The multiplicity of self: neuropsychological evidence and its implications for the self as a construct in psychological researchKlein, Stanley B.; Gangi, Cynthia E.
doi: 10.1111/j.1749-6632.2010.05441.xpmid: 20392272
This paper examines the issue of what the self is by reviewing neuropsychological research, which converges on the idea that the self may be more complex and differentiated than previous treatments of the topic have suggested. Although some aspects of self‐knowledge such as episodic recollection may be compromised in individuals, other aspects—for instance, semantic trait summaries—appear largely intact. Taken together, these findings support the idea that the self is not a single, unified entity. Rather, it is a set of interrelated, functionally independent systems. Implications for understanding the self in various areas of psychological research—e.g., neuroimaging, autism, amnesia, Alzheimer's disease, and mirror self‐recognition—are discussed in brief.
The neuropsychology of delusionsColtheart, Max
doi: 10.1111/j.1749-6632.2010.05496.xpmid: 20392273
Work in the field of cognitive neuropsychiatry over the past 20 years has made it plain that various forms of delusional belief are scientifically understandable in the sense that plausible neuropsychological explanations of their nature and genesis have been formulated. A two‐factor theory of delusional belief has emerged from this work. According to this theory, explaining the presence of a delusion requires (a) the presence a neuropsychological impairment that initially prompts the delusional belief and (b) the presence of a second neuropsychological impairment that interferes with processes of belief evaluation that would otherwise cause the delusional belief to be rejected. A very similar account of delusion has recently emerged from research on hypothesis evaluation using the associative‐learning paradigm with healthy control subjects and people with psychosis. Neuroimaging studies in this context suggest that the region of the brain specifically involved in hypothesis evaluation (and therefore, according to the two‐factor theory, impaired in people with delusions) is the right lateral prefrontal cortex.
Memory reconsolidation: an updateNader, Karim; Einarsson, Einar Örn
doi: 10.1111/j.1749-6632.2010.05443.xpmid: 20392274
Memory consolidation refers to the stabilization that a new memory has to undergo in order to persist. Recently, this dominant view of memory has been challenged by renewed interest in reconsolidation, where consolidated memories return to a transient unstable state following their retrieval, from which they must again stabilize in order to persist. In this review, we discuss how reconsolidation is supported by the same line of evidence as consolidation and recent findings of boundary conditions of reconsolidation. Furthermore, we discuss how recent controversies on the nature of amnesia following challenges to reconsolidation are using the same paradigm that failed to resolve the nature of amnesia after challenges to consolidation; we also discuss a new paradigm that can lead to more fruitful ways of studying amnesia in general.
What does the amygdala contribute to social cognition?Adolphs, Ralph
doi: 10.1111/j.1749-6632.2010.05445.xpmid: 20392275
The amygdala has received intense recent attention from neuroscientists investigating its function at the molecular, cellular, systems, cognitive, and clinical level. It clearly contributes to processing emotionally and socially relevant information, yet a unifying description and computational account have been lacking. The difficulty of tying together the various studies stems in part from the sheer diversity of approaches and species studied, in part from the amygdala's inherent heterogeneity in terms of its component nuclei, and in part because different investigators have simply been interested in different topics. Yet, a synthesis now seems close at hand in combining new results from social neuroscience with data from neuroeconomics and reward learning. The amygdala processes a psychological stimulus dimension related to saliency or relevance; mechanisms have been identified to link it to processing unpredictability; and insights from reward learning have situated it within a network of structures that include the prefrontal cortex and the ventral striatum in processing the current value of stimuli. These aspects help to clarify the amygdala's contributions to recognizing emotion from faces, to social behavior toward conspecifics, and to reward learning and instrumental behavior.
The anatomy of language: a review of 100 fMRI studies published in 2009Price, Cathy J.
doi: 10.1111/j.1749-6632.2010.05444.xpmid: 20392276
In this review of 100 fMRI studies of speech comprehension and production, published in 2009, activation is reported for: prelexical speech perception in bilateral superior temporal gyri; meaningful speech in middle and inferior temporal cortex; semantic retrieval in the left angular gyrus and pars orbitalis; and sentence comprehension in bilateral superior temporal sulci. For incomprehensible sentences, activation increases in four inferior frontal regions, posterior planum temporale, and ventral supramarginal gyrus. These effects are associated with the use of prior knowledge of semantic associations, word sequences, and articulation that predict the content of the sentence. Speech production activates the same set of regions as speech comprehension but in addition, activation is reported for: word retrieval in left middle frontal cortex; articulatory planning in the left anterior insula; the initiation and execution of speech in left putamen, pre‐SMA, SMA, and motor cortex; and for suppressing unintended responses in the anterior cingulate and bilateral head of caudate nuclei. Anatomical and functional connectivity studies are now required to identify the processing pathways that integrate these areas to support language.
The brain in time: insights from neuromagnetic recordingsHari, Riitta; Parkkonen, Lauri; Nangini, Cathy
doi: 10.1111/j.1749-6632.2010.05438.xpmid: 20392277
The millisecond time resolution of magnetoencephalography (MEG) is instrumental for investigating the brain basis of sensory processing, motor planning, cognition, and social interaction. We review the basic principles, recent progress, and future potential of MEG in noninvasive tracking of human brain activity. Cortical activation sequences from tens to hundreds of milliseconds can be followed during, e.g., perception, motor action, imitation, and language processing by recording both spontaneous and evoked brain signals. Moreover, tagging of sensory input can be used to reveal neuronal mechanisms of binaural interaction and perception of ambiguous images. The results support the emerging ideas of multiple, hierarchically organized temporal scales in human brain function. Instrumentation and data analysis methods are rapidly progressing, enabling attempts to decode the four‐dimensional spatiotemporal signal patterns to reveal correlates of behavior and mental contents.
Genetics as a tool for the dissociation of mental operations over the course of developmentFossella, John A.; Guise, Kevin; Fan, Jin
doi: 10.1111/j.1749-6632.2010.05439.xpmid: 20392278
In recent years it has become possible to differentiate separable aspects of attention and to characterize the anatomical structure and dynamic states of their underlying networks. When individual differences in the structure and dynamics of these networks are used as dependent measures in associations with individual genetic variation, it becomes possible to assign cellular and molecular changes that occur over the course of normal development to specific aspects of network structure and function. In this way, a more granular understanding of the physiology of neural networks can be obtained. Here we review a translational research strategy focused on how genetic variation contributes to the normal development of attentional function. We seek to use genetic information to help construct a multinode, multinetwork model that can explain, in part, individual differences in the development of attention over the course of development.
How reliable are the results from functional magnetic resonance imaging?Bennett, Craig M.; Miller, Michael B.
doi: 10.1111/j.1749-6632.2010.05446.xpmid: 20392279
Functional magnetic resonance imaging (fMRI) is one of the most important methods for in vivo investigation of cognitive processes in the human brain. Within the last two decades, an explosion of research has emerged using fMRI, revealing the underpinnings of everything from motor and sensory processes to the foundations of social cognition. While these results have revealed the potential of neuroimaging, important questions regarding the reliability of these results remain unanswered. In this paper, we take a close look at what is currently known about the reliability of fMRI findings. First, we examine the many factors that influence the quality of acquired fMRI data. We also conduct a review of the existing literature to determine if some measure of agreement has emerged regarding the reliability of fMRI. Finally, we provide commentary on ways to improve fMRI reliability and what questions remain unanswered. Reliability is the foundation on which scientific investigation is based. How reliable are the results from fMRI?
The neural mechanisms of visual selection: the view from neuropsychologyRiddoch, M. Jane; Chechlacz, Magda; Mevorach, Carmel; Mavritsaki, Eirini; Allen, Harriet; Humphreys, Glyn W.
doi: 10.1111/j.1749-6632.2010.05448.xpmid: 20392280
In this review, we discuss how neuropsychological impairments in visual selection can inform us about how selection normally operates. Using neuroanatomical and behavioral evidence on the disorders of neglect, extinction, and simultanagnosia, we propose functional and anatomical links between different aspects of visual selection and distinct sites in the posterior parietal cortex (PPC). This includes linking: (i) bottom‐up attentional capture and the right temporo‐parietal junction (TPJ); (ii) top‐down segmentation of displays and the medial PPC; (iii) grouping, individuation and identification, and the inferior intra‐parietal sulcus (IPS) bilaterally; and (iv) the suppression of saliency and the left IPS. In addition, when neuropsychological studies are combined with fMRI, there is evidence that these regions of the PPC interact with striate and extra‐striate cortical areas, which respond to specific properties of stimuli. Selection should be viewed as an emergent property of a network of areas involving both ventral and dorsal cortex.
Crossmodal spatial attentionSpence, Charles
doi: 10.1111/j.1749-6632.2010.05440.xpmid: 20392281
In this review, I highlight some of the most exciting recent developments in the area of crossmodal spatial attention, focusing on studies that question the automaticity of exogenous spatial orienting following the peripheral presentation of spatially uninformative unimodal cues. The latest research, showing that multisensory cues capture participants’ spatial attention more effectively than unimodal cues, is also reviewed. There has been a rapid growth of interest in the application of laboratory‐based studies of crossmodal attention to real‐world interface design, and this research is discussed, focusing, in particular, on the design of multisensory warning signals for drivers. Finally, I outline a number of key issues for future applied research in the study of crossmodal exogenous spatial attention.