Invited Address at the Occasion of the Bertelson Award 2005 Impairments in visual discrimination in amnesia: Implications for theories of the role of medial temporal lobe regions in human memory

A prominent and long-standing view of human long-term memory is that structures within the medial temporal lobe (MTL) work together to support the acquisition of memory for facts and events. In contrast to this view, recent studies in rats and non-human primates suggest dissociations in function between regions comprising the MTL. Evidence in support of such specialisation in humans, however, has been inconclusive, leading some researchers to propose that human MTL functions as a unitary system uniquely specialised for the acquisition and storage of long-term memory. This paper reviews some of the key studies from the animal and human literature that support an account of functional differentiation and discusses the different theoretical positions that have emerged from their findings. A series of recent experiments in humans designed to determine whether there is functional homogeneity in MTL regions across species are also reviewed and an alternative account of human memory—in which long-term memory is dependent upon representations distributed throughout the human brain rather than one specialised system—is proposed.     

Chronic psychological stress and the regulation of pro-inflammatory cytokines: a glucocorticoid-resistance model.

This study examined whether chronic stress impairs the immune system's capacity to respond to hormonal signals that terminate inflammation. Fifty healthy adults were studied; half were parents of cancer patients, and half were parents of healthy children. Parents of cancer patients reported more psychological distress than parents of healthy children. They also had flatter diurnal slopes of cortisol secretion, primarily because of reduced output during the morning hours. There was also evidence that chronic stress impaired the immune system's response to anti-inflammatory signals: The capacity of a synthetic glucocorticoid hormone to suppress in vitro production of the pro-inflammatory cytokine interleukin-6 was diminished among parents of cancer patients. Findings suggest a novel pathway by which chronic stress might alter the course of inflammatory disease.     

Treatment Adherence in Children with Sickle Cell Disease: Disease-Related Risk and Psychosocial Resistance Factors

To identify disease-related risk factors and psychosocial resistance factors that impact adherence to prescribed treatment in the context of admission to a Hematology Acute Care Unit (HACU) designed to provide acute care for children with sickle cell disease (SCD) presenting with pain or fever. A total of 73 primary caregivers and 24 children (if age 8 or older) completed standardized forms during the HACU admission. Treatment adherence variables (medical staff rating, SCD-related care activities, percentage of agreement between treatment recommendations made and care activities, and attendance at hematology clinic) indicated moderate-to-high adherence. Based on regression analyses, the risk variable of disease-related stress and the resistance variables of family flexibility and less reliance on passive coping accounted for significant portions of the variance in treatment adherence. Empirical evaluation of interventions designed to improve communication regarding expectations for the care of children with SCD and to support active family problem solving during times of SCD-related stress must be ongoing.     

Chisholm's Legacy on Intentionality

Abstract: The problem of intentionality, or how mind and language can take things in the world as “intentional objects,” engaged Chisholm throughout his philosophical career. This essay reviews and discusses his seminal contributions on this problem, from his early work in “Sentences about Believing” and Perceiving during the 1950s to his last and most mature account in The First Person, published in 1981 . Chisholm's final view was that de se reference, or a subject's directly taking himself as an intentional object, is fundamental and primitive, and that all other forms of intentional reference, such as de re and de dicto, can be understood on the basis of de se intentionality. The essay ends with a discussion of the worry that this account might lead to what may be called “intentional solipsism,” the proposition that the self is the only genuine object of intentional reference.     

A computational and perceptual account of motion lines

To indicate motion in a static drawing, artists often include lines trailing a moving object. The use of these motion lines is notable because they do not seem to be related to anything in the optic array. The dynamic behavior of a neural-network model for contour detection is analyzed and it is shown that it generates trails of oriented responses behind moving stimuli. The properties of the oriented response trails are shown to correspond to motion lines. The model generates trails of different orientations depending on the speed and length of the movement, and thereby predicts different uses of two types of motion lines. The model further predicts that motion lines should bias real motion in some situations. An experiment relating motion lines to ambiguous motion percepts demonstrates that motion lines contribute to motion percepts.