Connectionist modelling of the separable processing of consonants and vowels

describe two aphasic patients, with impaired processing of vowels and consonants, respectively. The impairments could not be captured according to the sonority hierarchy or in terms of a feature level analysis. Caramazza et al. claim that this dissociation demonstrates separate representation of the categories of vowels and consonants in speech processing. We present two connectionist models of the management of phonological representations. The models spontaneously develop separable processing of vowels and consonants. The models have two hidden layers and are given as input vowels and consonants represented in terms of their phonological distinctive features. The first model is presented with feature bundles one at a time and the hidden layers have to combine their output to reproduce a unified copy of the feature bundle. In the second model a "fine-coded" layer receives information about feature bundles in isolation, and a "coarse-coded" layer receives information about each feature bundle in the context of the prior and subsequent feature bundle. Coarse-coding facilitated processing of vowels and fine-coding processing of consonants. These models show that separable processing of vowels and consonants is an emergent effect of modular processors operating on feature-based representations. We argue that it is not necessary to postulate an independent level of representation for the consonant/vowel distinction, separate from phonological distinctive features.     

Discrimination and the positive-negative asymmetry effect: ideological and normative processes

Research using the minimal group paradigm demonstrates that categorization and ingroup identification can foster intergroup discrimination. However, the positive-negative asymmetry effect shows that less discrimination occurs when negative rather than positive outcomes are distributed. The normative hypothesis explains this asymmetry by the stronger inappropriateness of discrimination in negative than in positive outcome distributions. Results obtained in this minimal group paradigm study (N = 257) did not replicate the asymmetry effect: discrimination occurred in both positive and negative outcome distributions, even if norms against discrimination were stronger in negative than in positive outcome distributions. The absence of the asymmetry effect is explained by the effect of the discrimination-justifying ideology.     

Seven sins in the study of emotion: correctives from affective neuroscience

This brief commentary highlights seven sins in the study of emotion that are explicitly treated in contemporary affective neuroscience. These sins are (1) Affect and cognition are subserved by separate and independent neural circuits; (2) Affect is subcortical; (3) Emotions are in the head; (4) Emotions can be studied from a purely psychological perspective; (5) Emotions are similar in structure across age and species; (6) Specific emotions are instantiated in discrete locations in the brain; and (7) Emotions are conscious feeling states. Each of these is briefly discussed and evidence from affective neuroscience that bears on these sins is noted. The articles in this Special Issue underscore the vitality of research in affective neuroscience and illustrate how some of these sins can be addressed and rectified using concepts and methods from affective neuroscience.     

Velocity dependence of the interocular transfer of dynamic motion aftereffects

It is well established that motion aftereffects (MAEs) can show interocular transfer (IOT); that is, motion adaptation in one eye can give a MAE in the other eye. Different quantification methods and different test stimuli have been shown to give different IOT magnitudes, varying from no to almost full IOT. In this study, we examine to what extent IOT of the dynamic MAE (dMAE), that is the MAE seen with a dynamic noise test pattern, varies with velocity of the adaptation stimulus. We measured strength of dMAE by a nulling method. The aftereffect induced by adaptation to a moving random-pixel array was compensated (nulled), during a brief dynamic test period, by the same kind of motion stimulus of variable luminance signal-to-noise ratio (LSNR). The LSNR nulling value was determined in a Quest-staircase procedure. We found that velocity has a strong effect on the magnitude of IOT for the dMAE. For increasing speeds from 1.5 deg s(-1) to 24 deg s(-1) average IOT values increased about linearly from 18% to 63% or from 32% to 83%, depending on IOT definition. The finding that dMAEs transfer to an increasing extent as speed increases, suggests that binocular cells play a more dominant role at higher speeds.     

A methodology for describing and decomposing complex psychosocial and behavioral interventions

This article presents a comprehensive conceptual framework and methodology for characterizing multidimensional psychosocial and behavioral interventions for family caregivers of people with Alzheimer's disease. The methodology involved conducting a detailed task analysis of the interventions, and the application of the analytical hierarchy process. The authors were able to achieve high levels of consistency and reliability using this methodology to decompose and describe the interventions according to a complex conceptual framework comprising 3 dimensions: target domain, functional domain, and delivery system characteristics. Application of this methodology will enhance the ability to describe and measure interventions consistently, make comparisons across studies, isolate causal factors that achieve desired outcomes, and more generally elevate the science of psychosocial intervention research.     

Modeling memory decline in older adults: the importance of preclinical dementia, attrition, and chronological age

This longitudinal study examined memory loss in a sample of 391 initially nondemented older adults. Analyses decomposed observed memory loss into decline associated with preclinical dementia, study attrition, terminal decline, and chronological age. Measuring memory as a function of only chronological age failed to provide an adequate representation of cognitive change. Disease progression accounted for virtually all of the memory loss in the 25% of the sample that developed diagnosable dementia. In the remainder of the sample, both chronological age and study attrition contributed to observed memory loss. These results suggest that much of memory loss in aging adults may be attributable to the progression of preclinical dementia and other nonnormative aging processes that are not captured by chronological age.     

Aging and maintaining intentions over delays: do it or lose it

When execution of retrieved intentions must be briefly delayed, older adults display deficits in performing those intentions (G. O. Einstein, M. A. McDaniel, M. Manzi, B. Cochran, & M. Baker, 2000). This initial finding was extended by showing age-related deficits with 5-s unfilled delays, with instructions to rehearse during the delay, and with divided attention during initial retrieval of the intention. Performance increased with a break at the end of the delay period, such that when combined with full attention (during retrieval), older adults' performance approached that of younger adults. These results suggest that age compromises maintenance of information in awareness. Consequently, when forced to delay execution of retrieved intentions, older adults may rely more on plan reformulation and subsequent retrieval of the intention from long-term memory at the end of the delay.