Grammatical Encoding in Aphasia: Evidence from a “Processing Prosthesis”

Agrammatic aphasia is characterized by severely reduced grammatical structure in spoken and written language, often accompanied by apparent insensitivity to grammatical structure in comprehension. Does agrammatism represent loss of linguistic competence or rather performance factors such as memory or resource limitations? A considerable body of evidence supports the latter hypothesis in the domain of comprehension. Here we present the first strong evidence for the performance hypothesis in the domain of production: an augmentative communication system that markedly increases the grammatical structure of agrammatic speech while providing no linguistic information, functioning merely to reduce on-line processing demands. Copyright 2000 Academic Press and Unisys Corporation.     

Automatic auditory disambiguation of visual awareness

Multisensory integration can play a critical role in producing unified and reliable perceptual experience. When sensory information in one modality is degraded or ambiguous, information from other senses can crossmodally resolve perceptual ambiguities. Prior research suggests that auditory information can disambiguate the contents of visual awareness by facilitating perception of intermodally consistent stimuli. However, it is unclear whether these effects are truly due to crossmodal facilitation or are mediated by voluntary selective attention to audiovisually congruent stimuli. Here, we demonstrate that sounds can bias competition in binocular rivalry toward audiovisually congruent percepts, even when participants have no recognition of the congruency. When speech sounds were presented in synchrony with speech-like deformations of rivalling ellipses, ellipses with crossmodally congruent deformations were perceptually dominant over those with incongruent deformations. This effect was observed in participants who could not identify the crossmodal congruency in an open-ended interview (Experiment 1) or detect it in a simple 2AFC task (Experiment 2), suggesting that the effect was not due to voluntary selective attention or response bias. These results suggest that sound can automatically disambiguate the contents of visual awareness by facilitating perception of audiovisually congruent stimuli.     

Interculturality and Early Attachment: A Comparison of Urban/ <Emphasis Type="Italic">Non-Mapuche</Emphasis> and Rural/<Emphasis Type="Italic">Mapuche</Emphasis> Mother-Baby Dyads in Chile

It is well known in the field that culture and context play an important role in child rearing and parenting practices. However, many studies do not address the cultural dimension of attachment, although evidence indicates that aspects of early attachment differ across cultures. With the goal of comparing the quality of mother–baby interactions, this study analyzed attachment behaviors and maternal sensitivity in two settings: urban/non-Mapuche and rural/Mapuche in Chile. The sample was composed of 34 mother-baby dyads (17 urban/non-Mapuche and 17 rural/Mapuche) with 12-month-old children. During a feeding episode, the attachment style of the interaction was assessed with the Attachment during Stress scale, and maternal sensitivity was evaluated with the Child-Adult Relationship Experimental Index-Toddlers (CARE-Index). The groups differed in their interaction attachment style and in affective and proximity modalities: Urban/non-Mapuche mothers tended to have secure and ambivalent attachment styles, and rural/Mapuche mothers tended to have avoidant styles. When educational level is controlled, ethnicity group can explain the differences in mothers’ attachment styles. The findings of the study and their implications are discussed.     

Peak shift but not range effects in recognition of faces

University students were trained to discriminate between two gray-scale images of faces that varied along a continuum from a unique face to an average face created by morphing. Following training, participants were tested without feedback for their ability to recognize the positive face (S+) within a range of faces along the continuum. In Experiments 1 and 4, the range of stimuli presented during testing was manipulated. In Experiment 2, participants viewed different ranges of faces during an adaptation period that followed training and preceded testing. In all experiments, generalization functions revealed peak shifts or area shifts (fewer “yes” responses to novel faces on the negative side of the S+), but no systematic effects of the test or adaptation range. Peak shift was found both for upright and inverted faces and occurred even if the orientation of the face was reversed between training and test. Using similar methods, either an area shift or range effect (but not both together) was demonstrated for line tilt stimuli (Experiment 3), and the appearance of these effects depended on instructions. It appears that peak shift and area shift are robust across many different kinds of stimuli, but range effects may not readily occur with complex multidimensional stimuli.     

Structure and measurement of depression in youths: applying item response theory to clinical data

Our goals in this article were to use item response theory (IRT) to assess the relation of depressive symptoms to the underlying dimension of depression and to demonstrate how IRT-based measurement strategies can yield more reliable data about depression severity than conventional symptom counts. Participants were 3,403 children and adolescents from 12 contributing clinical and nonclinical samples; all participants had received the Kiddie Schedule of Affective Disorders and Schizophrenia for School-Aged Children. Results revealed that some symptoms reflected higher levels of depression and were more discriminating than others. Furthermore, use of IRT-based information about symptom severity and discriminability in the measurement of depression severity was shown to reduce measurement error and increase measurement fidelity.     

Strategies in landmark use by orangutans and human children

Landmark use has been demonstrated in a variety of organisms, yet the manner in which landmarks are encoded and subsequently used appears to vary between and sometimes within species, even when faced with identical landmark arrays. In the present experiments, orangutans and human children were shown a square array of identical landmarks and were trained to locate a hidden goal in the centre of the array. In Experiments 1 and 2, the search space appeared to be discrete, with white gridlines dividing up the space, and in Experiments 3a and 3b, the search space was uniformly coloured, making it appear continuous. In all experiments, following training, subjects were given a single expansion test, to determine their landmark strategy use, based on peak search activity. The orangutans appeared to use absolute directional vectors from individual landmarks, with peak search activities on the inner corners of the square array, and they used this strategy persistently. In contrast, human children showed two landmark-based strategies, absolute directional vectors and a relational or “middle” strategy, with the majority of children starting their search in the middle region. Although some children, especially young children, persistently used one strategy like the orangutans, many changed strategies when the original one failed to yield the hidden goal.     

Learning about environmental geometry: a flaw in Miller and Shettleworth's (2007) operant model

Many studies have examined how humans and other animals reestablish a sense of direction following disorientation in enclosed environments. Results showing that geometric shape of an enclosure is typically encoded, sometimes to the exclusion of featural cues, have led to suggestions that geometry might be encoded in a dedicated geometric module. Recently, Miller and Shettleworth (2007) proposed that the reorientation task be viewed as an operant task and they presented an associative operant model that appears to account for many empirical findings from reorientation studies. In this paper we show that, although Miller and Shettleworth's insights into the operant nature of the reorientation task may be sound, their mathematical model has a serious flaw. We present simulations to illustrate the implications of the flaw. We also propose that the output of a simple neural network, the perceptron, can be used to conduct operant learning within the reorientation task and can solve the problem in Miller and Shettleworth's model.     

Family climate of routine asthma care: associating perceived burden and mother-child interaction patterns to child well-being

This preliminary report links the literatures on family asthma management practices and on the characteristics of family interaction patterns thought to influence children's adjustment to a chronic physical illness. Specifically, this study of 60 families with a child with asthma examined the extent to which perceived burden of routine asthma care affected child mental health via its influence on parent-child interaction patterns. Mothers completed a measure of asthma management routine burden, mother and child were observed in a 15-minute interaction task, and children completed measures of child anxiety and asthma quality of life (QOL). Perceived routine burden significantly predicted child anxiety and QOL through its effect on mother-child rejection/criticism. The same pattern did not hold for mother intrusiveness/control. The results are discussed in terms of how overall family climate and regulation of routines affects child well-being. Implications for clinical practice and limitations of the study are provided.     

A Review of Research in the Social Scientific Study of Religion,Volume 15

Book reviewed in this article: Ralph L. Piedmont and David O. Moberg, Eds. (2005). Research in the Social Scientific Study of Religion, Volume 15.