Publications by authors named "Ro Julia Robotham"

6 Publications

  • Page 1 of 1

Object recognition and visual object agnosia.

Handb Clin Neurol 2021 ;178:155-173

Department of Psychology, University of Copenhagen, Copenhagen, Denmark.

The term visual agnosia is used to refer to recognition disorders that are confined to the visual modality, that are not due to an impairment in sensory functions, and that cannot be explained by other cognitive deficits or by general reduction in intellectual ability. Here, we describe the different types of visual agnosia that have been reported (form agnosia, integrative agnosia, associative agnosia, transformational and orientation agnosia as well as category-specific impairments such as pure alexia and prosopagnosia) and how they relate to the current understanding of visual object recognition. Together with related disorders such as simultanagnosia, texture agnosia, aphantasia, and optic aphasia, these visual perceptual impairments can have severe consequences for those affected. We suggest how in-depth assessment can be carried out to determine the type and the extent of these impairments. In the context of clinical assessment, a step-by-step approach reflecting a posterior to anterior gradient in visual object recognition, from more perceptual to more memory-related processes, is suggested. Individually tailored interventions targeting the identified impairments can be initiated based on the results of the assessment.
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http://dx.doi.org/10.1016/B978-0-12-821377-3.00008-8DOI Listing
January 2021

A free and simple computerized screening test for visual field defects.

Scand J Psychol 2019 Aug 26;60(4):289-294. Epub 2019 May 26.

Department of Psychology, University of Copenhagen, Copenhagen, Denmark.

About 30-40% of stroke patients suffer from visual field defects following injury. These can interfere with the standard neuropsychological assessment and complicate the interpretation of tests that use visual materials. However, information about the integrity of a patient's central visual field is often unavailable. We, therefore, designed a screening tool, the computerized visual field test (c-VFT), specifically targeted at providing easily available, but rough, information about patients' central visual field. c-VFT was tested in two samples of stroke patients. Eleven patients were tested on c-VFT and on the Esterman test. Five patients were tested on c-VFT and the Humphrey Visual Field Analyzer (HFA), central 10-2. Criterion validity of the c-VFT was investigated by calculating quadrantwise intraclass correlation for both comparisons. For the HFA comparison, we also calculated point-to-point intraclass correlation, sensitivity, and specificity. Analyses revealed moderately good correspondence between c-VFT and the Esterman test, and between c-VFT and HFA 10-2, respectively. When looking specifically at test points within one degree of visual angle apart in the two tests, intraclass correlation increased. For these points, the sensitivity of c-VFT was 0.89 and specificity was 0.97. While the c-VFT is not designed to be diagnostic nor to replace the detailed visual field analysis, this study shows that it provides a reasonable screening of the central visual field. The test can easily be used and will be made freely available to neuropsychological clinicians and researchers.
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http://dx.doi.org/10.1111/sjop.12546DOI Listing
August 2019

A Danish version of the Oxford cognitive screen: a stroke-specific screening test as an alternative to the MoCA.

Neuropsychol Dev Cogn B Aging Neuropsychol Cogn 2020 01 11;27(1):52-65. Epub 2019 Feb 11.

Cognitive Neuropsychology Centre, Department of Experimental Psychology, University of Oxford, Oxford, UK.

Cognitive deficits are common following stroke and have many negative consequences. They must be identified to provide appropriate interventions and care. In Denmark, the Montreal Cognitive Assessment (MoCA), a dementia screening tool, is commonly used to screen for cognitive deficits following stroke, despite its limitations in this context. This study aimed to make the Oxford Cognitive Screen (OCS), a stroke-specific cognitive screening tool, available in Danish and to provide population appropriate normative data. Additionally, the study aimed to evaluate the appropriateness of the MoCA cutoff of 25/26 currently used in Denmark. A sample of healthy Danish participants aged 36-89 was assessed using the Danish OCS and MoCA. Mean performance and 5th percentile cutoffs were calculated for both tests. OCS results were similar to results from European studies. For the MoCA, 5th percentile corresponded to 22.35, suggesting that the cutoff currently used in Denmark is inappropriate.
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http://dx.doi.org/10.1080/13825585.2019.1577352DOI Listing
January 2020

Tests of whole upright face processing in prosopagnosia: A literature review.

Neuropsychologia 2018 12 31;121:106-121. Epub 2018 Oct 31.

Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, 1353 Copenhagen, Denmark. Electronic address:

Prosopagnosia refers to an acquired or developmental deficit in face recognition. This neuropsychological impairment has received increasing attention over the last decade, in particular because of an increased scientific interest in developmental prosopagnosia. Studies investigating prosopagnosia have used a variety of different clinical and experimental tests to assess face processing abilities. With such a large variety of assessment methods available, test selection can be challenging. Some previous works have aimed to provide an overview of tests used to diagnose prosopagnosia. However, no overview that is based on a structured review of the literature is available. We review the literature to identify tests that have been used to assess the processing of whole upright faces in acquired and developmental prosopagnosia over the last five years (2013-2017). We not only review tests that have been used for diagnostic purposes, but also tests that have been used for experimental purposes. Tests are categorised according to i) their experimental designs and, ii) the stage of face processing that they assess. On this basis, we discuss considerations regarding test designs for future studies. A visual illustration providing a structured overview of paradigms available for testing the processing of whole upright faces is provided. This visual illustration can be used to inform test selection when designing a study and to apply a structured approach to interpreting findings from the literature. The different approaches to assessment of face processing in prosopagnosia have been necessary and fruitful in generating data and hypotheses about the cause of face processing deficits. However, impairments at different levels of face processing have often been interpreted as reflecting a deficit in the recognition stage of face processing. Based on the data now available on prosopagnosia, we advocate for a more structured approach to assessment, which may facilitate a better understanding of the key deficits in prosopagnosia and of the level(s) of face processing that are impaired.
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http://dx.doi.org/10.1016/j.neuropsychologia.2018.10.018DOI Listing
December 2018

Visual crowding in pure alexia and acquired prosopagnosia.

Cogn Neuropsychol 2018 10 14;35(7):361-370. Epub 2018 Jun 14.

a Department of Psychology , University of Copenhagen , Copenhagen , Denmark.

Visual crowding is a phenomenon that impairs object recognition when the features of an object are positioned too closely together. Crowding limits recognition in normal peripheral vision and it has been suggested to be the core deficit in visual agnosia, leading to a domain-general deficit in object recognition. Using a recently developed tool, we test whether crowding is the underlying deficit in four patients with category specific agnosias: Two with pure alexia and two with acquired prosopagnosia. We expected all patients to show abnormal crowding. We find that the two patients with acquired prosopagnosia show abnormal crowding effects in foveal vision, while the pure alexic patients do not, and that this constitutes a significant dissociation. Thus, abnormal crowding cannot explain all cases of visual agnosia. Much recent work has focused on similarities between pure alexia and acquired prosopagnosia. Here we show a difference in a basic visual mechanism-visual crowding.
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http://dx.doi.org/10.1080/02643294.2018.1483325DOI Listing
October 2018

On the use of cognitive neuropsychological methods in developmental disorders.

Cogn Neuropsychol 2018 Feb - Mar;35(1-2):94-97

a Department of Psychology , University of Copenhagen , Copenhagen , Denmark.

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http://dx.doi.org/10.1080/02643294.2017.1423048DOI Listing
February 2019