As an analogy, in V1 there is a large-scale map of eccentricity,

As an analogy, in V1 there is a large-scale map of eccentricity, but what is represented is not eccentricity per se but the orientation and spatial frequency of visual information at that particular eccentricity. Similarly, in these big and small object regions, what is represented is not an abstract sense of real-world selleck chemicals llc size per se, but something specific about the objects that have that particular size in the world. The Big-PHC region had a less pronounced preference for big relative to small objects when those objects were imagined at atypical sizes (marginally significant interaction: Big-PHC-L: F(1,27) =

5.9, p = 0.051; Big-PHC-R: F(1,31) = 5.4, p = 0.053). This result suggests that activity in this region may in part reflect the physical size an observer imagines the object to be (e.g., see Cate et al., 2011). However, a potentially more parsimonious account of these data is that this modulation in the big region is driven by its peripheral preference, as observed in the retinal size manipulation experiment (Figure 4). If observers were imagining giant peaches at a large retinal size and tiny pianos

at a small retinal size, and the imagined retinal size affects the spatial extent of activation in early visual areas, then this would give rise to the results observed in the Big-PHC region. Consistent with this interpretation, the small regions did not have any strong modulations by retinal size, and did not show an interaction in the atypical size conditions. While there was no reliable modulations in early visual cortex above baseline in these data (Table S2), previous

research supports this interpretation: bigger real-world objects are imagined at bigger retinal sizes (Konkle and Oliva, 2011), and imagining objects at bigger retinal sizes has been shown to drive more peripheral retinotopic responses in early visual areas when measured against a listening baseline (Kosslyn et al., 1995). Most categories of objects do not have a spatially contiguous and highly selective cortical representation, but instead activate a swath of ventral and lateral temporal cortex to varying degrees (Carlson et al., 2003, Cox and Savoy, 2003, Haxby Methisazone et al., 2001, Norman et al., 2006 and O’Toole et al., 2005). Here, we show that within this cortex there are large-scale differential responses to big and small real-world objects. Big versus small object preferences are arranged in a medial-to-lateral organization in ventral temporal cortex in both the left and right hemispheres, and this is mirrored along the lateral surface. Within this large-scale organization, several regions show strong differential activity that survive strict whole-brain contrasts, both at the single subject level and at the group level.

The second type of functional difference was based on a simulated

The second type of functional difference was based on a simulated null distribution. The null hypothesis of each term-wise test is that there is no difference in the proportion of genes with that term between the genes with enriched expression in the layer AZD6244 cell line being considered and all cortex-expressed classifiable genes. Briefly, for each layer, genes were simulated with replacement from

the set of all classifiable genes with a probability reflecting the precision of the classifier for that layer. Otherwise, genes were selected with replacement from one of the predicted sets with a likelihood that would best simulate the quantified sources of false positives for that classifier (see Supplemental Experimental Procedures). This continued until the number of simulated genes matched the number of genes in the predicted set (or the number of genes associated with a term in that functional database, for conditional databases). p values for the one-sided test were empirically determined from 200,000 such simulations for every term included in the background distribution, including those terms having no p value in the foreground. This was also done for genes predicted to have no layer enrichment. To account for multiple testing, q values (which reflect the smallest false discovery rate at which

a term would be significant) were calculated from empirical p values Luminespib in vivo with QVALITY v1.11 (Käll et al., 2008) on a per-database basis for both types of functional comparisons. Leukotriene C4 synthase Enrichments not meeting a q value threshold of 0.05 were discarded, controlling false positives at or below 5%. We identified in our cortical transcript set 4,587 multiexonic intergenic transcripts with no overlap with Ensembl protein-coding gene annotations (gene build 59). Cortical transcripts with one or more exonic base overlapping an Ensembl protein coding gene exon were used for expanding that gene for purposes of defining

intergenic space (Ponting and Belgard, 2010). We calculated, in both orientations (forward and reverse), the coding potential of all intergenic transcripts using the coding potential calculator (Kong et al., 2007) and identified 1,879 intergenic noncoding transcripts longer than 200 bp (lincRNAs). These lincRNAs can be clustered into 1,055 lincRNA loci, defined as the set of transcripts that share at least one intronic or exonic base on either strand. A 982 bp region of Anxa5 (ENSMUSG00000027712) matching probe RP_040324_01_D04 ( Lein et al., 2007) and a 520 bp region of its associated lincRNA (Gm11549) matching probe RP_060220_05_F09 ( Lein et al., 2007) were separately PCR amplified and cloned into the pCR4-TOPO vector (Invitrogen). P56 C57BL/6 male mouse brains were frozen in OCT (Merck, Darmstadt, Germany) on dry ice, and 14 μm coronal cryosections were cut and mounted on positively charged slides. Digoxigenin-labeled riboprobe synthesis and hybridization were performed as described previously ( Isaacs et al.