Tamers,deniers, and me

Philosophical Studies - This paper critically examines a prominent and perennial strategy—found in thinkers as diverse as Kant and Shamik Dasgupta—of simultaneously embracing the...     

The evolution of alexia in two cases of posterior cortical atrophy

Posterior cortical atrophy (PCA) is an uncommon presentation of Alzheimer's disease (AD), characterised by prevalent anatomo-functional involvement of posterior cortical areas. Accordingly, the main clinical features at onset are disorders of high-order visual processing, such as alexia and impairments of visuo-spatial and visuo-constructional abilities. The clinical features in the early stages of disease are variable, and they have been suggested to stem from prevalent ventral or dorsal brain pathology, and/or asymmetric hemispheric involvement. With disease progression, these differences tend to blur with the increasing severity of neuropsychological dysfunction. We report two PCA patients showing different patterns of reading impairment (respectively, letter-by-letter reading and neglect dyslexia). A follow-up study suggested that the qualitative features of alexia remain distinctive with disease evolution. In addition, single photon emission tomography (SPECT) studies revealed different patterns of hypoperfusion, consistent with the alexia types. A careful reading assessment can provide important insights to the pattern of progression of the disease in patients with PCA up to the late stages of the pathology.     

Closing-in behaviour in preschool children

Many pre-school children show closing-in behaviour (CIB) in graphic copying tasks: a tendency to place their copy abnormally close to or even on top of the model. Similar phenomena have been studied in patients with dementia, though it is unclear whether the superficial similarities between CIB in development and dementia reflect common underlying cognitive mechanisms. The aim of the present study was to investigate the cognitive functions involved in CIB in pre-school children. Forty-one children (3–5 years) were assessed for CIB, and completed a neuropsychological battery targeting visuospatial abilities, short term memory (verbal and spatial) and attention (sustained attention, selective attention and attention switching). Binary logistic regression found that performance on the attention subtests was the best unique predictor of CIB. A second analysis, in which the three attention subtests were entered as separate predictors, suggested that attention switching ability was most strongly related to CIB. These results support the view that CIB in children reflects inadequate attentional control. The convergence of these results with similar observations in patients with dementia further suggests that similar cognitive factors underlie CIB in these two populations.     

Learning to Attend and to Ignore Is a Matter of Gains and Losses

ABSTRACT— Efficient goal-directed behavior in a crowded world is crucially mediated by visual selective attention (VSA), which regulates deployment of cognitive resources toward selected, behaviorally relevant visual objects. Acting as a filter on perceptual representations, VSA allows preferential processing of relevant objects and concurrently inhibits traces of irrelevant items, thus preventing harmful distraction. Recent evidence showed that monetary rewards for performance on VSA tasks strongly affect immediately subsequent deployment of attention; a typical aftereffect of VSA (negative priming) was found only following highly rewarded selections. Here we report a much more striking demonstration that the controlled delivery of monetary rewards also affects attentional processing several days later. Thus, the propensity to select or to ignore specific visual objects appears to be strongly biased by the more or less rewarding consequences of past attentional encounters with the same objects.     

Mirror writing in pre-school children: a pilot study

Mirror writing refers to the production of individual letters, whole words or sentences in reverse direction. Unintentional mirror writing has been observed in young children learning to write and interpreted as the manifestation of different cognitive impairments. We report on mirror writing instances in a sample of 108 pre-school children. Results showed MW to be age-related but independent from handedness and left-right discrimination abilities. We propose an account of mirror writing as reflecting dissociation between acquired motor programmes for letter shape composition and unspecified spatial direction of hand movements. Before learning to write, the child’s directional cognitive system is assumed to be dichotomous, thus inducing the production of randomly oriented asymmetrical letters.     

Protecting Sexual Minority Youth from Research Risks: Conflicting Perspectives

We describe the dilemmas we encountered in the informed consent process for an HIV prevention project targeting Black gay, bisexual, and non-gay identified young men. We highlight the complexities of applying informed parental consent procedures to sexual minority youth and identify some of the challenges that researchers who work with sexual minority youth face when they must balance the needs and rights of this population against the needs and rights accorded to parents by federal guidelines for protecting minor participants in research.     

Dissociating mental transformations and visuo-spatial storage in working memory: evidence from representational neglect

A study is reported of visuo-spatial working memory in two individuals suffering from a cognitive deficit known as unilateral spatial neglect, and seven healthy control participants. Both patients have difficulties reporting details on the left side of imaged representations, and one has an additional difficulty with perceptual input to the left of his body midline. All participants were asked to report the location and identity of objects presented in novel 2 x 2 arrays that were either present throughout or were described orally by the experimenter, with no visual input. On half of the trials, the report was to be made from the opposite perspective, requiring 180 degree mental rotation of the mentally represented array. The patients show an impaired ability to report details from the presented or the imagined left, but had no difficulty with mental rotation. Results point to a clear separation between the processes of perception and those of visuo-spatial working memory. Results also suggest that the patients might be suffering from damage to the system used for holding visuo-spatial representations rather than a difficulty with attending to elements of that representation.     

Group-as-a-whole concepts and the therapeutic milieu on the inpatient psychiatric unit

This paper focuses on large group process on the inpatient psychiatric unit. General systems theory and group-as-a-whole concepts are used to understand the dynamics of the therapeutic milieu. Using this information as a tool, the therapist can make various interventions on an individual and group level that will help patients understand and deal with their own psychopathology. Another benefit of this process is that it will develop a community on the psychiatric unit where patients help each other to get well. Three clinical examples are used to illustrate the relevance of this concept. With the advent of short-term psychiatric hospitalization, the therapeutic milieu has shown a drastic decline. Emphasis has been placed on the individual as opposed to the group and a valuable therapeutic tool has been lost. Using a group-as-a-whole concept can help reverse this trend and make the milieu on the inpatient psychiatric unit instrumental in the recovery of the patient.     

Representational pseudoneglect in line bisection

"Representational pseudoneglect" refers to a bias toward the left side of space that occurs when visual information is remembered. Recently a number of demonstrations of such representational pseudoneglect have appeared. In the present article, we report an experiment in which we adopted the classic line bisection paradigm to study representational pseudoneglect. Participants bisected horizontal lines that were shown in extrapersonal space. When the lines were visible on the screen, there was no evidence of any leftward bias. However, when lines were bisected from memory, the participants demonstrated a clear bias to the left. This is the first demonstration of a leftward bias in the bisection of remembered visually presented lines.