Humans Have Precise Knowledge Of Familiar Geographical Slants

Whereas maps primarily represent the 2-dimensional layout of the environment, people are also aware of the 3-dimensional layout of their environment. An experiment conducted on a small colregt edinpus tested whether the remembered slants of familiar paths were precisely represented. Three measures of slant (verbal, manual, and pictorial) were collected in 2 different between-subject conditions (perception and memory) for 5 familiar paths on the campus of Swarthmore College, ranging in slant from 0.5 to 8.6. Estimates from memory and from perception did not differ for any of the measures. Moreover, estimates from all measures, though different in mean value, were correlated within participant, suggesting a common underlying representation was consulted in all cases

Differential sustained and transient temporal processing across visual streams.

How do high-level visual regions process the temporal aspects of our visual experience? While the temporal sensitivity of early visual cortex has been studied with fMRI in humans, temporal processing in high-level visual cortex is largely unknown. By modeling neural responses with millisecond precision in separate sustained and transient channels, and introducing a flexible encoding framework that captures differences in neural temporal integration time windows and response nonlinearities, we predict fMRI responses across visual cortex for stimuli ranging from 33 ms to 20 s. Using this innovative approach, we discovered that lateral category-selective regions respond to visual transients associated with stimulus onsets and offsets but not sustained visual information. Thus, lateral category-selective regions compute moment-to-moment visual transitions, but not stable features of the visual input. In contrast, ventral category-selective regions process both sustained and transient components of the visual input. Our model revealed that sustained channel responses to prolonged stimuli exhibit adaptation, whereas transient channel responses to stimulus offsets are surprisingly larger than for stimulus onsets. This large offset transient response may reflect a memory trace of the stimulus when it is no longer visible, whereas the onset transient response may reflect rapid processing of new items. Together, these findings reveal previously unconsidered, fundamental temporal mechanisms that distinguish visual streams in the human brain. Importantly, our results underscore the promise of modeling brain responses with millisecond precision to understand the underlying neural computations

How Accurate Is Memory For Familiar Slope?

Geographical slant is generally overestimated. It has been reported that these overestimations are even greater in memory than in perception (Creem & Proffitt, 1998). However, these prior studies have used imagery instructions, which may encourage biased responding. We asked two groups of undergraduates to provide verbal, and pictorial or proprioceptive slope estimates of 5 familiar campus paths ranging in actual slope from 0.5 to 8.6 deg. One set of 30 participants was led to the base of each path and made their estimates while looking at it (Perception Condition). The other set of 30 participants made estimates from memory (Memory Condition). Maps, satellite photos and verbal names for the paths were used in the memory condition to ensure that participants understood the location of the path to be judged. Half the participants in each condition were asked to hold out their unseen hand to represent the slope of the path. Hand orientation was measured precisely with a micro-inclinometer. Following this they made verbal estimates. The other half of the participants adjusted a 2D line on a computer screen to represent the slope of the path prior to making verbal estimates. All three measures showed the same patterns. For one of the shallower paths (1.2 deg), proprioceptive estimates from memory were slightly lower (2.3 deg) than the proprioceptive estimates of those viewing the path (4.0 deg), t(28) = 2.08, p = .046. For all other paths and measures, there was no evident or consistent difference between memory and perception on any of the measures. Non-verbal estimates were lower than verbal estimates, but all estimates overestimated all hills both in perception and in memory. We conclude that memory for familiar paths includes unbiased (normal) perceptual information about path inclination. Creem, S.H., & Proffitt, D.R. (1998). Psychonomic Bulletin and Review 5(1):22-36

An Imputed Dissociation Might Be an Artifact: Further Evidence for the Generalizability of the Observations of Durgin et al. 2010

We recently showed that palm board measures are systematically inaccurate for full-cue surfaces within reach of one\u27s hand, whereas free-hand gestures and reaching actions are quite accurate for such surfaces (Durgin, Hajnal, Li, Tonge, & Stigliani, 2010). Proffitt and Zadra (2010) claim that our demonstration that palm boards are highly inaccurate is irrelevant to interpreting past and present findings concerning dissociations between verbal reports and palm board estimates. In their paper they offer a theoretical representation of the findings of Bhalla and Proffitt (1999) and argue that our analysis is incompatible with their account. We offer here an alternative account of the findings of Bhalla and Proffitt, based on their actual data (which are fully compatible with our original analysis). We further show how our account generalizes to more recent studies that continue (1) to mistakenly describe null statistical effects on (insensitive) palm boards as evidence of a dissociation from (more sensitive) verbal measures that show a similar relative magnitude of change and (2) to introduce uncontrolled demand characteristics. (C) 2010 Elsevier B.V. All rights reserved

Palm Boards Are Not Action Measures: An Alternative to the Two-Systems Theory of Geographical Slant Perception

Whereas most reports of the perception of outdoor hills demonstrate dramatic overestimation, estimates made by adjusting a palm board are much closer to the true hill orientation. We test the dominant hypothesis that palm board accuracy is related to the need for motor action to be accurately guided and conclude instead that the perceptual experience of palm-board orientation is biased and variable due to poorly calibrated proprioception of wrist flexion. Experiments 1 and 3 show that wrist-flexion palm boards grossly underestimate the orientations of near, reachable surfaces whereas gesturing with a free hand is fairly accurate. Experiment 2 shows that palm board estimates are much lower than free hand estimates for an outdoor hill as well. Experiments 4 shows that wrist flexion is biased and noisy compared to elbow flexion, while Experiment 5 shows that small changes in palm board height produce large changes in palm board estimates. Together, these studies suggest that palm boards are biased and insensitive measures. The existing literature arguing that there are two systems in the perception of geographical slant is re-evaluated, and a new theoretical framework is proposed in which a single exaggerated representation of ground-surface orientation guides both action and perception. (C) 2010 Elsevier B.V. All rights reserved

Palm Boards Are Not Action Measures: An Alternative To The Two-Systems Theory Of Geographical Slant Perception

Whereas most reports of the perception of outdoor hills demonstrate dramatic overestimation, estimates made by adjusting a palm board are much closer to the true hill orientation. We test the dominant hypothesis that palm board accuracy is related to the need for motor action to be accurately guided and conclude instead that the perceptual experience of palm-board orientation is biased and variable due to poorly calibrated proprioception of wrist flexion. Experiments 1 and 3 show that wrist-flexion palm boards grossly underestimate the orientations of near, reachable surfaces whereas gesturing with a free hand is fairly accurate. Experiment 2 shows that palm board estimates are much lower than free hand estimates for an outdoor hill as well. Experiments 4 shows that wrist flexion is biased and noisy compared to elbow flexion, while Experiment 5 shows that small changes in palm board height produce large changes in palm board estimates. Together, these studies suggest that palm boards are biased and insensitive measures. The existing literature arguing that there are two systems in the perception of geographical slant is re-evaluated, and a new theoretical framework is proposed in which a single exaggerated representation of ground-surface orientation guides both action and perception

An Imputed Dissociation Might Be An Artifact: Further Evidence For The Generalizability Of The Observations Of Durgin, Et Al., 2010

We recently showed that palm board measures are systematically inaccurate for full-cue surfaces within reach of one\u27s hand, whereas free-hand gestures and reaching actions are quite accurate for such surfaces (Durgin, Hajnal, Li, Tonge, & Stigliani, 2010). Proffitt and Zadra (2010) claim that our demonstration that palm boards are highly inaccurate is irrelevant to interpreting past and present findings concerning dissociations between verbal reports and palm board estimates. In their paper they offer a theoretical representation of the findings of Bhalla and Proffitt (1999) and argue that our analysis is incompatible with their account. We offer here an alternative account of the findings of Bhalla and Proffitt, based on their actual data (which are fully compatible with our original analysis). We further show how our account generalizes to more recent studies that continue (1) to mistakenly describe null statistical effects on (insensitive) palm boards as evidence of a “dissociation” from (more sensitive) verbal measures that show a similar relative magnitude of change and (2) to introduce uncontrolled demand characteristics

The Cytoarchitecture of Domain-specific Regions in Human High-level Visual Cortex

Abstract A fundamental hypothesis in neuroscience proposes that underlying cellular architecture (cytoarchitecture) contributes to the functionality of a brain area. However, this hypothesis has not been tested in human ventral temporal cortex (VTC) that contains domain-specific regions causally involved in perception. To fill this gap in knowledge, we used cortex-based alignment to register functional regions from living participants to cytoarchitectonic areas in ex vivo brains. This novel approach reveals 3 findings. First, there is a consistent relationship between domain-specific regions and cytoarchitectonic areas: each functional region is largely restricted to 1 cytoarchitectonic area. Second, extracting cytoarchitectonic profiles from face- and place-selective regions after back-projecting each region to 20-μm thick histological sections indicates that cytoarchitectonic properties distinguish these regions from each other. Third, some cytoarchitectonic areas contain more than 1 domain-specific region. For example, face-, body-, and character-selective regions are located within the same cytoarchitectonic area. We summarize these findings with a parsimonious hypothesis incorporating how cellular properties may contribute to functional specialization in human VTC. Specifically, we link computational principles to correlated axes of functional and cytoarchitectonic segregation in human VTC, in which parallel processing across domains occurs along a lateral–medial axis while transformations of information within domain occur along an anterior–posterior axis

JASPAR 2018: update of the open-access database of transcription factor binding profiles and its web framework

International audienceJASPAR (http://jaspar.genereg.net) is an open-access database of curated, non-redundant transcription factor (TF)-binding profiles stored as position frequency matrices (PFMs) and TF flexible models (TFFMs) for TFs across multiple species in six tax-onomic groups. In the 2018 release of JASPAR, the CORE collection has been expanded with 322 new PFMs (60 for vertebrates and 262 for plants) and 33 PFMs were updated (24 for vertebrates, 8 for plants and 1 for insects). These new profiles represent a 30% expansion compared to the 2016 release. In addition , we have introduced 316 TFFMs (95 for vertebrates , 218 for plants and 3 for insects). This release incorporates clusters of similar PFMs in each taxon and each TF class per taxon. The JASPAR 2018 CORE vertebrate collection of PFMs was used to predict TF-binding sites in the human genome. The predictions are made available to the scientific community through a UCSC Genome Browser track data hub. Finally , this update comes with a new web framework with an interactive and responsive user-interface, along with new features. All the underlying data can be retrieved programmatically using a RESTful API and through the JASPAR 2018 R/Bioconductor package