Spatial neglect during electrocortical stimulation mapping in the right hemisphere

Spatial processing was assessed following implantation of subdural electrodes in the nondominant hemisphere with electrocortical stimulation mapping (ESM) in two patients before epilepsy surgery. The first patient had mild hemispatial neglect/extinction during ESM of posterior temporal and inferior parietal areas. These areas were resected, and the patient had postoperative deficits that were similar to those occurring with ESM. The second patient was found to have marked hemispatial neglect during stimulation of parietal areas. These areas were not resected, and the patient had no neglect following surgery. These results suggest that ESM can help predict spatial processing deficits associated with cortical resection, and may help prevent postoperative impairments following resection in right parietal or temporal regions.     

Intracranial mapping of auditory perception: Event-related responses and electrocortical stimulation

ObjectiveWe compared intracranial recordings of auditory event-related responses with electrocortical stimulation mapping (ESM) to determine their functional relationship.MethodsIntracranial recordings and ESM were performed, using speech and tones, in adult epilepsy patients with subdural electrodes implanted over lateral left cortex. Evoked N1 responses and induced spectral power changes were obtained by trial averaging and time-frequency analysis.ResultsESM impaired perception and comprehension of speech, not tones, at electrode sites in the posterior temporal lobe. There was high spatial concordance between ESM sites critical for speech perception and the largest spectral power (100% concordance) and N1 (83%) responses to speech. N1 responses showed good sensitivity (0.75) and specificity (0.82), but poor positive predictive value (0.32). Conversely, increased high-frequency power (>60 Hz) showed high specificity (0.98), but poorer sensitivity (0.67) and positive predictive value (0.67). Stimulus-related differences were observed in the spatial-temporal patterns of event-related responses.ConclusionsIntracranial auditory event-related responses to speech were associated with cortical sites critical for auditory perception and comprehension of speech.SignificanceThese results suggest that the distribution and magnitude of intracranial auditory event-related responses to speech reflect the functional significance of the underlying cortical regions and may be useful for pre-surgical functional mapping.     

Taking tests in the magnet: Brain mapping standardized tests

Standardized psychometric tests are sophisticated, well‐developed, and consequential instruments; test outcomes are taken as facts about people that impact their lives in important ways. As part of an initial demonstration that human brain mapping techniques can add converging neural‐level evidence to understanding standardized tests, our participants completed items from standardized tests during an fMRI scan. We compared tests for diagnosing posttraumatic stress disorder (PTSD) and the correlated measures of Neuroticism, Attachment, and Centrality of Event to a general‐knowledge baseline test. Twenty‐three trauma‐exposed participants answered 20 items for each of our five tests in each of the three runs for a total of 60 items per test. The tests engaged different neural processes; which test a participant was taking was accurately predicted from other participants’ brain activity. The novelty of the application precluded specific anatomical predictions; however, the interpretation of activated regions using meta‐analyses produced encouraging results. For instance, items on the Attachment test engaged regions shown to be more active for tasks involving judgments of others than judgments of the self. The results are an initial demonstration of a theoretically and practically important test‐taking neuroimaging paradigm and suggest specific neural processes in answering PTSD‐related tests. Hum Brain Mapp 38:5706–5725, 2017. © 2017 Wiley Periodicals, Inc.     

Arachnoid cyst with rupture into the subdural space.

Arachnoid cysts which develop in relation to the cerebral hemispheres are usually found in the middle cranial fossa. These cysts are usually asymptomatic but can produce symptoms if there is haemorrhage into the cyst or the development of an associated subdural hematoma. Recent publications have emphasised the association of arachnoid cysts of the middle fossa with subdural haematomas. This report describes a case of an asymptomatic arachnoid cyst which ruptured into the subdural space. This event was followed by the development of symptoms despite the lack of haemorrhage.     

Preoperative functional MRI localization of language areas in Chinese patients with brain tumors Validation with intraoperative electrocortical mapping

Ten Chinese patients with brain tumors involving language regions were selected.Preoperative functional MRI was performed to locate Broca’s or Wernicke’s area,and the cortex that was essential for language function was determined by electrocortical mapping.A site-by-site comparison between functional MRI and electrocortical mapping was performed with the aid of a neuronavigation device.Results showed that the sensitivity and specificity of preoperative functional MRI were 80.0% and 85.0% in Broca’s area and 66.6% and 85.2% in Wernicke’s area,respectively.These experimental findings indicate that functional MRI is an accurate,reliable technique with which to identify the location of Wernicke’s area or Broca’s area in patients with brain tumors.     

Effect of cocaine on electrocortical activity in fetal sheep.

The effect of cocaine on the behavioral state of six fetal sheep was studied during gestational ages between 128-135 days. Two to eight days after surgery, fetuses received either a continuous 60 min intravenous infusion of cocaine HCl (33.4 mg) or saline. The infusions were preceded and followed by control periods of 102 min. Cocaine induced a disruption in fetal behavioral state cyclicity and a decrease in the amount of time spent in rapid eye movement sleep (P < 0.01) and non-rapid eye movement sleep (P < 0.05) during the infusion, but not during the recovery period. Spectral amplitude of the electrocortical activity at all three cortical locations increased within most one-third octave bands between 0.8-4 Hz and decreased within most bands between 16-25 Hz (P < 0.05) compared to controls. There were no differences in spectral amplitude between pre- and post-cocaine periods at any location over the 25 frequency bands studied (P > 0.6) except for one frequency band centered at 12.5 Hz. The effects of a one hour cocaine infusion on fetal cortical electrical activity are diffuse, but short-lived, and occur independently of changes in fetal oxygenation.     

When space merges into language

We present data from right brain-damaged patients, with and without spatial heminattention, which show the influence of hemispatial deficits on spoken language processing. We explored the findings of a previous study, which used an emphatic stress detection task and suggested spatial transcoding of a spoken active sentence in a 'language line'. This transcoding was impaired in its initial portion (the subject-word) when the neglect syndrome was present. By expanding the original methodology, the present study provides a deeper understanding of the level of spoken language processing involved in the heminattentional bias. To ascertain the role played by syntactic structure, active and passive sentences were compared. Sentences comprised of musical notes and of a sequence of unrelated nouns were also compared to determine whether the bias was manifest with any sequence of events (not only linguistic ones) deployed over time, and with a sequence of linguistic events not embedded in a structured syntactic frame. Results showed that heminattention exerted an influence only when a syntactically structured linguistic input (=sentence with agent of action, action and recipient of action) was processed, and that it did not interfere when a sequence of non-linguistic sounds or unrelated words was presented. Furthermore, when passing from active to passive sentences, the heminattentional bias was inverted, suggesting that heminattention primarily involves the logical subject of the sentence, which has an inverted position in passive sentences. These results strongly suggest that heminattention acts on the spatial transcoding of the deep structure of spoken language.     

Radial coherence, wave velocity and damping of electrocortical waves.

Mean squared coherence was calculated as a function of frequency (1-32 Hz) and electrode separation (1-8 mm) from 64-channel extradural arrays on occipito-parietal association cortex of cats. A 2-parameter theoretical function was then fitted to sets of pooled estimates. The theoretical function described coherences between recording sites of small separation for linear, non-dispersive, dissipative waves moving on an infinite homogeneous plane medium, and driven by spatio-temporally noisy inputs. Residuals of fit were then plotted as a function of frequency and distance, and were found to show no systematic trends with frequency, but an irregular and generally increasing relation to distance. This was the result predicted for linear non-dispersive waves on a surface actually folded, and with significant additional wave action generated between electrodes. Further recordings of coherence from more widely separated electrodes indicated that boundary conditions were absorbing or remote, rather than closed or reentrant. The phase velocity for electrocortical waves obtained from autoregression estimates of temporal damping and parameters of fit to coherence, was found in the range 0.1-0.29 m/sec, and appeared independent of the direction of electrode alignment. This compares with the velocity of 0.33 m/sec for alpha waves earlier found by Lopes da Silva and Storm van Leeuwen.     

Lessons learned from a comparison of language localisation using fMRI and electrocortical mapping: case studies of neocortical epilepsy patients

Electrocortical mapping (ECM) is recognised as an established method for localisation of eloquent cortex in patients undergoing resective surgery for epilepsy management. Functional MRI (fMRI) has been utilised for language and other cortical function localisation. We describe language localisation in two patients using both ECM and fMRI. Co-registration of fMRI and ECM revealed that although two fMRI tasks localised multiple language areas, the verb generation task had an advantage over the semantic decision/tone decision task in that there was a clear overlap between the language areas identified by the verb generation task and ECM. In addition to the language areas detected by ECM, fMRI showed other language-related areas that may be important for post-operative language outcome. Therefore, fMRI may provide additional and complementary information to ECM in presurgical evaluation of patients with epilepsy. The correlation between fMRI and ECM may depend on the language testing methods utilised during the procedures.     

Shifting visual attention in space: an electrophysiological analysis using high spatial resolution mapping.

OBJECTIVES: Evidence from cortical electrophysiology and functional imaging converges on the view that visual spatial selective attention results in a facilitation of early sensory processing in visual cortical structures. Little is known, however, about the neural control processes that lead to this facilitation. The present study was aimed at further investigating these control processes and their neural correlates by analyzing high spatial resolution maps of brain activity that were evoked by attention-directing cues, but occurred prior to presentation of the target stimulus. METHODS: Subjects (n=14) were presented with central arrow cues that instructed them to attend covertly to either a left or right field location in order to compare two subsequent target stimuli simultaneously presented to the location. On half of the trials, targets were presented to the cued location, while in the other half, targets were presented to the opposite visual field location. Subjects had to respond via button press on 16% of the trials when target stimuli were identical. Event-related potentials (ERPs) were recorded from 92 scalp electrodes which allowed a sufficiently finegrained analysis of the regional specificity of the ERP components. RESULTS: In response to the cues, an initial component over occipital-parietal electrode sites was consistent with an early involvement of the posterior-parietal cortex, perhaps in the initial step of attentional orienting. A second component over the lateral-prefrontal cortex is consistent with the voluntary control and maintenance of attention, a function known to be subserved by frontal cortical structures. A late component narrowly focussed over occipital-temporal electrode sites is most plausibly related to activation of parts of the ventral extrastriate cortex. CONCLUSIONS: The data support the current view that voluntarily orienting visual attention in space leads to top-down modulations in cortical excitability of ventral extrastriate regions initiated by posterior-parietal and mediated by lateral-prefrontal cortical structures.     

A model of topological mapping of space in bat hippocampus

The mammalian hippocampus plays a key role in spatial learning and memory, but the exact nature of the hippocampal representation of space is still being explored. Recently, there has been a fair amount of success in modeling hippocampal spatial maps in rats, assuming a topological perspective on spatial information processing. In this article, we use the topological approach to study the formation of a 3D spatial map in bats, which produces several insights into neurophysiological mechanisms of the hippocampal spatial leaning. First, we demonstrate that, in order to produce accurate maps of the environment, place cell should be organized into functional groups, which can be interpreted as cell assemblies. Second, the model suggests that the readout neurons in these cell assemblies should function as integrators of synaptic inputs, rather than detectors of place cells' coactivity, which allows estimating the integration time window. Lastly, the model suggests that, in contrast with relatively slow moving rats, suppressing θ‐precession in bats improves the place cells capacity to encode spatial maps, which is consistent with the experimental observations. © 2016 Wiley Periodicals, Inc.     

Transforming sheltered workshops into affirmative businesses: an outcome evaluation

This paper examines the outcomes associated with Voices, Opportunities and Choices Employment Club (VOCEC), which used the resources of a sheltered workshop to evolve affirmative businesses for people receiving mental health services. Quantitative and qualitative methodologies were used to understand the impact of VOCEC on employment and well-being outcomes compared to the former sheltered workshops and to competitive work. The results suggest that VOCEC has been successful in creating paid employment opportunities at levels approximating minimum wage and establishing a structure to incubate new businesses. The evaluation revealed the process by which Associates experience their participation as rewarding. It also indicated constraints on participation within the VOCEC model.     

Serotonin release into plasma during common carotid artery thrombosis in rats.

BACKGROUND AND PURPOSE: We have tested the hypothesis that platelet-derived serotonin is released into the bloodstream during cerebrovascular thrombosis. METHODS: Nonocclusive common carotid artery thrombosis was produced photochemically in 22 anesthetized adult male Wistar rats using the photosensitizing dye rose bengal and irradiation with an argon-pumped dye laser. Plasma serotonin levels were recorded before, during, and after photothrombosis by intra-arterial in vivo microdialysis with the probe placed distal to the site of thrombosis. RESULTS: During and immediately after the common carotid artery thrombosis, serotonin levels increased significantly to a peak value of 781 nmol/l (p less than 0.001 by analysis of variance), representing a 15-fold increase compared with baseline levels. The increased serotonin levels gradually decreased but remained significantly elevated for 90 minutes. Ultrastructural analysis of the carotid thrombi identified a dense mass of aggregated platelets at various stages of degranulation. CONCLUSIONS: These results are the first to demonstrate directly that serotonin accumulation occurs in plasma during and after the acute phase of common carotid artery thrombosis. Increased plasma serotonin levels may play a major role in the cerebral blood flow and blood-brain barrier abnormalities previously documented in this model of large-vessel thrombotic stroke.     

Self regulation of electrocortical activity in schizophrenia and schizotypy: a review.

Contrary to the belief that schizophrenic patients will be unable to learn self control of electrocortical activity due to attentional and motivational deficits, the two studies which have investigated this, both involving operant conditioning of slow cortical potentials, have demonstrated that self regulation can take place. This was particularly true of a study of interhemispheric control. Learning difficulties were found to be more to do with sustaining motivation towards the end of sessions or training programs, rather than in initial learning. Schizotypical features in the normal population have in the case of anhedonia been associated with slower learning, while withdrawn introversion has been associated with faster learning. In view of the affirmative evidence and advances in understanding the functional significance of electroencephalographic (EEG) rhythms, the undertaking of therepeutic regimens with electrocortical operant conditioning is warranted in the schizophrenia spectrum.     

Transforming poison into medicine: the role of dualism in psychiatry

This article draws attention to a generalizable phenomenon called "transforming poison into medicine," illustrating both literal and figurative applications. The purpose of such illustrations is to support a strong philosophical claim, namely the currently incomplete reduction (if not the ultimate irreducibility) of intentional mind-states - e.g., beliefs, desires, volitions - to electro-chemical brain-states. Such incomplete reduction (or irreducibility) holds profound implications for the ineluctable role of dualism in neuroscience and psychiatry alike.     

Transforming Trauma into Healing and Being: a Non-Dual Therapy Approach

This article explores and outlines the non-dual approach to the treatment of trauma, as cultivated and inspired by the first author’s own healing journey. Throughout Gary, the first author’s personal exploration, and through his work with clients, he realized that complete healing of trauma requires movement beyond conventional trauma therapies. Therefore, the authors first examine the nuances of trauma, such as the experience of becoming frozen in trauma (i.e., physically, emotionally, behaviorally, and neurologically) and its subsequent therapeutic unthawing (i.e., through the holistic treatment at all levels of processing). From here, a deeper understanding of the impact of trauma is cultivated by examining the role of choiceless awareness, as it allows one to drop the interpretations of traumatic events and move into the dark emotions and allow the energy to transform into essence, while allowing any expression of physical embodiment to take place. By utilizing the non-dual approach of promoting acceptance of the experience, one moves more deeply toward the root that intensifies trauma in the first place: One’s overarching instinctual grasping onto survival. In addressing such instinctual grasping, one experiences the great death, learning the art of dying in each moment, which leads to a movement through consciousness itself, into eternal timeless presence free from past and future. Gary’s journey through trauma, as well as three case studies in which he employed the non-dual approach to trauma treatment, are examined to illustrate the process of utilizing trauma to awaken into no-self-awareness and non-dual being. Finally, caveats and issues that may arise during this process are discussed.     

Transforming mental health and substance abuse data systems in the United States

State efforts to improve mental health and substance abuse service systems cannot overlook the fragmented data systems that reinforce the historical separateness of systems of care. These separate systems have discrete approaches to treatment, and there are distinct funding streams for state mental health, substance abuse, and Medicaid agencies. Transforming mental health and substance abuse services in the United States depends on resolving issues that underlie separate treatment systems--access barriers, uneven quality, disjointed coordination, and information silos across agencies and providers. This article discusses one aspect of transformation--the need for interoperable information systems. It describes current federal and state initiatives for improving data interoperability and the special issue of confidentiality associated with mental health and substance abuse treatment data. Some achievable steps for states to consider in reforming their behavioral health data systems are outlined. The steps include collecting encounter-level data; using coding that is compliant with the Health Insurance Portability and Accountability Act, including national provider identifiers; forging linkages with other state data systems and developing unique client identifiers among systems; investing in flexible and adaptable data systems and business processes; and finding innovative solutions to the difficult confidentiality restrictions on use of behavioral health data. Changing data systems will not in itself transform the delivery of care; however, it will enable agencies to exchange information about shared clients, to understand coordination problems better, and to track successes and failures of policy decisions.