Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory.

We used both structural and functional brain imaging techniques to investigate the neural basis of absolute pitch (AP), a specialized skill present in some musicians. By using positron emission tomography, we measured cerebral blood f low during the presentation of musical tones to AP possessors and to control musicians without AP. Listening to musical tones resulted in similar patterns of increased cerebral blood f low in auditory cortical areas in both groups, as expected. The AP group also demonstrated activation of the left posterior dorsolateral frontal cortex, an area thought to be related to learning conditional associations. However, a similar pattern of left dorsolateral frontal activity was also observed in non-AP subjects when they made relative pitch judgments of intervals, such as minor or major. Conversely, activity within the right inferior frontal cortex was observed in control but not in AP subjects during the interval-judgment task, suggesting that AP possessors need not access working memory mechanisms in this task. MRI measures of cortical volume indicated a larger left planum temporale in the AP group, which correlated with performance on an pitch-naming task. Our findings suggest that AP may not be associated with a unique pattern of cerebral activity but rather may depend on the recruitment of a specialized network involved in the retrieval and manipulation of verbal-tonal associations.The existence of special perceptuomotor skills in certain individuals presents many puzzling questions for cognitive neuroscience. One such ability whose cerebral substrate remains essentially unknown is absolute pitch (AP), also known as perfect pitch, a relatively rare ability that refers to a long-term internal representation for the pitch of tones in the musical scale (1, 2). It is typically manifested behaviorally by the ability to identify, by the name of the musical note, the pitch of any sound without reference to another sound or by producing a given musical tone on demand. In contrast, relative pitch (RP), which is well-developed among most trained musicians, refers to the ability to make pitch judgments about the relation between notes, such as within a musical interval.Knowledge about the neural basis for AP is sparse, but three pieces of information are relevant. (i) A case study (3) of an AP possessor who underwent surgical excision within the left temporal lobe for control of epilepsy did not find any deterioration of AP ability; instead, some improvement was noted, which was attributed to a reduction of interference from seizure activity. This finding would suggest that AP does not depend on the integrity of the left anterior temporal lobe but does not clarify which neural structures are crucial for the expression of AP. (ii) Anatomical structural measurements (4) have indicated that there is a more marked left hemispheric asymmetry among AP subjects in the region of the planum temporale (PT), an area of associative auditory cortex often thought to be related to language processes (5)...

The symptoms of 36 people with varying degrees of intellectual disability (ID) who had had an ICD-10 depressive syndrome in the preceding year were compared with 46 non-depressed people with comparable degrees of ID. Throughout the spectrum of ID, symptoms of depressed affect and sleep disturbance were significantly different between the groups. While symptoms in people with mild ID were reflected in the standard diagnostic criteria, this was not the case in people with moderate and severe ID. With increasing disability there was a move towards 'behavioural depressive equivalents' such as aggression, screaming and self-injurious behaviour. Diagnostic criteria for depression among people with severe ID, should place more emphasis on behavioural 'depressive equivalents'.

OBJECT Awake craniotomy is currently a useful surgical approach to help identify and preserve functional areas during cortical and subcortical tumor resections. Methodologies have evolved over time to maximize patient safety and minimize morbidity using this technique. The goal of this study is to analyze a single surgeon's experience and the evolving methodology of awake language and sensorimotor mapping for glioma surgery. METHODS The authors retrospectively studied patients undergoing awake brain tumor surgery between 1986 and 2014. Operations for the initial 248 patients (1986–1997) were completed at the University of Washington, and the subsequent surgeries in 611 patients (1997–2014) were completed at the University of California, San Francisco. Perioperative risk factors and complications were assessed using the latter 611 cases. RESULTS The median patient age was 42 years (range 13–84 years). Sixty percent of patients had Karnofsky Performance Status (KPS) scores of 90–100, and 40% had KPS scores less than 80. Fifty-five percent of patients underwent surgery for high-grade gliomas, 42% for low-grade gliomas, 1% for metastatic lesions, and 2% for other lesions (cortical dysplasia, encephalitis, necrosis, abscess, and hemangioma). The majority of patients were in American Society of Anesthesiologists (ASA) Class 1 or 2 (mild systemic disease); however, patients with severe systemic disease were not excluded from awake brain tumor surgery and represented 15% of study participants. Laryngeal mask airway was used in 8 patients (1%) and was most commonly used for large vascular tumors with more than 2 cm of mass effect. The most common sedation regimen was propofol plus remifentanil (54%); however, 42% of patients required an adjustment to the initial sedation regimen before skin incision due to patient intolerance. Mannitol was used in 54% of cases. Twelve percent of patients were active smokers at the time of surgery, which did not impact completion of the intraoperative mapping procedure. Stimulation-induced seizures occurred in 3% of patients and were rapidly terminated with ice-cold Ringer's solution. Preoperative seizure history and tumor location were associated with an increased incidence of stimulation-induced seizures. Mapping was aborted in 3 cases (0.5%) due to intraoperative seizures (2 cases) and patient emotional intolerance (1 case). The overall perioperative complication rate was 10%. CONCLUSIONS Based on the current best practice described here and developed from multiple regimens used over a 27-year period, it is concluded that awake brain tumor surgery can be safely performed with extremely low complication and failure rates regardless of ASA classification; body mass index; smoking status; psychiatric or emotional history; seizure frequency and duration; and tumor site, size, and pathology.

P lasticity, or the ability to change in response to experience, is an inherent feature of the brain that allows for the development and maintenance of nervous system function. 27 Brain plasticity manifests itself through various mechanisms at different levels; representative examples for such mechanisms at the molecular, cellular, and tissue levels, respectively, include trafficking of neurotransmitter receptors, the rearrangement of neuronal axons and dendrites, and the generation of new neurons and glia.5 Animal experiments have characterized brain plasticity and described its mechanistic basis in nonhuman subjects, but few detailed and direct investigations of plasticity have been made in humans. 12,14,18,27 A greater knowledge of human brain plasticity, particularly in the setting of disease, is fundamental to understanding the clinical course of neurological conditions, to applying abbreviatioNs ADP = after-discharge potential; DES = direct electrical stimulation; FLAIR = fluid-attenuated inversion-recovery; fMRI = functional MRI; GTR = grosstotal resection; PET = positron emission tomography; STR = subtotal resection; TMS = transcranial magnetic stimulation; WHO = World Health Organization. Intraoperative mapping during repeat awake craniotomy reveals the functional plasticity of adult cortex *derek g. southwell, md, phd, shawn l. hervey-Jumper, md, david w. perry, phd, and mitchel s. berger, md Department of Neurological Surgery, University of California, San Francisco, California obJective To avoid iatrogenic injury during the removal of intrinsic cerebral neoplasms such as gliomas, direct electrical stimulation (DES) is used to identify cortical and subcortical white matter pathways critical for language, motor, and sensory function. When a patient undergoes more than 1 brain tumor resection as in the case of tumor recurrence, the use of DES provides an unusual opportunity to examine brain plasticity in the setting of neurological disease. methods The authors examined 561 consecutive cases in which patients underwent DES mapping during surgery for glioma resection. "Positive" and "negative" sites-discrete cortical regions where electrical stimulation did (positive) or did not (negative) produce transient sensory, motor, or language disturbance-were identified prior to tumor resection and documented by intraoperative photography for categorization into functional maps. In this group of 561 patients, 18 were identified who underwent repeat surgery in which 1 or more stimulation sites overlapped with those tested during the initial surgery. The authors compared intraoperative sensory, motor, or language mapping results between initial and repeat surgeries, and evaluated the clinical outcomes for these patients. results A total of 117 sites were tested for sensory (7 sites, 6.0%), motor (9 sites, 7.7%), or language (101 sites, 86.3%) function during both initial and repeat surgeries. The mean interval between surgical procedures was 4.1 years. During initial surgeries, 95 (81.2%) of 117 sites were found to...