Expanding Echo: Coordinated Head Articulations as Nonmanual Enhancements in Sign Language Phonology

Echo phonology was originally proposed to account for obligatory coordination of manual and mouth articulations observed in several sign languages. However, previous research into the phenomenon lacks clear criteria for which components of movement can or must be copied when the articulators are so different. Nor is there discussion of which nonmanual articulators can echo manual movement. Given the prosodic properties of echoes (coordination of onset/offset and of dynamics such as speed) as well as general motoric coordination of various articulators in the human body, we expect that the mouth is not the only nonmanual articulator involved in echo phonology. In this study, we look at a fixed set of lexical items across 36 sign languages and establish that the head can echo manual movement with respect to timing and to the axis/axes of manual movement. We propose that what matters in echo phonology is the visual percept of temporally coordinated movement that repeats a salient movement property in such a way as to give the visual impression of a copy. Our findings suggest that echoes are not obligatory motor couplings of two or more articulators but may enhance phonological distinctions that are otherwise difficult to see.     

Cross-species differences in color categorization

Berlin and Kay (1969) found systematic restrictions in the color terms of the world’s languages and were inclined to look to the primate visual system for their origin. Because the visual system does not provide adequate neurophysiological discontinuities to supply natural color category boundaries, and because recent evidence points to a linguistic origin (Davidoff, Davies, & Roberson, 1999), a new approach was used to investigate the controversial issue of the origin of color categories. Baboons and humans were given the same task of matching-to-sample colors that crossed the blue/green boundary. The data and consequent modeling were remarkably clear-cut. All human subjects matched our generalization probe stimuli as if to a sharp boundary close to the midpoint between their training items. Despite good color discrimination, none of the baboons showed any inclination to match to a single boundary but rather responded with two boundaries close to the training stimuli. The data give no support to the claim that color categories are explicitly instantiated in the primate color vision system.     

The effects of metabolic stress and vagotomy on emotional learning in an animal model of anxiety

The aim of the present study is to evaluate the role of the blood glucose (BG) level in emotional learning in the elevated plus maze (EPM), an animal model of anxiety. In Experiment 1, male Wistar rats were submitted to different EPM trial lengths (1- or 5-min). Blood samples were withdrawn before and after the maze exploration, through a polyethylene cannula chronically implanted into the jugular vein. In Experiment 2, the animals received either saline or 2-deoxy-D-glucose, a glucoprivic drug (2-DG, 250 or 500 mg kg(-1)) by i.p. route, 30 min before a 5-min EPM exposure and were retested in the maze (Trial1/Trial2 EPM procedure) 24 h later. In an independent group of rats, blood samples were withdrawn 0, 5, 15, and 30 min after 2-DG administration, through the jugular vein, to determine BG. In Experiment 3, the animals underwent a vagotomy and were tested in a Trial1/Trial2 EPM procedure four weeks later. The results showed that rats exploring the EPM for 5 min displayed increased fear and higher hyperglycemia than those exploring the EPM for 1 min. In addition, rats submitted to 5-min EPM Trial1 length displayed higher level of fear on Trial2, as well as higher percentage of shortening of the %Open arm entries and %Open arm time from Trial1 to Trial2, which characterizes the occurrence of emotional learning. In contrast, rats previously vagotomized or treated with 2-DG (500 mg kg(-1)) showed the same level of fear on both EPM trials and a low percentage of shortening, from Trial1 to Trial2, of the %Open arm entries and %Open arm time, indicating poor emotional learning. The data is discussed regarding the role of glycaemia in emotional learning in the EPM.     

Learning under stress: how does it work?

The effects of stress on learning and memory are not always clear: both facilitating and impairing influences are described in the literature. Here we propose a unifying theory, which states that stress will only facilitate learning and memory processes: (i) when stress is experienced in the context and around the time of the event that needs to be remembered, and (ii) when the hormones and transmitters released in response to stress exert their actions on the same circuits as those activated by the situation, that is, when convergence in time and space takes place. The mechanism of action of stress hormones, particularly corticosteroids, can explain how stress within the context of a learning experience induces focused attention and improves memory of relevant information.     

Intellectual development of infants, children and adolescents with congenital heart disease

Cardiac disease is the most common congenital defect in children, affecting between 3 and 10 in every 1000 live births. While significant advances in medical and surgical management have resulted in increasing numbers of survivors, it is also recognized that there is a growing population of children living with neurological impairment and lowered intellectual function. The aetiology of such impairment is multi-factorial and hypoxia is one of the factors involved. This article provides an overview of the effects of hypoxia on the intellectual development of infants, children and adolescents with congenital heart disease.     

Anxiety sensitivity-physical concerns as a moderator of the emotional consequences of emotion suppression during biological challenge: an experimental test using individual growth curve analysis

Anxiety-related responding to, and recovery from, a 5-min 10% carbon dioxide-enriched air presentation among 80 participants with no history of psychopathology was examined. Half of participants were instructed to suppress challenge-induced emotional responses, whereas their matched counterparts were instructed to observe such responses. Responding from immediately post-challenge through a 10-min recovery period was analyzed as a function of Anxiety Sensitivity-Physical Concerns and experimental condition using individual growth curve modeling. Anxiety Sensitivity-Physical Concerns moderated the effect of suppression only on emotion valence during recovery. In terms of main effects, suppression resulted in increased heart rate during recovery and Anxiety Sensitivity-Physical Concerns was positively associated with post-challenge self-reported anxiety. Results are discussed in terms of the potential role of inhibition-oriented affect regulation processes in the etiology of panic disorder.     

Learning a new human-computer alphabet: the role of similarity and practice

Two purposes motivated this study: (a) to quantify the difficulty in learning various symbols of the alphabet used to enter data into a personal digital assistant (PDA), and (b) to investigate the interaction of item difficulty with practice conditions that promote varying levels of cognitive effort. Levels of compatibility between members of the PDA alphabet and English were quantified through introspective ratings in Experiment 1 and objective performance measures in Experiment 2. Three levels of item compatibility were learned under conditions of proactive or retroactive augmented information in Experiment 3. Contrary to expectations, the item similarity effect did not interact with practice schedules—a retroactive augmented information condition resulted in degraded levels of acquisition performance, but superior retention levels, compared to the proactive condition. These findings are discussed in terms of the relative merits of cognitive effort in skill acquisition.     

The effectiveness of early head start for 3-year-old children and their parents: lessons for policy and programs

Early Head Start, a federal program begun in 1995 for low-income pregnant women and families with infants and toddlers, was evaluated through a randomized trial of 3,001 families in 17 programs. Interviews with primary caregivers, child assessments, and observations of parent-child interactions were completed when children were 3 years old. Caregivers were diverse in race-ethnicity, language, and other characteristics. Regression-adjusted impact analyses showed that 3-year-old program children performed better than did control children in cognitive and language development, displayed higher emotional engagement of the parent and sustained attention with play objects, and were lower in aggressive behavior. Compared with controls, Early Head Start parents were more emotionally supportive, provided more language and learning stimulation, read to their children more, and spanked less. The strongest and most numerous impacts were for programs that offered a mix of home-visiting and center-based services and that fully implemented the performance standards early.