Emer M. E. Forde

Task-related changes in cortical synchronization are spatially coincident with the hemodynamic response.

Using group functional Magnetic Resonance Imaging (fMRI) and group Magnetoencephalography (MEG) we studied two cognitive paradigms: A language task involving covert letter fluency and a visual task involving biological motion direction discrimination. The MEG data were analyzed using an adaptive beam-former technique known as Synthetic Aperture Magnetometry (SAM), which provides continuous 3-D images of cortical power changes. These images were spatially normalized and averaged across subjects to provide a group SAM image in the same template space as the group fMRI data. The results show that frequency-specific, task-related changes in cortical synchronization, detected using MEG, match those areas of the brain showing an evoked cortical hemodynamic response with fMRI. The majority of these changes were event-related desynchronizations (ERDs) in the 5-10 Hz and 15-25 Hz frequency ranges. Our study demonstrates how SAM, spatial normalization, and intersubject averaging enable group MEG studies to be performed. SAM analysis also allows the MEG experiment to have exactly the same task design as the corresponding fMRI experiment. This new analysis framework represents an important advance in the use of MEG as a cognitive neuroimaging technique and also allows mutual cross-validation with fMRI.

Food Allergy in Young Adults: Perceptions and Psychological Effects

Although food allergy can have serious health consequences, little is currently known about people’s perceptions of food allergy. The present study examined the differences in awareness and perceptions of food allergy and anxiety between young people with and without a food allergy. Participants completed a questionnaire which asked about their perceptions and knowledge of allergies, perceived health competence and anxiety. Of the 162 participants 24 reported they were allergic to at least one food; these people perceived that their allergy had significantly less of an impact on their lives than others believed it would. Allergy status interacted with perceived health competence to affect anxiety. People with an allergy and with high health competence reported the greatest anxiety levels. Very few of the sample knew the meaning of the term ‘anaphylaxis’. Findings are discussed in terms of health education implications and possibilities.

The Role of Semantic Knowledge and Working Memory in Everyday Tasks

We present a single case study of a patient, HG, who was severely impaired on routine everyday tasks, such as cleaning his teeth and preparing a cup of tea. We used the Action Coding System developed by Schwartz et al. (1991) to provide quantitative and qualitative measures of his performance in a number of experimental manipulations: (a) with task-congruent objects only, (b) with task-congruent objects and semantic distractors, (c) with a set of written commands to follow, (d) when he was given one command at a time, (e) when he was shown how the task should be performed before starting himself, and (f) when the task was divided into smaller subgoals. In general, the majority of HGs errors were step omissions, perseverations, sequence errors, and semantic errors. These semantic errors are particularly interesting since HG was able to name, gesture to, and define all the objects when they were presented in isolation or in task-congruent arrays. We suggest that semantic errors may arise for a number of reasons: (1) impaired access from semantic memory to a network representing action schema, (2) degradation of stored schema, and (3) behavior that is abnormally driven by the goal, by preceding actions, or by salient objects rather than by an appropriate association between these elements in working memory.

The role of semantic knowledge in short-term memory.

In this paper we examine the role of stored semantic knowledge in recall from short-term memory. We assessed the performance of a patient (FK), who showed a consistent lack of semantic knowledge for some words (‘unknown’) but not others (‘known’) on a range of serial recall tasks using both spoken and written words. Overall, FK was significantly better at recalling lists of known compared with unknown words. His recall of unknown words was characterized by numerous phonological errors, such as repeating ‘bear skunk’ as ‘bunk scare’. FK showed a relatively normal primacy effect in immediate recall, but a striking lack of a recency effect. This pattern of performance is useful for constraining theoretical accounts of language production and verbal short-term memory and for understanding the role that long-term semantic knowledge may play in maintaining information in short-term memory.

Naming a giraffe but not an animal: Base-level but not superordinate naming in a patient with impaired semantics.

We report data on patient FK, who presented with a marked deficit in accessing semantic knowledge about objects when tested across a range of input and output modalities. FK also showed a high degree of item-specific consistency in object identification, over and above effects due to object familiarity. We show that, despite being better at naming some objects than others, FK was equally poor at discriminating the superordinate categories of the stimuli. Also, he tended to be better at matching nameable items to a base-level label than to a superordinate-level label. We discuss the implications of the data for models of semantic memory.

The role of local and global processing in the recognition of living and nonliving things

We report a study on a patient (DW) with integrative visual agnosia and a category-specific recognition impairment for living things. We assessed DWs local and global processing and tested if his integrative agnosia could have led directly to his category-specific impairment. The main findings were: (i) DW was faster at identifying local compared to global letters. (ii) DW showed no local-to-global (or global-to-local) interference effects in selective attention tasks. (iii) DW showed a congruency effect in a divided attention task, suggesting that, when his attention was cued to both levels, he could process information simultaneously and integrate local and global information. (iv) Controls were poorer at naming nonliving compared to living things when presented with silhouettes. These data suggest that local and global information are differentially weighted in the visual recognition of living and nonliving things, and that an impairment in processing the overall shape of an object can lead to a category-specific deficit for living things. Crucially, this implies that category-specific impairments do not necessarily reflect damage to the semantic system, and models of semantic memory based on this assumption need to be revised.

Dissociations in routine behaviour across patients and everyday tasks.

We present a single case study of a patient, FK, who was severely impaired on routine, everyday tasks, such as preparing a cup of tea. We used the action coding system developed by Schwartz et al to provide quantitative and qualitative measures of his performance in a number of experimental manipulations. In section A, we established FK’s baseline performance on a range of tasks with (a) task-congruent objects only and (b) task-congruent objects and semantic distracters. In section B, we aimed to facilitate FK’s performance by (a) giving him a pictorial representation of the goal, (b) giving him a set of written commands to follow, (c) giving him one command at a time, (d) demonstrating how the task should be performed and (e) dividing the task into smaller subgoals. We compared FK’s performance with another patient, HG, to establish if there are qualitative differences between patients with ‘action disorganization syndrome’. In section C, we aimed to hinder FK’s performance by interrupting his execution of routine tasks. By comparing the factors that facilitated and impaired FK’s performance in sections B and C, we hoped to isolate the key cognitive processes required to generate and control routine behaviour. In section D, we investigated how task demands impact on our ability to complete different everyday activities. The results of these experiments have important clinical implications for rehabilitation programmes for patients with action disorganization syndrome and can also help to distinguish between contemporary theoretical accounts of routine behaviour. In particular, we propose that patients who can be classified under the umbrella term of ‘action disorganization syndrome’ do not all have a reduction to ‘non-specific cognitive resources’ but can have qualitatively different impairments to a specialized action production system.

Medical students’ attitudes towards abortion: a UK study

Background: There is little research into medical students’ or doctors’ attitudes to abortion, yet knowing this is important, as policy makers should be aware of the views held by professionals directly involved in abortion provision and changing views may have practical implications for the provision of abortion in the future. Methods: We surveyed 300 medical students about their views on abortion, their beliefs about the status of the fetus and the rights of the mother, their attitude towards UK law and their willingness to be involved in abortion provision as qualified doctors. Results: 62% of medical students were pro-choice, 33% pro-life and 7% undecided. Students’ views correlated with gender, year of study and holding a religious belief. Their beliefs about abortion, the status of the fetus and the rights of women significantly correlated with their attitudes towards the UK law and their willingness to be involved in abortion provision. Students’ willingness to be involved in abortion provision was related to their views on abortion, the extent of participation required, the circumstances of the pregnancy and the stage of pregnancy. Conclusions: The percentage of pro-choice students was lower than that found in research on general practitioners’ attitudes to abortion. It is unclear whether this is because students become more pro-choice as they progress through their medical career or because there is genuinely a change in attitudes to abortion.

Disordered knowledge of action order in action disorganisation syndrome.

We report data on stored knowledge of everyday tasks in a patient, FK, with ‘action disorganisation syndrome’. In section 1, we analysed his explicit knowledge of the component actions, and their temporal order. FK showed generally impaired knowledge of everyday tasks relative to controls, and, when knowledge of the temporal order of the actions was probed, he showed particular impairments for the actions making up the final steps in tasks. In section 2 we assessed FK’s implicit knowledge of the tasks, by evaluating how knowledge of the tasks influenced his ability to act out sets of instructions. We demonstrate that FK had some implicit knowledge of the tasks, but also, when actions had to be performed in the order as instructed, there was better knowledge of order for actions performed early rather than late in the task. We suggest that disordered task schema contributed to FK’s deficits, with impairments on ‘end’ actions being vulnerable when task order was important for performance.

A longitudinal study of category-specific agnosia.

We report a 12-year longitudinal case study on a 60-year-old male patient (DW) with category-specific agnosia. The extent to which DW’s impairment has changed over time was evaluated using identical tests at time 1 (1988) and time 2 (2000). In particular, we assessed his ability to identify pictures and real objects, to draw from memory, and to access stored semantic information about living and non-living things. The principal findings were: (i) DW was significantly better at identifying real objects in comparison with line drawings. (ii) DW presented with a category-specific impairment for living things that remained consistent over the 12-year period. (iii) He significantly improved in his ability to identify real non-living objects over the 12-year period but real living objects remained at floor. (iv) His ability to access stored visual knowledge declined over time. On the basis of these data, we suggest that visual perception is required to maintain intact visual memories over a period of time. We also suggest that integrative visual agnosia co-occurs with a category-specific impairment for living things because the recognition of these items requires more global processing than for non-living things. In addition, we suggest that degradation to stored visual knowledge can cause category-specific naming impairments for living compared with non-living things because naming living things requires access to more detailed visual knowledge.