Illumination-invariance of Plateau's midgray

In a classical experiment Plateau [(1872). Sur la mesure des sensations physiques, et sur la loi qui lie l’intensité de la cause excitante. Bulletins de L’Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique, 2me Série, 33, 376-388] found that the midgray operation is illumination-invariant. Falmagne [(1985). Elements of psychophysical theory. New York: Oxford University Press] provided a formalization of this finding that gives rise to two functional equations, the solutions of which determine the possible forms of the psychophysical function. This approach is generalized so that it explicitly refers to the illuminance, and can be applied to the experimentally well-studied class of center-surround stimuli. It is shown that the illumination-invariance of both cross-context matches and Plateau's midgray specify the psychophysical function up to an increasing function of the relative luminance of stimulus/illumination and center/surround, respectively. Relating this result to that implied by Wallach's ratio principle clarifies the role of Plateau's midgray in experimental research on achromatic color perception. Further generalizing the framework extends its scope to more complex experimental settings and the therein observed invariances.     

An Examination of a Functional Mixed-Effects Modeling Approach to the Analysis of Longitudinal Data

Growth curve modeling is one of the main analytical approaches to study change over time. Growth curve models are commonly estimated in the linear and nonlinear mixed-effects modeling framework in which both the mean and person-specific curves are modeled parametrically with functions of time such as the linear, quadratic, and exponential. However, when more complex nonlinear trajectories need to be estimated and researchers do not have a priori knowledge of an appropriate functional form of growth, parametric models may be too restrictive. This paper reviews functional mixed-effects models, a nonparametric extension of mixed-effects models that permit both the mean and person-specific curves to be estimated without assuming a prespecified functional form of growth. Details of the model are presented along with results from a simulation study and an empirical example. The simulation study showed functional mixed-effects models performed reasonably well under various conditions commonly associated with longitudinal panel data, such as few time points per person, irregularly spaced time points across persons, missingness, and nonlinear trajectories. The usefulness of functional mixed-effects models is illustrated by analyzing empirical data from the Early Childhood Longitudinal Study – Kindergarten Class of 1998–1999.     

非工作时间连通行为对工作—家庭平衡满意度的影响研究：一个有调节的中介模型

工作-家庭平衡满意度（SWFB）这一新兴构念正日益受到学界关注,信息时代下的新工作特征——非工作时间连通行为对SWFB已产生不可忽视的影响。本文基于工作-家庭边界理论,探讨非工作时间连通行为对SWFB的影响机制。通过问卷调查了237份配对样本数据,结果表明：非工作时间连通行为负向预测SWFB,心理脱离中介了非工作时间连通行为与SWFB间关系;工作-家庭中心性调节了心理脱离在非工作时间连通行为与SWFB间的中介作用。     

Personality, anxiety and functional dysphonia

Psychological factors are considered for the predisposition and perpetuation of functional dysphonia. In the present study 61 patients with functional dysphonia were compared with 61 healthy controls, matched by age, sex, and occupation with respect to Cloninger’s personality model, mood, and anxiety.The patients with functional dysphonia presented significantly higher scores than the healthy controls with respect to “harm avoidance” (HA); depressive symptoms; symptoms of unspecific and general anxiety; symptoms of specific anxiety concerning “health”, “illness”, and “extraversion versus introversion”. No significant differences were found in “novelty seeking” (NS), “reward dependence” (RD), “persistence” (PE), or in state-anxiety and anxiety of social situations. These results were found considering univariate and multivariate analyses and confirm the relationship of psychological factors such as personality traits, mood, and anxiety on one hand and conversion disorder in general and functional dysphonia in particular on the other hand. This important relationship should be considered in the diagnostic and therapeutic interventions of functional dysphonia.     

Functional neuroimaging of cognition: state-of-the-art

This paper presents a brief overview of functional neuroimaging studies of cognitive processes. A "publication profile" is identified for PET and fMRI studies of cognitive functions. It is shown that the number of publications has increased exponentially over the last ten years, and that a set of ten journals accounts for the vast majority of publications. It is argued that the field has moved from a state of explorative character to a state of high theoretical sophistication. With special reference to the contributions in this issue of Scandinavian Journal of Psychology, methodological, topical, regional, and clinical implications of cognitive neuroscientific studies are discussed.     

Social reinforcement of somatic versus psychological description of depressive events

The cultural construction of illness model explains the clinical observation that psychological correlates of depression such as sadness and worthlessness are frequently reported in Western cultures, whereas somatic or vegetative complaints are often associated with depression in non-Western cultures. This study employed Portnoy and Salzinger's (J. Gen. Psychol. 70 (1964) 311) verbal conditioning paradigm to determine whether social contingencies, in the form of verbal and non-verbal reinforcement contingent upon verbal responses, affect the reporting of experiences related to depressive events. Using an ABA design, this experimental study (N=36) demonstrated that one's reporting of experiences of hypothetical depressive events, via psychological, somatic, or neutral verbal response classes, can be conditioned by verbal and non-verbal positive social reinforcement, and therefore socially constructed through environmental contingencies. This suggests one pathway by which culture can shape symptom presentation. Implications for clinical interviewing and behavioral assessment, especially in the cross-cultural context, are discussed.     

A critical boundary to the left-hemisphere advantage in visual-word processing

Two experiments explored boundary conditions for the ubiquitous left-hemisphere advantage in visual-word recognition. Subjects perceptually identified words presented directly to the left or right hemisphere. Strong left-hemisphere advantages were observed for UPPERCASE and lowercase words. However, only a weak effect was observed for AlTeRnAtInG-cAsE words, and a numerical reversal of the typical left-hemisphere advantage was observed for words in a visual prototype font (a very unfamiliar word format). Results support the theory that dissociable abstract and specific neural subsystems underlie visual-form recognition and fail to support the theory that a visual lexicon operates in the left hemisphere.     

Prototype-distortion category learning: a two-phase learning process across a distributed network

This paper reviews a body of work conducted in our laboratory that applies functional magnetic resonance imaging (fMRI) to better understand the biological response and change that occurs during prototype-distortion learning. We review results from two experiments (Little, Klein, Shobat, McClure, & Thulborn, 2004; Little & Thulborn, 2005) that provide support for increasing neuronal efficiency by way of a two-stage model that includes an initial period of recruitment of tissue across a distributed network that is followed by a period of increasing specialization with decreasing volume across the same network. Across the two studies, participants learned to classify patterns of random-dot distortions (Posner & Keele, 1968) into categories. At four points across this learning process subjects underwent examination by fMRI using a category-matching task. A large-scale network, altered across the protocol, was identified to include the frontal eye fields, both inferior and superior parietal lobules, and visual cortex. As behavioral performance increased, the volume of activation within these regions first increased and later in the protocol decreased. Based on our review of this work we propose that: (i) category learning is reflected as specialization of the same network initially implicated to complete the novel task, and (ii) this network encompasses regions not previously reported to be affected by prototype-distortion learning.     

Category-specific effects on the identification of non-manipulable objects

Theories of category-specific effects on visual object identification predict easier identification of non-living than living objects. The Sensory-Functional theory credits greater representational weighting of the visual properties of living objects independent of greater weighting of the functional properties of non-living objects. It predicts a lost or reversed non-living advantage for non-manipulable objects. Normal participants matched pictures of non-manipulable objects with words describing three levels of identity while visual object similarity, and concept familiarity were controlled. Consistent with the Sensory-Functional theory, living objects were matched faster than non-living objects. Concept familiarity facilitated subordinate matches. Visual similarity hampered subordinate matches and facilitated basic matches.