Investigation of the single case in neuropsychology: confidence limits on the abnormality of test scores and test score differences

Crawford, John R.; Garthwaite, Paul H.

doi:10.1016/s0028-3932(01)00224-x

Cited by 882 publications

(700 citation statements)

References 27 publications

Supporting

Mentioning

692

Contrasting

Unclassified

Order By: Relevance

“…For verification trials, the chance level was 50% (i.e., labels and greebles matched in half of the trials). Differences between prosopagnosics and controls were evaluated for statistical significance using Crawford's modified t test for single case studies (28).…”

Section: Resultsmentioning

confidence: 99%

Normal acquisition of expertise with greebles in two cases of acquired prosopagnosia

Rezlescu

Barton

Pitcher

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Face recognition is generally thought to rely on different neurocognitive mechanisms than most types of objects, but the specificity of these mechanisms is debated. One account suggests the mechanisms are specific to upright faces, whereas the expertise view proposes the mechanisms operate on objects of high withinclass similarity with which an observer has become proficient at rapid individuation. Much of the evidence cited in support of the expertise view comes from laboratory-based training experiments involving computer-generated objects called greebles that are designed to place face-like demands on recognition mechanisms. A fundamental prediction of the expertise hypothesis is that recognition deficits with faces will be accompanied by deficits with objects of expertise. Here we present two cases of acquired prosopagnosia, Herschel and Florence, who violate this prediction: Both show normal performance in a standard greeble training procedure, along with severe deficits on a matched face training procedure. Herschel and Florence also meet several response time criteria that advocates of the expertise view suggest signal successful acquisition of greeble expertise. Furthermore, Herschel's results show that greeble learning can occur without normal functioning of the right fusiform face area, an area proposed to mediate greeble expertise. The marked dissociation between face and greeble expertise undermines greeble-based claims challenging face-specificity and indicates face recognition mechanisms are not necessary for object recognition after laboratorybased training.

show abstract

Section: Resultsmentioning

confidence: 99%

Normal acquisition of expertise with greebles in two cases of acquired prosopagnosia

Rezlescu

Barton

Pitcher

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…In order to investigate neuropsychological individual changes in the treatment group versus controls' scores, single case analyses were performed using the procedure formalized by Crawford and Garthwaite (2002) to deal with single cases in cognitive neuropsychology appropriately. More precisely, modified t-tests were used to determine whether each individual's performance at followup was significantly better than the corresponding control group's scores for the seven cognitive tasks that were significantly influenced by the computerized training.…”

Section: _______________________ Figure 1 About Here ________________mentioning

confidence: 99%

“…Lastly, single-case analyses via modified t-test (Crawford & Garthwaite, 2002) was conducted too, to investigate computerized training effects also at individual patient's level. A p value < 0.05 was considered statistically significant throughout the analyses.…”

mentioning

confidence: 99%

Computerized Structured Cognitive Training in Patients Affected by Early-Stage Alzheimer's Disease is Feasible and Effective: A Randomized Controlled Study

Cavallo

Hunter

Hiele

et al. 2016

Arch Clin Neuropsychol

View full text Add to dashboard Cite

“…In order to identify those participants with Asperger syndrome who fell outside of the normal distribution we compared each individual with the whole control group on every performance measure. We adopted the procedure of Crawford and Garthwaite (2002) for comparing a single case with a modestly sized control group. This procedure uses the t-distribution, which is more resistant to departures from normality in the control group than the standard methodology of using z-scores.…”

Section: Multiple Case Series Analysismentioning

confidence: 99%

Executive processes in Asperger syndrome: Patterns of performance in a multiple case series

2006

View full text Add to dashboard Cite

Mixed evidence exists for executive dysfunction in autism spectrum disorders (ASD). This may be because of the nature of the tasks used, the heterogeneity of participants, and difficulties with recruiting appropriate control groups. A comprehensive battery of 'executive' tests was administered to 22 individuals with Asperger syndrome and 22 well-matched controls. Performance was analysed both between groups and on an individual basis to identify outliers in both the ASD and control groups. There were no differences between the groups on all 'classical' tests of executive function. However, differences were found on newer tests of executive function. Specifically, deficits in planning, abstract problem solving and especially multitasking. On the tests that discriminated the groups, all of the ASD individuals except one were identified as significantly impaired (i.e. below the 5th percentile of the control mean) on at least one executive measure. This study provides evidence for significant executive dysfunction in Asperger syndrome. Greatest dysfunction appeared in response initiation and intentionality at the highest level-the ability to engage and disengage actions in the service of overarching goals. These deficits are best observed through using more recent, ecologically valid tests of executive dysfunction. Moreover, performance on these measures correlated with autistic symptomatology. Keywords: Executive functions; Autism spectrum disorder; Problem solving; Multitasking; Prefrontal cortex 2 Executive processes in Asperger syndromeGoldsmiths Research Online 'Executive function' is traditionally used as an umbrella term for abilities such as planning,working memory, impulse control, inhibition and shifting set, as well as the initiation and monitoring of action (Roberts, Robbins, & Weiskrantz, 1998;Stuss & Knight, 2002). Animal, behavioural and neuropsychological studies have linked these functions to frontal structures of the brain, and to prefrontal cortex in particular. Additionally, a number of neurodevelopmental disorders have been linked to executive dysfunction, including autism spectrum disorder (ASD; see Russell, 1997). The core features of autism are abnormalities of social interaction, impairments in verbal and non-verbal communication and a restricted repertoire of interests and activities, all present from early childhood (American Psychiatric Association, 1994). If executive dysfunction is a central component of ASD then this would have important implications for diagnosis, intervention and our theoretical understanding of the syndrome. However, the presence, or causal nature of executive dysfunction to autism is much debated. Systematic reviews of the literature reveal mixed evidence for executive dysfunction in ASD, although difficulties in planning, mental flexibility and generativity have been documented (see Pennington, & Ozonoff, 1996, for review). Mixed findings may arise from a number of issues, including the nature of the tasks administered as well as the nature of the autism a...

show abstract

Investigation of the single case in neuropsychology: confidence limits on the abnormality of test scores and test score differences

Cited by 882 publications

References 27 publications

Normal acquisition of expertise with greebles in two cases of acquired prosopagnosia

Normal acquisition of expertise with greebles in two cases of acquired prosopagnosia

Computerized Structured Cognitive Training in Patients Affected by Early-Stage Alzheimer's Disease is Feasible and Effective: A Randomized Controlled Study

Executive processes in Asperger syndrome: Patterns of performance in a multiple case series

Contact Info

Product

Resources

About