Top-Down Modulations from Dorsal Stream in Lexical Recognition: An Effective Connectivity fMRI Study

Both the ventral and dorsal visual streams in the human brain are known to be involved in reading. However, the interaction of these two pathways and their responses to different cognitive demands remains unclear. In this study, activation of neural pathways during Chinese character reading was acquired by using a functional magnetic resonance imaging (fMRI) technique. Visual-spatial analysis (mediated by the dorsal pathway) was disassociated from lexical recognition (mediated by the ventral pathway) via a spatial-based lexical decision task and effective connectivity analysis. Connectivity results revealed that, during spatial processing, the left superior parietal lobule (SPL) positively modulated the left fusiform gyrus (FG), while during lexical processing, the left SPL received positive modulatory input from the left inferior frontal gyrus (IFG) and sent negative modulatory output to the left FG. These findings suggest that the dorsal stream is highly involved in lexical recognition and acts as a top-down modulator for lexical processing

The representation of conceptual knowledge: visual, auditory and olfactory imagery compared with semantic processing.

Two experiments comparing imaginative processing in different modalities and semantic processing were carried out to investigate the issue of whether conceptual knowledge can be represented in different format. Participants were asked to judge the similarity between visual images, auditory images, and olfactory images in the imaginative block, if two items belonged to the same category in the semantic block. Items were verbally cued in both experiments. The degree of similarity between the imaginative and semantic items was changed across experiments. Experiment 1 showed that the semantic processing was faster than the visual and the auditory imaginative processing, whereas no differentiation was possible between the semantic processing and the olfactory imaginative processing. Experiment 2 revealed that only the visual imaginative processing could be differentiated from the semantic processing in terms of accuracy. These results showed that the visual and auditory imaginative processing can be differentiated from the semantic processing, although both visual and auditory images strongly rely on semantic representations. On the contrary, no differentiation is possible within the olfactory domain. Results are discussed in the frame of the imagery debate

Gentrification on the Planetary Urban Frontier : The Evolution of Turner’s Noösphere

As capitalist urbanization evolves, so too does gentrification. Theories and experiences that have anchored the reference points of gentrification in the Global North for half a century are now rapidly evolving into more cosmopolitan, dynamic world urban systems of variegated gentrifications. These trends seem to promise a long-overdue postcolonial provincialization of the entrenched Global North bias of urban theory. Yet there is a jarring paradox between the material realities of some of the largest non-military urban displacements in human history in the Global South, alongside a growing reluctance to ‘impose’ Northern languages, theories, and politics of gentrification to understand these processes. In this paper, I negotiate this paradox through an engagement of several seemingly unrelated empirical trends and theoretical debates in urban studies and gentrification. My central argument is that interdependent yet partially autonomous developments in urban entrepreneurialism and transnational markets in labor, real estate, and education are transcending the dichotomy between gentrification in cities (the traditional focus of so much place-based research) versus gentrification as a dimension of planetary urbanization. Amidst the planetary technological transformations now celebrated as “cognitive capitalism” and a communications-consciousness “noösphere,” these developments are coalescing into a global, cosmopolitan, and multicultural tapestry of explicitly evolutionary class transformations of urban space that adapt to multiply-scaled contingencies of urban history, socio-cultural difference, state power, and terrains of resistance. The argument proceeds in three steps. First, I explain how social Darwinism was deeply embedded within conventional urban theory in the decades before Ruth Glass gave us a language for the discussion of gentrification, thus perpetuating debates over narrow empirical issues at the expense of deeper critical scrutiny of the evolutionary logics of socio-spatial classifications. Second, I examine the recent movement for a “cosmopolitan decolonization” of gentrification theory that has emerged at the precise moment when powerful alliances are consolidating the networked infrastructures of gentrification on an unprecedented scale. Third, I analyze the contemporary evolution of gentrification as a recombinant blend of old and new, as the means of class transformation of urban space are accelerated through intensified competition in work, education, and housing. The built environments of planetary urbanization provide ample opportunities not only for diverse cosmopolitan descendants of old-fashioned urban renewal in the style of Haussmann’s Paris or Moses’ New York, but also for new generations of ‘capitalists with conscience’ -- entrepreneurial coalitions closing ‘moral rent gaps’ by integrating the economic profits of gentrification with the discourses and practices of environmental sustainability, socially responsible development, and global fields of educational opportunity. All of these escalating competitions are legitimated as inclusive multicultural meritocracies. Yet the relentless optimism of competitive innovation in the cognitive-capitalist noösphere is creating dangerous new frontiers of human ecology that reproduce the social-Darwinist “form of society” that Frederick Jackson Turner envisioned in his theorization of the “recurrence of the process of evolution” in America’s colonial-settler waves of violent dispossession.Arts, Faculty ofGeography, Department ofReviewedFacult