Diagnosing developmental prosopagnosia: repeat assessment using the Cambridge Face Memory Test

Developmental prosopagnosia (DP) is a cognitive condition characterized by a relatively selective impairment in face recognition. Currently, people are screened for DP via a single attempt at objective face-processing tests, usually all presented on the same day. However, several variables probably influence performance on these tests irrespective of actual ability, and the influence of repeat administration is also unknown. Here, we assess, for the first known time, the test–retest reliability of the Cambridge Face Memory Test (CFMT)—the leading task used worldwide to diagnose DP. This value was found to fall just below psychometric standards, and single-case analyses revealed further inconsistencies in performance that were not driven by testing location (online or in-person), nor the time-lapse between attempts. Later administration of an alternative version of the CFMT (the CFMT-Aus) was also found to be valuable in confirming borderline cases. Finally, we found that performance on the first 48 trials of the CFMT was equally as sensitive as the full 72-item score, suggesting that the instrument may be shortened for testing efficiency. We consider the implications of these findings for existing diagnostic protocols, concluding that two independent tasks of unfamiliar face memory should be completed on separate days.

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The Use of Virtual Environments for Survey Spatial Ability Evaluation in Topographical Disorientation

Behavioural Neurology ◽

10.1155/2008/953640 ◽

2008 ◽

Vol 19 (1-2) ◽

pp. 81-85 ◽

Cited By ~ 2

Author(s):

Francesca Morganti ◽

Maria Luisa Rusconi ◽

Anna Paladino ◽

Giuliano Geminiani ◽

Antonella Carassa

Keyword(s):

Virtual Environments ◽

Spatial Ability ◽

Medial Temporal Lobe ◽

Single Case ◽

Control Group ◽

Sense Of Presence ◽

Spatial Tasks ◽

Topographical Disorientation ◽

Spatial Test ◽

Selective Impairment

Due to their interactivity and to the sense of presence they afford, virtual environments constitute an interesting opportunity to study spatial cognition. In accordance with this perspective, we aimed to introduce a spatial test in virtual simulation in order to investigate the survey spatial ability in patients with topographical disorientation. To do this, we used the “planning in advance task” in a virtual environment that constitutes an effective procedure to experimentally evaluate survey maps. With this procedure we present the single case of a woman, with a right medial temporal lobe lesion, who shows a selective impairment in the acquisition of new spatial relationships. The patient’s performance in “planning in advance task” was compared with that of a control group made up of 40 female subjects matched for age and education. Results show how the patient revealed a significantly lower spatial performance when compared to the control group, demonstrating an inability to solve survey-type spatial tasks in complex virtual environments.

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Objective Patterns of Face Recognition Deficits in 165 Adults with Self-Reported Developmental Prosopagnosia

Brain Sciences ◽

10.3390/brainsci9060133 ◽

2019 ◽

Vol 9 (6) ◽

pp. 133 ◽

Cited By ~ 7

Author(s):

Sarah Bate ◽

Rachel J. Bennetts ◽

Nicola Gregory ◽

Jeremy J. Tree ◽

Ebony Murray ◽

...

Keyword(s):

Face Recognition ◽

Face Perception ◽

Semantic Processing ◽

Severe Form ◽

Short Term ◽

Face Memory ◽

Familiar Face ◽

Unfamiliar Face ◽

Prevalent Form

In the last 15 years, increasing numbers of individuals have self-referred to research laboratories in the belief that they experience severe everyday difficulties with face recognition. The condition “developmental prosopagnosia” (DP) is typically diagnosed when impairment is identified on at least two objective face-processing tests, usually involving assessments of face perception, unfamiliar face memory, and famous face recognition. While existing evidence suggests that some individuals may have a mnemonic form of prosopagnosia, it is also possible that other subtypes exist. The current study assessed 165 adults who believe they experience DP, and 38% of the sample were impaired on at least two of the tests outlined above. While statistical dissociations between face perception and face memory were only observed in four cases, a further 25% of the sample displayed dissociations between impaired famous face recognition and intact short-term unfamiliar face memory and face perception. We discuss whether this pattern of findings reflects (a) limitations within dominant diagnostic tests and protocols, (b) a less severe form of DP, or (c) a currently unrecognized but prevalent form of the condition that affects long-term face memory, familiar face recognition or semantic processing.

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The Fractionation of Arithmetical Skills: A Single Case Study

The Quarterly Journal of Experimental Psychology Section A ◽

10.1080/14640748208400856 ◽

1982 ◽

Vol 34 (1) ◽

pp. 31-51 ◽

Cited By ~ 246

Author(s):

Elizabeth K. Warrington

Keyword(s):

Single Case ◽

Semantic Knowledge ◽

Knowledge Systems ◽

Single Case Study ◽

Simple Addition ◽

Numeracy Skills ◽

Selective Impairment ◽

Arithmetical Calculation ◽

Cerebral Haematoma

A single case study of a patient with a selective impairment of arithmetical calculation is reported. DRC became severely acalculic after sustaining a left parietal intra-cerebral haematoma. His numeracy skills were documented as fully as possible. It was found that his knowledge of the significance of individual numbers and his concept of quantity appeared to be intact, but simple addition, subtraction and multiplication were all performed laboriously and inaccurately and his performance was inconsistent from trial to trial. Further it was shown that it was his knowledge of arithmetical facts not his knowledge of arithmetical operations which was impaired. The findings are discussed in relation to models of arithmetical calculation and it is concluded that for DRC there was a deficit in accessing one category of verbal semantic knowledge systems, namely arithmetical facts.

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