A face is more than just the eyes, nose, and mouth: fMRI evidence that face-selective cortex represents external features.

What is a face? Intuition, along with abundant behavioral and neural evidence, indicates that internal features (e.g., eyes, nose, mouth) are critical for face recognition, yet some behavioral and neural findings suggest that external features (e.g., hair, head outline, neck and shoulders) may likewise be processed as a face. Here we directly test this hypothesis by investigating how external (and internal) features are represented in the brain. Using fMRI, we found highly selective responses to external features (relative to objects and scenes) within the face processing system in particular, rivaling that observed for internal features. We then further asked how external and internal features are represented in regions of the cortical face processing system, and found a similar division of labor for both kinds of features, with the occipital face area and posterior superior temporal sulcus representing the parts of both internal and external features, and the fusiform face area representing the coherent arrangement of both internal and external features. Taken together, these results provide strong neural evidence that a "face" is composed of both internal and external features.

Biased emotional attention in patients with dental phobia.

Biased motivated attention towards phobia-relevant pictures is a typical finding in specific phobia. In the visual system, the allocation of motivated attention is indexed by two event-related potential components - the Early Posterior Negativity and the Late Positive Potential. Enhanced Early Posterior Negativity and Late Positive Potential amplitudes are reliably observed in specific phobia such as, for instance, snake, spider, or blood-injection-injury phobia and to some extent also in dental phobia. However, regarding dental phobia results are sparse and its theoretical concept is not undisputed. To further elucidate the electrophysiological characteristics of dental phobia, we investigated visual emotional processing in dental phobia patients and controls. Subjects viewed neutral, phobia-irrelevant and phobia-relevant pictures while magnetoencephalographic and behavioural measures were recorded. All patients reported a history of traumatic experiences and depressive and anxiety symptoms, as well as dissociative and posttraumatic symptoms. In the magnetoencephalography, patients showed generally less evoked neural activation at parietal and temporal regions and a reduced differentiation between picture categories compared to controls. At the behavioural level, patients rated phobia-relevant pictures as clearly more negative as did controls. In contrast to previous reports, our results suggest that dental phobia cannot be associated with the typical effects of biased motivated attention seen in other specific phobias. Instead, results indicate that dental phobia shares typical characteristics with mild forms of posttraumatic stress disorder.

Kinematics of ventrally mediated grasp-to-eat actions: right-hand advantage is dependent on dorsal stream input.

Studies have suggested a left-hemisphere specialization for visually guided grasp-to-eat actions by way of task-dependent kinematic asymmetries (i.e., smaller maximum grip apertures for right-handed grasp-to-eat movements than for right-handed grasp-to-place movements or left-handed movements of either type). It is unknown, however, whether this left-hemisphere/right-hand kinematic advantage is reliant on the dorsal "vision-for-action" visual stream. The present study investigates the kinematic differences between grasp-to-eat and grasp-to place actions performance during closed-loop (i.e., dorsally mediated) and open-loop delay (i.e., ventrally mediated) conditions. Twenty-one right-handed adult participants were asked to reach to grasp small food items to (1) eat them, or (2) place them in a container below the mouth. Grasps were performed in both closed-loop and open-loop delay conditions, in separate sessions. We show that participants displayed the right-hand grasp-to-eat kinematic advantage in the closed-loop condition, but not in the open-loop delay condition. As no task-dependent kinematic differences were found in ventrally mediated grasps, we posit that the left-hemisphere/right-hand advantage is dependent on dorsal stream processing.

Perception and Processing of Faces in the Human Brain Is Tuned to Typical Feature Locations.

UNLABELLED: Faces are salient social stimuli whose features attract a stereotypical pattern of fixations. The implications of this gaze behavior for perception and brain activity are largely unknown. Here, we characterize and quantify a retinotopic bias implied by typical gaze behavior toward faces, which leads to eyes and mouth appearing most often in the upper and lower visual field, respectively. We found that the adult human visual system is tuned to these contingencies. In two recognition experiments, recognition performance for isolated face parts was better when they were presented at typical, rather than reversed, visual field locations. The recognition cost of reversed locations was equal to ∼60% of that for whole face inversion in the same sample. Similarly, an fMRI experiment showed that patterns of activity evoked by eye and mouth stimuli in the right inferior occipital gyrus could be separated with significantly higher accuracy when these features were presented at typical, rather than reversed, visual field locations. Our findings demonstrate that human face perception is determined not only by the local position of features within a face context, but by whether features appear at the typical retinotopic location given normal gaze behavior. Such location sensitivity may reflect fine-tuning of category-specific visual processing to retinal input statistics. Our findings further suggest that retinotopic heterogeneity might play a role for face inversion effects and for the understanding of conditions affecting gaze behavior toward faces, such as autism spectrum disorders and congenital prosopagnosia. SIGNIFICANCE STATEMENT: Faces attract our attention and trigger stereotypical patterns of visual fixations, concentrating on inner features, like eyes and mouth. Here we show that the visual system represents face features better when they are shown at retinal positions where they typically fall during natural vision. When facial features were shown at typical (rather than reversed) visual field locations, they were discriminated better by humans and could be decoded with higher accuracy from brain activity patterns in the right occipital face area. This suggests that brain representations of face features do not cover the visual field uniformly. It may help us understand the well-known face-inversion effect and conditions affecting gaze behavior toward faces, such as prosopagnosia and autism spectrum disorders.

Endovascular Internal Trapping of Ruptured Occipital Artery Pseudoaneurysm Associated with Occipital-Internal Jugular Vein Fistula in Neurofibromatosis Type 1.

Spontaneous cervical extradural pseudoaneurysms or arteriovenous fistulas (AVFs) are rare vascular diseases. We report a case of ruptured occipital artery (OA) pseudoaneurysm associated with occipital-internal jugular vein (IJV) fistula in neurofibromatosis type 1. Endovascular internal trapping via the OA was attempted; however, the distal entry of the OA could not be accessed because of the high shunt flow and tortuosity of the OA. The distal part of the OA was obliterated with coil via a transvenous approach through the IJV and pseudoaneurysm. The proximal entry of the OA was obliterated with coil and glue under proximal flow control with a balloon, and the fistula was successfully obliterated without placement of coils in the pseudoaneurysm. When ordinary internal trapping via a transarterial approach is not possible, the transvenous approach should be considered as an alternative for AVF associated with an aneurysmal component.

Successful non-operative management of left atrioesophageal fistula following catheter ablation.

Atrioesophageal fistula (AEF) is a potentially lethal complication of catheter radiofrequency ablation for atrial fibrillation. A 49-year-old man with paroxysmal atrial fibrillation who underwent catheter ablation around the pulmonary vein was admitted 31 days after the procedure, suffering seizures and fever. Magnetic resonance imaging of the brain showed ischemia and multiple lesions of acute infarction in the right occipital lobe of the cerebrum. Computed tomography (CT) of the chest showed a small accumulation of air between the posterior left atrium and the esophagus, suggesting an AEF. Endoscopic snaring of the esophageal mucosa, repeated a few times, supported by nil by mouth and antibiotic therapy, resulted in improvement of his condition with no recurrence of symptoms. Subsequent chest CT scans confirmed disappearance of the leaked air and the patient was discharged home 45 days after admission with no neurological compromise.

The role of the occipital face area in the cortical face perception network.

Functional magnetic resonance imaging (fMRI) studies have identified spatially distinct face-selective regions in human cortex. These regions have been linked together to form the components of a cortical network specialized for face perception but the cognitive operations performed in each region are not well understood. In this paper, we review the evidence concerning one of these face-selective regions, the occipital face area (OFA), to better understand what cognitive operations it performs in the face perception network. Neuropsychological evidence and transcranial magnetic stimulation (TMS) studies demonstrate the OFA is necessary for accurate face perception. fMRI and TMS studies investigating the functional role of the OFA suggest that it preferentially represents the parts of a face, including the eyes, nose, and mouth and that it does so at an early stage of visual perception. These studies are consistent with the hypothesis that the OFA is the first stage in a hierarchical face perception network in which the OFA represents facial components prior to subsequent processing of increasingly complex facial features in higher face-selective cortical regions.

Reduction in jaw opening: a neglected symptom of giant cell arteritis.

Reduction in jaw opening is a neglected symptom of giant cell arteritis (GCA) in clinical practice and in the scientific literature. We describe the case of a 71-year-old woman with GCA who was misdiagnosed as occipital neuritis and craniomandibular dysfunction because of headaches in the occipital region and reduction in jaw opening. The reported case reminds us not to overlook reduction in jaw opening as a symptom to reveal GCA in elderly patients.

[Cerebral actinomycosis pseudotumor: a case report]. / Actinomycose cérébrale d'aspect pseudotumoral: à propos d'un cas.

INTRODUCTION: Cerebral actinomycosis is rare and difficult to diagnose. CASE REPORT: We report a case of a 45-year-old man hospitalized for seizures associated with fever and left hemiparesis. The white cell count and C-reactive protein were elevated. HIV serology was negative. Blood cultures remained sterile. The CT scan revealed hyperdense nodular lesions in the occipital area, with annular contrast uptake and peripheral edema causing a mass effect, suggestive of brain metastasis. The pathology examination of a surgical specimen disclosed cerebral actinomycosis. A dental origin of the infection was suspected. Hemiparesis remained after a 12-month antibiotic regimen associated with dental care and short-term corticosteroid therapy. CONCLUSION: Actinomycosis should be discussed as a possible diagnosis for all cerebral lesions, particularly in patients with a potential dental infection. Histology is required for positive diagnosis. Antibiotic therapy alone is generally sufficient; surgery is often performed for diagnostic purposes.

[Mandibular reconstruction with free osteocutaneous fibula flap using the occipital artery as recipient vessel]. / Mandibularekonstrukció arteria occipitalisra varrt szabad osteocutan fibulalebennyel.

Authors performed reconstructive surgery for extensive skin and mandibular bone defect following gunshot injury to the left side of the face. The soft tissue and bone defect was reconstructed with the free osteocutaneous fibula flap harvested from the left lower leg, as suitable local reconstructive flap was not available. The bony continuity was reestablished with a 7 cm long fibula segment. Microvascular anastomoses were performed to the left occipital artery and the left internal jugular vein. The occipital artery was chosen as the external carotid system was completely missing on the right side and was missing several branches on the left side due to the trauma. The fibular segment became fully incorporated and 95% of the flap healed by primary intention.

Perception of face parts and face configurations: an FMRI study.

fMRI studies have reported three regions in human ventral visual cortex that respond selectively to faces: the occipital face area (OFA), the fusiform face area (FFA), and a face-selective region in the superior temporal sulcus (fSTS). Here, we asked whether these areas respond to two first-order aspects of the face argued to be important for face perception, face parts (eyes, nose, and mouth), and the T-shaped spatial configuration of these parts. Specifically, we measured the magnitude of response in these areas to stimuli that (i) either contained real face parts, or did not, and (ii) either had veridical face configurations, or did not. The OFA and the fSTS were sensitive only to the presence of real face parts, not to the correct configuration of those parts, whereas the FFA was sensitive to both face parts and face configuration. Further, only in the FFA was the response to configuration and part information correlated across voxels, suggesting that the FFA contains a unified representation that includes both kinds of information. In combination with prior results from fMRI, TMS, MEG, and patient studies, our data illuminate the functional division of labor in the OFA, FFA, and fSTS.

Reading epilepsy from the dominant temporo-occipital region.

BACKGROUND: Reading epilepsy is a rare form of epilepsy, classified among idiopathic, age- and localisation-related (partial) epilepsies as a reflex epilepsy syndrome. Seizures usually consist of myoclonic jerks restricted to the jaw. However, distinct ictal features including visual symptoms and paroxysmal a- or dyslexia are described in some patients. The anatomical substrate of ictogenesis in reading epilepsy remains poorly understood. METHODS: The authors report here the case of a primary reading epilepsy for which ictal semiology was characterised by visual symptoms and dyslexia, investigated by MRI, interictal high-resolution EEG and PET, ictal video-EEG and SPECT. Brain MRI was normal. Interictal high-resolution EEG was performed with 64 scalp channels, a realistic head model and different algorithms to solve the inverse problem. RESULTS: Interictal source localisations highlighted the left occipito-temporal junction. Interictal PET demonstrated bilateral occipito-temporal hypometabolism with left-sided predominance. Ictal EEG showed a rhythmic discharge in left temporo-parieto-occipital junction channels, with left occipito-temporal predominance. MRI fusion of the coregistered subtraction between ictal and interictal SPECT individualised relative hyperperfusion affecting (a) the left occipito-parietal junction area, (b) the left lateral middle and inferior temporal gyri and (c) the left inferior frontal area. CONCLUSION: Besides reading-induced myoclonic jerks of the jaw, a second variant of reading epilepsy exists with clearly partial seizures manifested by visual symptoms and a- or dyslexia. These seizures originate from the occipito-temporal region of the dominant hemisphere, corresponding to the posterior part of the neural network that underlies the function of reading.

Holistic perception of individual faces in the right middle fusiform gyrus as evidenced by the composite face illusion.

The perception of a facial feature (e.g., the eyes) is influenced by the position and identity of other features (e.g., the mouth) supporting an integrated, or holistic, representation of individual faces in the human brain. Here we used an event-related adaptation paradigm in functional magnetic resonance imaging (fMRI) to clarify the regions representing faces holistically across the whole brain. In each trial, observers performed the same/different task on top halves (aligned or misaligned) of two faces presented sequentially. For each face pair, the identity of top and bottom parts could be both identical, both different, or different only for the bottom half. The latter manipulation resulted in a composite face illusion, i.e., the erroneous perception of identical top parts as being different, only for aligned faces. Release from adaptation in this condition was found in two sub-areas of the right middle fusiform gyrus responding preferentially to faces, including the "fusiform face area" ("FFA"). There were no significant effects in homologous regions of the left hemisphere or in the inferior occipital cortex. Altogether, these observations indicate that face-sensitive populations of neurons in the right middle fusiform gyrus are optimally tuned to represent individual exemplars of faces holistically.

The effects of chewing-side preference on human brain activity during tooth clenching: an fMRI study.

Chewing-side preference (CSP) may be associated with dominant cerebral hemispheric organisation. However, little information exists regarding whether CSP is reflected by preferential activity in the opposite (to the CSP) cerebral hemisphere. The aim of this study was to investigate the effects of CSP on cerebral cortex response to bilateral tooth clenching. Sixteen right-handed participants with left (two men: 29·0±8·4 years old, six women: 32·3±4·8 years old) or right (four men: 31·0±6·1 years old, four women: 30·8±4·7 years old) CSP were scanned by functional magnetic resonance imaging during moderate levels of voluntary tooth clenching. The on-off sequence of scanning was 30 s of clenching (on) and 30 s of rest (off) a total of five times. The results showed that blood oxygen level-dependent signals in the contralateral (to the CSP) primary sensorimotor cortex increased more than in the ipsilateral primary sensorimotor cortex in participants with both left and right CSP (P≤0·001). The supplementary motor area was activated in participants with left (P≤0·001) but not right CSP. Activation of the inferior frontal gyrus and inferior parietal lobule was greater in participants with right versus left CSP (P≤0·001). Significant (P≤0·001) activation was observed in the parahippocampal gyrus in five of eight participants with left CSP, whereas no activation was observed in those with right CSP. These findings suggest a relationship between hemispheric dominance and CSP in the primary sensorimotor cortex responsible for bilateral tooth clenching.

Chronic jaw pain attenuates neural oscillations during motor-evoked pain.

Motor- and pain-related processes separately induce a reduction in alpha and beta power. When movement and pain occur simultaneously but are independent of each other, the effects on alpha and beta power are additive. It is not clear whether this additive effect is evident during motor-evoked pain in individuals with chronic pain. We combined highdensity electroencephalography (EEG) with a paradigm in which motor-evoked pain was induced during a jaw force task. Participants with chronic jaw pain and pain-free controls produced jaw force at 2% and 15% of their maximum voluntary contraction. The chronic jaw pain group showed exacerbated motor-evoked pain as force amplitude increased and showed increased motor variability and motor error irrespective of force amplitude. The chronic jaw pain group had an attenuated decrease in power in alpha and lower-beta frequencies in the occipital cortex during the anticipation and experience of motor-evoked pain. Rather than being additive, motor-evoked pain attenuated the modulation of alpha and beta power, and this was most evident in occipital cortex. Our findings provide the first evidence of changes in neural oscillations in the cortex during motor-evoked jaw pain.

Crowned dens syndrome, yet another rheumatic disease imposter.

OBJECTIVE: Crowned dens syndrome (CDS) is defined as acute cervical or occipital pain due to a local inflammatory reaction related to calcifications in the ligaments surrounding the odontoid process. Virtually, all previous descriptions of CDS have related to calcium pyrophosphate dehydrate (CPPD) arthropathy. METHODS: We prospectively identified a total of twenty-four consecutive inpatients with Crowned dens syndrome from January 2016 to December 2017 in our institution. RESULTS: All patients (age range 54 to 87 years, 67% females) presented with acute onset pain in the upper neck and/or occiput accompanied with extreme neck stiffness. Most patients (79%) had elevated inflammatory markers. Four patients underwent temporal artery biopsy, which was negative for arteritis in all cases, and one was subjected to lumbar puncture, which was non-contributory. Seventeen patients (71%) had known rheumatic disease on presentation: 10 patients had the diagnosis of calcium pyrophosphate dehydrate arthropathy, 3 patients had ankylosing spondylitis, 2 patients had rheumatoid arthritis, 1 patient had Behcet's disease, and 1 suffered from Familial Mediterranean Fever. In 4 more patients, crowned dens syndrome was the presenting symptom of calcium pyrophosphate dehydrate disease. All patients were treated with glucocorticoids as 0.5 mg/kg prednisone plus colchicine 0.5 mg bid resulting in dramatic improvement in both clinical (head/neck pain alleviated and cervical spinal mobility regained) and laboratory measures. CONCLUSIONS: Crowned dens syndrome should be considered, and craniocervical junction imaged in the context of acute cervical or occipital pain with stiffness and elevated inflammation markers not only in patients previously diagnosed with calcium pyrophosphate dehydrate arthropathy but also in diverse clinical settings.Key Points• This report highlights that crowned dens syndrome should be considered in various clinical setting besides calcium pyrophosphate dehydrate (CPPD) arthropathy.• Vigilance to this syndrome allows rapid treatment and may spare the patient unnecessary invasive procedures (i.e., temporal artery biopsy or lumbar puncture).

Fine tuning the correlation limit of spatio-temporal signal space separation for magnetoencephalography.

Head, jaw and tongue movements contribute to speech artifacts in magnetoencephalography (MEG). Their sources lay close to MEG sensors, therefore, the spatio-temporal signal space separation method (tSSS), specifically suppressing nearby artifacts, can be used for speech artifact suppression. After data reconstruction by signal space separation (referred as SSS), tSSS identifies artifacts by their correlated temporal behavior inside and outside the sensor helmet. The artifacts to be eliminated are thresholded by the quantitative level of this correlation determined by correlation limit (CL). Unnecessarily high CL value may result in suboptimal interference suppression. We evaluated the performance of tSSS with different CLs on MEG data containing speech artifacts. MEG was recorded with 204 planar gradiometers and 102 magnetometers in two subjects counting aloud. The recorded data were processed by tSSS using CLs 0.98, 0.8 and 0.6, and traces were compared. The speech artifact was increasingly suppressed with decreasing CL, but sufficient suppression was achieved at different CL in each subject. Alpha rhythm was not suppressed with CL 0.98 or 0.8; some amplitude reduction with CL 0.6 occurred in one subject. The tSSS is a robust tool suppressing MEG artifacts. It can be fine tuned for challenging artifacts which, after insufficient rejection might resemble brain signals.

Cerebral activations resulting from virtual dental treatment.

Pain, and anxiety of pain, for some people are serious problems in dental treatment. It is a common practical experience that even entering a dental surgery office, or the sound of a dental drill, may evoke vegetative correlates of toothache without any underlying disease. This everyday phenomenon suggests the hypothesis of a corresponding activation of pain-related brain areas by virtual dental treatment. Twenty healthy subjects viewed two different video clips presenting a dental treatment from the first-person perspective (simulation movie) and a moving hand holding an electrical toothbrush (control movie). Using functional magnetic resonance imaging, the cerebral hemodynamic responses that occurred during simulation and control movies were compared. Virtual dental treatment was associated with increased activity in pain-related brain areas such as the cingulate cortex, the insula, and primary and secondary somatosensory cortexes (SI, SII). The brain activation pattern indicates not only affective-motivational but also sensory-discriminative pain components during virtual dental treatment in all volunteers. Volunteers with a higher level of dental anxiety showed stronger activation of SI and SII. This may be a result of their higher anticipation of pain.

An unusual mechanism for brain abscess formation in a child.

INTRODUCTION: Intracranial infection is an uncommon but serious complication of head injury. CASE REPORT: This study describes a boy with a traumatic head injury caused by his mother's teeth stemming from a traffic accident, without initial alteration of consciousness or focal neurological signs, who subsequently developed an occipital lobe abscess 3 weeks later. Brain abscess culturing yielded human oral flora. To date, our case is the only report documenting skull fracture with subsequent brain abscess formation caused by human oral flora stemming from traumatic injury from his mother's teeth. DISCUSSION: A high index of suspicion should be maintained, and early imaging such as computed tomography should be considered for patients with symptoms of intracranial infection or who are at high risk, even after a minor head injury. Early diagnosis, appropriate antibiotic therapy based on knowledge of the causative microbes, and surgery are the major prognostic factors for brain abscess.

The initial representation of individual faces in the right occipito-temporal cortex is holistic: electrophysiological evidence from the composite face illusion.

Identifying a facial feature (e.g. the eyes) is influenced by the position and identity of other features (e.g. the mouth) of the face, supporting the view that an individual face is represented as a whole in the human brain. To clarify how early in the time-course of face processing this holistic individual representation is accessed we recorded event-related potentials during an adaptation paradigm of the composite face illusion (CFI). Observers performed a matching task on top halves of two faces presented sequentially. For each face pair, top and bottom face halves could be both identical, both different, or only the bottom half differed. The signal was larger over the right occipito-temporal cortex at about 160 ms (N170) when the attended top half differed between the two faces than when identical top halves were repeated. Crucially, a larger N170 was also found when the top halves of the two faces were the same, yet the observers had the illusion that they differed (CFI). This effect was not found when the two face halves were spatially misaligned. These observations indicate that the earliest perceptual representation of an individual face in the human brain is holistic rather than based on independent face parts.