (AD) has been associated with memory impairment due to alterations in the medial temporal lobe (MTL) and the precuneus. Therefore, the goal of this study was to investigate the effects of AD on the brain networks associated with the hippocampus and precuneus during an encoding memory task. 68 mild cognitive impairment patients (MCI), 21 AD patients, and 20 healthy controls (HC) were included. Participants were instructed to memorize landscapes while undergoing fMRI scanning, followed by a recognition test. MCI were followed up clinically for 18 months to track conversion status. Independent component analysis (ICA) was performed to investigate AD effects on precuneus and MTL networks during memory encoding. Behavioral analyses indicate that HC had a better performance than MCI converters (MCIc) and AD. ICA showed that MCIc had significantly higher activation in the MTL-associated network than MCI non converters (MCIn) and AD, including bilateral hippocampus, parahippocampus, and fusiform gyrus. Furthermore, the precuneus-associated network fitted the default mode network, showing a negative correlation with behavioral performance. These findings indicate that the hyperactivation of the hippocampal network displayed by MCIc has potential discrimination capacity to distinguish them of MCIn, and could be interpreted as a compensatory mechanism.

Introducción: Recientes estudios sugieren que el bilingüismo es uno de los factores que contribuye a la reserva cognitiva, ya que las personas bilingües suelen manifestar los síntomas de la enfermedad de Alzheimer (EA) significativamente más tarde que los monolingües. Otros estudios han revelado que los bilingües muestran mayor atrofia e hipometabolismo comparados con los monolingües, pese a tener el mismo diagnóstico. Sin embargo, todas estas investigaciones incluyen participantes bilingües y monolingües que muestran diferencias en nivel educativo, nivel socioeconómico o estatus de inmigración. El objetivo de este trabajo es investigar las bases neurales del supuesto efecto protector del bilingüismo. Metodología: Una muestra de 68 pacientes con deterioro cognitivo leve (DCL) fue incluida en el estudio, con 26 bilingües y 42 monolingües. Se recogieron imágenes 3D de resonancia magnética a partir de las cuales se compararon los volúmenes de sustancia gris de ambos grupos. Resultados: Bilingües y monolingües no mostraron diferencias significativas en variables demográficas ni en rendimiento cognitivo en pruebas psicológicas. Sin embargo, los bilingües mostraron menor volumen de sustancia gris (mayor atrofia cerebral) que los monolingües en las siguientes áreas: precuneus izquierdo, área de Wernicke izquierda, ínsula/giro de Heschl bilateral y vermis cerebelar bilateral. Conclusión: Los bilingües, con la misma edad, nivel educativo y manifestación de síntomas de la enfermedad, muestran mayor atrofia de sustancia gris que los monolingües en áreas relevantes para la EA. Esto sugiere que el bilingüismo actúa como un factor protector de la demencia, ya que requiere mayor atrofia cerebral para llegar al mismo estado patológico. Introduction: Evidence from previous studies suggests that bilingualism is one of the factors which contributes to cognitive reserve, by showing that bilingual individuals manifest symptoms of Alzheimer’s disease (AD) significantly later than monolinguals. Other evidences revealed that bilinguals show greater amounts of atrophy or hypometabolism compared to monolinguals, despite having the same diagnosis of AD and similar symptoms. However, these previous studies included samples in which bilinguals and monolinguals showed differences in education, immigration and/or socioeconomic status. The aim of this work was to investigate the neural bases of these putative protective effects of bilingualism. Methods: A sample of 68 patients with mild cognitive impairment (MCI), 26 bilinguals and 42 monolinguals, was included in the study. Whole-brain 3-D magnetic resonance images were collected in order to compare the gray matter volume of both groups. Results: Bilinguals and monolinguals showed no significant differences in sociodemographic variables nor cognitive performance in neuropsychological testing. However, bilinguals showed less gray matter volume (more brain atrophy) than monolinguals in the following areas: left precuneus, left Wernicke’s area, bilateral insula/Heschl’s gyrus and bilateral cerebellar vermis. Conclusion: Bilinguals with the same age, level of education and manifestation of symptoms as monolinguals, show higher levels of gray matter atrophy than monolinguals in relevant areas for AD. This suggests that bilingualism acts as a protective factor against dementia, since it requires more brain atrophy in order to get to the same pathological state.

Identifying emotional states and explicitly putting them into words, known as affect labeling, reduces amygdala activation. Crucially, bilinguals do not only label emotions in their native language; they sometimes do it in their foreign language as well. However, one’s foreign languages are less emotional and more cognitively demanding than one’s native language. Because of these differences, it is unclear whether labeling emotions in a foreign language will also cause downregulation of affect. Here, 26 unbalanced bilinguals were scanned while labeling emotional faces either in their native or foreign languages. Results on affect labeling in a foreign language revealed that not only did it not reduce amygdala activation, but it also evoked higher activation than affect labeling in a native language. Overall, foreign language processing undermines affect labeling, and it suggests that the language in which people name their emotions has important consequences in how they experience them. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42761-021-00039-9.

Structural and functional neuroimaging studies have shown that brain areas associated with fear and anxiety (defensive system areas) are modulated by individual differences in sensitivity to punishment (SP). However, little is known about how SP is related to brain functional connectivity and the factors that modulate this relationship. In this study, we investigated whether a simple methodological manipulation, such as performing a resting state with eyes open or eyes closed, can modulate the manifestation of individual differences in SP. To this end, we performed an exploratory fMRI resting state study in which a group of participants (n = 88) performed a resting state with eyes closed and another group (n = 56) performed a resting state with eyes open. All participants completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire. Seed-based functional connectivity analyses were performed in the amygdala, hippocampus, and periaqueductal gray (PAG). Our results showed that the relationship between SP and left amygdala-precuneus and left hippocampus-precuneus functional connectivity was modulated by eye state. Moreover, in the eyes open group, SP was negatively related to the functional connectivity between the PAG and amygdala and between the PAG and left hippocampus, and it was positively related to the functional connectivity between the amygdala and hippocampus. Together, our results may suggest underlying differences in the connectivity between anxiety-related areas based on eye state, which in turn would affect the manifestation of individual differences in SP. This work was supported by grants from Generalitat Valenciana (PROMETEO/2017/109) and Ministerio de Economía y Competitividad (PSI2016-78805-R) to C.A. Also, it was supported by a grant from Jaume I University (UJI-B2016-21) to A.B-L. Additionally, this work was supported by a pre-doctoral graduate program grant (National FPU to J.A-V, L.M-M, E.V-R and N.A) and a post-doctoral graduate program grant (Juan de la Cierva to V.C and postdoc-UJI to A.M-P and M-Á.P-G). Author E.B was funded by a post-doctoral grant from the "Generalitat Valenciana (2018 APOSTD)" and the "European Social Fund (Investing in your future)"

Structural and functional neuroimaging studies have shown that brain areas associated with fear and anxiety (defensive system areas) are modulated by individual differences in sensitivity to punishment (SP). However, little is known about how SP is related to brain functional connectivity and the factors that modulate this relationship. In this study, we investigated whether a simple methodological manipulation, such as performing a resting state with eyes open or eyes closed, can modulate the manifestation of individual differences in SP. To this end, we performed an exploratory fMRI resting state study in which a group of participants (n = 88) performed a resting state with eyes closed and another group (n = 56) performed a resting state with eyes open. All participants completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire. Seed-based functional connectivity analyses were performed in the amygdala, hippocampus, and periaqueductal gray (PAG). Our results showed that the relationship between SP and left amygdala-precuneus and left hippocampus-precuneus functional connectivity was modulated by eye state. Moreover, in the eyes open group, SP was negatively related to the functional connectivity between the PAG and amygdala and between the PAG and left hippocampus, and it was positively related to the functional connectivity between the amygdala and hippocampus. Together, our results may suggest underlying differences in the connectivity between anxiety-related areas based on eye state, which in turn would affect the manifestation of individual differences in SP.

The adhesio interthalamica (AI) is a small midline brain structure that connects the left and right thalamus. According to in vivo data, between 2.3–22.3% of the general population lack the AI, and the question of whether this absence is more prevalent in males than in females is a matter of debate. Despite the existence of these demographic figures, it remains unclear how this distinctive feature affects healthy people, or what specific anatomic profile is related to the presence or absence of the AI. The aim of this study was to investigate whole brain gray matter (GM) volumetric differences depending on the presence or absence of the AI. A total of 240 healthy adult volunteers completed one MRI scanning session. After the AI assessment, the data from 110 participants were included in the final sample, of which 12.9% of the participants (n = 31) presented complete AI absence vs. 32.9% of participants (n = 79) who presented complete AI presence. Then, whole-brain group comparison analysis revealed that the absent AI brain, compared to the present AI brain, was associated with lower GM volume in the premotor cortex, inferior frontal gyrus, and anterior temporal cortex. Interestingly, neuroscience research has linked emotional and cognitive control brain processing to the latter two regions. The importance of these findings lies in providing a neuroanatomical profile for the absent AI brain in healthy human adults.

Current evidence suggests that volitional opening or closing of the eyes modulates brain activity and connectivity. However, how the eye state influences the functional connectivity of the primary visual cortex has been poorly investigated. Using the same scanner, fMRI data from two groups of participants similar in age, sex and educational level were acquired. One group (n = 105) performed a resting state with eyes closed, and the other group (n = 63) performed a resting state with eyes open. Seed-based voxel-wise functional connectivity whole-brain analyses were performed to study differences in the connectivity of the primary visual cortex. This region showed higher connectivity with the default mode and sensorimotor networks in the eyes closed group, but higher connectivity with the salience network in the eyes open group. All these findings were replicated using an open source shared dataset. These results suggest that opening or closing the eyes may set brain functional connectivity in an interoceptive or exteroceptive state. This work was supported by grants from Generalitat Valenciana (AICO/2018/038) and Ministerio de Economía y Competitividad (PSI2016–78805-R) to CA. Additionally, this work was supported by a pre-doctoral graduate program grant (FPU15/00825) to JA; a post-doctoral graduate program grant (APOSTD-2018 from the Generalitat Valenciana and the European Social Fund: “Investing in your future”) to EB; and a post-doctoral graduate program grant (FJCI-2014-19589) to VC. Financial support for the replication sample data used in this project was provided by a grant from the National Natural Science Foundation of China (30770594) and a grant from the National High Technology Program of China (863: 2008AA02Z405). The authors declare no competing interests.

Alzheimer's disease (AD) is associated with brain network dysfunction. Network-based investigations of brain connectivity have mainly focused on alterations in the strength of connectivity; however, the network breakdown in AD spectrum is a complex scenario in which multiple pathways of connectivity are affected. To integrate connectivity changes that occur under AD-related conditions, here we developed a novel metric that computes the connectivity distance between cortical regions at the voxel level (or nodes). We studied 114 individuals with mild cognitive impairment, 24 with AD, and 27 healthy controls. Results showed that areas of the default mode network, salience network, and frontoparietal network display a remarkable network separation, or greater connectivity distances, from the rest of the brain. Furthermore, this greater connectivity distance was associated with lower global cognition. Overall, the investigation of AD-related changes in paths and distances of connectivity provides a novel framework for characterizing subjects with cognitive impairment; a framework that integrates the overall network topology changes of the brain and avoids biases toward unreferenced connectivity effects. This research was supported by a grant from the National Institutes of Health (NIH) (grant No. R01AG061445 and R01AG061811) (K23-EB019023 to J. Sepulcre).

Background Evidence from previous studies suggests that bilingualism contributes to cognitive reserve because bilinguals manifest the first symptoms of Alzheimer’s disease (AD) up to 5 years later than monolinguals. Other cross-sectional studies demonstrate that bilinguals show greater amounts of brain atrophy and hypometabolism than monolinguals, despite sharing the same diagnosis and suffering from the same symptoms. However, these studies may be biased by possible pre-existing between-group differences. Methods In this study, we used global parenchymal measures of atrophy and cognitive tests to investigate the protective effect of bilingualism against dementia cross-sectionally and prospectively, using a sample of bilinguals and monolinguals in the same clinical stage and matched on sociodemographic variables. Results Our results suggest that the two groups did not differ in their cognitive status at baseline, but bilinguals had less parenchymal volume than monolinguals, especially in areas related to brain atrophy in dementia. In addition, a longitudinal prospective analysis revealed that monolinguals lost more parenchyma and had more cognitive decline than bilinguals in a mean follow-up period of 7 months. Conclusion These results provide the first prospective evidence that bilingualism may act as a neuroprotective factor against dementia and could be considered a factor in cognitive reserve.

Working memory training causes functional adaptations in the brain, which include changes in activation and functional connectivity that remain stable over time. Few studies have investigated gray matter (GM) changes after working memory training, and they have produced heterogeneous results without clarifying the stable effects of training. The present study was designed to test for sustained and transient anatomic changes after only 200 min of working memory training. The voxel-based morphometry technique was used in order to investigate the GM changes produced by a brief single n-back training, immediately and 5 weeks after finishing it. The sample was composed by 59 human participants who underwent MRI scanning and were assigned to either a training group or a passive control group. Results showed sustained GM volume enlargement in the right superior parietal cortex and a transient GM decrease in the right putamen. The brain adaptation in the right superior parietal cortex was stronger in individuals who showed greater improvements in performance. The results provide further evidence that a brief working memory training is able to produce brain plasticity in structures related to the trained task. This work was supported by grants from Universitat Jaume I (P1•1B2013-63) and Ministerio de Economia y Competitividad (PSI2013-47504-R and PSI2016-78805-R). Authors J. Adrián-Ventura, E. Villar-Rodriguez, L. Marin-Marin and N. Aguirre were supported by a pre-doctoral graduate program grant (National FPU to J.A-V, L.M-M, E.V-R and N.A). In addition, this work was supported by a post-doctoral graduate program grant to V. Costumero, M-Á. Palomar-García and A. Miró-Padilla (Juan de la Cierva to V.C and postdoc-UJI to M-Á.P-G and A.M.P). Author E. Bueichekú was funded by a postdoctoral grant from the "Generalitat Valenciana (2018 APOSTD)" and the "European Social Fund (Investing in your future)".

Cocaine addiction is characterized by alterations in motivational and cognitive processes involved in goal-directed behavior. Recent studies have shown that addictive behaviors can be attributed to alterations in the activity of large functional networks. The aim of this study was to investigate how cocaine addiction affected the left frontoparietal network during goal-directed behavior in a stop-signal task (SST) with reward contingencies by correct task performance. Twenty-eight healthy controls (HC) and 30 abstinent cocaine-dependent patients (ACD) performed SST with monetary reward contingencies while undergoing a functional magnetic resonance imaging scan. The results showed that the left frontoparietal network (FPN) displayed an effect of cocaine addiction depending on reward contingencies rather than inhibition accuracy; and, second, we observed a negative correlation between dependence severity and the modulation of the left FPN network by the monetary reward in ACD. These findings highlight the role of the left FPN in the motivational effects of cocaine dependence.

Cocaine addicts present reduced activity in the left frontoparietal network, a brain network associated with cognitive control, during the processing of non-drug reward related stimuli (Costumero et al., Addiction Biology 22:479-489, 2015). However, the involvement of this network in drug-related stimuli processing remains unclear. Here, fifteen cocaine-dependent men and fifteen healthy matched controls viewed cocaine-related, erotic, aversive, and neutral pictures during an fMRI session. Group independent component analysis was then performed to investigate how functional networks were modulated by the different emotional images. The results showed that the cocaine-dependent group showed stronger left frontoparietal network activity during the processing of cocaine-related pictures than the control group. Furthermore, the activity of this network during cocaine image processing was positively associated with the years of cocaine use in addicted subjects. In conclusion, our results indicate that the left frontoparietal network is affected in cocaine-dependent men, and may be related to the cognitive control deficits shown in addiction.

Alzheimer's disease (AD) is a neurological disorder that creates neurodegenerative changes at several structural and functional levels in human brain tissue. The fractal dimension (FD) is a quantitative parameter that characterizes the morphometric variability of the human brain. In this study, we investigate spherical harmonic-based FD (SHFD), thickness, and local gyrification index (LGI) to assess whether they identify cortical surface abnormalities toward the conversion to AD. We study 33 AD patients, 122 mild cognitive impairment (MCI) patients (50 MCI converters and 29 MCI nonconverters), and 32 healthy controls (HC). SHFD, thickness, and LGI methodology allowed us to perform not only global level but also local level assessments in each cortical surface vertex. First, we found that global SHFD decreased in AD and future MCI converters compared to HC, and in MCI converters compared to MCI nonconverters. Second, we found that local white matter SHFD was reduced in AD compared to HC and MCI mainly in medial temporal lobe. Third, local white-matter SHFD was significantly reduced in MCI converters compared to MCI nonconverters in distributed areas, including the medial frontal lobe. Thickness and LGI metrics presented a reduction in AD compared to HC. Thickness was significantly reduced in MCI converters compared to healthy controls in entorhinal cortex and lateral temporal. In summary, SHFD was the only surface measure showing differences between MCI individuals that will convert or remain stable in the next 4 years. We suggest that SHFD may be an optimal complement to thickness loss analysis in monitoring longitudinal changes in preclinical and clinical stages of AD. Hum Brain Mapp 38:5905-5918, 2017. © 2017 Wiley Periodicals, Inc.

Introducción: La teoría de la sensibilidad al refuerzo (tsr) propone el sistema de activación conductual (sac) como el sistema motivacional encargado de dirigir la con- ducta hacia la obtención de estímulos apetitivos. A nivel neurobiológico, este sistema se ha relacionado con el circuito cerebral de la recompensa. Así mismo, se ha pro- puesto el rasgo de personalidad de sensibilidad a la recompensa (sr) como modulador de la actividad del sac. En el presente trabajo estudiamos la relación entre la actividad del sac, medida por medio del cuestionario spsrq, y el volumen de sustancia gris en áreas de recompensa. Métodos: Realizamos un análisis de morfometría basada en el vóxel (vbm) en una muestra de 216 hombres e investigamos la asociación entre los valores de volumen obtenidos y las puntuaciones en la escala sr del spsrq mediante un análisis de regresión. El procesado y análisis de las imágenes se realizó mediante spm8. Resultados: A nivel cortical, los análisis de vbm mostraron una correlación ne- gativa entre las puntuaciones de la escala sr y el volumen de sustancia gris en el córtex prefrontal lateral, la ínsula y el lóbulo temporal superior. A nivel subcortical, ob- servamos una reducción en el volumen del estriado (núcleo caudado). Conclusiones: Nuestros resultados apoyan investigaciones previas y aportan nuevas evidencias acerca de las diferencias anatómicas en áreas relacionadas con el control inhibitorio y la toma de decisiones en participantes con un sac sobreactivado. Introduction: The Reinforcement Sensitivity Theory (rst) proposes the Behavioral Activation System (bas) as the motivational system responsible for direct behavior toward appetitive stimuli. Neurobiologically, this system has been related to the brain reward circuitry. Additionally, the personality trait of Sensitivity to Reward (sr) has been proposed as modulator of bas activity. In this work, we studied the relationship between the bas activity, as measured by the spsrq questionnaire, and the gray matter volume in reward-related areas. Methods: We carried out a voxel-based morphometry analysis in a sample of 216 male participants and we investigated the association between the data volume obtained and the sr scale scores by means of a regression analysis. Image processing and statistical analyses were carried out using spm8. Results: At the cortical level, vbm analysis showed a negative correlation between sr scores and the gray matter volume in the lateral prefrontal cortex, the insula, and the superior temporal lobe. Subcortically, we found a reduction in the striatum volume (caudate nucleus). Conclusion: Our results support previous studies and provide new evidence about anatomical differences in brain areas related to inhibitory control and decision-making in participants with an overactive bas.

This is a post-peer-review, pre-copyedit version of an article published in Cognitive, Affective, & Behavioral Neuroscience. The final authenticated version is available online at: https://doi.org/10.3758/s13415-019-00688-1. The behavioral approach system (BAS), based on reinforcement sensitivity theory (RST), is a neurobehavioral system responsible for detecting and promoting motivated behaviors towards appetitive stimuli. Anatomically, the frontostriatal system has been proposed as the core of the BAS, mainly the ventral tegmental area and the ventral striatum and their dopaminergic connections with medial prefrontal structures. The RST also proposes the personality trait of reward sensitivity as a measurable construct of stable individual differences in BAS activity. However, the relationship between this trait and brain connectivity “at rest” has been poorly studied, mainly because previous investigations have focused on studying brain activity under reward-related contingency paradigms. Here, we analyzed the influence of reward sensitivity on the resting-state functional connectivity (rs-FC) between BAS-related areas by correlating the BOLD time series with the scores on the Sensitivity to Reward (SR) scale in a sample of 89 healthy young adults. Rs-FC between regions of interest were all significant. Results also revealed a positive association between SR scores and the rs-FC between the VTA and the ventromedial prefrontal cortex, and between the latter structure and the anterior cingulate cortex. These results suggest that reward sensitivity could be associated with different resting-state activity in the mesocortical pathway.

Reinforcement Sensitivity Theory (RST) proposes a widely used taxonomy of human personality linked to individual differences at both behavioral and neuropsychological levels that describe a predisposition to psychopathology. However, the body of RST research was based on animal findings, and little is known about their anatomical correspondence in humans. Here we set out to investigate MRI structural correlates (i.e. voxel-based morphometry) of the main personality dimensions proposed by the RST in a group of 400 healthy young adults who completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ). Sensitivity to punishment scores correlated positively with the gray matter volume in the amygdala, whereas sensitivity to reward scores correlated negatively with the volume in the left lateral and medial prefrontal cortex. Moreover, a negative relationship was found between the striatal volume and the reward sensitivity trait, but only for male participants. The present results support the neuropsychological basis of the RST by linking punishment and reward sensitivity to anatomical differences in limbic and frontostriatal regions, respectively. These results are interpreted based on previous literature related to externalizing and internalizing disorders, and they highlight the possible role of SPSRQ as a measure of proneness to these disorders. This work was supported by grants from Generalitat Valenciana (PROMETEO/2017/109) and Ministerio de Economía y Competitividad (PSI2016–78805-R) to C.A. Also, this work was supported by a pre-doctoral graduate program grant (National FPU to J.A-V.) and a post-doctoral graduate program grant (Juan de la Cierva to V.C.).

Cocaine addiction is characterized by alterations in motivational and cognitive processes. Recent studies have shown that some alterations present in cocaine users may be related to the activity of large functional networks. The aim of this study was to investigate how these functional networks are modulated by non-drug rewarding stimuli in cocaine-dependent individuals. Twenty abstinent cocaine-dependent and 21 healthy matched male controls viewed erotic and neutral pictures while undergoing a functional magnetic resonance imaging scan. Group independent component analysis was then performed in order to investigate how functional networks were modulated by reward in cocaine addicts. The results showed that cocaine addicts, compared with healthy controls, displayed diminished modulation of the left frontoparietal network in response to erotic pictures, specifically when they were unpredicted. Additionally, a positive correlation between the length of cocaine abstinence and the modulation of the left frontoparietal network by unpredicted erotic images was found. In agreement with current addiction models, our results suggest that cocaine addiction contributes to reduce sensitivity to rewarding stimuli and that abstinence may mitigate this effect.

Background. Experimental asymmetrical disconnection in animals is a lesion technique used to demonstrate the involvement of specific brain circuits in complex behaviors. Using this surgical technique it has been demonstrated that cortico-limbic-striatal circuits, involving medial prefrontal cortex (mPFC), basolateral amygdala (BLA), and nucleus accumbens (Nacb), regulate decision-making processes. In particular, disruption of Nacb and BLA communication impairs motivated behavior. In addition, disconnections between the BLA and mPFC increase choice of riskier options, suggesting that this circuit facilitates tracking of actions and outcomes to temper urges for riskier rewards and to maintain effort. Case Description. A young patient with disruptive aggressive behaviors and cocaine abuse problems was diagnosed from “impulse control dysfunction” and “limbic dysfunction syndrome”. Neuroimaging tests indicated atrophy of left hemisphere, and moderate general reduction in brain metabolism. Surgical intervention, very similar to the experimental technique previously described, was employed. Thermal coagulation lesions were targeted at left hemisphere anterior cingulate (AC), anterior capsula (ALIC), and stria terminalis. In the right hemisphere targets were ALIC and amygdala. Two months later, after relapse of aggressivity, a second surgery extended previous lesions in left ALIC and AC in the right hemisphere. Neuroimages after 5 and 15 years demonstrate the extent of those lesions. Conclusions. Recent neuropsychological tests in this patient that assessed frontal and striatal functions show high impulsivity, impairment of planning processes and difficulties in cost/benefit decision making compared with normative samples. There is evidence showing that addiction and schizophrenia have very little improvements from surgical interventions. Moreover, combining more than one brain target may make outcomes worse.

The behavioral approach system (BAS) from Gray’s reinforcement sensitivity theory is a neurobehavioral system involved in the processing of rewarding stimuli that has been related to dopaminergic brain areas. Gray’s theory hypothesizes that the functioning of reward brain areas is modulated by BAS-related traits. To test this hypothesis, we performed an fMRI study where participants viewed erotic and neutral pictures, and cues that predicted their appearance. Forty-five heterosexual men completed the Sensitivity to Reward scale (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire) to measure BAS-related traits. Results showed that Sensitivity to Reward scores correlated positively with brain activity during reactivity to erotic pictures in the left orbitofrontal cortex, left insula, and right ventral striatum. These results demonstrated a relationship between the BAS and reward sensitivity during the processing of erotic stimuli, filling the gap of previous reports that identified the dopaminergic system as a neural substrate for the BAS during the processing of other rewarding stimuli such as money and food

Alzheimer's disease (AD) is a neurological disorder that creates neurodegenerative changes at several structural and functional levels in human brain tissue. The fractal dimension (FD) is a quantitative parameter that characterizes the morphometric variability of the human brain. In this study, we investigate spherical harmonic-based FD (SHFD), thickness, and local gyrification index (LGI) to assess whether they identify cortical surface abnormalities toward the conversion to AD. We study 33 AD patients, 122 mild cognitive impairment (MCI) patients (50 MCI converters and 29 MCI nonconverters), and 32 healthy controls (HC). SHFD, thickness, and LGI methodology allowed us to perform not only global level but also local level assessments in each cortical surface vertex. First, we found that global SHFD decreased in AD and future MCI converters compared to HC, and in MCI converters compared to MCI nonconverters. Second, we found that local white matter SHFD was reduced in AD compared to HC and MCI mainly in medial temporal lobe. Third, local white-matter SHFD was significantly reduced in MCI converters compared to MCI nonconverters in distributed areas, including the medial frontal lobe. Thickness and LGI metrics presented a reduction in AD compared to HC. Thickness was significantly reduced in MCI converters compared to healthy controls in entorhinal cortex and lateral temporal. In summary, SHFD was the only surface measure showing differences between MCI individuals that will convert or remain stable in the next 4 years. We suggest that SHFD may be an optimal complement to thickness loss analysis in monitoring longitudinal changes in preclinical and clinical stages of AD. Hum Brain Mapp 38:5905-5918, 2017. © 2017 Wiley Periodicals, Inc.

Sensory deprivation reorganizes neurocircuits in the human brain. The biological basis of such neuroplastic adaptations remains elusive. In this study, we applied two complementary graph theory-based functional connectivity analyses, one to evaluate whole-brain functional connectivity relationships and the second to specifically delineate distributed network connectivity profiles downstream of primary sensory cortices, to investigate neural reorganization in blind children compared with sighted controls. We also examined the relationship between connectivity changes and neuroplasticity-related gene expression profiles in the cerebral cortex. We observed that multisensory integration areas exhibited enhanced functional connectivity in blind children and that this reorganization was spatially associated with the transcription levels of specific members of the cAMP Response Element Binding protein gene family. Using systems-level analyses, this study advances our understanding of human neuroplasticity and its genetic underpinnings following sensory deprivation.

The chance to achieve a reward starts up the required neurobehavioral mechanisms to adapt our thoughts and actions in order to accomplish our objective. However, reward does not equally reinforce everybody but depends on interindividual motivational dispositions. Thus, immediate reward contingencies can modulate the cognitive process required for goal achievement, while individual differences in personality can affect this modulation. We aimed to test the interaction between inhibition-related brain response and motivational processing in a stop signal task by reward anticipation and whether individual differences in sensitivity to reward (SR) modulate such interaction. We analyzed the cognitive-motivational interaction between the brain pattern activation of the regions involved in correct and incorrect response inhibition and the association between such brain activations and SR scores. We also analyzed the behavioral effects of reward on both reaction times for the "go" trials before and after correct and incorrect inhibition in order to test error prediction performance and postinhibition adjustment. Our results show enhanced activation during response inhibition under reward contingencies in frontal, parietal, and subcortical areas. Moreover, activation of the right insula and the left putamen positively correlates with the SR scores. Finally, the possibility of reward outcome affects not only response inhibition performance (e.g., reducing stop signal reaction time), but also error prediction performance and postinhibition adjustment. Therefore, reward contingencies improve behavioral performance and enhance brain activation during response inhibition, and SR is related to brain activation. Our results suggest the conditions and factors that subserve cognitive control strategies in cognitive motivational interactions during response inhibition.

Reward sensitivity, or the tendency to engage in motivated approach behavior in the presence of rewarding stimuli, may be a contributory factor for vulnerability to disinhibitory behaviors. Although evidence exists for a reward sensitivity-related increased response in reward brain areas (i.e. nucleus accumbens or midbrain) during the processing of reward cues, it is unknown how this trait modulates brain connectivity, specifically the crucial coupling between the nucleus accumbens, the midbrain, and other reward-related brain areas, including the medial orbitofrontal cortex and the amygdala. Here, we analysed the relationship between effective connectivity and personality in response to anticipatory reward cues. Forty-four males performed an adaptation of the Monetary Incentive Delay Task and completed the Sensitivity to Reward scale. The results showed the modulation of reward sensitivity on both activity and functional connectivity (psychophysiological interaction) during the processing of incentive cues. Sensitivity to reward scores related to stronger activation in the nucleus accumbens and midbrain during the processing of reward cues. Psychophysiological interaction analyses revealed that midbrain-medial orbitofrontal cortex connectivity was negatively correlated with sensitivity to reward scores for high as compared with low incentive cues. Also, nucleus accumbens-amygdala connectivity correlated negatively with sensitivity to reward scores during reward anticipation. Our results suggest that high reward sensitivity-related activation in reward brain areas may result from associated modulatory effects of other brain regions within the reward circuitry.

Pre-clinical and clinical studies in cocaine addiction highlight alterations in the striatal dopaminergic reward system that subserve maintenance of cocaine use. Using an instrumental conditioning paradigm with monetary reinforcement, we studied striatal functional alterations in long-term abstinent cocaine-dependent patients and striatal functioning as a function of abstinence and treatment duration. Eighteen patients and 20 controls underwent functional magnetic resonance imaging during a Monetary Incentive Delay task. Region of interest analyses based on masks of the dorsal and ventral striatum were conducted to test between-group differences and the functional effects in the cocaine group of time (in months) with no more than two lapses from the first time patients visited the clinical service to seek treatment at the scanning time (duration of treatment), and the functional effects of the number of months with no lapses or relapses at the scanning session time (length of abstinence). We applied a voxel-wise and a cluster-wise FWE-corrected level (pFWE) at a threshold of P

The dopaminergic system provides the basis for the interaction between motivation and cognition. It is triggered by the possibility of obtaining rewards to initiate the neurobehavioral adaptations necessary to achieve them by directing the information from motivational circuits to cognitive and action circuits. In drug addiction, the altered dopamine (DA) modulation of the meso-cortico-limbic reward circuitry, such as the prefrontal cortex (PFC), underlies the disproportionate motivational value of drug use at the expense of other nondrug reinforcers and the user’s loss of control over his/her drug intake. We examine how the magnitude of the reward affects goal-directed processes in healthy control (HC) subjects and abstinent cocaine dependent (ACD) patients by using functional magnetic resonance imaging (fMRI) during a counting Stroop task with blocked levels of monetary incentives of different magnitudes (€0, €0.01, €0.5, €1 or €1.5). Our results showed that increasing reward magnitude enhances (1) performance facilitation in both groups; (2) left dorsolateral prefrontal cortex (DLPFC) activity in HC and left superior occipital cortex activity in ACD; and (3) left DLPFC and left putamen connectivity in ACD compared to HC. Moreover, we observed that (4) dorsal striatal and pallidum activity was associated with craving and addiction severity during the parametric increases in the monetary reward. In conclusion, the brain response to gradients in monetary value was different in HC and ACD, but both groups showed improved task performance due to the possibility of obtaining greater monetary rewards. This research has been supported by Grants PSI2012-33054 from the Spanish Ministry of Economy and Competitiveness (http://www.mineco.gob.es/), and by 2011I040 from the Spanish National Drug Strategy (http://www.pnsd.msssi.gob.es/) to ABL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

A “disinhibited” cognitive profile has been proposed for individuals with high reward sensitivity, characterized by increased engagement in goal-directed responses and reduced processing of negative or unexpected cues, which impairs adequate behavioral regulation after feedback in these individuals. This pattern is manifested through deficits in inhibitory control and/or increases in RT variability. In the present work, we aimed to test whether this profile is associated with the activity of functional networks during a stop-signal task using independent component analysis (ICA). Sixty-one participants underwent fMRI while performing a stop-signal task, during which a manual response had to be inhibited. ICA was used to mainly replicate the functional networks involved in the task (Zhang and Li, 2012): two motor networks involved in the go response, the left and right fronto-parietal networks for stopping, a midline error-processing network, and the default-mode network (DMN), which was further subdivided into its anterior and posterior parts. Reward sensitivity was mainly associated with greater activity of motor networks, reduced activity in the midline network during correct stop trials and, behaviorally, increased RT variability. All these variables explained 36% of variance of the SR scores. This pattern of associations suggests that reward sensitivity involves greater motor engagement in the dominant response, more distractibility and reduced processing of salient or unexpected events, which may lead to disinhibited behavior. This study was supported by grants from MINECO (PSI2013-45378-R, PSI2012-33054 and CSD2007-00012), the Spanish National Drug Strategy of the Spanish Ministry of Health and Consumption (4623/2011), the Generalitat Valenciana (GV/2012/042) and Universitat Jaume I (P1-1A2010-01 and P1·1B2013-63). PFC was supported by a FPU fellowship from the Spanish Ministry of Education (AP-2010-6060).

High reward sensitivity has been linked with motivational and cognitive disorders related with prefrontal and striatal brain function during inhibitory control. However, few studies have analyzed the interaction among reward sensitivity, task performance and neural activity. Participants (N = 57) underwent fMRI while performing a Go/No-go task with Frequent-go (77.5%), Infrequent-go (11.25%) and No-go (11.25%) stimuli. Task-associated activity was found in inhibition-related brain regions, with different activity patterns for right and left inferior frontal gyri (IFG): right IFG responded more strongly to No-go stimuli, while left IFG responded similarly to all infrequent stimuli. Reward sensitivity correlated with omission errors in Go trials and reaction time (RT) variability, and with increased activity in right and left IFG for No-go and Infrequent-go stimuli compared with Frequent-go. Bilateral IFG activity was associated with RT variability, with reward sensitivity mediating this association. These results suggest that reward sensitivity modulates behavior and brain function during executive control. This research has been supported by the Brainglot Project of the 2010 CONSOLIDER-INGENIO Program (CSD2007-00012), and also by grants from MINECO (PSI2012-33054), the Spanish National Drug Strategy (4623/2011), the Spanish Ministry of Health and Consumption, the Generalitat Valenciana (GV/2012/042) and the Universitat Jaume I (P1-1A2010-01) to A. Barrós-Loscertales.

According to the Reinforcement Sensitivity Theory, behavioral studies have found that individuals with stronger reward sensitivity easily detect cues of reward and establish faster associations between instrumental responses and reward. Neuroimaging studies have shown that processing anticipatory cues of reward is accompanied by stronger ventral striatum activity in individuals with stronger reward sensitivity. Even though establishing response-outcome contingencies has been consistently associated with dorsal striatum, individual differences in this process are poorly understood. Here, we aimed to study the relation between reward sensitivity and brain activity while processing response-reward contingencies. Forty-five participants completed the BIS/BAS questionnaire and performed a gambling task paradigm in which they received monetary rewards or punishments. Overall, our task replicated previous results that have related processing high reward outcomes with activation of striatum and medial frontal areas, whereas processing high punishment outcomes was associated with stronger activity in insula and middle cingulate. As expected, the individual differences in the activity of dorsomedial striatum correlated positively with BAS-Drive. Our results agree with previous studies that have related the dorsomedial striatum with instrumental performance, and suggest that the individual differences in this area may form part of the neural substrate responsible for modulating instrumental conditioning by reward sensitivity. The project was supported by grants PSI2010-20,168 from Ministerio de Economía y Competitividad, P1•1B2011-09 from the Universitat Jaume I to CA, and grants 040/2011 from Spanish National Drug Strategy Ministerio de Sanidad y Consumo, and PSI2012-33,054 from Ministerio de Economía y Competitividad to ABL.

The existence of a behavioral advantage of bilinguals over monolinguals during executive tasks is controversial. A new approach to this issue is to investigate the effect of bilingualism on neural control when performing these tasks as a window to understand when behavioral differences are produced. Here, we tested if early bilinguals use more language-related networks than monolinguals while performing a go/no-go task that includes infrequent no-go and go trials. The RTs and accuracy in both groups did not differ. An independent component analyses (ICA) revealed, however, that bilinguals used the left fronto-parietal network and the salience network more than monolinguals while processing go infrequent cues and no-go cues, respectively. It was noteworthy that the modulation of these networks had opposite correlates with performance in bilinguals and monolinguals, which suggests that between-group differences were more qualitative than quantitative. Our results suggest that bilinguals may differently develop the involvement of the executive control networks that comprise the left inferior frontal gyrus during cognitive control tasks than monolinguals MINECO . Grant Number: PSI2013-47504-R and CSD2007-0012 Universitat Jaume I . Grant Number: P1•1B2013-63

Introducción: La motivación apetitiva influye sobre procesos cognitivos como el control inhibitorio, y dicha influencia parece asociarse con cambios en la actividad del sistema dopaminérgico. Por otra parte, las diferencias individuales en Sensibilidad a la Recompensa (SR) parecen modular la actividad de las áreas cerebrales que constituyen dicho sistema. El objetivo de este estudio es determinar si las diferencias individuales en sr modulan la actividad cerebral de áreas implicadas en una tarea de control inhibitorio, cuando se recompensa la ejecución correcta a lo largo de la misma. Metodología: Nueve sujetos diestros participaron en el estudio. Se utilizó una tarea de señal de stop con contingencias de reforzamiento monetario. Para medir la SR se empleó el cuestionario SPSRQ de Torrubia y cols. (2001). El procesamiento de las imágenes y el análisis estadístico se realizó mediante el SPM8. Resultados: Los resultados funcionales mostraron un efecto de inhibición (p < 0.005, a nivel de vóxel no corregido) en áreas frontales, parietales y estriatales involucradas en procesos de control inhibitorio. Por otra parte, se observó un efecto de interacción inhibición-reforzamiento (p < 0.005, a nivel de vóxel no corregido) en el giro frontal inferior (GFI) izquierdo y el estriado. Además, se obtuvo una correlación positiva (r = 0.842, p < 0.01) entre la puntuación en la escala SR y la actividad del GFI. Conclusión: La SR incrementa la actividad del GFI izquierdo durante la inhibición conductual recompensada monetariamente. Las diferencias individuales en personalidad modulan la interacción entre procesos cognitivos y motivacionales. Introduction: Appetitive motivation has an effect on cognitive processes such inhibitory control. This effect is suggested to be associated with functional changes in the dopaminergic system. On the other hand, individual differences in Sensitivity to Reward (SR) seem to modulate brain activity in this system. The aim of this study was to find out whether individual differences in SR would modulate brain activity of regions implicated in an inhibitory control task when correct performance was rewarded. Methods: Nine right-handed participants took part in the study. They performed a stop-signal task with monetary contingencies. The SPSRQ questionnaire (Torrubia et al., 2001) was used to measure SR. Image processing and statistical analyses were carried out using SPM8. Results: Our findings showed that the frontal cortex, parietal cortex and striatum, were active during the stop-signal task performance (p

Current perspectives on cognitive control acknowledge that individual differences in motivational dispositions may modulate cognitive processes in the absence of reward contingencies. This work aimed to study the relationship between individual differences in Behavioral Activation System (BAS) sensitivity and the neural underpinnings involved in processing a switching cue in a task-switching paradigm. BAS sensitivity was hypothesized to modulate brain activity in frontal regions, ACC and the striatum. Twenty-eight healthy participants underwent fMRI while performing a switching task, which elicited activity in fronto-striatal regions during the processing of the switch cue. BAS sensitivity was negatively associated with activity in the lateral prefrontal cortex, anterior cingulate cortex and the ventral striatum. Combined with previous results, our data indicate that BAS sensitivity modulates the neurocognitive processes involved in task switching in a complex manner depending on task demands. Therefore, individual differences in motivational dispositions may influence cognitive processing in the absence of reward contingencies. Brainglot Project of the CONSOLIDER-INGENIO Program CSD2007-00012 MINECO PSI2012-33054 Spanish National Drug Strategy 4623/2011 Spanish Ministry of Health and Consumption Generalitat Valenciana GV/2012/042 Universitat Jaume I P1-1A2010-01

Cocaine addiction is characterized by alterations in motivational and cognitive processes. Recent studies have shown that some alterations present in cocaine users may be related to the activity of large functional networks. The aim of this study was to investigate how these functional networks are modulated by non-drug rewarding stimuli in cocaine-dependent individuals. Twenty abstinent cocaine-dependent and 21 healthy matched male controls viewed erotic and neutral pictures while undergoing a functional magnetic resonance imaging scan. Group independent component analysis was then performed in order to investigate how functional networks were modulated by reward in cocaine addicts. The results showed that cocaine addicts, compared with healthy controls, displayed diminished modulation of the left frontoparietal network in response to erotic pictures, specifically when they were unpredicted. Additionally, a positive correlation between the length of cocaine abstinence and the modulation of the left frontoparietal network by unpredicted erotic images was found. In agreement with current addiction models, our results suggest that cocaine addiction contributes to reduce sensitivity to rewarding stimuli and that abstinence may mitigate this effect.

The chance to achieve a reward starts up the required neurobehavioral mechanisms to adapt our thoughts and actions in order to accomplish our objective. However, reward does not equally reinforce everybody but depends on interindividual motivational dispositions. Thus, immediate reward contingencies can modulate the cognitive process required for goal achievement, while individual differences in personality can affect this modulation. We aimed to test the interaction between inhibition-related brain response and motivational processing in a stop signal task by reward anticipation and whether individual differences in sensitivity to reward (SR) modulate such interaction. We analyzed the cognitive-motivational interaction between the brain pattern activation of the regions involved in correct and incorrect response inhibition and the association between such brain activations and SR scores. We also analyzed the behavioral effects of reward on both reaction times for the "go" trials before and after correct and incorrect inhibition in order to test error prediction performance and postinhibition adjustment. Our results show enhanced activation during response inhibition under reward contingencies in frontal, parietal, and subcortical areas. Moreover, activation of the right insula and the left putamen positively correlates with the SR scores. Finally, the possibility of reward outcome affects not only response inhibition performance (e.g., reducing stop signal reaction time), but also error prediction performance and postinhibition adjustment. Therefore, reward contingencies improve behavioral performance and enhance brain activation during response inhibition, and SR is related to brain activation. Our results suggest the conditions and factors that subserve cognitive control strategies in cognitive motivational interactions during response inhibition.

Existing evidence suggests that the presence of reward cues modifies the activity in attentional networks, however, the nature of these influences remains poorly understood. Here, we performed independent component analysis (ICA) in two fMRI datasets corresponding to two incentive delay tasks, which compared the response to reward (money and erotic pictures) and neutral cues, and yielded activations in the ventral striatum using a general linear model approach. Across both experiments, ICA revealed that both the right frontoparietal network and default mode network time courses were positively and negatively modulated by reward cues, respectively. Moreover, this dual neural response pattern was enhanced in individuals with strong reward sensitivity. Therefore, ICA may be a complementary tool to investigate the relevant role of attentional networks on reward processing, and to investigate reward sensitivity in normal and pathological populations.