Book Review: Brown, James Dean. (2016) Introducing Needs Analysis and English for Specific Purposes. Oxford: Routledge, pp. 231

Book Review: Brown, James Dean. (2016) Introducing Needs Analysis and English for Specific Purposes. Oxford: Routledge, pp. 23

Reciprocal anatomical relationship between primary sensory and prefrontal cortices in the human brain

The human brain exhibits remarkable interindividual variability in cortical architecture. Despite extensive evidence for the behavioral consequences of such anatomical variability in individual cortical regions, it is unclear whether and how different cortical regions covary in morphology. Using a novel approach that combined noninvasive cortical functional mapping with whole-brain voxel-based morphometric analyses, we investigated the anatomical relationship between the functionally mapped visual cortices and other cortical structures in healthy humans. We found a striking anticorrelation between the gray matter volume of primary visual cortex and that of anterior prefrontal cortex, independent from individual differences in overall brain volume. Notably, this negative correlation formed along anatomically separate pathways, as the dorsal and ventral parts of primary visual cortex showed focal anticorrelation with the dorsolateral and ventromedial parts of anterior prefrontal cortex, respectively. Moreover, a similar inverse correlation was found between primary auditory cortex and anterior prefrontal cortex, but no anatomical relationship was observed between other visual cortices and anterior prefrontal cortex. Together, these findings indicate that an anatomical trade-off exists between primary sensory cortices and anterior prefrontal cortex as a possible general principle of human cortical organization. This new discovery challenges the traditional view that the sizes of different brain areas simply scale with overall brain size and suggests the existence of shared genetic or developmental factors that contributes to the formation of anatomically and functionally distant cortical regions

Distractibility in daily life is reflected in the structure and function of human parietal cortex

We all appreciate that some of our friends and colleagues are more distractible than others. This variability can be captured by pencil and paper questionnaires in which individuals report such cognitive failures in their everyday life. Surprisingly, these self-report measures have high heritability, leading to the hypothesis that distractibility might have a basis in brain structure. In a large sample of healthy adults, we demonstrated that a simple self-report measure of everyday distractibility accurately predicted gray matter volume in a remarkably focal region of left superior parietal cortex. This region must play a causal role in reducing distractibility, because we found that disrupting its function with transcranial magnetic stimulation increased susceptibility to distraction. Finally, we showed that the self-report measure of distractibility reliably predicted our laboratory-based measure of attentional capture. Our findings distinguish a critical mechanism in the human brain causally involved in avoiding distractibility, which, importantly, bridges self-report judgments of cognitive failures in everyday life and a commonly used laboratory measure of distractibility to the structure of the human brai

Intra-hemispheric integration underlies perception of tilt illusion

The integration of inputs across the entire visual field into a single conscious experience is fundamental to human visual perception. This integrated nature of visual experience is illustrated by contextual illusions such as the tilt illusion, in which the perceived orientation of a central grating appears tilted away from its physical orientation, due to the modulation by a surrounding grating with a different orientation. Here we investigated the relative contribution of local, intra-hemispheric and global, inter-hemispheric integration mechanisms to perception of the tilt illusion. We used Dynamic Causal Modelling of fMRI signals to estimate effective connectivity in human early visual cortices (V1, V2, V3) during bilateral presentation of a tilt illusion stimulus. Our analysis revealed that neural responses associated with the tilt illusion were modulated by intra- rather than inter-hemispheric connectivity. Crucially, across participants, intra-hemispheric connectivity in V1 correlated with the magnitude of the tilt illusion, while no such correlation was observed for V1 inter-hemispheric connectivity, or V2, V3 connectivity. Moreover, when the illusion stimulus was presented unilaterally rather than bilaterally, the illusion magnitude did not change. Together our findings suggest that perception of the tilt illusion reflects an intra-hemispheric integration mechanism. This is in contrast to the existing literature, which suggests inter-hemispheric modulation of neural activity as early as V1. This discrepancy with our findings may reflect the diversity and complexity of integration mechanisms involved in visual processing and visual perception

Perceptual organization and consciousness

With chapter written by leading researchers in the field, this is the state-of-the-art reference work on this topic, and will be so for many years to come

Neuroscience in the Public Sphere

The media are increasingly fascinated by neuroscience. Here, we consider how neuroscientific discoveries are thematically represented in the popular press and the implications this has for society. In communicating research, neuroscientists should be sensitive to the social consequences neuroscientific information may have once it enters the public sphere

Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas

Visual perception depends not only on local stimulus features but also on their relationship to the surrounding stimulus context, as evident in both local and contextual influences on figure-ground segmentation. Intermediate visual areas may play a role in such contextual influences, as we tested here by examining LG, a rare case of developmental visual agnosia. LG has no evident abnormality of brain structure and functional neuroimaging showed relatively normal V1 function, but his intermediate visual areas (V2/V3) function abnormally. We found that contextual influences on figure-ground organization were selectively disrupted in LG, while local sources of figure-ground influences were preserved. Effects of object knowledge and familiarity on figure-ground organization were also significantly diminished. Our results suggest that the mechanisms mediating contextual and familiarity influences on figure-ground organization are dissociable from those mediating local influences on figure-ground assignment. The disruption of contextual processing in intermediate visual areas may play a role in the substantial object recognition difficulties experienced by LG

Variability in visual cortex size reflects tradeoff between local orientation sensitivity and global orientation modulation

The surface area of early visual cortices varies several fold across healthy adult humans and is genetically heritable. But the functional consequences of this anatomical variability are still largely unexplored. Here we show that interindividual variability in human visual cortical surface area reflects a tradeoff between sensitivity to visual details and susceptibility to visual context. Specifically, individuals with larger primary visual cortices can discriminate finer orientation differences, whereas individuals with smaller primary visual cortices experience stronger perceptual modulation by global orientation contexts. This anatomically correlated tradeoff between discrimination sensitivity and contextual modulation of orientation perception, however, does not generalize to contrast perception or luminance perception. Neural field simulations based on a scaling of intracortical circuits reproduce our empirical observations. Together our findings reveal a feature-specific shift in the scope of visual perception from context-oriented to detail-oriented with increased visual cortical surface area

Modalizing: A Function-Driven Approach

This thesis is about modals: words like ‘possible’ and ‘necessary’, ‘must’ and ‘can’. More specifically, it is about their roles in our lives. More specifically still, I want to approach, via the issue of modal function, the relationship between what I call ordinary and philosophical modalizing: the modalizing that we learn in the wild, and the modalizing that we learn in the philosophy classroom. What are the commonalities between these activities? What are their differences? In order to focus and dramatize the issue, I begin by introducing a figure whom I call the Ascetic Modalizer. The Ascetic Modalizer insists against there being theoretically significant continuities between the modals that we ordinarily use to talk about powers and dispositions, and the modals that some philosophers have called absolute. After arguing that modal semantics, metaphysics, and epistemology may prove too slow a route towards progress in this debate, I suggest that we approach the matter via the neglected topic of modal function. To get clear on modal function, however, one must first get clear on conditionals. I therefore argue for some novel assertability conditions for subjunctive conditionals, which are informed by the functions of these important constructions. In the process, I shed some light on the differences between kinds of supposition. This discussion of conditionals and suppositions then allows me to draw together two different research programmes in the theory of modal function. With those resources in hand, I investigate the roles of some ordinary and philosophical modals in our practical and theoretical deliberations. I argue that in so far as those functions are concerned, the Ascetic Modalizer may be right to be sceptical of modal unification. Finally, I show how the preceding discussion intersects with two ancient ideas about modality: that deductive validity requires necessary truth-preservation, and that necessity implies actuality