Contrast summation across eyes and space is revealed along the entire dipper function by a "Swiss cheese" stimulus.

Previous contrast discrimination experiments have shown that luminance contrast is summed across ocular (T. S. Meese, M. A. Georgeson, & D. H. Baker, 2006) and spatial (T. S. Meese & R. J. Summers, 2007) dimensions at threshold and above. However, is this process sufficiently general to operate across the conjunction of eyes and space? Here we used a "Swiss cheese" stimulus where the blurred "holes" in sine-wave carriers were of equal area to the blurred target ("cheese") regions. The locations of the target regions in the monocular image pairs were interdigitated across eyes such that their binocular sum was a uniform grating. When pedestal contrasts were above threshold, the monocular neural images contained strong evidence that the high-contrast regions in the two eyes did not overlap. Nevertheless, sensitivity to dual contrast increments (i.e., to contrast increments in different locations in the two eyes) was a factor of ∼1.7 greater than to single increments (i.e., increments in a single eye), comparable with conventional binocular summation. This provides evidence for a contiguous area summation process that operates at all contrasts and is influenced little, if at all, by eye of origin. A three-stage model of contrast gain control fitted the results and possessed the properties of ocularity invariance and area invariance owing to its cascade of normalization stages. The implications for a population code for pattern size are discussed.

"You have ruined this entire experiment…shall we stop talking now?" Orientations to the experimental setting as an interactional resource

One limitation widely noted in sociolinguistics is the tension presented by the ‘observer’s paradox’ (Labov, 1972), i.e. the notion that everyday language is ‘susceptible to contamination by observation’ (Stubbs, 1983: 224). The observer’s paradox has been perceived to present significant challenges to traditional sociolinguistic researchers seeking to explore the processes at work during ordinary interaction. More recently, scholars have begun to argue that in fact the presence of a recording device, rather than being a mere constraint on spoken interaction, is in itself an interactional resource explicitly oriented to by participants (Speer & Hutchby 2003; Gordon 2012). Drawing on a collection of transcripts collected in experimental conditions as part of a wider project exploring the relationship between language and identity, this paper seeks to explore how these orientations manifest themselves in the context of Instant Messaging (IM) conversations. We show different orientations to the experimental setting, and different understandings of the role of the researcher – represented in this case by the IM chat archive – as both a topic of discussion and as a participant themselves.