Knowing where and knowing what: a double dissociation

We report a double dissociation between visuo-spatial abilities and semantic knowledge (knowledge of the names and attributes of objects and people), in two brain-injured people with longstanding stable impairments, using a wide range of tests to explore the extent of the dissociation, MU, who has bilateral lesions of occipito-parietal cortex, shows severe spatial disorientation with relatively well-preserved semantic knowledge. He is contrasted with JBR, who has bilateral temporal lobe damage and shows severe semantic problems and no impairment on visuo-spatial tasks. Our findings thus demonstrate a double dissociation between the performance of semantic and spatial tasks by MU and JBR. This pattern is consistent with Ungerleider and Mishkin's (1982) neurophysiological hypothesis of separable cortical visual pathways; one which is specialised for spatial perception and follows a dorsal route from occipital to parietal lobes, and the other following a more ventral route from occipital to temporal lobes, whose target is semantic information needed in specifying what an object is.     

The existence of a fatigue syndrome after glandular fever

This prospective cohort study was designed to test whether a distinct fatigue syndrome existed after the onset of glandular fever. Two hundred and fifty primary care patients, with either glandular fever or an ordinary upper respiratory tract infection (URTI) were interviewed three times in the 6 months after the clinical onset of their infection. At each interview a standardized psychiatric interview was given and physical symptoms were assessed. There were 108 subjects with and Epstein-Barr virus (EBV) infection; 83 subjects had glandular fever not caused by EBV and 54 subjects had an ordinary URTI. Five subjects were excluded because they had no evidence of an infection. Principal components analyses of symptoms supported the existence of a fatigue syndrome, particularly in the two glandular fever groups. The addition of symptoms not elicited by the standard interviews gave the full syndrome. This included physical and mental fatigue, excessive sleep, psychomotor retardation, poor concentration, anhedonia, irritability, social withdrawal, emotional lability, and transient sore throat and neck gland swelling with pain. A fatigue syndrome probably exists after glandular fever.     

A new analysis of life-span age trends in visual illusion.

Tested the magnitude of the over- and underestimated portions of the Ebbinghaus (Titchner circles) illusion in 688 Ss ranging in age from 5 to 70 yrs. Results indicate that the overestimated portion decreases while the underestimated portion yields increasing illusory distortion as a function of age. Both configurations produced nonlinear age trends. These results suggest that reports of inconsistent age trends in illusions may be the result of combining increasing and decreasing age functions found in some components of the same illusion configuration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual and memory search by process schizophrenics.

Compared the response times (RTs) of 20 process schizophrenics (10 paranoid and 10 nonparanoid) and 20 nonhospitalized controls (mean ages 39.2, 30.0, and 34.1 yrs, respectively) on a hybrid visual and memory search task in which Ss searched displays of up to 15 letters, reporting whether or not displays contained a target, which in different conditions was drawn from a memorized set of 1, 3, or 6 letters. RTs of all groups increased linearly with the product of the number in the memorized target set and the number of displayed letters. Although the intercepts and RTs of the schizophrenics (there were no paranoid–nonparanoid differences) exceeded those of controls, no group differences were found in slopes or in rates of increase in RT as a function of the number of memorized or displayed items. Results are interpreted in terms of a model proposed by W. Schneider and R. M. Shiffrin (1977), which indicates that process schizophrenics are retarded in processes associated with response production but not in a variety of processing stages involved in the comparison of displayed and memorized information. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of The assessment of aphasia and related disorders (2nd ed).

Reviews the book, The assessment of aphasia and related disorders (2nd ed.) by Harold Goodglass and Edith Kaplan (1983). The authors state in the preface that much has been learned about aphasia since the first edition of this book was published, through both formal research and clinical experience. Unfortunately, there is little to reflect this in the revised text: The most striking feature of this second edition is the similarity to the original publication. There are a few instances where the text has been rewritten to provide better clarification and to include more recent information. For example, the section in Chapter 2 on "loss of grammar and syntax" has been extended and includes recent references. However, the major portion of each chapter (with the exception of Chapter 3 on the statistical background) is essentially a reproduction of the 1972 text. The extent of this word-for-word reproduction includes the phrase "recent historical papers" to refer to papers published in the 1960s. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immunological characterisation of barley polypeptides in lager foam

Eight monoclonal antibodies (mAb) recognising barley polypeptides have been identified from a library developed to wheat prolamins. The specificity or the mAb has been determined using enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Six were of broad specificity, recognising D, B, C and γ-hordeins to varying degrees by both techniques. IFRN 0610 preferentially recognised γ-hordeins by ELISA but was highly specific for this hordein group by immunoblotting. Another mAb, IFRN 0624, bound to a M_r ∽ 18000 polypeptide belonging to the CM protein (trypsin/α-amylase inhibitor) family by immunoblotting. This, or a related protein, was detected by 0624 in all hordein fractions using ELISA. These mAb, together with two others described previously and found to recognise the repeat motif of C hordein, were used in ELISA and immunoblot analysis of Octyl-Sepharose fractions of lager foam. Hordein polypeptides were found in all foam fractions, indicating that much foam protein originates from the malt. The CM-like protein was found present in a virtually unmodified form. In contrast, the repeat motif of C hordein was not detected, indicating that it had either been destroyed or masked by other beer constituents. The foam stabilising agent, propylene glycol alginate (PGA), increased the apparent hydrophobicity of hordein fragments suggesting that at least part of the activity of PGA is mediated by interactions with the hordein components of foam.     

Surface Modification of Exfoliated Layered Gadolinium Hydroxide for the Development of Multimodal Contrast Agents for MRI and Fluorescence Imaging

A novel method for modifying the surface of magnetic‐resonance‐contrasting layered gadolinium hydroxide (LGdH) is developed providing them with water‐ and bio‐compatibility and acid‐resistance, all of which are essential for medical applications. A stable colloid of exfoliated layers is synthesized by exchanging interlayer anions of LGdH with oleate ions. The delaminated layers are successively coated with phospholipids with poly(ethylene glycol) tail groups, and their effectiveness as a contrast agent for magnetic resonance imaging (MRI) is demonstrated. The adaptability of this surface modification approach for incorporating functional molecules and fabricating a fluorescent colloid of LGdH, which has the potential utility as a multimodal probe, is also demonstrated. This result provides a novel approach for expanding the applications of layered inorganic materials and developing a new class of MRI contrast agents.     

Comparative resistance of food proteins to adult and infant in vitro digestion models

IgE‐mediated allergy to milk and egg is widespread in industrialised countries and mainly affects infants and young children. It may be connected to an incomplete digestion of dietary proteins causing an inappropriate immune response in the gut. In order to study this, a biochemical model of infant gastroduodenal digestion has been developed, which has reduced levels of protease (eightfold for pepsin and tenfold for trypsin and chymotrypsin), phosphatidylcholine and bile salts, compared with the adult model. This model has been used to study the behaviour of three characterised food‐relevant proteins (bovine β‐lactoglobulin (β‐Lg), β‐casein (β‐CN) and hen's egg ovalbumin), all of which are relevant cows' milk and hens' egg allergens. Digestion products were characterised using electrophoresis, immunochemical techniques and MS. These showed that ovalbumin and β‐CN were digested more slowly using the infant model compared with the adult conditions. Resistant fragments of β‐CN were found in the infant model, which correspond to previously identified IgE epitopes. Surprisingly, β‐Lg was more extensively degraded in the infant model compared with the adult one. This difference was attributed to the tenfold reduction in phosphatidylcholine concentration in the infant model limiting the protective effect of this phospholipid on β‐Lg digestion.     

Food processing increases casein resistance to simulated infant digestion

The objective of this study was to determine whether processing could modify the resistance of casein (CN) to digestion in infants. A range of different dairy matrices was manufactured from raw milk in a pilot plant and subjected to in vitro digestion using an infant gut model. Digestion products were identified using MS and immunochemical techniques. Results obtained showed that CNs were able to resist digestion, particularly κ‐ and αs₂‐CN. Resistant areas were identified and corresponded to fragments hydrophobic at pH 3.0 (gastric conditions) and/or carrying post‐translational modifications (phosphorylation and glycosylation). Milk processing led to differences in peptide patterns and heat treatment of milk tended to increase the number of peptides found in digested samples. This highlights the likely impact of milk processing on the allergenic potential of CNs.