Temporal Scalp Regions Research Articles

Neurophysiological measures of auditory sensory processing are associated with adaptive behavior in children with Autism Spectrum Disorder

BackgroundAtypical auditory cortical processing is consistently found in scalp electrophysiological and magnetoencephalographic studies of Autism Spectrum Disorder (ASD), and may provide a marker of neuropathological brain development. However, the relationship between atypical cortical processing of auditory information and adaptive behavior in ASD is not yet well understood.MethodsWe sought to test the hypothesis that early (100-175 ms) auditory processing in ASD is related to everyday adaptive behavior through the examination of auditory event-related potentials (AEPs) in response to simple tones and Vineland Adaptive Behavior Scales in a large cohort of children with ASD (N = 84), aged 6–17, and in age- and IQ- matched neurotypically (NT) developing controls (N = 132).ResultsStatistical analyses revealed significant group differences in early AEPs over temporal scalp regions (150-175 ms), and the expected rightward lateralization of the AEP (100-125 ms and 150-175 ms) to tonal stimuli in both groups. Lateralization of the AEP (150-175 ms) was significantly associated with adaptive functioning in the socialization domain.ConclusionsThese results lend support to the hypothesis that atypical processing of sensory information is related to everyday adaptive behavior in autism.

Typical and atypical neural mechanisms support spoken word processing in Angelman syndrome

Angelman syndrome (AS) is known to affect expressive and receptive communication abilities. This study examined individual differences in neural mechanisms underlying speech processing in children with AS (n = 24, M age = 10.01 years) and typical development (n = 30, M age = 10.82 years) using auditory event-related potentials during passive listening to common English words and novel pseudowords. A group of adults with AS (n = 7, M = 31.78 years) provided data about the upper developmental range. The typically developing group demonstrated the expected more negative amplitudes in response to words than pseudowords within 250–500 ms after stimulus onset at the left temporal scalp region. Children and adults with AS exhibited a similar left-lateralized pattern of word-pseudoword differentiation at temporal and parietal regions, but not the midline parietal memory response for known words observed in the typically developing group, suggesting typical-like word-pseudoword differentiation along with possible alterations in the automatic recall of word meaning. These results have important implications for understanding receptive and expressive communication processes in AS and support the use of auditory neural responses for characterizing individual differences in neurodevelopmental disorders with limited speech.

A Routine Electroencephalography Monitoring System for Automated Sports-Related Concussion Detection.

Cases of concussions in the United States keep increasing and are now up to 2 million to 3 million incidents per year. Although concussions are recoverable and usually not life-threatening, the degree and rate of recovery may vary depending on age, severity of the injury, and past concussion history. A subsequent concussion before full recovery may lead to more-severe brain damage and poorer outcomes. Electroencephalography (EEG) recordings can identify brain dysfunctionality and abnormalities, such as after a concussion. Routine EEG monitoring can be a convenient method for reducing unreported injuries and preventing long-term damage, especially among groups with a greater risk of experiencing a concussion, such as athletes participating in contact sports. Because of the relative availability of EEG compared to other brain-imaging techniques (e.g., functional magnetic resonance imaging), the use of EEG monitoring is growing for various neurological disorders. In this longitudinal study, EEG was analyzed from 4 football athletes before their athletic season and also within 7 days of concussion. Compared to a control group of 4 additional athletes, a concussion was detected with up to 99.5% accuracy using EEG recordings in the Theta-Alpha band. Classifiers that use data from only a subset of the EEG electrodes providing reliable detection are also proposed. The most effective classifiers used EEG recordings from the Central scalp region in the Beta band and over the Temporal scalp region using the Theta-Alpha band. This proof-of-concept study and preliminary findings suggest that EEG monitoring may be used to identify a sports-related concussion occurrence with a high level of accuracy and thus reduce the chance of unreported concussion.

A rare case of temporal and infratemporal space abscess secondary to masseteric space infection

Abscess in the temporal and infratemporal space are very rare. They develop as a result of the extraction of infected maxillary molars. Temporal space infections or abscess can be seen in the superficial or deep temporal regions. A 27-year-old lady who had undergone extraction of 2nd mandibular molar five days ago came with complaints of painful swelling over left cheek and restricted mouth opening. On examination, an ill-defined diffuse parotid swelling was seen and treated with empirical antibiotics for which patient didn't respond. On examination, a diffuse hourglass swelling was seen extending from left parotid region to temporal region. CT scan revealed a bulky parotid gland with abscess involving parotid, masticator, infratemporal and temporal scalp region with reactive cervical lymphadenopathy on the left side. Surgical drainage of the abscess was done from the temporal space; subsequently, all other space abscess resolved. On conclusion, masseteric space infection leads to infratemporal and temporal space abscess as they communicate. Drainage of abscess from temporal space is adequate to resolve the abscess from other masticator spaces.

The Effect of Meditation on Comprehension of Statements About One-Self and Others: A Pilot ERP and Behavioral Study.

The main goal of this study was to examine the effect of long-term meditation practice on behavioral indicators and ERP peak characteristics during an error-recognition task, where participants were presented with emotionally negative (evoking anxiety or aggression) written sentences describing self-related or non-self-related emotional state and personality traits. In total, 200 sentences written in Russian with varying emotional coloring were presented during the task, with half of the sentences containing a grammatical error that the participants were asked to identify. The EEG was recorded in age-matched control individuals (n = 17) and two groups of Samatha meditators with relatively short- (3–5 years’ experience, n = 18) and long-term (10–30 years’ experience, n = 18) practice experience. Task performance time (TPT) and accuracy of error detection (AED) were chosen as behavioral values. Amplitude, time latency and cortical distribution of P300 and P600 peaks of ERP were used as a value of speech-related brain activity. All statistical effects of meditation were estimated, controlling for age and sex. No behavioral differences between two groups of meditators were found. General TPT was shorter for both groups of meditators compared to the control group. Non-meditators reacted significantly slower to sentences about aggression than to sentences about anxiety or non-emotional sentences, whereas no significance was found between meditator groups. Non-meditators had better AED for the sentences about one-self than for the sentences about other people, whereas the meditators did not show any significant difference. The amplitude of P300 peak in frontal and left temporal scalp regions was higher for long-term meditators in comparison with both intermediate and control groups. The latency of P300 and P600 in left frontal and temporal regions positively correlated with TPT, whereas the amplitude of P300 in these regions had a negative correlation with TPT. We demonstrate that long-term meditation practice increases the ability of an individual to process negative emotional stimuli. The differences in behavioral reactions after onset of negative information that was self-related and non-self-related, which is typical for non-meditators, disappeared due to the influence of meditation. ERP results could be interpreted as a value of increase in voluntary control over emotional state during meditational practice.

Decoding English Alphabet Letters Using EEG Phase Information.

Increasing evidence indicates that the phase pattern and power of the low frequency oscillations of brain electroencephalograms (EEG) contain significant information during the human cognition of sensory signals such as auditory and visual stimuli. Here, we investigate whether and how the letters of the alphabet can be directly decoded from EEG phase and power data. In addition, we investigate how different band oscillations contribute to the classification and determine the critical time periods. An English letter recognition task was assigned, and statistical analyses were conducted to decode the EEG signal corresponding to each letter visualized on a computer screen. We applied support vector machine (SVM) with gradient descent method to learn the potential features for classification. It was observed that the EEG phase signals have a higher decoding accuracy than the oscillation power information. Low-frequency theta and alpha oscillations have phase information with higher accuracy than do other bands. The decoding performance was best when the analysis period began from 180 to 380 ms after stimulus presentation, especially in the lateral occipital and posterior temporal scalp regions (PO7 and PO8). These results may provide a new approach for brain-computer interface techniques (BCI) and may deepen our understanding of EEG oscillations in cognition.

Physiology of the scalp

Human scalp reveals aremarkable difference to hairy skin of other body regions. The structure of the scalp offers effective protection against water loss and contributes to thermoregulation due to significant vascularization. The scalp is innervated by the trigeminus nerve. The majority of the population complain about "sensitive" scalp. However, sensory, regional, ethnic or pathologic parameters contributing to "sensitive" scalp are largely unknown. Quantitative sensory tests and superficial topical application test of irritant substances were performed. Extremely high thresholds to thermal and mechanical stimuli were recorded at the vertex compared to occipital or temporal scalp regions, or the hairy skin of other body regions such as trunk or distal extremities. Pronounced scalp hypersensitivity can be found in Asians as compared to Caucasians and under pathologic conditions, such as alopecia, dandruff, or migraine. Putative causes of "sensitive" scalp can be afacilitated transdermal penetration of irritant substances, altered neuronal innervation or receptor expression, or peripheral and central sensitization of sensory afferents.

Influences of encoding and retrieval on the steady-state visual evoked potential

The steady-state visual evoked potential (SSVEP) is a powerful tool to study basic perceptual functions in the human electroencephalogram (EEG) (e.g. selective attention). The present study aimed at finding support for the SSVEP's sensitivity to higher cognitive functions (e.g. memory). We tagged pictures of meaningless objects with 15 Hz within a combined subsequent-memory and recognition-memory design. The EEG was recorded from 128 electrodes. The subsequent-memory design revealed that SSVEPs are influenced by encoding-related processes. In particular, successful encoding was associated with higher SSVEP amplitudes at central-parietal scalp electrodes and reduced activity at left occipital sites. Recognition memory led to higher SSVEP amplitudes at right temporal scalp regions and to an amplitude reduction at midline electrodes. For the first time it was demonstrated that the SSVEP technique is a useful tool to study memory encoding and retrieval. SSVEPs might reflect the ongoing dynamics within an externally driven and widespread task-relevant network. This offers remarkable possibilities for future research on electrophysiological correlates of mnemonic functioning.

An ERP Study of Emotional Face Processing in the Adult and Infant Brain

To examine the ontogeny of emotional face processing, event-related potentials (ERPs) were recorded from adults and 7-month-old infants while viewing pictures of fearful, happy, and neutral faces. Face-sensitive ERPs at occipital-temporal scalp regions differentiated between fearful and neutral/happy faces in both adults (N170 was larger for fear) and infants (P400 was larger for fear). Behavioral measures showed no overt attentional bias toward fearful faces in adults, but in infants, the duration of the first fixation was longer for fearful than happy faces. Together, these results suggest that the neural systems underlying the differential processing of fearful and happy/neutral faces are functional early in life, and that affective factors may play an important role in modulating infants' face processing.

Nevus sebaceus of Jadassohn revisited with reconstruction options

Nevus sebaceus of Jadassohn (NS) has the classic presentation on the head and neck of a yellow-orange-colored, waxy, pebble-like, papule or plaque. Its reported malignant potential varies between 0.8% and 50%. The common location of NS on the temporal hairline leaves a cosmetic defect. We retrospectively reviewed a consecutive series of patients with NS located in the temporal scalp region. Thirteen patients were included. Twelve patients were reconstructed with a temporal flap. One patient had a primary linear scalp closure after excision. Clinical, histopathologic, surgical, and photographic records were used to review the clinical, anatomic, and pathologic presentation of the lesions. Reconstructions were rated on a scale of 1-5 by two independent examiners. The cosmetic results were also assessed by the patients. Patients ranged in age from 3 to 40 years. All of the lesions were located in the temporal area of the scalp. All cases were pathologically determined as NS. Two cases contained basal cell carcinoma (15%). Two cases were re-excisions of confirmed NS. One case was excised and closed with difficulty using a linear primary closure. Rotation flaps based on the superior temporal artery were used for the reconstruction of the defects in 12 patients. Nine of the flaps were anterior rotation flaps and three were posterior. The average score for the cosmetic results of the patients was 3.75, with the lowest score being 2, and the highest 5. The score for the linear closure was 2. A rotation flap based on the superficial temporal artery is an excellent reconstructive solution for NS located in the temporal scalp region.

Perceptual learning modulates sensory evoked response during vowel segregation

With practice, people become better at discriminating two similar stimuli, such as two sounds. The neural mechanisms that underlie this type of learning have been of interest to researchers investigating neural plasticity associated with learning and recovery of function following stroke. We utilized event related potentials (ERP) to study the neural substrates underlying auditory discrimination learning. Stimuli were five steady-state American English vowels. On each trial, participants were presented with a pair of vowels created by summing together the digital waveforms of two different vowels. Listeners were instructed to identify both vowels in the pair. ERPs were recorded during two sessions separated by 1 week. Half of the participants practised the discrimination task during the intervening week while the other half served as controls and did not receive any training. Trained listeners showed greater improvement in accuracy than untrained participants. In both groups, vowels generated N1 and P2 waves at the fronto-central and temporal scalp regions. The behavioral effects of training were paralleled by decreased N1 and P2 latencies as well as enhanced P2 amplitude in the trained compared with untrained listeners. The effects of training on sensory evoked responses are consistent with the proposal that perceptual learning is associated with changes in sensory cortices.

Level-repetition effects in hierarchical stimulus processing: timing and location of cortical activity

The specific mechanisms that underlie repetition priming effects are only partly understood. We examined the timing and extent of brain activity in response to level-repeated and level-shifted conditions during hierarchical stimulus processing. A response cost in behavioral reaction times was evident for level-shifted compared to level-repeated conditions. Larger event-related potentials amplitudes for level-shifted conditions were evident over occipital scalp regions for an early component peaking at 132 ms post-stimulus onset. A negative potential over posterior temporal electrodes that peaked at 204 ms showed asymmetries in amplitudes that were consistent with lateralized differences in global and local level processing. A positive potential peaking at 290 ms also showed differences between level-repeated and level-shifted conditions over left parietal and left posterior temporal scalp regions. The study demonstrates cortical activity related to repetition priming for both local and global level targets. Early sensory (‘P1’) and later cortical processing can be affected by the need to shift attention across hierarchical levels. The results support the existence of multiple processes underlying level-repetition effects.

Reversed temporal region asymmetries of P300 topography in left- and right-handed schizophrenic subjects

The auditory P300 evoked potential was recorded in 36 subjects: left- (LH) and right-handed (RH) schizophrenic males and LH and RH normal controls. LH and RH normals showed no asymmetry in P300 scalp topography. LH and RH schizophrenics, however, showed lateralized asymmetries in temporal scalp regions: left < right P300 voltage asymmetry in RH schizophrenics and left > right P300 voltage asymmetry in LH schizophrenics. These data suggest that the schizophrenic pathology of P300 neural generators is lateralized according to handedness and provide the first evidence that LH and RH schizophrenics can be dissociated based on left-right voltage asymmetries in P300 topography. These findings further emphasize the need for control of handedness in P300 studies of schizophrenia.

Preservation of P300 event-related potential topographic asymmetries in schizophrenia with use of either linked-ear or nose reference sites

Previous studies of the auditory P300 event-related potential (ERP) from our laboratory have reported a left- greater than right-sided attenuation in medicated chronic schizophrenics compared with normal controls. A possible confound in these studies has been the use of the linked-ear reference (LER), which has been criticized on the grounds that it might either induce or suppress topographic asymmetries. To test the effects of LER on P300 asymmetries in schizophrenia, we recorded ERPs with both LER and a nose reference (NR) in a group of 20 chronic medicated schizophrenics and in group of 20 age-matched normal controls. We here report: (1) confirmation of our previous P300 findings of left temporal scalp region deficit using both LER and NR with a 28-electrode montage; this feature was prominent in the wave form associated with the target stimulus, without the use of the wave form subtractions of our previous studies; (2) no statistically significant topographic differences between the LER and NR for either the schizophrenic or normal subjects; and (3) better performance of the LER in differentiating schizophrenics versus normal controls, due to lower wave form variability. We conclude that the LER is preferable for studies using subject groups and methodology similar to the present study.

Two Syndromes of Schizophrenic Psychopathology Associated with Left vs. Right Temporal Deficits in P300 Amplitude

In four schizophrenic patients, we examined the relationship between clinical course, including neuroleptic response, and the following biological and psychological measures: topography of the auditory P300 event-related potential, computerized tomography (CT), Andreasen's positive and negative symptom scales, the Thought Disorder Index, and a neuropsychological test battery. Two previous studies in our laboratory had shown that schizophrenic patients were differentiated from a matched normal control group by a left temporal scalp region deficit in P300 topography. This present report compares two schizophrenic patients with the typical left temporal P300 topography deficit with two schizophrenic patients with a right temporal P300 topography deficit. The two right temporal deficit patients had more positive symptoms, more thought disorder, more severely impaired functioning, earlier age of onset, poorer response to neuroleptic medications, more diffuse cognitive deficits on a neuropsychological testing battery, and poorer premorbid history than the two left temporal deficit patients. There was some evidence for the presence of more CT abnormalities suggestive of frontal lobe pathology in the right temporal deficit patients.

Correlations between abnormal auditory P300 topography and positive symptoms in schizophrenia: A preliminary report

P300 component amplitude in the left temporal scalp region, shown in three previous studies to differentiate normals from schizophrenics, was found to be significantly correlated with the Thought Disorder Index (TDI) and the Scale for the Assessment of Positive Symptoms (SAPS). These correlations occurred primarily in the P300 waveform derived from the Goodin paradigm. These findings suggest a brain processing disturbance in positive symptom schizophrenia that may be reflected by electrophysiological abnormalities detectable in the temporal scalp region.

P300 in schizophrenia: Confirmation and statistical validation of temporal region deficit in P300 topography

Comparison of normal and medicated schizophrenic groups on (he auditory P300 component of the event-related potential confirmed our earlier finding of a left temporal deficit in P300 amplitude in schizophrenia. A difference in P300 topography between groups was evident in both color mapping and in grand-averaged waveforms, which was statistically validated by the presence of a group-by-scalp region interaction ( p < 0.05) The left temporal area in schizophrenics was denoted as the region of greatest deficit and of maximal statistical separation ( p < 0.05) relative to normals by t statistic mapping (SPM), Hotelling's T-squared “protected” contrasts of individual scalp regions, and the relative ratio of left scalp amplitudes to right scalp amplitudes. The left temporal scalp region yielding maximal group separation in the previous study also statistically separated the schizophrenic group from the normal group. This feature correctly differentiated 9 of II schizophrenics and 7 of 9 controls. These findings are compatible with other histological, metabolic, and electrophysiological studies suggesting temporal lobe abnormality in schizophrenia.

An evaluation of ambulatory, cassette EEG monitoring: I. Montage design.

Ambulatory EEGs using cassette tape recorders have only four channels. Questions have been raised about the limitations this imposes on detection of focal interictal epileptiform events. A review of EEGs from inpatients undergoing prolonged monitoring demonstrated an overwhelming representation of these abnormalities in the frontal and anterior temporal scalp regions. Three-channel montages were designed to sample these regions and were tested by simultaneously recording them with multichannel montages. Successful montages combining a frontal transverse and two longitudinal channels adequately detected 74 to 100% of interictal epileptic events.

Catheter embolization of the feeding vessels in six cases of intracranial meningiomas (author's transl)

Meningiomas are known for their propensity to hemorrhage during surgery. When massive hemorrhaging occurs, exision of the tumor occasionally becomes difficult or incomplete. For this reason, it appeared to us that preoperative gelfoam embolization of the feeding vessels of meningiomas should facilitate surgery by abolishing or diminishing the risk of hemorrhage. The authors have undertaken embolization of 6 intracranial meningiomas which possessed predominant or exclusive external carotid vascularization. The cases included 2 male and 4 female patients. The age of the youngest was 42, and the oldest 64 yrs. The distribution of tumor sites was as follows: 2 in the convexity, 2 in the parasagittal region, 1 in the middle cranial fossa, and 1 in the tentoriurn. Histological examinations of the resected tumors revealed 5 to be meningothelial and 1 angioblastic. Cerebral catheterization by the retrograde transfemoral route was performed. The embolization in all 6 cases was effected with gelfoam, cut into fine strips. The delay between embolization and craniotomy varied between 1 day and 7 days, with a mean of 5.5 days. The results of embolization were evaluated on the basis of operative findings and the postoperative sequelae. In 2 cases (the 2 convexity meningiomas), the surgery (bone flap, section of the dural attachment and excision of the meningioma itself) was bloodless. In one of these convexity meningiomas, histological examinations of surgical specimens revealed fragments of gelfoam in the fine vessels within the capsule as well as the tumor tissue. In 2 cases (1 tentorial and 1 parasagittal), the surgery was minimally hemorrhagic, considering the volume and site of the tumor. In 1 case (the middle cranial fossa meningioma), preoperative embolization of the external carotid branches appeared to have a little effect. In this case, hemostasis of the dural attachment at the base of the middle cranial fossa was extremely difficult to maintain. This patient died 4 days after the operation. Complications related to the embolization were seen in 2 cases with transient pain in the temporal scalp region, and in 1 case with ischemic scalp complications. The findings of repeated CT scan after the embolization were useful for detecting possible changes within the tumor tissue itself. When performed as an integral part of the preoperative angiographic evaluation in case of meningiomas, careful embolization of the feeding vessels causes little increase in danger to the patient, while it clearly facilitates surgery by reducing the high risk of hemorrhage during the operative procedure.