Terms Of Brain Function Research Articles

Local Administrations of Iron Oxide Nanoparticles in the Prefrontal Cortex and Caudate Putamen of Rats Do Not Compromise Working Memory and Motor Activity

Iron oxide nanoparticles (IONPs) have come into focus for their use in medical applications although possible health risks for humans, especially in terms of brain functions, have not yet been fully clarified. The present study investigates the effects of IONPs on neurobehavioural functions in rats. For this purpose, we infused dimercaptosuccinic acid-coated IONPs into the medial prefrontal cortex (mPFC) and caudate putamen (CPu). Saline (VEH) and ferric ammonium citrate (FAC) were administered as controls. One- and 4-week post-surgery mPFC-infused animals were tested for their working memory performance in the delayed alternation T-maze task and in the open field (OF) for motor activity, and CPu-infused rats were tested for their motor activity in the OF. After completion of the experiments, the brains were examined histologically and immunohistochemically. We did not observe any behavioural or structural abnormalities in the rats after administration of IONPs in the mPFC and the CPu. In contrast, administration of FAC into the CPu resulted in decreased motor activity and increased the number of microglia in the mPFC. Perls’ Prussian blue staining revealed that FAC- and IONP-treated rats had more iron-containing ramified cells than VEH-treated rats, indicating iron uptake by microglia. Our results demonstrate that local infusions of IONPs into selected brain regions have no adverse impact on locomotor behaviour and working memory.

A cultural-ecosocial systems view for psychiatry.

While contemporary psychiatry seeks the mechanisms of mental disorders in neurobiology, mental health problems clearly depend on developmental processes of learning and adaptation through ongoing interactions with the social environment. Symptoms or disorders emerge in specific social contexts and involve predicaments that cannot be fully characterized in terms of brain function but require a larger social-ecological view. Causal processes that result in mental health problems can begin anywhere within the extended system of body-person-environment. In particular, individuals' narrative self-construal, culturally mediated interpretations of symptoms and coping strategies as well as the responses of others in the social world contribute to the mechanisms of mental disorders, illness experience, and recovery. In this paper, we outline the conceptual basis and practical implications of a hierarchical ecosocial systems view for an integrative approach to psychiatric theory and practice. The cultural-ecosocial systems view we propose understands mind, brain and person as situated in the social world and as constituted by cultural and self-reflexive processes. This view can be incorporated into a pragmatic approach to clinical assessment and case formulation that characterizes mechanisms of pathology and identifies targets for intervention.

Rationale for revisions to the definition of death and criteria for its determination in Canada

Clarity regarding the biomedical definition of death and the criteria for its determination is critical to inform practices in clinical care, medical research, law, and organ donation. While best practices for death determination by neurologic criteria and circulatory criteria were previously outlined in Canadian medical guidelines, several issues have arisen to force their reappraisal. Ongoing scientific discovery, corresponding changes in medical practice, and legal and ethical challenges compel a comprehensive update. Accordingly, the A Brain-Based Definition of Death and Criteria for its Determination After Arrest of Neurologic or Circulatory Function in Canada project was undertaken to a develop a unified brain-based definition of death, and to establish criteria for its determination after devastating brain injury and/or circulatory arrest. Specifically, the project had three objectives: (1) to clarify that death is defined in terms of brain functions; (2) to clarify how a brain-based definition of death is articulated; and (3) to clarify the criteria for determining if the brain-based definition is met. The updated death determination guideline therefore defines death as the permanent cessation of brain function and describes corresponding circulatory and neurologic criteria to ascertain the permanent cessation of brain function. This article explores the challenges that prompted revisions to the biomedical definition of death and the criteria for its determination and outlines the rationales underpinning the project’s three objectives. By clarifying that all death is defined in terms of brain function, the project seeks to align guidelines with contemporary medicolegal understandings of the biological basis of death.

The Logic of the Body: Retrieving Theological Psychology

The Logic of the Body: Retrieving Theological Psychology

Problematic smartphone use is associated with differences in static and dynamic brain functional connectivity in young adults.

This study aimed to investigate the possible associations between problematic smartphone use and brain functions in terms of both static and dynamic functional connectivity patterns. Resting-state functional magnetic resonance imaging data were scanned from 53 young healthy adults, all of whom completed the Short Version of the Smartphone Addiction Scale (SAS-SV) to assess their problematic smartphone use severity. Both static and dynamic functional brain network measures were evaluated for each participant. The brain network measures were correlated the SAS-SV scores, and compared between participants with and without a problematic smartphone use after adjusting for sex, age, education, and head motion. Two participants were excluded because of excessive head motion, and 56.9% (29/51) of the final analyzed participants were found to have a problematic smartphone use (SAS-SV scores ≥ 31 for males and ≥ 33 for females, as proposed in prior research). At the global network level, the SAS-SV score was found to be significantly positively correlated with the global efficiency and local efficiency of static brain networks, and negatively correlated with the temporal variability using the dynamic brain network model. Large-scale subnetwork analyses indicated that a higher SAS-SV score was significantly associated with higher strengths of static functional connectivity within the frontoparietal and cinguloopercular subnetworks, as well as a lower temporal variability of dynamic functional connectivity patterns within the attention subnetwork. However, no significant differences were found when directly comparing between the groups of participants with and without a problematic smartphone use. Our results suggested that problematic smartphone use is associated with differences in both the static and dynamic brain network organizations in young adults. These findings may help to identify at-risk population for smartphone addiction and guide targeted interventions for further research. Nevertheless, it might be necessary to confirm our findings in a larger sample, and to investigate if a more applicable SAS-SV cutoff point is required for defining problematic smartphone use in young Chinese adults nowadays.

Domestic crickets (Acheta domesticus) as an animal model to study Parkinson's disease

Impaired glutamatergic neurotransmission and neuronal metabolic dysfunction are classic alterations in the pathophysiology of Parkinson's disease (PD). The substantia nigra compacta of the brain (the area where the primary pathological lesion is located) is particularly exposed to oxidative stress and metabolic damage. A reduced ability to cope with metabolic demands, possibly related to impaired mitochondrial function, may make the substantia nigra highly vulnerable to the effects of glutamate, which acts as a neurotoxin in the presence of impaired cellular energy metabolism. Taking into account that insects and mammals share a similar molecular architecture in terms of brain function, this work investigated whether domestic crickets (Acheta domesticus) can be used as an animal model for the study of PD. For this, the crickets received an intra‐lymphatic injection (between the second and third tergit of the ventral abdominal segment) of glutamate (10 µl; 2M). Control animals received a similar volume of PBS solution. Twenty‐four hours after treatment, the brains of the animals were dissected. We use our oxygraph‐2K system (OROBOROS Instruments) to determine mitochondrial respiration by activating mitochondrial complexes (CI, CII, CI&II, and CIV) and the production of reactive oxygen species (ROS). Our preliminary results showed that glutamate treatment significantly reduced the respiration of mitochondrial complexes CI, CII, and CI&II, even though the activity of complex IV (an indicator of the number of mitochondria) was not reduced between treatments. On the other hand, mitochondrial production of reactive oxygen species (ROS) in glutamate‐treated animals was significantly increased when both mitochondrial complexes I&II were active, but this pattern was reversed when only one of the complexes I or II was active. Because similar alterations have been observed in the brains of mammals with Parkinson's disease, these results strongly suggest that domestic crickets can be used as an animal model to investigate the mitochondrial mechanisms involved in this disease.

Induction of Relaxation by Autonomous Sensory Meridian Response

Background: Autonomous sensory meridian response (ASMR) is used by young people to induce relaxation and sleep and to reduce stress and anxiety; it comprises somatosensation caused by audiovisual stimuli (triggers) that lead to positive emotions. Auditory stimuli play the most important role among the triggers involved in ASMR and have been reported to be more triggering than visual stimuli. On the other hand, classical music is also known to have a relaxing effect. This is the first study to clarify the difference in brain activation associated with relaxation effects between ASMR and classical music by limiting ASMR to auditory stimulation alone.Methods: Thirty healthy subjects, all over 20 years of age, underwent fMRI while listening to ASMR and classical music. We compared the differences in brain activation associated with classical music and ASMR stimulation. After the experiment, the subjects were administered a questionnaire on somatosensation and moods. After the experiment, the participants were asked whether they experienced ASMR somatosensation or frisson. They were also asked to rate the intensity of two moods during stimulation: “comfortable mood,” and “tingling mood”.Result: The results of the questionnaire showed that none of the participants experienced any ASMR somatosensation or frisson. Further, there was no significant difference in the ratings given to comfort mood, but there was a significant difference in those given to tingling mood. In terms of brain function, classical music and ASMR showed significant activation in common areas, while ASMR showed activation in more areas, with the medial prefrontal cortex being the main area of activation during ASMR.Conclusion: Both classical music and the ASMR auditory stimulus produced a pleasant and relaxed state, and ASMR involved more complex brain functions than classical music, especially the activation of the medial prefrontal cortex. Although ASMR was limited to auditory stimulation, the effects were similar to those of listening to classical music, suggesting that ASMR stimulation can produce a pleasant state of relaxation even if it is limited to the auditory component, without the somatic sensation of tingling. ASMR stimulation is easy to use, and appropriate for wellness purposes and a wide range of people.

Altered Functional Networks of Alpha and Low-Beta Bands During Upper Limb Movement and Association with Motor Impairment in Chronic Stroke.

Background: Impaired movement after stroke is closely associated with altered brain functions, and thus the investigation on neural substrates of patients with stroke can pave a way for not only understanding the underlying mechanisms of neuropathological traits, but also providing an innovative solution for stroke rehabilitation. The objective of this study was to precisely investigate altered brain functions in terms of power spectral and brain network analyses. Methods: Altered brain function was investigated by using electroencephalography (EEG) measured while 34 patients with chronic stroke performed movement tasks with the affected and unaffected hands. The relationships between functional brain network indices and Fugl-Meyer Assessment (FMA) scores were also investigated. Results: A stronger low-beta event-related desynchronization was found in the contralesional hemisphere for both affected and unaffected movement tasks compared with that of the ipsilesional hemisphere. More efficient whole-brain networks (increased strength and clustering coefficient, and prolonged path length) in the low-beta frequency band were revealed when moving the unaffected hand compared with when moving the affected hand. In addition, the brain network indices of the contralesional hemisphere indicated higher efficiency and cost-effectiveness than those of the ipsilesional hemisphere in both the alpha and low-beta frequency bands. Moreover, the alpha network indices (strength, clustering coefficient, path length, and small-worldness) were significantly correlated with the FMA scores. Conclusions: Efficient functional brain network indices are associated with better motor outcomes in patients with stroke and could be useful biomarkers to monitor stroke recovery during rehabilitation.

Ordering of Transformed Recorded Electroencephalography (EEG) Signals by a Novel Precede Operator

Recorded electroencephalography (EEG) signals can be represented as square matrices, which have been extensively analyzed using mathematical methods to extract invaluable information concerning brain functions in terms of observed electrical potentials; such information is critical for diagnosing brain disorders. Several studies have revealed that certain such square matrices—in particular, those related to so-called “elementary EEG signals”—exhibit properties similar to those of prime numbers in which every square EEG matrix can be regarded as a composite of these signals. A new approach to ordering square matrices is pivotal to extending the idea of square matrices as composite numbers. In this paper, several ordering concepts are investigated and a new technique for ordering matrices is introduced. Finally, some properties of this matrix order are presented, and the potential applications of this technique to analyzing EEG signals are discussed.

The gender-binary cycle: the perpetual relations between a biological-essentialist view of gender, gender ideology, and gender-labelling and sorting.

Gender inequality is one of the most pressing issues of our time. A core factor that feeds gender inequality is people's gender ideology-a set of beliefs about the proper order of society in terms of the roles women and men should fill. We argue that gender ideology is shaped, in large parts, by the way people make sense of gender differences. Specifically, people often think of gender differences as expressions of a predetermined biology, and of men and women as different 'kinds'. We describe work suggesting that thinking of gender differences in this biological-essentialist way perpetuates a non-egalitarian gender ideology. We then review research that refutes the hypothesis that men and women are different 'kinds' in terms of brain function, hormone levels and personality characteristics. Next, we describe how the organization of the environment in a gender-binary manner, together with cognitive processes of categorization drive a biological-essentialist view of gender differences. We then describe the self-perpetuating relations, which we term the gender-binary cycle, between a biological-essentialist view of gender differences, a non-egalitarian gender ideology and a binary organization of the environment along gender lines. Finally, we consider means of intervention at different points in this cycle. This article is part of the theme issue 'The political brain: neurocognitive and computational mechanisms'.

Scaling laws in natural conversations among elderly people.

Language is a result of brain function; thus, impairment in cognitive function can result in language disorders. Understanding the aging of brain functions in terms of language processing is crucial for modern aging societies. Previous studies have shown that language characteristics, such as verbal fluency, are associated with cognitive functions. However, the scaling laws in language in elderly people remain poorly understood. In the current study, we recorded large-scale data of one million words from group conversations among healthy elderly people and analyzed the relationship between spoken language and cognitive functions in terms of scaling laws, namely, Zipf's law and Heaps' law. We found that word patterns followed these scaling laws irrespective of cognitive function, and that the variations in Heaps' exponents were associated with cognitive function. Moreover, variations in Heaps' exponents were associated with the ratio of new words taken from the other participants' speech. These results indicate that the exponents of scaling laws in language are related to cognitive processes.

Environmentally relevant concentration of cypermethrin or/and sulfamethoxazole induce neurotoxicity of grass carp: Involvement of blood-brain barrier, oxidative stress and apoptosis

In water environment, the interaction between environmental pollutants is very complex, among which pesticides and antibiotics are dominant. However, most studies only focus on individual toxic effects, rather combined. In this study, the sub-chronic exposure effect of cypermethrin (CMN, 0.65 μg/L), sulfamethoxazole (SMZ, 0.30 μg/L) and their mixture on grass crap (Ctenopharyngodon idellus) was investigated. The brain tight junction, oxidative stress and apoptosis-related indices were determined after 42 days of exposure. In terms of brain function, acetyl cholinesterase (AChE) activity was significantly inhibited by CMN, SMZ and their mixtures during exposure periods. Obvious histological damage from cellular and subcellular levels were also observed, which were further confirmed by a decrease in tight junction protein levels. Malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OHdG) contents were significantly increased by individual compounds and mixtures, in which the content of glutathione (GSH) displayed the opposite trend. In mechanism, nuclear factor (erythrocyte derived 2) like 2(Nrf2) pathway was activated, which may trigger cellular protection to cope with CMN and SMZ exposure. However, apoptosis was also detected from the level of mRNA and histochemistry. In general, these two exogenous induced similar biological responses. The neurotoxicity of CMN was strengthened by SMZ with regard to these indices in most cases and vice versa. This study will reveal the potential co-ecological risks of pesticide and antibiotic in the aquatic organism, and provide basic data for their safety and risk assessment.

S245. BRAIN CONNECTIVITY CHANGES AFTER COGNITIVE REMEDIATION: A RESTING-STATE STUDY

BackgroundSome studies have showed how Cognitive Remediation is able to improve activation patterns in the frontal lobe. However, only few data on neuroconnectivity has been reported yet. Resting-state fMRI approach seems to be a promising methodology with potentiality for testing neuroconnectivity.MethodsA randomized and controlled trial was carried out with three groups: patients receiving Cognitive Remediation Therapy (CRT), patients receiving Social Skills Training (SST) as an active control, and a healthy control (HC) group. A resting-state fMRI data was acquired in part of the sample (n = 26 patients, n = 10 healthy controls) of a partner study (NCT 02341131). A data-driven approach using independent component analysis (ICA) was used to identify functional brain networks, which were compared between groups and group per time using a dual-regression approach.ResultsICA results revealed reduced functional connectivity between patients and controls in sensorimotor, basal ganglia, default mode and visual networks at baseline (p<0.05 FEW-corrected). After treatment, time per group analyses evidenced increased connectivity in sensorimotor network. Furthermore, group comparison at follow-up showed similar connectivity patterns between patients and healthy controls in sensorimotor network, but also in default mode and basal ganglia networks.DiscussionCognitive remediation could be able to strengthen some aspects of brain connectivity networks. Our data could be in line of the hypothesis of disconnectivity in schizophrenia. However, cognitive remediation but also social skills training seemed to be able to induce detectable changes in brain functioning in terms of restoring some aspects on the connectivity pattern.

Cholinesterase-inhibiting Potential and Anti-BACE1 Activities of Edible Leaves of Selected Thai Local Plants

Alzhiemer’s disease (AD) is common amongst the elderly and is associated with decline in brain functions in terms of memory and cognitive loss. The causes of the disease may occur through loss of presynaptic markers of cholinergic system and deposition of amyloid fibrils in the brain. Cholinesterases (ChEs) including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are the key enzymes controlling degradation of neurotransmitters, acetylcholines (AChs), in cholinergic hypothesis. Whereas overproduction of b-secretase (BACE1) can generate insoluble b-amyloid peptides. Thus, retardation on enzyme reactions can lead to potential AD prevention. The aim of this research was to investigate in vitro anti-AD activity through key enzymes inhibitions from Thai local plants with edible sour leaves, including Garcinia cowa Roxb., Spondias pinnata (Linn.f.) Kurz, Syzygium gratum (Wight) S.N. Mitra., Tamarind indica L. and Cratoxylum formosum (Jack) Dyer. Leaves were extracted in organic solvents with different polarity index values (ethanol and hexane). As results, all plants possessed different degrees of anti-ChEs activity, in which ethanolic extracts of Spondias pinnata and Tamarind indica exhibited significantly higher ChEs inhibitory activities than Syzygium gratum, Garcinia cowa and Cratoxylum formosum, respectively. Interestingly, most hexane extracts exhibited higher anti-AChE activities than ethanol extracts, while the contrary results were observed in anti-BChE activity. Besides, only Cratoxylum formosum, Garcinia cowa and Tamarind indica extracts possessed anti-BACE1 activity. The information received from this study would be great support of future drug development or nutraceutical agents against AD occurrence regarding its cholinergic and b-amyloid formation hypotheses.

Effects of acute aerobic and resistance exercise on executive function: An ERP study

ObjectivesThis study addressed the effects of acute, moderate-intensity aerobic and resistance exercise on the shifting aspect of cognition following a 30-min recovery period. It also explored the neuro-electrical activation that underlies the relationship between acute exercise and cognitive function through the examination of P3b and N1 components of event-related potentials. DesignA counterbalanced, repeated-measures experimental design. MethodsThirty-five volunteer young adults completed two experimental sessions (i.e., acute aerobic exercise (AE) and resistance exercise (RE), matched in terms of intensity, and one reading session (control). The AE entailed cycling at 60–70% of maximal heart rate reserve for 30min. In the RE session, participants performed seven exercises with two sets of 8–12 repetitions at 70% of 10-repetition maximum. Each participant's neuro-electrical activation was recorded 30min after each session while s/he completed the task-switching test. ResultsAfter the 30-min recovery period, both AE and RE elicited shorter response times in global switching (ηp2=0.24) and local switching (ηp2=0.16) were observed when compared to control. Additionally, larger P3b amplitudes (but not N1 amplitudes) were evident in global switching (ηp2=0.15) and local switching (ηp2=0.16), regardless of exercise modality. ConclusionsThe present findings suggest that acute exercise has positive effects on cognitive function. Exercise-induced alterations during the later stages of mental processing might result in superior performance. There were significant selective benefits in terms of brain function regardless of exercise modality.

The unfolding argument: Why IIT and other causal structure theories cannot explain consciousness.

How can we explain consciousness? This question has become a vibrant topic of neuroscience research in recent decades. A large body of empirical results has been accumulated, and many theories have been proposed. Certain theories suggest that consciousness should be explained in terms of brain functions, such as accessing information in a global workspace, applying higher order to lower order representations, or predictive coding. These functions could be realized by a variety of patterns of brain connectivity. Other theories, such as Information Integration Theory (IIT) and Recurrent Processing Theory (RPT), identify causal structure with consciousness. For example, according to these theories, feedforward systems are never conscious, and feedback systems always are. Here, using theorems from the theory of computation, we show that causal structure theories are either false or outside the realm of science.

Effects of emotionally induced language sounds on brain activations for communication

Emotions play an important role in human communication. We conducted a study to identify the effect of emotions in language sounds in terms of brain functions. The sounds of Japanese sentences spoken with and without emotion were reversed to eliminate their semantic influence on the subjects’ emotional perception. Three sets of sentences with non-emotional and happy, sad, and angry emotional tones were recorded and reversed. The brain activities of 20 native Japanese speakers in their twenties were monitored by near-infrared spectroscopy (NIRS) while they listened to the reversed Japanese sounds with and without the emotions. Our analysis of the experimental results demonstrated that almost all the brain areas monitored by the NIRS probes were activated more when the subjects listened to emotional language sounds than to non-emotional sounds. In particular, the frontopolar cortex area, which is associated with short-term memory, was significantly activated. Since short-term memory is known to provide important information for communication, these results suggest that emotional aspects of language sounds are essential for successful communication and thus should be implemented in human–robot communication systems.

Joint pattern analysis applied to PET DAT and VMAT2 imaging reveals new insights into Parkinson's disease induced presynaptic alterations.

Most neurodegenerative diseases are known to affect several aspects of brain function, including neurotransmitter systems, metabolic and functional connectivity. Diseases are generally characterized by common clinical characteristics across subjects, but there are also significant inter-subject variations. It is thus reasonable to expect that in terms of brain function, such clinical behaviors will be related to a general overall multi-system pattern of disease-induced alterations and additional brain system-specific abnormalities; these additional abnormalities would be indicative of a possible unique system response to disease or subject-specific propensity to a specific clinical progression.Based on the above considerations we introduce and validate the use of a joint pattern analysis approach, canonical correlation analysis and orthogonal signal correction, to analyze multi-tracer PET data to identify common (reflecting functional similarities) and unique (reflecting functional differences) information provided by each tracer/target. We apply the method to [11C]-DTBZ (VMAT2 marker) and [11C]-MP (DAT marker) data from 15 early Parkinson's disease (PD) subjects; the behavior of these two tracers/targets is well characterized providing robust reference information for the method's outcome. Highly significant common subject profiles were identified that decomposed the characteristic dopaminergic changes into three distinct orthogonal spatial patterns: 1) disease-induced asymmetry between the less and more affected dorsal striatum; 2) disease-induced gradient with caudate and ventral striatum being relatively spared compared to putamen; 3) progressive loss in the less affected striatum, which correlated significantly with disease duration (p < 0.01 for DTBZ, p < 0.05 for MP). These common spatial patterns reproduce all known aspects of these two targets/tracers. In addition, orthogonality of the patterns may indicate different mechanisms underlying disease initiation or progression. Information unique to each tracer revealed a residual striatal asymmetry when targeting VMAT2, consistent with the notion that VMAT2 density is highly related to terminal degeneration; and a residual DAT disease-induced gradient in the striatum with relative DAT preservation in the substantia nigra. This finding may be indicative either of a possible DAT specific early disease compensation and/or related to disease origin.These results demonstrate the applicability and relevance of the joint pattern analysis approach to datasets obtained with two PET tracers; this data driven method, while recapitulating known aspects of the PD-induced tracer/target behaviour, was found to be statistically more robust and provided additional information on (i) correlated behaviors of the two systems, identified as orthogonal patterns, possibly reflecting different disease-induced alterations and (ii) system specific effects of disease. It is thus expected that this approach will be very well suited to the analysis of multi-tracer and/or multi-modality data and to relating the outcomes to different aspects of disease.

Brain electroencephalographic segregation as a biomarker of learning

The aim of the present study was to understand whether modeling brain function in terms of network structure makes it possible to find markers of prediction of motor learning performance in a sensory motor learning task. By applying graph theory indexes of brain segregation – such as modularity and transitivity – to functional connectivity data derived from electroencephalographic (EEG) rhythms, we further studied pre- (baseline) versus post-task brain network architecture to understand whether motor learning induces changes in functional brain connectivity. The results showed that, after the training session with measurable learning, transitivity increased in the alpha1 EEG frequency band and modularity increased in the theta band and decreased in the gamma band, suggesting that brain segregation is modulated by the cognitive task. Furthermore, it was observed that theta modularity at the baseline negatively correlated with the performance improvement; namely, the lower this connectivity index at the baseline pre-task period, the higher the improvement of performance with training. The present results show that brain segregation is modulated by the cognitive task and that it is possible to predict performance by the study of pre-task EEG rhythm connectivity parameters.

Brain disease, connectivity, plasticity and cognitive therapy: A neurological view of mental disorders

IntroductionOur conception of the mind-brain relationship has evolved from the traditional idea of dualism to current evidence that mental functions result from brain activity. This paradigm shift, combined with recent advances in neuroimaging, has led to a novel definition of brain functioning in terms of structural and functional connectivity. The purpose of this literature review is to describe the relationship between connectivity, brain lesions, cerebral plasticity, and functional recovery. DevelopmentAssuming that brain function results from the organisation of the entire brain in networks, brain dysfunction would be a consequence of altered brain network connectivity. According to this approach, cognitive and behavioural impairment following brain damage result from disrupted functional organisation of brain networks. However, the dynamic and versatile nature of these circuits makes recovering brain function possible. Cerebral plasticity allows for functional reorganisation leading to recovery, whether spontaneous or resulting from cognitive therapy, after brain disease. ConclusionsCurrent knowledge of brain connectivity and cerebral plasticity provides new insights into normal brain functioning, the mechanisms of brain damage, and functional recovery, which in turn serve as the foundations of cognitive therapy.