Cognitive estimation in neurological disorders

Abstract

The Cognitive Estimation Test (CET) was devised by Shallice & Evans (1978) in an attempt to quantify the tendency observed in some patients with frontal lobe lesions to produce bizarre estimates in response to questions to which people do not usually know exact answers (e.g. 'what is the height of a double-decker bus?'), despite performing normally on standard intelligence tests. In the present study, the CET performance of a large number of patients suffering from head injury, brain tumour, ruptured aneurysm (anterior communicating artery and other), multiple sclerosis, dementia, encephalitis, Korsakoff's syndrome and anxiety/depression were compared with CET scores from 150 healthy controls. Patients with Korsakoff syndrome demonstrated significantly impaired CET performance. A subgroup of patients with discrete frontal lesions was compared with a group with localized non-frontal lesions. No significant difference in CET performance was observed between anterior and posterior lesioned patients. The sensitivity of the CET to anterior brain dysfunction is called into question by the present findings.

Cognitive Estimation and Affective Judgments in Alcoholic Korsakoff Patients

“…Thus, cognitive estimation discussed as an executive function was also disturbed in the patients confirming the findings of Kopelman (1991a), Kopelman et al (1999), and Taylor and O'Carroll, (1995). The Korsakoff patients in our study exhibited deficits in all tested estimation dimensions ('size,' 'weight,' 'quantity,' and 'time') whereby time estimations were the most deteriorated.…”

“…Though Leng and Parkin (1988) did not find impairments in the Cognitive Estimation Test (CET) of Shallice and Evans (1978) in Korsakoff patients, Shoqueirat, Mayes, MacDonald, Meudell, and Pickering (1990) revised this finding. Comparing the CET performance of patients with different neurological disorders including Alzheimer's disease, head injury, encephalitis and others (Taylor & O'Carroll, 1995) the most pronounced deficits were found in the Korsakoff patients. Kopelman (1991a) on the other hand, observed no differences in the CET performance between patients with Alzheimer's disease and Korsakoff patients whereas in all other tests of frontal functions, Alzheimer patients were more deteriorated.…”

How many segments are there in an orange: normative data for the new Cognitive Estimation Task in an Italian population

“…The CET advantage found in our Italian male participants has previously been reported in other CET studies [5,8,31], including the British sample administered the same CET [7]. While previous CET studies have shown that higher levels of education are associated with lower CET error scores [5,7,8], performance on this Italian version was not related to education.…”

“…While previous CET studies have shown that higher levels of education are associated with lower CET error scores [5,7,8], performance on this Italian version was not related to education. This is surprising given that our participants had a wide range of educational levels (ranging from 5 years to 18 years and more) compared to previous studies that have tended to recruit individuals that do not have as low a level of education [7], have only high or low education levels [2,27] or the participants' education levels are not specified [28] and do report education effects.…”

“…There is also the ongoing debate in the literature regarding whether the CET should be considered a measure of global cognitive abilities rather than frontal executive abilities [8]. For the moment, given that clinicians and researchers continue to widely use the CET as a quick and easy assessment of executive dysfunction, the provision of Italian normative data for these new parallel CET versions is timely.…”