There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Principles of Neural Science

Information processing in the cerebral cortex involves interactions among distributed areas. Anatomical connectivity suggests that certain areas form local hierarchical relations such as within the visual system. Other connectivity patterns, particularly among association areas, suggest the presence of large-scale circuits without clear hierarchical relations. In this study the organization of networks in the human cerebrum was explored using resting-state functional connectivity MRI. Data from 1,000 subjects were registered using surface-based alignment. A clustering approach was employed to identify and replicate networks of functionally coupled regions across the cerebral cortex. The results revealed local networks confined to sensory and motor cortices as well as distributed networks of association regions. Within the sensory and motor cortices, functional connectivity followed topographic representations across adjacent areas. In association cortex, the connectivity patterns often showed abrupt transitions between network boundaries. Focused analyses were performed to better understand properties of network connectivity. A canonical sensory-motor pathway involving primary visual area, putative middle temporal area complex (MT+), lateral intraparietal area, and frontal eye field was analyzed to explore how interactions might arise within and between networks. Results showed that adjacent regions of the MT+ complex demonstrate differential connectivity consistent with a hierarchical pathway that spans networks. The functional connectivity of parietal and prefrontal association cortices was next explored. Distinct connectivity profiles of neighboring regions suggest they participate in distributed networks that, while showing evidence for interactions, are embedded within largely parallel, interdigitated circuits. We conclude by discussing the organization of these large-scale cerebral networks in relation to monkey anatomy and their potential evolutionary expansion in humans to support cognition.

The organization of the human cerebral cortex estimated by intrinsic functional connectivity

The majority of functional neuroscience studies have focused on the brain's response to a task or stimulus. However, the brain is very active even in the absence of explicit input or output. In this Article we review recent studies examining spontaneous fluctuations in the blood oxygen level dependent (BOLD) signal of functional magnetic resonance imaging as a potentially important and revealing manifestation of spontaneous neuronal activity. Although several challenges remain, these studies have provided insight into the intrinsic functional architecture of the brain, variability in behaviour and potential physiological correlates of neurological and psychiatric disease.

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Spontaneous fluctuations in brain activity observed with functional magnetic resonance imaging.

Introduction to functional MRI hardware

Background: The underlying brain mechanisms of altered cognitive function associated with adjuvant chemotherapy for breast cancer, commonly designated “chemobrain”, have yet to be determined. Recent research indicates that compromised cognitive function may already exist prior to treatment, adding to the complexity of determining the true impact of adjuvant chemotherapy on brain function. We examined whether two common symptoms associated with breast cancer diagnosis, worry and fatigue, might influence neurocognitive responses during functional magnetic resonance imaging (fMRI) before adjuvant therapy. Methods: Seventy five women (29–75 years) awaiting either adjuvant chemotherapy (n=25) or radiation therapy (n=25) for localized breast cancer and age-matched controls without breast cancer (n=25) were enrolled. Participants performed a verbal working memory task (VWMT) with varying levels of demand for cognitive control during fMRI scanning and provided self-reports of worry and fatigue after scanning. Imaging data were analyzed using the general linear model implemented in SPM5; comparative statistics were used to determine group differences in self-report and behavioral measures. Results: In general, the pre-chemotherapy group showed compromised cognitive functioning relative to the other groups. Specifically, they reported higher worry than the pre-radiation therapy (p=.036) and control (p=.047) groups. The pre-chemotherapy group also identified greater fatigue than controls (p=.04); the pre-radiation group reported a fatigue level between the other two groups. In the VWMT, the pre-chemotherapy group was less accurate than controls (p=.05), while the mean accuracy for the pre-radiation group again fell between these two groups. fMRI results showed that the control group selectively increased recruitment of executive control brain regions including the left inferior frontal gyrus (LIFG) and the anterior cingulate cortex (ACC) in response to high vs. low demand conditions. However, recruitment of LIGF and ACC by the control group was greater than that by both the pre-chemotherapy (p=.01 and p=.003 respectively) and the pre-radiation groups (p=.027 and p=.02 respectively). Overall, higher fatigue was correlated with failure to increase recruitment of the LIFG and ACC in high vs. low demand conditions (p=.002 and p=.078 respectively). Greater worry was correlated with failure to suppress task-irrelevant activation of default network regions, particularly the posterior cingulate cortex, in high vs. low demand conditions, and with lower accuracy in the VWMT (p=.01). Thus, fatigue and worry made independent contributions to altered neurocognitive responses prior to any adjuvant treatment. Discussion: These findings suggest that women awaiting adjuvant chemotherapy are vulnerable to compromised cognitive functioning, specifically in the domains of attention and working memory, related to higher worry and fatigue. Worry and fatigue may contribute to the cognitive impact often attributed to adjuvant chemotherapy. Therapeutic interventions to counteract worry and fatigue hold potential for optimizing cognitive function prior to adjuvant treatment for breast cancer. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD04-08.

PD04-08: Altered Neurocognitive Responses Prior to Adjuvant Therapy for Breast Cancer: A Functional MRI Analysis of the Impact of Worry and Fatigue.

Bipolar disorder (BD) is associated with a range of social cognitive deficits. This study investigated the functioning of the mentalizing brain system in BD probed by an eye gaze perception task during fMRI. Compared with healthy controls (n = 21), BD participants (n = 14) showed reduced preferential activation for self-directed gaze discrimination in the medial prefrontal cortex (mPFC) and temporo-parietal junction (TPJ), which was associated with poorer cognitive and social functioning. Aberrant functions of the mentalizing system should be further investigated as marker of social dysfunction and treatment targets. HighlightsO_LISocial dysfunction in bipolar disorder (BD) may be due to altered mentalizing. C_LIO_LIIndividuals with BD showed reduced activation in the mentalizing brain system. C_LIO_LIAberrant activity of the mentalizing system was associated with poorer functioning. C_LI

/pdf/aberrant-activation-of-the-mentalizing-brain-system-during-1yzq1s5lvj.pdf

Aberrant Activation of the Mentalizing Brain System During Eye Gaze Discrimination in Bipolar Disorder

Bipolar disorder (BD) is associated with a range of social cognitive deficits. This study investigated the functioning of the mentalizing brain system in BD probed by an eye gaze perception task during fMRI. Compared with healthy controls (n = 21), BD participants (n = 14) showed reduced preferential activation for self-directed gaze discrimination in the medial prefrontal cortex (mPFC) and temporo-parietal junction (TPJ), which was associated with poorer cognition/social cognition. Aberrant functions of the mentalizing system should be further investigated as marker of social dysfunction and treatment targets.

Scott Peltier

Papers

Introduction to functional MRI hardware

PD04-08: Altered Neurocognitive Responses Prior to Adjuvant Therapy for Breast Cancer: A Functional MRI Analysis of the Impact of Worry and Fatigue.

Aberrant Activation of the Mentalizing Brain System During Eye Gaze Discrimination in Bipolar Disorder

Aberrant activation of the mentalizing brain system during eye gaze discrimination in bipolar disorder.

Altered resting connectivity between the insula and cingulate cortex is related to chronic fibromyalgia pain