Darren J. Edwards

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What makes a category seem natural or intuitive? In this paper, an unsupervised categorization task was employed to examine observer agreement concerning the categorization of nine different stimulus sets. The stimulus sets were designed to capture different intuitions about classification structure. The main empirical index of category intuitiveness was(More)
We asked 169 participants to spontaneously categorize nine sets of items. A category structure was assumed to be more intuitive if a large number of participants consistently produced the same classification. Our results provide a rich empirical framework for examining models of unsupervised categorization—and illustrate a corresponding profound modeling(More)
Reversible inactivation of the cortex by surface cooling is a powerful method for studying the function of a particular area. Implanted cooling cryoloops have been used to study the role of individual cortical areas in auditory processing of awake-behaving cats. Cryoloops have also been used in rodents for reversible inactivation of the cortex, but recently(More)
The dream-lag effect refers to there being, after the frequent incorporation of memory elements from the previous day into dreams (the day-residue), a lower incorporation of memory elements from 2 to 4 days before the dream, but then an increased incorporation of memory elements from 5 to 7 days before the dream. Participants (n=8, all female) kept a daily(More)
In the present study, we investigated possible influences on the unitization of responses. In Experiments 1, 2, 3, and 6, we found that when the same small fragment (i.e., a few consecutive responses in a sequence) was presented as part of two larger sequences, participants responded to it faster when it was part of the sequence that was presented more(More)
Supervised and unsupervised categorization have been studied in separate research traditions. A handful of studies have attempted to explore a possible convergence between the two. The present research builds on these studies, by comparing the unsupervised categorization results of Pothos et al. ( 2011 ; Pothos et al., 2008 ) with the results from two(More)
Studies of supervised Categorization have demonstrated limited Categorization performance in participants with autism spectrum disorders (ASD), however little research has been conducted regarding unsupervised Categorization in this population. This study explored unsupervised Categorization using two stimulus sets that differed in their difficulty of(More)
The discovery and structure-activity relationship of a novel series of indole-2-carboxamide antagonists of the cannabinoid CB(1) receptor is disclosed. Compound 26i was found to be a high potency, selective cannabinoid CB(1) antagonist.
We examined the effect of context on the learning of spatial coding in four experiments. Two partially overlapping sets of stimuli, which had the very same stimulus-response spatial coding, were presented in unique contexts. Results show contextual locking-that is, response times to the very same item in a more common context (80%) were significantly(More)
PRIMARY OBJECTIVE This study explored over-selectivity (executive dysfunction) using a standard unsupervised categorization task. Over-selectivity has been demonstrated using supervised categorization procedures (where training is given); however, little has been done in the way of unsupervised categorization (without training). METHODS AND PROCEDURE A(More)