Increased functional connectivity patterns in mild Alzheimer's disease: A rsfMRI study.

Background: Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder. In view of our rapidly aging population, there is an urgent need to identify Alzheimer's disease (AD) at an early stage. A potential way to do so is by assessing the functional connectivity (FC), i.e., the statistical dependency between two or more brain regions, through novel analysis techniques. Methods: In the present study, we assessed the static and dynamic FC using different approaches. A resting state (rs)fMRI dataset from the Alzheimer's disease neuroimaging initiative (ADNI) was used (n = 128). The blood-oxygen-level-dependent (BOLD) signals from 116 regions of 4 groups of participants, i.e., healthy controls (HC; n = 35), early mild cognitive impairment (EMCI; n = 29), late mild cognitive impairment (LMCI; n = 30), and Alzheimer's disease (AD; n = 34) were extracted and analyzed. FC and dynamic FC were extracted using Pearson's correlation, sliding-windows correlation analysis (SWA), and the point process analysis (PPA). Additionally, graph theory measures to explore network segregation and integration were computed. Results: Our results showed a longer characteristic path length and a decreased degree of EMCI in comparison to the other groups. Additionally, an increased FC in several regions in LMCI and AD in contrast to HC and EMCI was detected. These results suggest a maladaptive short-term mechanism to maintain cognition. Conclusion: The increased pattern of FC in several regions in LMCI and AD is observable in all the analyses; however, the PPA enabled us to reduce the computational demands and offered new specific dynamic FC findings.

Non-linear Functional Brain Co-activations in Short-Term Memory Distortion Tasks.

Recent works shed light on the neural correlates of true and false recognition and the influence of time of day on cognitive performance. The current study aimed to investigate the modulation of the false memory formation by the time of day using a non-linear correlation analysis originally designed for fMRI resting-state data. Fifty-four young and healthy participants (32 females, mean age: 24.17 ± 3.56 y.o.) performed in MR scanner the modified Deese-Roediger-McDermott paradigm in short-term memory during one session in the morning and another in the evening. Subjects' responses were modeled with a general linear model, which includes as a predictor the non-linear correlations of regional BOLD activity with the stimuli, separately for encoding and retrieval phases. The results show the dependence of the non-linear correlations measures with the time of day and the type of the probe. In addition, the results indicate differences in the correlations measures with hippocampal regions between positive and lure probes. Besides confirming previous results on the influence of time-of-day on cognitive performance, the study demonstrates the effectiveness of the non-linear correlation analysis method for the characterization of fMRI task paradigms.

Revisiting Nonlinear Functional Brain Co-activations: Directed, Dynamic, and Delayed.

The center stage of neuro-imaging is currently occupied by studies of functional correlations between brain regions. These correlations define the brain functional networks, which are the most frequently used framework to represent and interpret a variety of experimental findings. In the previous study, we first demonstrated that the relatively stronger blood oxygenated level dependent (BOLD) activations contain most of the information relevant to understand functional connectivity, and subsequent work confirmed that a large compression of the original signals can be obtained without significant loss of information. In this study, we revisit the correlation properties of these epochs to define a measure of nonlinear dynamic directed functional connectivity (nldFC) across regions of interest. We show that the proposed metric provides at once, without extensive numerical complications, directed information of the functional correlations, as well as a measure of temporal lags across regions, overall offering a different and complementary perspective in the analysis of brain co-activation patterns. In this study, we provide further details for the computations of these measures and for a proof of concept based on replicating existing results from an Autistic Syndrome database, and discuss the main features and advantages of the proposed strategy for the study of brain functional correlations.

Psychological Distress in Erectile Dysfunction: The Moderating Role of Attachment.

INTRODUCTION: In clinical consultations, men with erectile dysfunction do not always express personal, sexual, and interpersonal concerns. AIM: We explore whether the attenuated impact of erectile dysfunction may be explained by a regulation of negative affect that causes activation of the attachment system. METHODS: The study sample consisted of 69 men diagnosed with erectile dysfunction, mean (SD) age 56 (10.83) years. Participants completed self-reported questionnaires to assess erectile dysfunction severity, attachment style, sexual satisfaction, relationship satisfaction, and psychological symptoms. MAIN OUTCOME MEASURE: The moderating role of attachment between erectile dysfunction and sexual satisfaction, relationship satisfaction, and psychological distress was evaluated using multiple linear regression and moderation analysis. RESULTS: All men in the sample had high attachment avoidance, distributed between the dismissive-avoidant (69.6%) and fearful-avoidant (30.4%) substyles, but low levels of psychological symptoms. Despite their erectile dysfunction, 27 patients (39.1%) rated their sexual life as satisfactory, and 46 (66.7%) rated their relationship with their partner as satisfactory. Men with fearful-avoidant attachment reported feeling more sexual desire and less sexual satisfaction than men with dismissive-avoidant attachment. Multiple linear regression analysis showed that sexual satisfaction variance was explained by erectile dysfunction severity, attachment anxiety, and relationship satisfaction scores. Moderation analysis showed that attachment anxiety, but not relationship satisfaction, moderated the impact of erectile dysfunction on sexual satisfaction. CONCLUSION: The avoidance dimension of attachment, which tends to be high in patients with erectile dysfunction, involves deactivation of the sexual system in an effort to minimize the emotional distress associated with erectile dysfunction, which damages sexual and relationship intimacy and delays the decision to obtain professional help. The presence of high attachment avoidance and the moderating value of attachment anxiety allow us to propose specific treatments for these men. Maestre-Lorén F, Castillo-Garayoa JA, López-i-Martín X, et al. Psychological Distress in Erectile Dysfunction: The Moderating Role of Attachment. Sex Med 2021;9:100436.

Experience-dependent neuroplasticity in trained musicians modulates the effects of chronic pain on insula-based networks - A resting-state fMRI study.

Recent resting-state fMRI studies associated extensive musical training with increased insula-based connectivity in large-scale networks involved in salience, emotion, and higher-order cognitive processes. Similar changes have also been found in chronic pain patients, suggesting that both types of experiences can have comparable effects on insula circuitries. Based on these observations, the current study asked the question whether, and if so in what way, different forms of experience-dependent neuroplasticity may interact. Here we assessed insula-based connectivity during fMRI resting-state between musicians and non-musicians both with and without chronic pain, and correlated the results with clinical pain duration and intensity. As expected, insula connectivity was increased in chronic pain non-musicians relative to healthy non-musicians (with cingulate cortex and supplementary motor area), yet no differences were found between chronic pain non-musicians and healthy musicians. In contrast, musicians with chronic pain showed decreased insula connectivity relative to both healthy musicians (with sensorimotor and memory regions) and chronic pain non-musicians (with the hippocampus, inferior temporal gyrus, and orbitofrontal cortex), as well as lower pain-related inferences with daily activities. Pain duration correlated positively with insula connectivity only in non-musicians, whereas pain intensity exhibited distinct relationships across groups. We conclude that although music-related sensorimotor training and chronic pain, taken in isolation, can lead to increased insula-based connectivity, their combination may lead to higher-order plasticity (metaplasticity) in chronic pain musicians, engaging brain mechanisms that can modulate the consequences of maladaptive experience-dependent neural reorganization (i.e., pain chronification).

Power Spectral Density and Functional Connectivity Changes due to a Sensorimotor Neurofeedback Training: A Preliminary Study.

Neurofeedback is a form of neuromodulation based on learning to modify some aspects of cortical activity. Sensorimotor rhythm (SMR) oscillation is one of the most used frequency bands in neurofeedback. Several studies have shown that subjects can learn to modulate SMR power to control output devices, but little is known about possible related changes in brain networks. The aim of this study was to investigate the enhanced performance and changes in EEG power spectral density at somatosensory cerebral areas due to a bidirectional modulation-based SMR neurofeedback training. Furthermore, we also analyzed the functional changes in somatosensory areas during resting state induced by the training as exploratory procedure. A six-session neurofeedback protocol based on learning to synchronize and desynchronize (modulate) the SMR was implemented. Moreover, half of the participants were enrolled in two functional magnetic resonance imaging resting-state sessions (before and after the training). At the end of the training, participants showed a successful performance enhancement, an increase in SMR power specific to somatosensory locations, and higher functional connectivity between areas associated with somatosensory activity in resting state. Our research increases the better understanding of the relation between EEG neuromodulation and functional changes and the use of SMR training in clinical practice.

Using Deep Learning and Resting-State fMRI to Classify Chronic Pain Conditions.

Chronic pain is known as a complex disease due to its comorbidities with other symptoms and the lack of effective treatments. As a consequence, chronic pain seems to be under-diagnosed in more than 75% of patients. At the same time, the advance in brain imaging, the popularization of machine learning techniques and the development of new diagnostic tools based on these technologies have shown that these tools could be an option in supporting decision-making of healthcare professionals. In this study, we computed functional brain connectivity using resting-state fMRI data from one hundred and fifty participants to assess the performance of different machine learning models, including deep learning (DL) neural networks in classifying chronic pain patients and pain-free controls. The best result was obtained by training a convolutional neural network fed with data preprocessed using the MSDL probabilistic atlas and using the dynamic time warping (DTW) as connectivity measure. DL models had a better performance compared to other less costly models such as support vector machine (SVM) and RFC, with balanced accuracy ranged from 69 to 86%, while the area under the curve (ROC) ranged from 0.84 to 0.93. Also, DTW overperformed correlation as connectivity measure. These findings support the notion that resting-state fMRI data could be used as a potential biomarker of chronic pain conditions.

Insula-based networks in professional musicians: Evidence for increased functional connectivity during resting state fMRI.

Despite considerable research on experience-dependent neuroplasticity in professional musicians, detailed understanding of an involvement of the insula is only now beginning to emerge. We investigated the effects of musical training on intrinsic insula-based connectivity in professional classical musicians relative to nonmusicians using resting-state functional MRI. Following a tripartite scheme of insula subdivisions, coactivation profiles were analyzed for the posterior, ventral anterior, and dorsal anterior insula in both hemispheres. While whole-brain connectivity across all participants confirmed previously reported patterns, between-group comparisons revealed increased insular connectivity in musicians relative to nonmusicians. Coactivated regions encompassed constituents of large-scale networks involved in salience detection (e.g., anterior and middle cingulate cortex), affective processing (e.g., orbitofrontal cortex and temporal pole), and higher order cognition (e.g., dorsolateral prefrontal cortex and the temporoparietal junction), whereas no differences were found for the reversed group contrast. Importantly, these connectivity patterns were stronger in musicians who experienced more years of musical practice, including also sensorimotor regions involved in music performance (M1 hand area, S1, A1, and SMA). We conclude that musical training triggers significant reorganization in insula-based networks, potentially facilitating high-level cognitive and affective functions associated with the fast integration of multisensory information in the context of music performance. Hum Brain Mapp 38:4834-4849, 2017. © 2017 Wiley Periodicals, Inc.

Altered Dynamic of EEG Oscillations in Fibromyalgia Patients at Rest.

OBJECTIVE: Previous fMRI findings have shown that chronic pain patients display an altered activation and functional connectivity of the pain network. The aim of the present study was to analyze EEG dynamics in fibromyalgia patients (n = 20) and pain-free controls (n = 18) at rest. METHODS: Spectral power density, source current density, and intra- and inter-hemispheric coherence were analyzed from 64 EEG channels during 5-minutes eyes-closed rest. RESULTS: Results indicated that fibromyalgia patients displayed reduced power density of the delta EEG band (2-4 Hz) over right insula, right superior and middle temporal gyri as compared with pain-free controls. Fibromyalgia patients also exhibited greater power density than pain-free controls in two segments of the beta band (16-23 Hz and 23-30 Hz) over right middle frontal lobe and midcingulate gyrus. Pain duration in fibromyalgia patients was negatively correlated with delta power from right insula. Greater centro-parietal intra-hemispheric coherence was observed at the left hemisphere on theta (4-8 Hz), and beta-3 (23-30 Hz) frequency bands in fibromyalgia patients than in pain-free controls. Individual differences in depression, anxiety or negative affect did not account for these findings. CONCLUSIONS: Fibromyalgia leads to an altered dynamic of the brain network involved in the processing of pain even at rest. Furthermore ,: our results provide further support for the feasibility of resting-state EEG analyses as a clinical biomarker for the characterization of chronic pain states.

Are physiotherapists reliable proxies for the recognition of pain in individuals with cerebral palsy? A cross sectional study.

BACKGROUND: Pain is an important problem for individuals with cerebral palsy (CP). In addition to pain associated to the pathology, individuals with CP are often exposed to physiotherapy procedures which may cause or relieve pain. OBJECTIVE: The major aim of this study was to compare pain ratings self-reported by individuals with cerebral palsy and ratings about pain in others provided by their physiotherapists. METHOD: Cross-sectional study. Children and young adults with cerebral palsy (n = 50) and their physiotherapists (n = 18) completed semi-structured interviews about clinical pain, as well as about procedural pain and pain relief elicited by standardized health procedures. Moreover, pain ratings were obtained during the application of hamstring stretching and passive joint mobilization. RESULTS: Moderate-to-high agreement was observed between individuals with cerebral palsy and their physiotherapists on presence and intensity of pain, pain interference with physical activities and current and retrospective pain ratings elicited by physiotherapy procedures. By contrast, agreement regarding pain relief elicited by physiotherapy techniques was low. CONCLUSIONS: Our data suggest that although physiotherapists may be reliable proxies for the recognition of pain in individuals with cerebral palsy, further research should be done to improve the communication between health professionals and individuals with cerebral palsy around pain.

Altered corticomuscular coherence elicited by paced isotonic contractions in individuals with cerebral palsy: a case-control study.

The purpose of the study was to analyze corticomuscular coherence during planning and execution of simple hand movements in individuals with cerebral palsy (CP) and healthy controls (HC). Fourteen individuals with CP and 15 HC performed voluntary paced movements (opening and closing the fist) in response to a warning signal. Simultaneous scalp EEG and surface EMG of extensor carpi radialis brevis were recorded during 15 isotonic contractions. Time-frequency corticomuscular coherence (EMG-C3/C4) before and during muscular contraction, as well as EMG intensity, onset latency and duration were analyzed. Although EMG intensity was similar in both groups, individuals with CP exhibited longer onset latency and increased duration of the muscular contraction than HC. CP also showed higher corticomuscular coherence in beta EEG band during both planning and execution of muscular contraction, as well as lower corticomuscular coherence in gamma EEG band at the beginning of the contraction as compared with HC. In conclusion, our results suggest that individuals with CP are characterized by an altered functional coupling between primary motor cortex and effector muscles during planning and execution of isotonic contractions. In addition, the usefulness of corticomuscular coherence as a research tool for exploring deficits in motor central processing in persons with early brain damage is discussed.

Apego y psicopatología en adolescentes y jóvenes que han sufrido maltrato: implicaciones clínicas / Attachment and psychopathology in formerly maltreated adolescents and young adults: Clinical implications

Se estudia la relación entre apego y psicopatología en una muestra de 40 adolescentes y jóvenes que han sufrido maltrato intrafamiliar. El apego se evalúa mediante el cuestionario RQ de Bartholomew, que distingue cuatro estilos de apego en función de la imagen positiva o negativa del self y de los demás: apego seguro, preocupado, temeroso y evitativo. Los resultados del estudio muestran que el apego inseguro, sobre todo el subtipo evitativo, es el más prevalente. Algo más de la mitad de la muestra (52.5%) presenta sintomatología clínicamente significativa (evaluada mediante el SCL-90-R), en especial hostilidad, obsesión-compulsión, ideación paranoide, psicoticismo y sensibilidad interpersonal. Los estilos de apego con una visión negativa del self (preocupado y temeroso) tienden a presentar más sintomatología psicopatológica. Se discuten las implicaciones clínicas de estos resultados

In this research, the relationship between attachment and psychopathology was studied in a sample of 40 adolescents and young adults who have suffered from intrafamily maltreatment. Attachment was assessed with Bartholomew’s RQ, which distinguishes four attachment styles depending on the positive or negative image of the self and others: secure, preoccupied, fearful and dismissive attachment. Results show that insecure attachment, particularly the dismissive subtype, is the most prevalent one. Slightly more than half of the sample (52.5%) shows clinically significant symptoms (as assessed with the SCL-90-R), particularly hostility, obsessive-compulsive, paranoid ideation, psychoticism, and interpersonal sensitivity. Attachment styles with a negative vision of the self (preoccupied and fearful) tend to show more psychopathological symptoms. The clinical implications of these results are also discussed

Antecedent events as predictive variables for behavioral function.

Challenging behavior is one of the largest barriers to ensuring that people with intellectual disabilities (ID) are able to participate in the community. These difficulties have become one of the main causes of social exclusion. The research into and treatment of challenging behavior has usually involved the identification of its function and the manipulation of the events or environmental conditions that influence its occurrence (antecedent variables). The present research explores the relationship between antecedents and behavioral function and the extent to which antecedent variables may act as predictors of behavioral function. This relationship is explored using two standardized instruments: Questions About Behavioral Function and Contextual Assessment Inventory. Data from the validation of these instruments for the Spanish population involved 300 participants with ID and 328 challenging behaviors. The results suggest that social/cultural variables are most related to challenging behavior, whereas biological variables seem to only be related to physically maintained behavior.

Agonistic strategies and spatial distribution in captive sooty mangabeys (Cercocebus atys).

The aim of this article is to study the relationship between the dominance hierarchy and the spatial distribution of a group of captive sooty mangabeys (Cercocebus atys). The analysis of the spatial distribution of individuals in relation to their rank in the dominance hierarchy showed a clear linear hierarchy in which the dominant individual was located in central positions with regard to the rest of the group members. The large open enclosure where the group was living allowed them to adopt a high-risk agonistic strategy in which individuals attacked other individuals whose rank was significantly different from their own. The comparison of the results with a previous study of mangabeys showed that, although the dominance ranks of both groups were similar, the fact that they lived in facilities with different layouts caused different agonistic strategies to emerge and allowed the dominant individual to assume different spatial locations.

Altered psychophysiological responses to the view of others' pain and anger faces in fibromyalgia patients.

UNLABELLED: Facial expression provides information for an accurate estimation of others' pain. Nevertheless, little is known about psychophysiological responses to pain faces in chronic pain. Event-related potentials and brain oscillations, corrugator activity, and heart rate were recorded in 20 fibromyalgia patients and 20 pain-free controls when viewing pain, anger, happy, and neutral faces. Pain and anger faces elicited greater unpleasantness and arousal than happy and neutral faces, and pain faces evoked greater corrugator response than the rest of faces in all participants. Fibromyalgia patients displayed greater cardiac deceleration to all facial expressions than pain-free controls, and enhanced N100 amplitudes to pain and anger faces in comparison with neutral faces. Pain-free controls were characterized by enhanced N100 amplitudes to happy faces as compared to patients, and by more positive event-related potential amplitudes to happy than to other faces in the time window of 200 to 300 ms. Fibromyalgia patients showed greater theta power in response to pain and anger faces, as well as more reduced alpha power than pain-free controls to all faces. These findings suggest that information processing in fibromyalgia might be characterized by enhanced defensive reactions and increased mobilization of attention resources to pain and anger faces, and by reduced allocation of attention to happy faces. PERSPECTIVE: Our findings suggest that brain and cardiac activity elicited by viewing facial expressions of pain and anger in others is altered in fibromyalgia patients. This cognitive bias toward negative emotions could be used in clinical settings as a psychobiological marker during the assessment and treatment of fibromyalgia.

Questions About Behavioral Function (QABF): adaptation and validation of the Spanish version.

People with intellectual disabilities (ID) often engage in problem behaviors, such as verbal or physical aggression, property destruction, or self-injury. These behaviors become a challenge for the families and for professionals. Functional behavioral assessment (FBA) is a method used to identify variables that influence or maintain challenging behaviors (CB) and aid in the development of intervention plans. Two major concerns of FBA are that it is time-consuming and requires specialized professionals to interpret data from the natural or experimental environment. Therefore, indirect FBA methods can be used as an alternative. An instrument with excellent psychometric properties that aims to identify the function of behavior is the Questions About Behavioral Function (QABF). This study presents the adaptation of the QABF in Spain. Data from 300 participants with ID and 328 behavioral problems were obtained. An exploratory factor analysis was conducted to identify the components of the QABF, and the test-retest reliability was assessed to evaluate the stability of the QABF over time.

Somatosensory activity modulation during observation of other's pain and touch.

We examined whether somatosensory activity could be modulated by the observation of bodily experiences. For this purpose, somatosensory-evoked potentials elicited by non-painful stimulation were recorded when subjects were viewing a hand penetrated by a needle, touched by a cotton swab or at resting without stimulation. Participants were instructed to adopt an egocentric perspective when viewing the videos and to rate pain intensity and unpleasantness supposedly experienced by the model, as well as the unpleasantness induced by the video clips. Results indicated that pain videos were rated as more unpleasant than touch videos, and that observation of both pain and touch video clips led to a significant enhancement of P50 amplitudes as compared to viewing a hand without stimulation. Moreover, enhanced P50 amplitudes during observation of both pain and touch in others were associated with increased unpleasant ratings induced by the video clips, as well as with high scores in a perspective taking scale (IRI). These findings provide support for the involvement of an attentional bottom-up mechanism which could be responsible to enhance sensory processing of somatic information when observing bodily experiences in others irrespective of whether they are painful or not.

Disrupted functional connectivity of the pain network in fibromyalgia.

OBJECTIVE: To investigate the impact of chronic pain on brain dynamics at rest. METHODS: Functional connectivity was examined in patients with fibromyalgia (FM) (n = 9) and healthy controls (n = 11) by calculating partial correlations between low-frequency blood oxygen level-dependent fluctuations extracted from 15 brain regions. RESULTS: Patients with FM had more positive and negative correlations within the pain network than healthy controls. Patients with FM displayed enhanced functional connectivity of the anterior cingulate cortex (ACC) with the insula (INS) and basal ganglia (p values between .01 and .05), the secondary somatosensory area with the caudate (CAU) (p = .012), the primary motor cortex with the supplementary motor area (p = .007), the globus pallidus with the amygdala and superior temporal sulcus (both p values < .05), and the medial prefrontal cortex with the posterior cingulate cortex (PCC) and CAU (both p values < .05). Functional connectivity of the ACC with the amygdala and periaqueductal gray (PAG) matter (p values between .001 and .05), the thalamus with the INS and PAG (both p values < .01), the INS with the putamen (p = .038), the PAG with the CAU (p = .038), the secondary somatosensory area with the motor cortex and PCC (both p values < .05), and the PCC with the superior temporal sulcus (p = .002) was also reduced in FM. In addition, significant negative correlations were observed between depression and PAG connectivity strength with the thalamus (r = -0.64, p = .003) and ACC (r = -0.60, p = .004). CONCLUSIONS: These findings demonstrate that patients with FM display a substantial imbalance of the connectivity within the pain network during rest, suggesting that chronic pain may also lead to changes in brain activity during internally generated thought processes such as occur at rest.

Age-related changes of pain experience in cerebral palsy and healthy individuals.

OBJECTIVE: Pain is a serious problem for many individuals with cerebral palsy (CP). Pain and injury in early life may cause long-term changes in somatosensory and pain processing. Nevertheless, no information exists regarding the influence of age on pain reports and touch sensitivity among persons with CP or the influence of age on the quality of life in individuals with CP. DESIGN: The present cross-sectional study investigated pain characteristics, touch sensitivity, and quality of life in 86 individuals with CP and 115 healthy volunteers. Participants were grouped by age in children (6-10 years), adolescents (11-17 years), and young adults (18-30 years). Touch sensitivity at different body locations were tested by using von Frey monofilaments. Data about pain and quality of life were obtained from a semi-structured interview and questionnaires. RESULTS: Participants with CP reported more pain as well as more reduced touch sensitivity and quality of life than healthy controls. Neither pain reports nor touch sensitivity or quality of life were influenced by age in CP, whereas significant age-related changes were observed in healthy participants. Multiple regression analyses also showed that age was the best predictor of current pain intensity in healthy controls but not in individuals with CP. CONCLUSION: These findings emphasize the importance of considering the presence of pain at very early ages in CP. Furthermore, these results provide clinicians and researchers with a new age-related psychosocial and psychophysiological perspective to investigate the mechanisms that could be involved in the presence and maintenance of pain in this population.