Tracking and capture of constant and varying velocity stimuli: a cross-species comparison of pigeons and humans

The mechanisms underlying tracking and capture of moving objects in non-human animals are poorly understood. This set of experiments sought to further explore aspects of anticipatory tracking in pigeons and to conduct comparisons with human participants. In Experiment 1a, pigeons were presented with two types of varying velocities (fast-slow-fast or slow-fast-slow) in separate phases. They were readily able to track and anticipate both of these motion types. To examine the effects of predictability on anticipatory tracking, Experiment 1b presented the pigeons with the same two varying velocities randomly intermixed within a session. This resulted in reduced capture success, later capture, and errors that no longer anticipated ahead of the motion, suggesting that the anticipatory mechanism had been disrupted. This implies that the mechanisms involved in pigeon tracking are different from the predictive extrapolation mechanism proposed in humans. Experiment 2 tested this by presenting adult humans with a tracking task that was similar to tasks previously received by the pigeons. The capture behavior of humans was similar to the pigeons, but the errors revealed different processes underlying their tracking behavior.     

A study of emotionalism in patients undergoing rehabilitation following severe acquired brain injury

The present study describes the phenomenon of emotionalism in a sample of brain injured patients of mixed aetiology, with a view to identifying issues relevant to clinical management, and possible causal factors. 82 subjects with severe acquired brain injury undergoing rehabilitation participated in a structured interview in which they were asked to report the presence/absence of emotionalism and degree of distress associated with it. Their overt crying behaviour was also observed and recorded. Independent variables that predicted crying during the interview were identified using a multiple logistic regression procedure. Prevalence rates of emotionalism-tearfulness were high in this sample (52% self-report, 36--41% Emotionalism-laughter was much less common (13%) Emotionalism-tearfulness was usually accompanied by negative affect, occurred in response to identifiable precipitants, and was often controllable. It was associated with major personal distress in about half the subjects who reported it. Independent variables which predicted crying behaviour were female gender and focal damage to the right cerebral hemisphere. It is concluded that an increased readiness to cry is common in people with severe acquired brain injury of mixed aetiology. The behaviour is meaningful, though not always distressing. The intensity of the behaviour is variable, and it may be most appropriate to regard emotionalism as a dimension rather than a syndrome. Implications for clinical management are discussed.     

Personality pathology among individuals with a lifetime history of anorexia nervosa

Anorexia nervosa (AN) appears to be associated with certain personality features. The degree to which personality pathology persists after the acute phase of illness is unclear. This study aimed to investigate personality pathology in a large sample (n = 153) of women with histories of AN using the Dimensional Assessment of Personality Pathology (DAPP) and to evaluate the persistence of pathological personality features by comparing women with acute (n = 83) and remitted AN (n = 55). Women with AN demonstrated high levels of emotional dysregulation, social inhibition and compulsivity relative to age-matched healthy women (n = 124). Identity problems, intimacy problems and schizotypal features were highlighted as important. The same 14 pathological personality dimensions were significantly elevated in both ill and remitted participants, though remitted individuals' scores were reduced on 4 of the subscales. These results indicate that pathological personality features in AN are persistent traits, although some features may become exaggerated in the acute phase.     

Metalinguistic Awareness in Children: A Developmental Progression

The purpose of this study was to determine if a developmental order exists in the metalinguistic ability of children to make judgments about the form of language while simultaneously attending to a meaningful linguistic context. The stimulus material consisted of a short story into which 20 nonsense lexical items had been substituted. The 20 stimuli were comprised of phonotactically illegal and legal sequences of phonemes. In addition, the lexical items had been positioned to replace either structure or content words within the story. The participants were 90 Caucasian children who were divided into nine age groupings from 4;0 to 12;11. Baseline data were obtained from 10 adults. All subjects were required to respond to the audio-recorded stimuli by pressing a button whenever a nonsense item was perceived. The data were analyzed for both number of correct responses and reaction times. Results revealed a major shift in metalanguage ability occurring between 7 and 8 years of age. The 8- to 12-year-olds responded correctly to more items and at significantly faster rates than the 4- to 7-year-olds. The adults outperformed the children on all tasks, showing that metalanguage development continues beyond childhood.     

Toward an Evolutionary Psychology of Religion and Personality

Evolutionary psychology is an emerging paradigm for the social sciences that offers a powerful metatheoretical framework for personality psychology and, as I attempt to demonstrate in this article, for the psychology of religion as well. I argue that religion is not an evolved adaptation; rather, the diverse range of beliefs, behavior, and experience that we collectively refer to as religion emerge as byproducts of numerous, domain-specific psychological mechanisms that evolved to solve other (mundane) adaptive problems. These include mechanisms for reasoning about the natural world (naive physics and biology), about other people' minds (naive psychology), and about specific kinds of interpersonal relationships (attachment, kinship, social exchange, coalitions, status hierarchies).     

Defensive aggression in terns: Discrimination and response to individual researchers

The defensive responses of roseate terns (Sterna dougallii) were studied during the middle of the breeding season when all reproductive stages (incubation, chick-hatching, chick-rearing) were represented, to determine the factors affecting levels of nest defense and whether terns responded differently towards a familiar versus an unfamiliar researcher. Defensive aggression generally varied as a function of researcher identity, time of day, section or location in the colony and nest density. These variables explained from 60 to 66% of the variation in defensive aggression. More terns mobbed one researcher with more dive attacks than the other researcher. Terns were more aggressive in areas where the chicks had just hatched and were most vulnerable. © 1993 Wiley-Liss, Inc.     

Shortage of highly skilled workers in Hong Kong and policy responses

As Hong Kong develops into a knowledge-based economy, there is a strong increase in demand for highly educated and highly skilled workers. At the same time, many other countries are also experiencing shortages of highly-skilled workers as the development of hi-tech and information technology sectors have become an international trend. In this article, we study the changes in demand and supply of highly-skilled workers in Hong Kong and analyse the role that natural population growth, immigration, emigration, and return migration play in relation to the supply of highly-skilled workers. We also give an account of the policy responses of the government of the Hong Kong Special Administrative Region in its attempt to attract highly-skilled professionals as well as the challenges facing Hong Kong in the light of keen international competition.     

Cognitive consequences of timeframe bias. On the link between working memory,cognitive switching,and time perspective

The present study examined how time perspective is associated with working memory updating and cognitive switching. Additionally, stress states and mood as potential mediators of the relationship between time perspective and cognitive performance were analysed. During two sessions participants (n = 200) completed a set of questionnaires measuring time perspective, task-related stress states, and mood. Moreover, in two separate sessions they performed working memory updating and switching tasks. The results indicated that two time perspectives, i.e. Present Fatalism and Past Positive, were associated with updating. Furthermore, mediation analysis showed that positive mood accounted for these relationships. Specifically, Present Fatalism was correlated with low positive mood and in turn, worse working memory scores, whereas Past Positive was associated with high positive mood leading to better performance on the working memory task. None of the time perspective dimensions correlated with cognitive switching. These findings shed more light on the cognitive consequences of timeframe bias and suggest new approaches in research on time perspective and cognitive functioning.