The rhinal cortex: 'gatekeeper' of the declarative memory system

Almost all studies probing neural activity underlying the declarative memory system in humans have investigated either memory encoding or retrieval. Here, however, we suggest integrating encoding and retrieval operations into a single operation executed by the rhinal cortex. The more familiar an item is, the less rhinal processing it requires and the less vigorously it is encoded into memory. Given the anatomical position and the functional properties of the rhinal cortex, this operation fulfills an essential task: it optimally allocates limited encoding resources away from familiar information and towards novel information. We propose a rhinal processing stage that optimizes the declarative memory system by fully integrating encoding and retrieval operations into a single 'gatekeeper' operation.     

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org

Call for Papers

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org     

Testing the concurrent and predictive relations among articulation accuracy, speech perception, and phoneme awareness

The relations among articulation accuracy, speech perception, and phoneme awareness were examined in a sample of 97 typically developing children ages 48 to 66 months. Of these 97 children, 46 were assessed twice at ages 4 and 5 years. Children completed two tasks for each of the three skills, assessing these abilities for the target phoneme /r/ and the control phoneme /m/ in the word-initial position. Concurrent analyses revealed that phoneme-specific relations existed among articulation, awareness, and perception. Articulation accuracy of /r/ predicted speech perception and phoneme awareness for /r/ after controlling for age, vocabulary, letter-word knowledge, and speech perception or phoneme awareness for the control phoneme /m/. The longitudinal analyses confirmed the pattern of relations. The findings are consistent with a model whereby children's articulation accuracy affects preexisting differences in phonological representations and, consequently, affects how children perceive, discriminate, and manipulate speech sounds.     

A non-finitely based quasi-variety of De Morgan algebras

In this paper we exhibit a non-finitely based, finitely generated quasi-variety of De Morgan algebras and determine the bottom of the lattices of sub-quasi-varieties of Kleene and De Morgan algebras.Supported by Vicerrectoría Académica de la Facultad de Ciencias and by División de Investigación, Sede Bogotá of the Universidad Nacional de Colombia.Special issue of Studia Logica: Algebraic Theory of Quasivarieties Presented by M. E. Adams, K. V. Adaricheva, W. Dziobiak, and A. V. Kravchenko     

Are long compound words identified serially via their constituents? Evidence from an eyemovement-contingent display change study

The processing of two-constituent 12- to 18-letter Finnish compound nouns was studied by using an eye-movement-contingent display change technique. In the display change condition, all but the first 2 letters of the second constituent were replaced by visually similar letters until the eyes moved across an invisible boundary. When the eyes crossed the boundary, the second constituent was changed to its intended form. In the control condition, there was no display change. The frequency of the first constituent was also varied. The major findings were that (1) fixation time on the first constituent was strongly affected by the frequency of the first constituent but was not at all affected by whether the second constituent was visible, but (2) fixation time on the word subsequent to the first constituent's having been left was strongly affected by the display change. These results are most parsimoniously explained by the serial access of the two constituents for these long compound words.     

Retrieval-induced forgetting in recall and recognition of thematically related and unrelated sentences

In three experiments, we assessed the effects of type of relation and memory test on retrieval-induced forgetting of facts. In Experiments 1 and 2, eight sets of four shared-subject sentences were presented for study. They were constructed so that half were thematically related and half were unrelated. A retrieval practice phase required participants to recall a subset of the studied sentences. In the final test, the participants were prompted to recall all the sentences (character cued in Experiment 1 and character plus stem cued in Experiment 2). The results showed that the retrieval-induced forgetting (RIF) effect was similar for thematically related and unrelated sentences, indicating that the presence of episodic relations among the sentences was sufficient to produce the effect. In Experiment 3, a recognition task was introduced and the RIF effect emerged in accuracy as well as in latency measures. The presence of this effect with item-specific cues is difficult to accommodate for noninhibitory theories of retrieval.     

Interpretations of Einstein’s Equation E = mc 2

Interpretations of Einstein’s equation differ primarily concerning whether E = mc² entails that mass and energy are the same property of physical systems, and hence whether there is any sense in which mass is ever ‘converted’ into energy (or vice versa). In this paper, I examine six interpretations of Einstein’s equation and argue that all but one fail to satisfy a minimal set of conditions that all interpretations of physical theories ought to satisfy. I argue that we should prefer the interpretation of Einstein’s equation that holds that mass and energy are distinct properties of physical systems. This interpretation also carries along the view that while most cases of ‘conversion’ are not genuine examples of mass being ‘converted’ into energy (or vice versa), it is possible that the there are such ‘conversions’ in the sense that a certain amount of energy ‘appears’ and an equivalent of mass ‘disappears’. Finally, I suggest that the interpretation I defend is the only one that does not blur the distinction between what Einstein called ‘principle’ and ‘constructive’ theories. This is philosophically significant because it emphasizes that explanations of Einstein’s equation and the ‘conversion’ of mass and energy must be top‐down explanations.     

Avoiding the death risk of avoiding a dread risk: the aftermath of March 11 in Spain

Abstract-After the airplane attacks of September 11, 2001, in the United States, many Americans drove instead of flying, to avoid the risk of terrorism. As a result, there were extra car accidents in which many people died. This study tested whether a similar effect occurred in Spain after the train bombings of March 11, 2004, in Madrid. Data on train travel, highway traffic, and fatal highway accidents were analyzed for the months immediately following March 11. Results show that, like Americans, Spaniards avoided the dread risk of terror attacks, but unlike Americans, they did not confront the death risk of fatal accidents instead. A sociopolitical interpretation for these findings is offered.     

Implicit learning of nonlocal musical rules: implicitly learning more than chunks

Dominant theories of implicit learning assume that implicit learning merely involves the learning of chunks of adjacent elements in a sequence. In the experiments presented here, participants implicitly learned a nonlocal rule, thus suggesting that implicit learning can go beyond the learning of chunks. Participants were exposed to a set of musical tunes that were all generated using a diatonic inversion. In the subsequent test phase, participants either classified test tunes as obeying a rule (direct test) or rated their liking for the tunes (indirect test). Both the direct and indirect tests were sensitive to knowledge of chunks. However, only the indirect test was sensitive to knowledge of the inversion rule. Furthermore, the indirect test was overall significantly more sensitive than the direct test, thus suggesting that knowledge of the inversion rule was below an objective threshold of awareness.