Data and Tools Integration in the Canadian Open Neuroscience Platform.

We present the Canadian Open Neuroscience Platform (CONP) portal to answer the research community's need for flexible data sharing resources and provide advanced tools for search and processing infrastructure capacity. This portal differs from previous data sharing projects as it integrates datasets originating from a number of already existing platforms or databases through DataLad, a file level data integrity and access layer. The portal is also an entry point for searching and accessing a large number of standardized and containerized software and links to a computing infrastructure. It leverages community standards to help document and facilitate reuse of both datasets and tools, and already shows a growing community adoption giving access to more than 60 neuroscience datasets and over 70 tools. The CONP portal demonstrates the feasibility and offers a model of a distributed data and tool management system across 17 institutions throughout Canada.

Interaction in Spoken Word Recognition Models: Feedback Helps.

Human perception, cognition, and action requires fast integration of bottom-up signals with top-down knowledge and context. A key theoretical perspective in cognitive science is the interactive activation hypothesis: forward and backward flow in bidirectionally connected neural networks allows humans and other biological systems to approximate optimal integration of bottom-up and top-down information under real-world constraints. An alternative view is that online feedback is neither necessary nor helpful; purely feed forward alternatives can be constructed for any feedback system, and online feedback could not improve processing and would preclude veridical perception. In the domain of spoken word recognition, the latter view was apparently supported by simulations using the interactive activation model, TRACE, with and without feedback: as many words were recognized more quickly without feedback as were recognized faster with feedback, However, these simulations used only a small set of words and did not address a primary motivation for interaction: making a model robust in noise. We conducted simulations using hundreds of words, and found that the majority were recognized more quickly with feedback than without. More importantly, as we added noise to inputs, accuracy and recognition times were better with feedback than without. We follow these simulations with a critical review of recent arguments that online feedback in interactive activation models like TRACE is distinct from other potentially helpful forms of feedback. We conclude that in addition to providing the benefits demonstrated in our simulations, online feedback provides a plausible means of implementing putatively distinct forms of feedback, supporting the interactive activation hypothesis.

A large, searchable, web-based database of aphasic performance on picture naming and other tests of cognitive function.

Many research questions in aphasia can only be answered through access to substantial numbers of patients and to their responses on individual test items. Since such data are often unavailable to individual researchers and institutions, we have developed and made available the Moss Aphasia Psycholinguistics Project Database: a large, searchable, web-based database of patient performance on psycholinguistic and neuropsychological tests. The database contains data from over 240 patients covering a wide range of aphasia subtypes and severity, some of whom were tested multiple times. The core of the archive consists of a detailed record of individual-trial performance on the Philadelphia (picture) Naming Test. The database also contains basic demographic information about the patients and patients' overall performance on neuropsychological assessments as well as tests of speech perception, semantics, short-term memory, and sentence comprehension. The database is available at http://www.mappd.org/ .

Effect of Representational Distance between Meanings on Recognition of Ambiguous Spoken Words.

Previous research indicates that mental representations of word meanings are distributed along both semantic and syntactic dimensions such that nouns and verbs are relatively distinct from one another. Two experiments examined the effect of representational distance between meanings on recognition of ambiguous spoken words by comparing recognition of unambiguous words, noun-verb homonyms, and noun-noun homonyms. In Experiment 1, auditory lexical decision was fastest for unambiguous words, slower for noun-verb homonyms, and slowest for noun-noun homonyms. In Experiment 2, response times for matching spoken words to pictures followed the same pattern and eye fixation time courses revealed converging, gradual time course differences between conditions. These results indicate greater competition between meanings of ambiguous words when the meanings are from the same grammatical class (noun-noun homonyms) than they when are from different grammatical classes (noun-verb homonyms).

jTRACE: a reimplementation and extension of the TRACE model of speech perception and spoken word recognition.

This article describes jTRACE, a freely available, cross-platform Java reimplementation of the TRACE model of spoken word recognition. The goal of the reimplementation is to facilitate the use of simulations by researchers who may not have the skills or time necessary to use or extend the original C implementation. In this article, we report a large-scale validation project, in which we have replicated a number of important previous simulations, and then we describe several new features in jTRACE designed to help researchers conduct original TRACE research, as well as to replicate earlier findings. These features include visualization tools, powerful scripting, built-in data graphing, adjustable levels of external and internal noise, and adjustable lexical characteristics, such as frequency of occurrence. Functions for saving and reloading entire simulations facilitate archiving, sharing, and replication and also make jTRACE ideal for educational use, since it comes bundled with several important simulations. jTRACE can be downloaded from magnuson.psy.uconn.edu/jtrace.