Posterior Precuneus Research Articles

The Neural Correlates of Visual Perspective Taking: a Critical Review

Visual perspective taking (VPT) enables us to understand, anticipate, and interact with other social beings by accurately computing how and what they see in their environment. The present review provides an up-to-date review of the neural mechanisms underpinning VPT that integrates all neuroscientific methods and, importantly, organizes studies based on the distinct cognitive dimensions of VPT they measure. Recent studies are characterized by a greater use of transcranial stimulation and a more diverse use of contrasts in analyses. Recent findings suggest namely that the temporoparietal junction has multiple roles in VPT and that the dorsal posterior precuneus is neither related to the inferential process nor the decentering process of VPT. By organizing the findings according the respective cognitive processes tapped into, this review sheds a new light on the neural bases of VPT and advocates for an approach that acknowledges the multidimensionality of VPT.

Distributed affective space represents multiple emotion categories across the human brain.

The functional organization of human emotion systems as well as their neuroanatomical basis and segregation in the brain remains unresolved. Here, we used pattern classification and hierarchical clustering to characterize the organization of a wide array of emotion categories in the human brain. We induced 14 emotions (6 ‘basic’, e.g. fear and anger; and 8 ‘non-basic’, e.g. shame and gratitude) and a neutral state using guided mental imagery while participants' brain activity was measured with functional magnetic resonance imaging (fMRI). Twelve out of 14 emotions could be reliably classified from the haemodynamic signals. All emotions engaged a multitude of brain areas, primarily in midline cortices including anterior and posterior cingulate gyri and precuneus, in subcortical regions, and in motor regions including cerebellum and premotor cortex. Similarity of subjective emotional experiences was associated with similarity of the corresponding neural activation patterns. We conclude that different basic and non-basic emotions have distinguishable neural bases characterized by specific, distributed activation patterns in widespread cortical and subcortical circuits. Regionally differentiated engagement of these circuits defines the unique neural activity pattern and the corresponding subjective feeling associated with each emotion.

O154 Deactivation of default mode network in focal epilepsy, inferred by single pulse electrical stimulation

Objective To investigate default-mode network (DMN) deactivation in different types of focal epilepsy by single pulse electric stimulation (SPES). Method We analyzed 18 patients with focal epilepsy (8 frontal, 8 temporal, 2 posterior), implanted with depth electrodes. SPES was applied to each pair of adjacent contacts in seiwure onset zone (SOZ), and responses were recorded from the 10 different DMN-hubs; The responses to SPES in Gamma, Ripple (R) and Fast-Ripple (FR) bands were quantified in a 60–250 ms time-window following each stimulation pulse and compared to baseline. Time of propagation was determined based on N1 latency. These responses were compared across the three epilepsy types. Results Overall, we observed a significant deactivation of the DMN in the upper frequency ranges for all epilepsies (75% drop from baseline for gamma and 93% for R and FR). In the gamma band, the stimulation of frontal SOZs deactivated the ipsilateral posterior cingulate and precuneus significantly more than in the other epilepsy-types, with shorter general latencies of 22, 25 and 23 ms, respectively. Discussion Our results might explain why in prefrontal focal epilepsies and in generalized epilepsies, thought to have a frontal generator, the consciousness is preferentially and significantly impaired. Significance This is a promising method for quantifying the engagement of the consciousness processing areas by the epileptic focus. Detailed illustrations and tables for all 10 DMN-hubs, in all 3 high-frequency bands are provided.

Cortical and Subcortical Contributions to Long-Term Memory-Guided Visuospatial Attention.

Long-term memory (LTM) helps to efficiently direct and deploy the scarce resources of the attentional system; however, the neural substrates that support LTM-guidance of visual attention are not well understood. Here, we present results from fMRI experiments that demonstrate that cortical and subcortical regions of a network defined by resting-state functional connectivity are selectively recruited for LTM-guided attention, relative to a similarly demanding stimulus-guided attention paradigm that lacks memory retrieval and relative to a memory retrieval paradigm that lacks covert deployment of attention. Memory-guided visuospatial attention recruited posterior callosal sulcus, posterior precuneus, and lateral intraparietal sulcus bilaterally. Additionally, 3 subcortical regions defined by intrinsic functional connectivity were recruited: the caudate head, mediodorsal thalamus, and cerebellar lobule VI/Crus I. Although the broad resting-state network to which these nodes belong has been referred to as a cognitive control network, the posterior cortical regions activated in the present study are not typically identified with supporting standard cognitive control tasks. We propose that these regions form a Memory-Attention Network that is recruited for processes that integrate mnemonic and stimulus-based representations to guide attention. These findings may have important implications for understanding the mechanisms by which memory retrieval influences attentional deployment.

Cocaine and HIV are independently associated with neural activation in response to gain and loss valuation during economic risky choice.

Stimulant abuse is disproportionately common in HIV-positive persons. Both HIV and stimulants are independently associated with deficits in reward-based decision making, but their interactive and/or additive effects are poorly understood despite their prevalent co-morbidity. Here, we examined the effects of cocaine dependence and HIV infection in 69 adults who underwent functional magnetic resonance imaging while completing an economic loss aversion task. We identified two neural networks that correlated with the evaluation of the favorable characteristics of the gamble (i.e. higher gains/lower losses: ventromedial prefrontal cortex, anterior cingulate, anterior and posterior precuneus and visual cortex) versus unfavorable characteristics of the gamble (i.e. lower gains/higher losses: dorsal prefrontal, lateral orbitofrontal, posterior parietal cortex, anterior insula and dorsal caudate). Behaviorally, cocaine and HIV had additive effects on loss aversion scores, with HIV-positive cocaine users being the least loss averse. Cocaine users had greater activation in brain regions that tracked the favorability of gamble characteristics (i.e. increased activation to gains, but decreased activation to losses). In contrast, HIV infection was independently associated with lesser activation in regions that tracked the unfavorability of gamble characteristics. These results suggest that cocaine is associated with an overactive reward-seeking system, while HIV is associated with an underactive cognitive control system. Together, these alterations may leave HIV-positive cocaine users particularly vulnerable to making unfavorable decisions when outcomes are uncertain.

Precuneal epilepsy: Clinical features and surgical outcome.

The precuneus is a complex and highly connected structure located in the medial portion of the superior parietal lobule. The clinical presentation of precuneal epilepsy is poorly characterized, mostly because these patients have seldom been distinguished from those with other types of parietal lobe epilepsy. The present study aims to improve the understanding of precuneal epilepsy by detailing its clinical features and surgical outcomes. Six previously unreported cases of drug-resistant precuneal epilepsy investigated between 2002 and 2014 were retrospectively studied. Seizure focus was confirmed by presence of a lesion, intracranial monitoring, or post-operative seizure control when applicable. Seizures arising from the precuneus have heterogeneous presentations, including body movement sensation, visual auras, eye movements, vestibular manifestations, and complex motor behaviors. Two patients with an anterior precuneus lesion described body movement sensations whereas two others with a posterior precuneus lesion experienced visual symptoms. Two of the five patients who underwent epilepsy surgery achieved good seizure control (Engel IA). One patient underwent gamma knife surgery with an Engel IV outcome. Surgical complications included contralateral visual field impairment, limb hypoesthesia and hemispatial neglect. One patient developed late-onset epilepsia partialis continua from a Rolandic subdural grid-related contusion. In absence of a clear precuneal epileptogenic lesion, recognition of a precuneal focus is challenging. Magnetoencephalography may sometimes localize the generator but invasive EEG remains in well-selected cases necessary to identify the seizure focus. Surgical failures may be explained by the widespread connectivity of the precuneus with distant and adjacent structures. Different ictal manifestations of precuneal epilepsy in this series provide a clinical correlate to the described functional subdivisions of the precuneus.

Diminished Posterior Precuneus Connectivity with the Default Mode Network Differentiates Normal Aging from Alzheimer's Disease.

Both normal aging and Alzheimer's disease (AD) have been associated with a reduction in functional brain connectivity. It is unknown how connectivity patterns due to aging and AD compare. Here, we investigate functional brain connectivity in 12 young adults (mean age 22.8 ± 2.8), 12 older adults (mean age 73.1 ± 5.2) and 12 AD patients (mean age 74.0 ± 5.2; mean MMSE 22.3 ± 2.5). Participants were scanned during 6 different sessions with resting state functional magnetic resonance imaging (RS-fMRI), resulting in 72 scans per group. Voxelwise connectivity with 10 functional networks was compared between groups (p < 0.05, corrected). Normal aging was characterized by widespread decreases in connectivity with multiple brain networks, whereas AD only affected connectivity between the default mode network (DMN) and precuneus. The preponderance of effects was associated with regional gray matter volume. Our findings indicate that aging has a major effect on functional brain interactions throughout the entire brain, whereas AD is distinguished by additional diminished posterior DMN-precuneus coherence.

Regional gray matter volume in the posterior precuneus is associated with general self-efficacy.

Motivation in doing a task is influenced not only by the expected outcome of the task but also by the belief that one has in successfully executing the task. Over time, individuals accumulate experiences that contribute toward a general belief in one's overall ability to successfully perform tasks, which is called general self-efficacy (GSE). We investigated the relationship between regional gray matter volume and individual differences in GSE. Brain anatomy was analyzed using magnetic resonance images obtained from 64 healthy right-handed participants who had completed Sherer's GSE scale. After controlling for other factors related to motivation, age, sex, and total gray matter volume of each participant, results showed that regional gray matter volume in the posterior part of the precuneus significantly and positively correlated with the GSE score. These results suggest that one's accumulated experiences of success and failure, which contribute toward GSE, also influence the anatomical characteristics of the precuneus.

Functional alterations of fronto-limbic circuit and default mode network systems in first-episode, drug-naïve patients with major depressive disorder: A meta-analysis of resting-state fMRI data

BackgroundThe neurobiological mechanisms of depression are increasingly being explored through resting-state brain imaging studies. However, resting-state fMRI findings have varied, perhaps because of differences between study populations, which included the disorder course and medication use. The aim of our study was to integrate studies of resting-state fMRI and explore the alterations of abnormal brain activity in first-episode, drug-naïve patients with major depressive disorder. MethodsRelevant imaging reports in English were searched, retrieved, selected and subjected to analysis by activation likelihood estimation, a coordinate-based meta-analysis technique (final sample, 31 studies). Coordinates extracted from the original reports were assigned to two categories based on effect directionality. ResultsCompared with healthy controls, the first-episode, medication-naïve major depressive disorder patients showed decreased brain activity in the dorsolateral prefrontal cortex, superior temporal gyrus, posterior precuneus, and posterior cingulate, as well as in visual areas within the occipital lobe, lingual gyrus, and fusiform gyrus, and increased activity in the putamen and anterior precuneus. LimitationsNot every study that has reported relevant data met the inclusion criteria. ConclusionResting-state functional alterations were located mainly in the fronto-limbic system, including the dorsolateral prefrontal cortex and putamen, and in the default mode network, namely the precuneus and superior/middle temporal gyrus. Abnormal functional alterations of the fronto-limbic circuit and default mode network may be characteristic of first-episode, drug-naïve major depressive disorder patients.

Potential Clinical Value of Multiparametric PET in the Prediction of Alzheimer's Disease Progression.

ObjectiveTo evaluate the potential clinical value of quantitative functional FDG PET and pathological amyloid-β PET with cerebrospinal fluid (CSF) biomarkers and clinical assessments in the prediction of Alzheimer’s disease (AD) progression.MethodsWe studied 82 subjects for up to 96 months (median = 84 months) in a longitudinal Alzheimer’s Disease Neuroimaging Initiative (ADNI) project. All preprocessed PET images were spatially normalized to standard Montreal Neurologic Institute space. Regions of interest (ROI) were defined on MRI template, and standard uptake values ratios (SUVRs) to the cerebellum for FDG and amyloid-β PET were calculated. Predictive values of single and multiparametric PET biomarkers with and without clinical assessments and CSF biomarkers for AD progression were evaluated using receiver operating characteristic (ROC) analysis and logistic regression model.ResultsThe posterior precuneus and cingulate SUVRs were identified for both FDG and amyloid-β PET in predicating progression in normal controls (NCs) and subjects with mild cognitive impairment (MCI). FDG parietal and lateral temporal SUVRs were suggested for monitoring NCs and MCI group progression, respectively. 18F-AV45 global cortex attained (78.6%, 74.5%, 75.4%) (sensitivity, specificity, accuracy) in predicting NC progression, which is comparable to the 11C-PiB global cortex SUVR’s in predicting MCI to AD. A logistic regression model to combine FDG parietal and posterior precuneus SUVR and Alzheimer’s Disease Assessment Scale-Cognitive (ADAS-Cog) Total Mod was identified in predicating NC progression with (80.0%, 94.9%, 93.9%) (sensitivity, specificity, accuracy). The selected model including FDG posterior cingulate SUVR, ADAS-Cog Total Mod, and Mini-Mental State Exam (MMSE) scores for predicating MCI to AD attained (96.4%, 81.2%, 83.6%) (sensitivity, specificity, accuracy). 11C-PiB medial temporal SUVR with MMSE significantly increased 11C-PiB PET AUC to 0.915 (p<0.05) in predicating MCI to AD with (77.8%, 90.4%, 88.5%) (sensitivity, specificity, accuracy).ConclusionQuantitative FDG and 11C-PiB PET with clinical cognitive assessments significantly improved accuracy in the predication of AD progression.

The Self-Pleasantness Judgment Modulates the Encoding Performance and the Default Mode Network Activity.

In this functional magnetic resonance imaging (fMRI) study, we evaluated the effect of self-relevance on cerebral activity and behavioral performance during an incidental encoding task. Recent findings suggest that pleasantness judgments reliably induce self-oriented (internal) thoughts and increase default mode network (DMN) activity. We hypothesized that this increase in DMN activity would relate to increased memory recognition for pleasantly-judged stimuli (which depend on internally-oriented attention) but decreased recognition for unpleasantly-judged items (which depend on externally-oriented attention). To test this hypothesis, brain activity was recorded from 21 healthy participants while they performed a pleasantness judgment requiring them to rate visual stimuli as pleasant or unpleasant. One hour later, participants performed a surprise memory recognition test outside of the scanner. Thus, we were able to evaluate the effects of pleasant and unpleasant judgments on cerebral activity and incidental encoding. The behavioral results showed that memory recognition was better for items rated as pleasant than items rated as unpleasant. The whole brain analysis indicated that successful encoding (SE) activates the inferior frontal and lateral temporal cortices, whereas unsuccessful encoding (UE) recruits two key medial posterior DMN regions, the posterior cingulate cortex (PCC) and precuneus (PCU). A region of interest (ROI) analysis including classic DMN areas, revealed significantly greater involvement of the medial prefrontal cortex (mPFC) in pleasant compared to unpleasant judgments, suggesting this region’s involvement in self-referential (i.e., internal) processing. This area may be responsible for the greater recognition performance seen for pleasant stimuli. Furthermore, a significant interaction between the encoding performance (successful vs. unsuccessful) and pleasantness was observed for the PCC, PCU and inferior frontal gyrus (IFG). Overall, our results suggest the involvement of medial frontal and parietal DMN regions during the evaluation of self-referential pleasantness. We discuss these results in terms of the introspective referential of pleasantness judgments and the differential brain modulation based on internally- vs. externally-oriented attention during encoding.

Abstract TP457: Brain Functional Alterations in Patients With Leukoaraiosis Associated Mild Cognitive Impairment

Background and aims: Recent studies demonstrated that a signal change of functional magnetic resonance imaging (fMRI) in certain brain areas during the resting state is a significant marker in patients with mild cognitive impairment (MCI). However, the research of resting-state fMRI (rs-fMRI) on leukoaraiosis (LA) associated MCI is scarce. The aim of this study was to investigate differences of the rs-fMRI default network between patients with LA-associated MCI and normal subjects, and provide functional imaging evidence of LA-associated MCI during early stages of the disease. Method: All subjects were outpatients or thier residents of the Department of Neurology of the Beijing Tiantan Hospital. They were divided into MCI group and control group according to their cognitive function assessing by the Hamilton Depression Scale, Clinical Dementia Rating (CDR), Mini Mental State Exam and Montreal Cognitive Assessment. Demographic information was recorded. Brain MRI characteristics were assessed using the Fazekas scale. The independent components of fMRI data were analyzed by fMRI tool box. The experimental data and confounding factors were analyzed by General Liner Model. Results: A total of 31 right-handed patients with LA-associated MCI and 27 right-handed healthy control subjects were included. The active areas participating in the resting state for LA-associated MCI group were mostly consistent with those of the control group. Compared with controls, the LA-associated MCI patients exhibited significantly lower blood oxygen level-dependent (BOLD) signals in the left anterior cingulate cortex (P=0.021) and right parahippocampal gyrus (P=0.032). Whereas higher BOLD signals during the resting state in LA-associated MCI patients were observed in the left caudate nucleus (P=0.015), right frontal lobe (P=0.004), superior temporal gyrus and inferior parietal gyrus (P=0.001), No significant difference was shown in the posterior cingulate cortex and precuneus (P=0.138). Conclusion: Our findings demonstrated that the discriminating functional activation in specific brain areas could be identified in patients with LA-associated MCI, which might be used as an useful neuroimaging evidence for the early recognition of these patients.

The Impact of UNC5C Genetic Variations on Neuroimaging in Alzheimer's Disease.

UNC5C, which is a transmembrane receptor for netrin-1 to trigger the apoptosis, has been confirmed as a new risk factor for Alzheimer's disease (AD) recently. However, there is lack of the evidence on the brain structure associated with the polymorphisms of UNC5C in AD. The objective of this study is to investigate the influence of UNC5C loci on the neuroimaging of strategic regions of AD. In 812 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset, we explored the genotypes of UNC5C loci in the volumes of the hippocampus, parahippocampal gyrus, posterior cingulate gyrus, middle temporal and precuneus, and the thickness of the entorhinal cortex which are measured by magnetic resonance imaging (MRI). We also investigated the atrophy rate of above structures influenced by UNC5C loci using the longitudinal data. UNC5C loci were associated with the volume of right middle temporal (rs34585936 Pc = 0.0031). Meanwhile, the polymorphisms of UNC5C loci could alter the atrophy rate of strategic regions especially the left hippocampus (rs72672784 Pc = 0.0090; rs13120458 Pc = 0.0434; rs34875919 Pc = 0.0434) and right precuneus (rs72672784 Pc = 0.0068; rs2001246 Pc = 0.0055; rs74690179 Pc = 0.0055). UNC5C genotypes were significantly associated with the volume of the middle temporal on MRI; meanwhile, UNC5C loci could alter the atrophy of strategic regions of AD such as the hippocampus and precuneus. And the above effects of polymorphisms of UNC5C were more obvious in the population with the impaired cognition than those with the normal cognition.

Application of cerebral MR perfusion imaging using pulsed arterial spin labeling technique in patients with amnestic-type mild cognitive impairment and mild Alzheimer disease

Objective To study the value of relative cerebral blood flow (rCBF) changes in patients with amnestic-type mild cognitive impairment (aMCI) and mild Alzheimer disease (AD) using MRI pulsed arterial spin labeling (PASL). Methods A prospective study recruited 37 aMCI patients (aMCI group) , 30 mild AD patients (mild AD group) and 30 healthy volunteers (normal control group) from March 2011 to December 2013, MRI using PASL for cerebral perfusion imaging was performed and data of rCBF were collected. Taking age as covariate, analysis of variance (ANONA) was carried out to assess the difference of rCBF among all the three groups, then Bonferroni was done between every two groups. A follow-up examination using PASL was performed in the seventeen patients of the aMCI group. And paired t-test was used for comparing the longitudinal change of their rCBF data. Results Compared with the normal control group, the aMCI group showed significant increase of rCBF in bilateral posterior cingulate cortices and precuneus (cluster number 2 785, P<0.05). While the mild AD group showed decrease of rCBF in the left inferior and superior parietal lobes, the angular, middle frontal lobe, as well as the right superior temporal lobe (cluster number 3 459-5 206, P<0.05). When compared with the aMCI group, the mild AD group showed regional hypoperfusion in bilateral middle frontal lobes, the left precuneus, the right postcentral and inferior parietal lobe (cluster number 3 236-19 863, P<0.05). In the longitudinal study of the 17 aMCI patients, an increased rCBF was found to coexist with reduced rCBF in the left inferior frontal and lateral occipital cortex, bilateral frontal poles and paracingulate gyrus, with hyperperfusion dominated. Increased rCBF was also detected in the left temporal lobe, the angular gyrus and precuneus, while decreased rCBF was present in the left putamen, the operculum and right corpus callosum (P<0.05). Conclusions ASL perfusion imaging is a valuable method for dynamic monitoring of the cerebral perfusion changes in aMCI and AD patients. PASL will assist in finding a useful imaging biomarker for early diagnosis of AD. Key words: Cognition disorders; Alzheimer disease; Magnetic resonance imaging

The resting-state functional connectivity of the hypothalamus and its relationships with gonadal steroid hormones and depression symptoms in perimenopausal women

This study aimed to investigate the resting-state functional connectivity of the hypothalamus and its relationships with gonadal steroid hormones and depression symptoms in perimenopausal women. Total 66 perimenopausal women voluntarily participated in this study from October 2012 to June 2013. Zung Self-rating Depression Scale (ZSDS) was used to assess depression symptoms. Plasma gonadal steroid hormones including estradiol, testosterone, and progesterone were determined by the chemiluminescence immunoassay. A 3.0 Tesla magnetic resonance imaging (MRI) scanner was utilized to acquire resting-state functional MRI data. The z-value functional connectivity map of each participant was calculated voxel-wisely based on the seed region of the hypothalamus. One sample t test of Statistical Parametric Mapping (SPM) were used to determine the brain areas with statistically significant functional connectivity to the hypothalamus, then multiple regression of SPM was used to calculate the correlated areas with 3 gonadal steroid hormones, respectively. Finally, Pearson correlation was performed to analyze bivariate correlations between mean z-values and ZSDS scores. Significant functional connectivity to the hypothalamus were found in brain areas as follows:the lateral inferior frontal gyrus, medial prefrontal cortex, dorsal lateral prefrontal cortex, orbitofrontal cortex, subgenual cortex, anterior cingulate cortex, posterior cingulate cortex, cuneus and precuneus, hippocampus and parahippocampal gyrus, and angular gyrus (False Discovery Rate q<0.05). Among these areas, the plasma testosterone level was positively related to the functional connectivity strength of the right angular gyrus, and negatively related to the strengths of the right subgenual cortex and bilateral medial superior frontal gyrus to the hypothalamus (PAlphaSim<0.05). Especially, mean z-value in the subgenual cortex was positively related to the ZSDS index score (r=0.279, P=0.023), and factor scores of the core depression symptoms (r=0.278, P=0.024) and somatic symptoms (r=0.357, P=0.003). In perimenopausal women, the hypothalamus has resting-state functional connectivity with widespread areas involved in the brain depression-related network and default mode network, and the plasma androgen level may modulate the functional connectivity strengths of the hypothalamus and decrease the susceptibility of perimenopausal women to depression.

Common and distinct networks for self-referential and social stimulus processing in the human brain.

Self-referential processing is a complex cognitive function, involving a set of implicit and explicit processes, complicating investigation of its distinct neural signature. The present study explores the functional overlap and dissociability of self-referential and social stimulus processing. We combined an established paradigm for explicit self-referential processing with an implicit social stimulus processing paradigm in one fMRI experiment to determine the neural effects of self-relatedness and social processing within one study. Overlapping activations were found in the orbitofrontal cortex and in the intermediate part of the precuneus. Stimuli judged as self-referential specifically activated the posterior cingulate cortex, the ventral medial prefrontal cortex, extending into anterior cingulate cortex and orbitofrontal cortex, the dorsal medial prefrontal cortex, the ventral and dorsal lateral prefrontal cortex, the left inferior temporal gyrus, and occipital cortex. Social processing specifically involved the posterior precuneus and bilateral temporo-parietal junction. Taken together, our data show, not only, first, common networks for both processes in the medial prefrontal and the medial parietal cortex, but also, second, functional differentiations for self-referential processing versus social processing: an anterior-posterior gradient for social processing and self-referential processing within the medial parietal cortex and specific activations for self-referential processing in the medial and lateral prefrontal cortex and for social processing in the temporo-parietal junction.

Experimental endotoxemia induces increased functional connectivity between the thalamus and the default mode network in healthy men

While functional MRI studies revealed altered task-related BOLD responses during experimental endotoxemia, little is known how systemic inflammation affects resting state activity of the brain. In this randomized, placebo-controlled study, healthy men received either low-dose (0.4 ng/kg) lipopolysaccharide (LPS) (N = 20) or saline (N = 25). Resting state activity was measured at baseline and 3.5 h post-injection. In multi-subject independent component analysis (ICA), 13 out of 30 components were identified which displayed the common networks assigned to resting state brain activity. Dual regression analyses revealed that LPS-treated subjects exhibited distinct patterns of connectivity within multiple resting state networks, including the somatosensory network compared to baseline and the fronto-parietal network compared to placebo. Seed based resting state analysis showed greater functional connectivity between left thalamus and right posterior insula, left posterior cingulate cortex (BA 31), left precuneus, and cerebellum (bilateral) after LPS injection compared to placebo. Together, our data indicate that resting state activity of the brain is altered during systemic inflammation, including an increased functional connectivity between the thalamus and other brain regions which are part of the default mode network. This may reflect an increased integrative processing of interoceptive input arising from the vagus/brainstem, aiming to maintain homeostasis, and to promote a more internally focused self-reflection during states of inflammation. It remains to be determined if LPS-induced alterations in resting state parameters are associated with immune-mediated mood impairments.

Insight into the precuneus: a novel seizure semiology in a child with epilepsy arising from the right posterior precuneus

To date, there is limited understanding of the role of the precuneus. fMRI studies have suggested its involvement in a wide spectrum of highly integrated tasks, including spatially-guided behaviour, visuo-spatial imagery, and consciousness. We present a patient with intractable parietal lobe epilepsy arising from a lesion localized to the right precuneus. Two seizure types with distinct semiologies were captured on video-EEG monitoring. The first type consisted of an urge described as a "feeling of wanting to move". On video analysis, the patient is seen to turn his head and body to his left. He remains conscious, he is able to answer questions and when asked, he can look to his right. This seizure was associated with an ictal pattern localized to the right parieto-occipital region. The second seizure type consisted of reading-induced visual distortion with macropsia and micropsia. Interictally, intermittent rhythmic slowing and spikes were seen and localized to the parietal midline and the right parieto-occipital regions. Our patient's seizures are positive phenomena of the right precuneus and its related processing network. They represent unique seizure semiologies that offer further insight into the role of the precuneus in spatial awareness, visuo-spatial processing and consciousness.

Cognitive Control Network Contributions to Memory-Guided Visual Attention.

Visual attentional capacity is severely limited, but humans excel in familiar visual contexts, in part because long-term memories guide efficient deployment of attention. To investigate the neural substrates that support memory-guided visual attention, we performed a set of functional MRI experiments that contrast long-term, memory-guided visuospatial attention with stimulus-guided visuospatial attention in a change detection task. Whereas the dorsal attention network was activated for both forms of attention, the cognitive control network(CCN) was preferentially activated during memory-guided attention. Three posterior nodes in the CCN, posterior precuneus, posterior callosal sulcus/mid-cingulate, and lateral intraparietal sulcus exhibited the greatest specificity for memory-guided attention. These 3 regions exhibit functional connectivity at rest, and we propose that they form a subnetwork within the broader CCN. Based on the task activation patterns, we conclude that the nodes of this subnetwork are preferentially recruited for long-term memory guidance of visuospatial attention.

Psychoanalysis and Functional Magnetic Resonance Imaging: a Systematic Review

Purpose of the Study In the last ten years it has sought a connection between the psychoanalysis and the neuroscience. The meeting point between these two branches is the neuropsychoanalysis [1]. Methods A literature search was conducted on March 2014. PubMed and Scopus databases were used to find studies for inclusion in the systematic review. The keywords used for the literature search were: ‘psychoanalysis”, ‘psychoanalytic psychotherapy”, ‘psychodynamic”, ‘psychodynamic psychotherapy”, ‘fmri”, ‘functional neuroimaging” and ‘functional magnetic resonance”. keywords were used together with the logical operator ‘and”. Only studies wich compared functional magnetic resonance imaging results before and after psychoanalytic psychotherapy in adult subjects were taken into account. Two (n=2) potentially relevant studies were obtained for the systematic review. AUTHOR SCANNER PARTICIPANTS TYPE OF THERAPY MAIN FINDINGS Buchheim et al. 2013 3.0 Tesla A female dysthymic patient with narcissistic traits Standard long-term psychoanal­ysis with a frequency of two face-to-face sessions per week. The results show the therapy hours modulated the attivaction of the ventrolateral and the dorsolateral prefrontal cortex, the perigenual portion of the medial prefrontal cortex, the posterior cingulate and precuneus, the middle temporal gyrus, and the anterior tip of the inferior temporal gyrus, and the occipital/calcarine cortex. Fischmann et al. 2013 3.0 Tesla 16 patients with recurrent major depressive disorders and 18 healthy volunteers 3-year psychoanalytic treatment After treatment, it was found a marked reduction in activation pattern occipital, left and right hippocampus, left and right thalamus, left precuneus, left middle cingulated cortex, left inferior frontal gyrus/pars orbitalis, left precentral gyrus, vermis, left inferior frontal gyrus, right middle temporal gyrus, superior parietal lobule, cerebellum, and right and left putamen. Summary As shown in the table, Buchheim et al. study results demostrate that the therapy hours modulated the attivaction of brain areas. After treatment, Fischmann et al. found a marked reduction in activation pattern. Conlcusions The common results of the studies investigated in this systematic review is represented by a reduction, a modulation or a normalization of the activation areas before and after the psychoanalytic psychotherapy.