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T Valentine

Publications and source records attributed to T Valentine.

28 records · Page 2Linked to original sources
PubMed1988

Upside-down faces: a review of the effect of inversion upon face recognition.

Several studies have found that face recognition is disproportionately impaired by stimulus inversion when compated to recognition of other classes of visual stimuli. This effect has been interpreted as evidence that face recognition benefits from a 'special' process which is not engaged by an inverted face. This paper reviews studies of the effect of inversion on face recognition in recognition memory tasks, matching tasks and upon cerebral hemisphere asymmetries. Evidence is drawn from developmental studies and from studies of brain-injured and normal adult subjects. It is concluded that the evidence that inverted faces are processed differently from upright faces is far from compelling, and therefore the effect of inversion provides little or no evidence of a unique process in face recognition. The inversion effect is interpreted in terms of expertise in face processing and the highly homogeneous nature of faces as a stimulus class.

Attention↗
PubMed1986

Tubuloreticular inclusions in placental chorionic villi of rhesus monkeys after maternal treatment with interferon.

Tubuloreticular inclusions were observed in placental chorionic villi of rhesus monkeys after pregnant female monkeys were injected intramuscularly with recombinant leukocyte A interferon (25 X 10(6) units/kg). They were identified in endothelial cells, fibroblasts, and Hofbauer cells of the chorionic villi, providing evidence that interferon crossed at least part of the maternal-fetal partition. Induction of tubuloreticular inclusions in these cells by exogenous interferon has not been previously reported. Tightly packed regular tubular arrangements appeared in endothelial and Hofbauer cells and loosely organized tubular arrays in fibroblasts. The maximum dimension of the tubuloreticular inclusions measured 3 micron and the diameter of the tubules was 20 nm. The tubuloreticular inclusions were continuous with, and surrounded by, smooth endoplasmic reticulum that was often connected to rough endoplasmic reticulum. The tubuloreticular inclusions were not detected in placental chorionic villi from monkeys not treated with interferon or from interferon-treated monkeys 30 days after cessation of treatment. These results indicate that the formation of tubuloreticular inclusions in rhesus monkey placentas was a transient response associated with elevated serum levels of interferon.

Animals↗
PubMed1986

The effects of distinctiveness in recognising and classifying faces.

In an earlier study it was found that distinctive familiar faces were recognised faster than typical familiar faces in a familiarity decision task. In the first experiment reported here this effect was replicated with the use of celebrities' faces rather than personally familiar faces. In the second and third experiments the effect of distinctiveness was found to reverse if the task was to distinguish between faces and jumbled faces. Subjects took longer to classify distinctive faces as faces than they did to classify typical faces. Thus distinctive faces were recognised faster, but were classified as faces more slowly than were typical faces, both when personally familiar faces and when famous faces were used as stimuli. These results are interpeted as evidence that faces are encoded by reference to a general face prototype.

Decision Making↗
PubMed1985

Identity priming in the recognition of familiar faces.

Morton (1969) proposed that word recognition is mediated by logogens--threshold devices whose thresholds would be lowered after 'firing' and only slowly return to near their original levels. Extension and revision of the original logogen model has occurred in response to results obtained in experiments which examine the effect of previous exposure to an item on later recognition thresholds. On the basis of results obtained in such identity priming studies, Warren & Morton (1982) argued that picture recognition might be mediated by pictogens--threshold devices which respond when any picture of an object is seen. Warren & Morton found that recognition of a pictured object was facilitated by earlier exposure to the same or a different picture of the object, but was not facilitated by earlier exposure to the object's name. Recently, several authors have suggested that face recognition might be mediated by units somewhat analogous to logogens or pictogens. In order to explore this analogy, Warren & Morton's procedure of identity priming in picture recognition was adopted to examine identity priming in the recognition of famous faces. When the recognition test involved naming a celebrity's face, identity priming was obtained from prior exposure to the celebrity's name, a different picture or the same picture as that used in the test. If the procedure was modified so that subsequent recognition did not require retrieval of the name, a pattern consistent with the word and picture recognition literature was found. Prior exposure to either a different or the same picture produced a priming effect but prior exposure to the celebrity's name did not. These results are generally consistent with the hypothesis of face recognition units. Differences between face recognition units and pictogens are also discussed.

Discrimination Learning↗
PubMed1984

Ultrastructure of normal, metaplastic, and abnormal human uterine cervix: use of montages to study the topographical relationship of epithelial cells.

The ultrastructure of the entire thicknesses of normal and abnormal human uterine cervical epithelia is studied with the use of slit-type grids. In four normal squamous epithelial specimens, basic similarities in the maturational sequence were apparent; however, significant variation in the progression of differentiation was also obvious. Because of this variation, it was not possible to always correlate cellular structure with cellular location within the epithelial strata. Four normal specimens containing combinations of squamous, columnar, and metaplastic cells show variations in the topographical relationships of these cells and stages in the transition of reserve to squamous cells in metaplastic zones. The presence of cells with features characteristic of squamous and columnar epithelia suggests a bipotentiality of reserve cells. Six abnormal specimens share several morphologic features, which usually, but not regularly, vary quantitatively with the extent of abnormality. Because of the inconsistent gradation of cellular features with lesion severity, it was essential that numerous ultrastructural parameters be considered in order to evaluate the extent of abnormality. Cellular features peculiar to individual specimens include edema, keratinization, phagocytic squamous cells, and cells similar in appearance to koilocytes described in condylomas. Electron micrograph montages of extensive unobstructed areas of normal and abnormal cervices and higher-magnification micrographs of cell components provide improved documentation of the variation in morphology of normal and abnormal epithelia. Use of montages also results in a clear view of ultrastructural changes accompanying the transition from normal to abnormal cervical epithelium.

Basement Membrane↗
PubMed1977

A murine tumor producing a matrix of basement membrane.

We have studied a murine tumor previously classified as a poorly differentiated chondrosarcoma. Although the cells in this tumor are surrounded by large quantities of extracellular matrix material, the matrix fails to react with stains specific for the sulfated glycosaminoglycans present in normal cartilage. Here we show at the ultrastructural level that the tumor matrix is a homogeneous, nonfibrillar material, resembling basement membrane. Neither the proteoglycan matrix granules nor collagen fibrils characteristic of cartilage are present in the tumor matrix. Amino acid analyses of whole tumor tissue, enzyme-solubilized tumor components, and the protein extracted from lathyritic tumors confirmed that the tumor matrix is a basement membrane collagen. The collagenous protein extracted from the tumor by nonenzymatic means contains three unique polypeptides larger than the alpha-chain components of the other types of collagen. These studies indicate that the tumor is not a type of chondrosarcoma but a basement membrane producing tumor.

Amino Acids↗