Identifying neural correlates of visual consciousness with ALE meta-analyses

Previous functional magnetic resonance imaging studies indicated that acupuncture could activate the brain regions in patients with migraine. However, these studies showed inconsistent results. This activation likelihood estimation (ALE) meta-analysis aimed to investigate the consistent activated change of brain regions between pre- and post-acupuncture treatment in migraineurs. We conducted a literature search in PubMed, Embase, Web of Science, the Cochrane Library, the China National Knowledge Infrastructure, the Chinese Science and Technology Periodical Database, the Wanfang Database, and the Chinese Biomedical Literature Database from their inception to 18 August, 2022, to obtain articles assessing the functional magnetic resonance imaging changes of acupuncture for migraine. Two investigators independently performed literature selection, data extraction, and quality assessment. The methodological quality was assessed with a modified version of the checklist. The reporting quality of interventions among included studies was evaluated by the Revised Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA). Our meta-analysis was conducted according to the GingerALE software. The Jackknife sensitivity analysis was used to assess the robustness of the results. 14 articles were finally included according to the eligible criteria. Regarding the immediate effect of acupuncture on migraine, the ALE meta-analysis demonstrated that the deactivation regions were mainly located in the superior frontal gyrus, and middle frontal gyrus (uncorrected P < 0.001). The ALE meta-analysis of the cumulative effect showed that the activation regions were the thalamus, superior frontal gyrus, posterior lobe of the cerebellum, insula, middle frontal gyrus, precentral gyrus, anterior cingulate, and the deactivation brain regions were located in the transverse temporal gyrus, postcentral gyrus, superior temporal gyrus, anterior cingulate, parahippocampal gyrus, inferior parietal lobule, and inferior occipital gyrus (uncorrected P < 0.001). Acupuncture could activate multiple brain areas related with the regulation of pain conduction, processing, emotion, cognition, and other brain regions in patients with migraine. In the future, the combination of multiple imaging technologies could be a new approach to deeply investigate the central mechanism of acupuncture for migraine.

The aim of the study was to elucidate the correlation between spatially distinct brain areas with a full bladder from the perspective of functional connectivity using resting-state functional magnetic resonance imaging (rs-fMRI) with simultaneous urodynamic testing in healthy volunteers. The brain regions with full and empty bladders were reported via rs-fMRI using a 3T magnetic resonance system. Then, we identified brain regions that are activated during bladder filling by calculating the amplitude of low-frequency fluctuation (ALFF) values using brain imaging software (DPABI and SPM8) and empirically derived six regions of interest (ROI) from analysis of activation were used as seeds for resting-state functional connectivity (rs-FC) analysis with the rest of the brain to examine differences in the two conditions. Statistical analysis was performed with a paired t-test and statistical significance was defined as a P < 0.01. Twenty-two healthy volunteers (11 men and 11 women) 35-64years of age were enrolled. The rs-fMRI scans of 22 healthy volunteers were analyzed. After motion correction, two subjects were excluded. Meaningful data were obtained on 20 of these subjects. Compared with an empty bladder, functional connection enhancement was noted mainly in the right inferior orbitofrontal cortex and bilateral calcarine gyrus, the left lingual gyrus, left fusiform gyrus, left superior occipital gyrus, right insula, right inferior temporal gyrus, superior parietal lobe, left insula, right lingual gyrus, right fusiform gyrus, left parahippocampal gyrus, right inferior temporal gyrus, superior parietal lobe, left calcarine gyrus, bilateral lingual gyrus, prefrontal cortex, including the middle frontal gyrus and superior frontal gyrus, the right middle temporal gyrus, bilateral posterior cingulate cortex, and right precuneus. The decrease in functional connection was mainly located in the right inferior orbitofrontal cortex, prefrontal cortex, including the superior frontal gyrus, orbitofrontal cortex, and anterior cingulate cortex, the left inferior orbitofrontal cortex, right insula, middle occipital gyrus, angular gyrus, inferior frontal gyrus, right insula, middle temporal gyrus, inferior parietal lobe, middle occipital gyrus, supplementary motor area, superior frontal gyrus, left insula, bilateral posterior cingulate cortex, bilateral precuneus, middle occipital gyrus, and right middle temporal lobe. There were significant changes in the functional connectivity of the brain between full and empty bladders in healthy volunteers, which suggests that the central neural processes involved in storage needs brain areas with integrated control. These findings are strong evidence for physicians to consider brain responses in urine storage and offer the provision of some normative data.

Functional magnetic resonance imaging (fMRI) has revealed inconsistent neural activity patterns in major depressive disorder (MDD) across cognitive and affective domains, and this study used an activation likelihood estimation (ALE) meta-analysis to examine brain function abnormalities in working memory, reward processing, and emotion processing. A systematic search was conducted in PubMed, Embase, Web of Science, ScienceDirect, and CNKI for fMRI studies comparing MDD patients with healthy controls (HCs), including data up to 3 December 2024. ALE meta-analysis was performed to examine activation patterns. Jackknife sensitivity analysis, risk of bias, and Newcastle-Ottawa scale were used to assess robustness and publication bias. Meta-regression analyses were conducted to explore the impact of covariates on the results. Sixty-nine studies (2,073 MDD individuals and 2,009 HCs) were included. MDD individuals showed hyperactivation in the bilateral parahippocampal gyrus, subcallosal gyrus, lentiform nucleus, left claustrum, insula, and anterior cingulate cortex, alongside hypoactivation in the right lentiform nucleus, parahippocampal gyrus, fusiform gyrus, and other regions. Domain-specific analyses revealed working memory-related hyperactivation in the right middle and superior frontal gyrus, reward-related hyperactivation in the bilateral lentiform nucleus, right claustrum, and left caudate, and emotion-related hyperactivation in the bilateral parahippocampal gyrus, bilateral lentiform nucleus, right subcallosal gyrus, right anterior cingulate cortex, and left claustrum. Jackknife sensitivity analysis confirmed robustness, with no significant publication bias or covariate impact. Aberrant activation in the lentiform and caudate nuclei across reward and emotion tasks suggests striatal dysfunction plays a key role in emotion-motivation interplay, highlighting the striatum as a potential target for future therapies.

Empathy is an essential component of our social lives, allowing us to understand and share other people's affective and sensory states, including pain. Evidence suggests a core neural network—including anterior insula (AI) and mid-cingulate cortex (MCC)—is involved in empathy for pain. However, a similar network is associated to empathy for non-pain affective states, raising the question whether empathy for pain is unique in its neural correlates. Furthermore, it is yet unclear whether neural correlates converge across different stimuli and paradigms that evoke pain-empathy. We performed a coordinate-based activation likelihood estimation (ALE) meta-analysis to identify neural correlates of empathy, assess commonalities and differences between empathy for pain and for non-pain negative affective states, and differences between pain-empathy evoking stimuli (i.e., facial pain expressions vs. acute pain inflictions) and paradigms (i.e., perceptual/affective vs. cognitive/evaluative paradigms). Following a systematic search, data from 128 functional brain imaging studies presenting whole-brain results of an empathy condition vs. baseline/neutral condition were extracted. Synthesizing neural correlates of empathy confirmed a core network comprising AI, MCC, postcentral gyrus, inferior parietal lobe, thalamus, amygdala, and brainstem. There was considerable overlap in networks for empathy for pain and empathy for non-pain negative affective states. Important differences also arose: empathy for pain uniquely activated bilateral mid-insula and more extensive MCC. Regarding stimuli, painful faces and acute pain inflictions both evoked the core empathy regions, although acute pain inflictions activated additional regions including medial frontal and parietal cortex. Regarding paradigms, both perceptual/affective and cognitive/evaluative paradigms recruited similar neural circuitry, although cognitive/evaluative paradigms activated more left MCC regions while perceptual/affective paradigms activated more right AI. Taken together, our findings reveal that empathy for pain and empathy for non-pain negative affective states share considerable neural correlates, particularly in core empathy regions AI and MCC. Beyond these regions, important differences emerged, limiting generalizability of findings across different affective/sensory states. Within pain-empathy studies, the core regions were recruited robustly irrespective of stimuli or instructions, allowing one to tailor designs according to specific needs to some extent, while ensuring activation of core regions.

SummaryWhen faced with ambiguous sensory input, conscious awareness may alternate between the different percepts that are consistent with the input. Visual phenomena leading to such multistable perception, where constant sensory input evokes different conscious percepts, are particularly useful for investigating the processes underlying perceptual awareness [1]. Understanding the role that high-level brain regions outside early visual cortex play in perceptual alternations could elucidate how top-down processes modulate conscious perception [2]. In two studies [3,4] published recently in Current Biology, different combinations of the present authors used repetitive transcranial magnetic stimulation (rTMS) to disrupt activity in human superior parietal cortex, and reported seemingly contradictory results [5] concerning the effect of disrupting the normal function of this area on bistable perception. Here we join forces to resolve this discrepancy.

Resting-state functional magnetic resonance imaging (rs-fMRI) was widely used as an effective tool in the diagnosis of neurodegenerative diseases. However, prior rs-fMRI studies reported inconsistent results for comparison between Parkinson's disease (PD) and healthy controls (HC). We searched studies published before December 2021 in databases (PubMed, Web of Science, and Google Scholar). An activation likelihood estimation (ALE) meta-analysis was made for functional changes in PD. The study finally included 25 studies (including 973 PD patients and 766 HC). PD patients showed reduced amplitude of low frequency fluctuations (ALFF) in the left superior temporal gyrus (STG), the left superior frontal gyrus (SFG), the left medial frontal gyrus (MFG), the left precuneus (PCUN), and the right lentiform nucleus, compared to HC. PD patients showed increased ALFF in the right SFG, the left superior parietal lobule (SPL), the left STG, the right fusiform gyrus, the left inferior temporal gyrus (ITG), and the right parahippocampal gyrus (PHG), compared to HC. PD patients showed reduced regional homogeneity (ReHo) in the right declive, the right MFG, the left culmen, and the left thalamus, compared to HC. PD patients showed increased ReHo in the right SFG, compared to HC. Additionally, PD patients showed reduced functional connectivity (FC) in the right posterior cingulate (PCG), compared to HC. The present ALE analysis has confirmed functional deficits in motor-, emotion-, and cognition-related regions in PD. Deficits in these regions in rs-fMRI studies could play a role in early diagnosis of PD.

A number of psychophysical methods that suppress retinal input from reaching awareness have been used to isolate and study the neural correlates of visual consciousness. I describe a novel disappearance phenomenon in which a low-contrast peripheral pattern is vividly erased from awareness: after adapting to the pattern for a few seconds, flashing a high-contrast patch over it can elicit the perceptual disappearance of the stimulus. This finding was explained in terms of nonlinear interaction between adaptation to sustained spatial pattern and rapid gain adjustment to transient change. It was next shown that transient changes contingent upon prior adaptation elicit perceptual alternations in structure from motion, binocular rivalry, Necker cube, and ambiguous apparent motion—linking disappearance phenomena and bistable perception. We next used binocular rivalry and inattentional blindness to examine if invisible inputs influence the neuronal mechanisms that adapt to different aspects of the stimuli. The face identity-specific aftereffect was found to be cancelled by binocular suppression or by inattentional blindness of the inducing face. Conversely, the same suppression did not interfere with the orientation-specific aftereffect. Thus, the competition between incompatible or interfering visual inputs to reach awareness is resolved before those aspects of information that are exploited in face identification are processed. Subsequent experiments showed that face identity aftereffect is invariant to eye movements, but fMRI adaptation in face-selective region of the fusiform cortex did not show such invariance. Therefore identity aftereffect originates either at the same level or subsequent to the level of face processing in the fusiform area. Next, we show that recognition of facial emotional expressions occurs after the level of attentional selection: visual search results were incompatible with preattentive processing of emotional categories. We thus suggest that the invisible or unattended faces are suppressed in early visual areas. This conjecture was experimentally confirmed by showing that when a stimulus is not attended, it evoked a weaker and weaker response in fMRI in subsequent stages of visual processing hierarchy. Thus, attention determines how far the visual input is processed and whether or not a high-level representation of the input would be constructed.

BackgroundThe increasing prevalence of Alzheimer’s disease (AD) and mild cognitive impairment (MCI) presents a significant societal and familial burden. Acupuncture has shown promise in modulating brain function; however, systematic evidence on its effects on brain functional networks in individuals with AD and MCI remains limited. This study aimed to quantitatively synthesize neuroimaging findings using activation likelihood estimation (ALE) meta-analyses.MethodsWe systematically searched PubMed, PsycINFO, Google Scholar, SinoMed, and China National Knowledge Infrastructure (CNKI) for neuroimaging studies on acupuncture in AD and MCI. Activation coordinates were analyzed using GingerALE software. Separate ALE meta-analyses were conducted for AD and MCI with family-wise error (FWE) correction (P<0.05) and a cluster-forming threshold of P<0.001 (5,000 permutations), achieving >80% post hoc power. Contrast analyses used P<0.01, a minimum cluster size of 200 mm3 (10,000 permutations), and 95% confidence intervals from permutation distributions.ResultsThirteen studies (702 participants: 105 with AD, 312 with MCI, and 285 controls) with 303 activation foci (153 increased and 150 decreased) were included in the analysis. In patients with AD, acupuncture enhanced activation in the right superior frontal gyrus (BA10), left cerebellar regions, and right inferior occipital gyrus (BA19), while reducing activation in the right middle frontal gyrus (BA6). In an individual with MCI, increased activation was found in the right superior and middle temporal gyri (BA38 and BA21), parahippocampal gyrus (BA28), bilateral posterior cerebellar lobes, and left superior parietal lobe (BA7), which was accompanied by decreased activity in the right superior frontal gyrus (BA6) and cerebellar regions. Combined analyses revealed convergent activation in the bilateral cerebellar tonsils, parahippocampal gyrus, right middle temporal gyrus, left superior parietal lobe, and right superior frontal gyrus, indicating shared modulatory effects across both disorders.ConclusionsAcupuncture consistently activates the frontal, temporal, parietal, and cerebellar regions linked to cognitive and sensorimotor functions. Stronger effects in individuals with MCI suggest greater neuroplastic responsiveness. These findings provide quantitative evidence supporting acupuncture as a potential adjunctive therapy for cognitive impairment in neurodegenerative diseases.

Cognitive control is a critical feature in adapting our behavior to environmental and internal demands with two types of inhibition having been identified, namely the proactive and the reactive. Aiming to shed light on their respective neural correlates, we decided to focus on the cerebral activity before or after presentation of the target demanding a subject’s stop as a way to separate the proactive from the reactive components associated with the tasks. Accordingly, we performed three Activation Likelihood Estimation (ALE) meta-analyses of fMRI studies exploring proactive and reactive inhibitory phases of cognitive control. For this purpose, we searched for fMRI studies investigating brain activity preceding or following target stimuli. Eight studies (291 subjects, 101 foci) were identified for the proactive analysis. Five of these studies and those previously analyzed by others (348 subjects, 199 foci) were meta-analyzed to explore the neural correlates of reactive inhibition. Overall, our results showed different networks for the two inhibitory components. Notably, we observed a contiguity between areas in the right inferior frontal gyrus pertaining to proactive inhibition and in the right middle frontal gyrus regarding reactive inhibition. These neural correlates allow proposal of a new comprehensive model of cognitive control.

The finger tapping task (FTT) is commonly used in the evaluation of dyskinesia among patients with Parkinson's disease (PD). Past research has indicated that cortical activation during FTT is different between self-priming and cue-priming conditions. To evaluate how priming conditions affect the distribution of brain activation and the reorganization of brain function, and to investigate the differences in brain activation areas during FTT between PD patients and healthy control (HC) participants, we conducted an activation likelihood estimation (ALE) meta-analysis on the existing literature. Analyses were based on data from 15 independent samples that included 181 participants with PD and 164 HC participants. We found that there was significantly more activation in the middle frontal gyrus, precentral gyrus, post-central gyrus, superior parietal lobe, inferior parietal lobule, cerebellum, and basal ganglia during FTT in PD patients than in HCs. In self-priming conditions, PD patients had less activation in the parietal lobe and insular cortex but more activation in the cerebellum than the HCs. In cue-priming conditions, the PD patients showed less activation in the cerebellum and frontal-parietal areas and more activation in the superior frontal gyrus and superior temporal gyrus than the HCs. Our study illustrates that cue-priming manipulations affect the distribution of activity in brain regions involved in motor control and motor performance in PD patients. In cue-priming conditions, brain activity in regions associated with perceptual processing and inhibitory control was enhanced, while sensory motor areas associated with attention and motor control were impaired.

<p id=C6>Emotion recognition has always been a hot topic in psychology. Although some studies have explored the brain mechanisms of dynamic facial expressions, dynamic bodily expressions and emotional voices, empirical studies have their own inevitable defects, which may lead to low statistical test power and effect size and inconsistent results. In addition, the existing meta-analyses of the three emotion carriers still have some deficiencies. Therefore, at present, the overall understanding of the three emotion carriers is relatively incomplete, and the commonness and differences of neural mechanisms among different emotion carriers were still poorly known. So, based on the background of high ecological validity, this study adopted the meta-analysis technique based on large-scale data synthesis method to overcome the above shortcomings. First, three separated activation likelihood estimation (ALE) meta-analyses were used to identify the brain regions activated by each emotion pattern, and then conjunction and contrast analysis of these activation maps were used to assess common and unique neural activity between the three emotion carriers. It is the first time that meta-analysis is used to explore the brain mechanism of dynamic bodily expressions, and it is also the first time that meta-analysis is used to explore the similarities and differences of neural activity among three emotion carriers: dynamic facial expressions, dynamic bodily expressions and emotional voices, and further improves the overall understanding of the neural mechanisms of dynamic facial expressions and emotional voices by previous meta-analyses. The results of single meta-analysis showed that the brain regions of dynamic facial expressions included superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), precentral gyrus (PG), inferior parietal lobule (IPL), middle occipital gyrus (MOG), inferior occipital gyrus (IOG), fusiform gyrus (FG), superior temporal gyrus (STG), middle temporal gyrus (MTG), inferior temporal gyrus (ITG), parahippocampal gyrus (PHG), cerebellum, amygdala, lentiform nucleus (LN) and insula. Dynamic bodily expressions caused activation of the middle occipital gyrus, inferior occipital gyrus, fusiform gyrus, superior temporal gyrus, middle temporal gyrus, inferior temporal gyrus, cuneus, lingual gyrus (LING), cerebellum, and parahippocampal gyrus. The activation of emotional voices was concentrated in the middle frontal gyrus, inferior frontal gyrus, precentral gyrus, superior temporal gyrus, middle temporal gyrus, heschl’s gyrus (HG), insula, amygdala and caudate nucleus (CN). Conjunction analysis suggested that the left middle temporal gyrus and the right superior temporal gyrus were activated by three emotion carrier across the modalities. The results of the contrast analysis proved that the visual stimuli was more advantaged than the auditory stimuli, especially the dynamic facial expressions, the dynamic bodily expressions also played an important role. However, the emotional voices had their own uniqueness. In sum, these findings validate, support, and extend the existing neural models of the three emotion carriers, revealing a central, universal region of the emotional processing, but with each emotion carrier relying on its own reliable specific neural circuits. This study provides consistent results across studies for researchers of emotional problems, and representative reference coordinate points for future region of interest (ROI) analysis, which is conducive to propose and test hypotheses of future researches, and also is conducive to the identification and neural regulation of patients with emotional disorders. Future researches should further validate and extend these findings to explore the neural mechanisms of emotional processing at different ages and their similarities and differences. In addition, it is necessary to study the brain mechanism of each emotion type and the similarity and difference of neural activity of each emotion in different carriers in the case of sufficient data. Examining the connection of different brain regions, and the different functions of a brain region also is necessary. Meanwhile, it is essential to focus on the neural basis of dynamic bodily expressions.

Background: Spatial ability is vital for human survival and development. However, the relationship between large-scale and small-scale spatial ability remains poorly understood. To address this issue from a novel perspective, we performed an activation likelihood estimation (ALE) meta-analysis of neuroimaging studies to determine the shared and distinct neural bases of these two forms of spatial ability.Methods: We searched Web of Science, PubMed, PsycINFO, and Google Scholar for studies regarding “spatial ability” published within the last 20 years (January 1988 through June 2018). A final total of 103 studies (Table 1) involving 2,085 participants (male = 1,116) and 2,586 foci were incorporated into the meta-analysis.Results: Large-scale spatial ability was associated with activation in the limbic lobe, posterior lobe, occipital lobe, parietal lobe, right anterior lobe, frontal lobe, and right sub-lobar area. Small-scale spatial ability was associated with activation in the parietal lobe, occipital lobe, frontal lobe, right posterior lobe, and left sub-lobar area. Furthermore, conjunction analysis revealed overlapping regions in the sub-gyrus, right superior frontal gyrus, right superior parietal lobule, right middle occipital gyrus, right superior occipital gyrus, left inferior occipital gyrus, and precuneus. The contrast analysis demonstrated that the parahippocampal gyrus, left lingual gyrus, culmen, right middle temporal gyrus, left declive, left superior occipital gyrus, and right lentiform nucleus were more strongly activated during large-scale spatial tasks. In contrast, the precuneus, right inferior frontal gyrus, right precentral gyrus, left inferior parietal lobule, left supramarginal gyrus, left superior parietal lobule, right inferior occipital gyrus, and left middle frontal gyrus were more strongly activated during small-scale spatial tasks. Our results further indicated that there is no absolute difference in the cognitive strategies associated with the two forms of spatial ability (egocentric/allocentric).Conclusion: The results of the present study verify and expand upon the theoretical model of spatial ability proposed by Hegarty et al. Our analysis revealed a shared neural basis between large- and small-scale spatial abilities, as well as specific yet independent neural bases underlying each. Based on these findings, we proposed a more comprehensive version of the behavioral model.

Effect of 24-h and 36-h acute total sleep deprivation on human attention: An activation likelihood estimation meta-analysis.

Afterimages: A Tool for Defining the Neural Correlate of Visual Consciousness

Neural correlates of theory of mind and empathy in schizophrenia: An activation likelihood estimation meta-analysis