Attention and expertise in multiple target tracking

An experiment is reported examining the role of attention and expertise in multiple target tracking. It compares the ability of professional radar operators (experts) and undergraduate students (novices) to acquire and track subsets of randomly moving targets amongst distractors, and respond appropriately to a probe. Participants undertook this tracking task alone then, subsequently, in conjunction with a second, digit categorization task. For half the participants, the second task commenced prior to the tracking task's target acquisition phase, for the remainder after. Results suggest experts are better than novices across all conditions. Further, a comparison of results between the two dual task conditions indicates that attentional resources make a contribution to target tracking in both novices and experts, but only appear to make a contribution to target acquisition in novices. The results have implications for theories of multiple target tracking; the selection of radar operators; and the monitoring of their training. Copyright © 2004 John Wiley & Sons, Ltd.     

Testing and Assessment Issues With Spanish‐English Bilingual Latinos

This article critically examines and integrates previous research in cross‐cultural and cross‐linguistic assessment. Issues that apply to the assessment of Latinos who speak both Spanish and English are examined. For ease of presentation, testing concerns with this population are divided into 3 broad areas: client issues, test issues, and clinician/assessor issues. Recommendations are made to assist in the provision of cross‐culturally and cross‐linguistically valid testing of Spanish‐English bilingual Latinos.     

Borderline Personality Disorder: towards a systemic formulation

The diagnostic label, Borderline Personality Disorder (BPD), is rapidly gaining currency in the UK. Although many systemic practitioners are skilled and experienced at working with the clinical difficulties associated with the diagnosis, there is little systemic literature on the topic. This paper discusses some of the difficulties for systemic practitioners in engaging with the concept of BPD and offers some pointers for the development of systemic practice in this area.     

The association between auditory memory span and speech rate in children from kindergarten to sixth grade.

This study reexamined the association between speech rate and memory span in children from kindergarten to sixth grade (N = 152) in order to potentially account for the inconsistencies within the published literature on this topic. Some of the inconsistencies in past research may reflect the different methods adopted in assessing speech rate. In particular, repeating word triples may itself involve memory demands, contaminating the correlation between speech rate and memory span in younger children. Analyses using composite speech rate and memory span measures showed that speech rate for word triples shared variance with memory span that was independent of speech rate for single words. Moreover, speech rate for word triples was largely redundant with age in explaining additional variation in memory span once the effects of speech rate for single words were controlled.     

The Stanford Encyclopedia of Philosophy: A Developed Dynamic Reference Work

The present information explosion on the World Wide Web poses a problem for the general public and the members of an academic discipline alike, of how to find the most authoritative, comprehensive, and up-to-date information about an important topic. At the Stanford Encyclopedia of Philosophy (SEP), we have since 1995 been developing and implementing the concept of a dynamic reference work (DRW) to provide a solution to these problems, while maintaining free access for readers. A DRW is much more than a web-based encyclopedia, and its scope far exceeds that of an electronic journal or preprint exchange. In this article we document the progress of the SEP toward full implementation of the DRW concept. We discuss the fiscal challenges posed by our desire to maintain free or low-cost access to the contents of the SEP, and we consider technological challenges posed by the desire to stay abreast of technological developments in document markup while making it easy for authors and subject editors to write and maintain entries representing the very best scholarship.     

Repetition deficits, list context, and word-class interactions in the RSVP of words in sentences.

We report a failure to find a repetition deficit in recall following the rapid serial visual presentation (RSVP) of words within sentences, using adjectives rather than nouns as the critical items. In a series of experiments that ruled out participant and procedural differences as the source of the failure, both word class and list context were found to moderate the repetition deficit, but grammatical necessity did not. The presence in the list of sentences in which the repeated adjectives were separated by more than three words (i.e., more than 400 ms in RSVP) not only eliminated the repetition deficit for the recall of those sentences but also for the recall of sentences in which the repeated adjectives were separated by three or fewer words (i.e., less than 400 ms in RSVP). However, although substantially reduced, a repetition deficit with noun-based materials was still found in this list context. Matching the adjective-based sentences with the noun-based sentences in sentence length and position of the critical items revealed that the moderating effect of word-class on the repetition deficit was mediated by the biases in sentence structure that using different word classes tend to induce.     

Blocking in rabbit eyeblink conditioning is not due to learned inattention: Indirect support for an error correction mechanism of blocking

Blocking is a classical conditioning task in which prior training to one cue such as a tone reduces learning about a second cue such as a light, when subsequently trained as a tone-light compound. Blocking has been theorized to come about through a US-modulated error correction mechanism, by Rescorla &; Wagner (1972) as well as through a mechanism of learned inattention as theorized by Mackintosh (1973). In the case of eyeblink conditioning, an error correction mechanism has been hypothesized to take place in the cerebellum while some form of inattention has been hypothesized to take place in the hippocampal region. The hypothesis we., are testing is whether the mechanism of learned inattention is involved in blocking in rabbit eyeblink conditioning. If blocking in eyeblink conditioning is produced by a mechanism of learned inattention, then training to a previously blocked cue should be slower than training to that cue in a naïve animal. Rabbits that had received tone training followed by tone-light training exhibited blocking. Rabbits that had been previously blocked to the light acquired conditioned responses to the light at the same rate as naïve rabbits. This finding failed to support the hypothesis that blocking in rabbit eyeblink conditioning is due to learned inattention, but does support the Rescorla-Wagner mechanism of error correction. The present finding along with previous work on error correction mechanism in the cerebellar-brainstem circuit (Kim et al., 1998) lend support to the theory that blocking, at least in rabbit eyeblink conditioning, seems to be due to an error correction mechanism rather than a learned inattention mechanism.     

A comparison of latent inhibition and learned irrelevance pre-exposure effects in rabbit and human eyeblink conditioning

The learning of an association between a CS and a US can be retarded by unreinforced presentations of the CS alone (termed latent inhibition or LI) or by un-correlated presentations of the CS and US (termed learned irrelevance or LIRR). In rabbit eyeblink conditioning, there have been some recent failures to replicate LI. LIRR has been hypothesized as producing a stronger retardation effect than LI based on both empirical studies and computational models. In the work presented here, we examined the relative strength of LI and LIRR in eyeblink conditioning in rabbits and humans. In both species, a number of pre-exposure trials sufficient to produce LIRR failed to produce LI (Experiments 1 & 3). Doubling the number of CS pre-exposures did produce LI in rabbits (Experiment 2), but not in humans (Experiment 4). LI was demonstrated in humans only after manipulations including an increased inter-trial interval or ITI (Experiment 5). Overall, it appears that LIRR is a more easily producible pre-exposure retardation effect than LI for eyeblink conditioning in both rabbits and humans. Several theoretical mechanisms for LI including the conditioned attention theory, stimulus compression, novelty, and the switching theory are discussed as possible explanations for the differences between LIRR and LI. Overall, future work involving testing the neural substrates of pre-exposure effects may benefit from the use of LIRR rather than LI.     

Completeness of Certain Bimodal Logics for Subset Spaces

Subset Spaces were introduced by L. Moss and R. Parikh in [8]. These spaces model the reasoning about knowledge of changing states.In [2] a kind of subset space called intersection space was considered and the question about the existence of a set of axioms that is complete for the logic of intersection spaces was addressed. In [9] the first author introduced the class of directed spaces and proved that any set of axioms for directed frames also characterizes intersection spaces.We give here a complete axiomatization for directed spaces. We also show that it is not possible to reduce this set of axioms to a finite set.