Abstracts from british neuropsychological society meeting 26-27 April 2000, London, UK

s from British Neuropsychological Society meeting 26-27 April 2000, London, UK Why is a verb like an inanimate object? Grammatical category and semantic category deficits Helen Bird, David Howard’ and Sue Franklin’ MRC Cognition and Brain Sciences Unit, Cambridge and ‘Department of Speech, University of Newcastle upon Q n e Objectives. We sought to determine whether grammatical category deficits, such as difficulties in naming nouns relative to verbs, might be explained within the framework which has been used to account for semantic category deficits, in terms of the relative weightings of perceptual and functional features within the semantic representations of these concepts. Methods. We present a mathematical model of the semantic representations of animate nouns, inanimate nouns and verbs in which verbs are represented as being rich in functional compared with sensory features. The model’s predictions are then tested on two patient groups. Resulrs. Sensory feature damage resulted in a deficit for naming living things but spared verb naming: functional feature damage resulted in a deficit for naming inanimate objects and verbs. As the model predicted, ‘verb spared’ patients were worse at naming living things than inanimate objects, and their definitions of both kmds were lacking in sensory information. For ‘verb deficit’ patients, naming success was predicted by imageability, and when this variable was controlled no class effect remained. Production of definitions revealed no differential damage to sensory or functional features, and no consistent effect of animacy was shown in naming. Conclusions. We conclude that damage to sensory features in semantic representations causes difficulties in naming concrete nouns relative to action verbs. While the model suggests that verb deficits might occur in patients for whom functional features are damaged. we conclude that the ‘verb deficit’ shown in our patients was an artefact of the lower imageability of verbs in confrontation naming tasks. visuospatial processing. The intact recognition of objects when viewed from a conventional viewpoint yet impairment on tests of object constancy raises issues concerning the role of ventral versus dorsal visual streams in such tasks. Why semantic dementia drives you to the dogs (but not the horses) M. Cappelletti, M. D. Kopelman and B. Butterworth University College London and King’s College London, London, UK Objectives. This paper will describe a patient with semantic dementia resulting from severe left temporal atrophy, comparing his performance in reading number and non-number words. Methods. The patient was administered tests of verbal fluency, semantics. number knowledge and mental calculation as well as reading tasks which included regular and irregular words of differing categories including number. Results. The patient had severe impairment in word-finding, reading, and semantics. Despite this, he showed remarkably preserved knowledge of number and arithmetical procedures. In particular, he showed reading and spelling disorders across all categories of word apart from number-words (e.g. one, four) and numerals (e.g. I , 4). His reading and spelling abilities were closely correlated with one another on a word-by-word basis, and with his ability to comprehend the words in question. The preserved reading of number words, relatively to other categories, held good after matching for such factors as word frequency and his own use of the words in his everyday conversation. Conclusions. The patient showed a pronounced dissociation between his reading of number words and other categories. These findings will be related to previous dissociations described in the literature, and a tentative theoretical explanation proposed. The implication of the findings for the patient’s wellestablished gambling habit will also be considered. Visual processing in posterior cortical atrophy: Investigation of a case series Diana Caine, Peter Nestor and John R. Hodges Objectives. To characterise the spatial and visuoperceptual abilities of seven patients presenting with prominent visual symptoms as the first sign of presumed Alzheimer’s disease: so-called posterior cortical atrophy (PCA). Although recognised for some years, this syndrome has not been previously investigated using a consistent battery of neuropsychological tasks informed by current concepts of differential visual processing streams across a series of cases. Methods. All seven patients underwent tests of early visual processing, spatial vision, object recognition, semantic memory, visual and auditory attention as well as MRI and FGD-PET imaging. Resulfs. All patients performed well on verbal semantic tasks and could correctly identify prototypical views of both line drawings and photographs of objects. By contrast, all showed marked impairment in higher order visuospatial processing. A subgroup of patients also had additional early visual deficits, with features of a Balint’s syndrome, including simultanagnosia. This subgroup showed deficits on tests of object constancy. Thus all of the patients had predominantly dorsal rather than ventral visual deficits, but some had more prominent posterior occipitoparietal dysfunction while others had more purely parietal problems. Conclusions. Patients with PCA have severe breakdown of dorsally based Effects of object familiarity on grasping: Neuropsychological and normative evidence Martin G. Edwards*, Glyn W. Humphreys, M. Jane Riddoch and Polly Haywood (*Address correspondence to: Martin G. Edwards, Behavioural Brain Sciences Centre. School of Psychology, University of Birmingham, Edgbaston, Birmingham. B 15 27°C UK) Objectives. Visual information used for perceptual judgements and object recognition can dissociate from the visual information used for visually guided action (Milner and Goodale. 1995). However, action to familiar objects has been found to improve optic ataxia (Jeannerod et al., 1994) and facilitate anarchic hand syndrome (Riddoch et al., 1998, 2000). suggesting some interaction between object recognition and action. The present study examines relations between stored object knowledge and action in the reaching and grasping of control participants and in a patient with visual object agnosia, H.J.A. Methods. We examined the reaching and grasping of both familiar objects and unfamiliar, neutral objects (blocks of wood), matched in size and weight. Results. H.J.A. ’s reaching and grasping differed from the controls in that he showed a wider grasp aperture and a longer time to decelerate. However, for H.J.A. , grasp apertures were smaller for familiar objects, despite not being 260 BNS Meeting Abstracts able to identify any of the objects. For the controls, reaches to familiar objects spent a shorter period in deceleration. Conclusions. These data suggest that object familiarity can affect reaching and grasping. We consider two accounts to explain this. The first assumes that common objects activate stored descriptions within the ventral stream (outside of awareness) and that this activation leads to the excitation of associated hand responses. The second account is that common objects evoke some components of familiar actions (e.g., associated grip responses) through another (possibly dorsal) route that does not involve complete recognition of the object. Asperger 's Syndrome following amygdala damage: the dissociation of theory of mind and executive functions C. Fine and R. J. R. Blair Objrcfives. We report an Asperger's Syndrome patient, BM, with early or congenital left amygdala damage. The first aim was to investigate to what extent BM showed impairment in theory of mind. The second aim was to determine the degree to which BM's theory of mind impairment was independent of executive functioning. Merlrods. BM was given ten tests of his theory of mind ability. assessing false belief understanding, mental state understanding in the comprehension of cartoons, and understanding of intended meaning in non-literal utterances. BM was also given sixteen tests of executive functioning, assessing his ability to inhibit dominant responses, create and maintain goal-related behaviours. and temporally sequence behaviour. Rrsulfu. BM performed consistently poorly on the ten theory of mind tasks. In contrast, his performance on all sixteen executive functions tests was normal. Conclusions. This is the first time that a dissociation between theory of mind and executive functions has been reported in the same individual, and indicates that the neurocognitive systems mediating theory of mind and executive functions are separable. We conclude that theory of mind is not simply a function of more general executive functions, and that executive functions can develop and function on-line, independently of theory of mind. Apperceptive agnosia and the recognition of object categories in dementia of the Alzheimer type Elaine Funnel1 Royal Holloway. University of London, London, UK Ohjrctiws. This paper investigates the visual recognition of particular categories of objects in an elderly woman (NA) with a progressive visual apperceptive agnosia associated with probable Alzheimer's disease Mrfltods. Objects from categories of living things (animals, birds, insects, fruit and vegetables) and categories of non-living things (clothes, furniture. rools. kitchen utensils, and musical instruments) were presented as line drawings for naming and as spoken words for defining on two separate occasions. Living and nonliving things were matched closely for word frequency, concept familiarity, and age-of-acquisition. Resulrs. On both test occasions, NA's visual recognition of object pictqres was more impaired for living than non-living things and particular items were affected consistently across test occasions. With the exception of body parts, categories of living things were more prone to visual, category-related errors, based on the overall shape of the object; whi