The role of semantic knowledge on the cognitive estimation task

Abstract

The current study investigated the role of semantic knowledge on the Cognitive Estimation Task (CET). In an initial experiment, the CET performance of 21 patients with frontal lobe lesions was compared with 21 healthy controls. The CET was found to be sensitive to the effects of frontal lobe lesions. In Experiment 2, 175 participants aged between 18 and 87 years performed the CET to examine the effects of healthy adult aging on the task. No significant age effects were evident. In Experiment 3, 27 patients with Alzheimer's disease (AD) were compared with 27 healthy controls on the CET. AD patients produced significantly more extreme cognitive estimates than the controls. A significant correlation was found between CET performance and performance on the General Knowledge of the World Task, a task intended to assess semantic knowledge. The hypothesis is put forward that healthy older adults are able to use their intact semantic knowledge to compensate for problem-solving deficits when generating cognitive estimates. In contrast, owing to degradation in semantic abilities, AD patients are unable to benefit from semantic knowledge and instead tend to produce bizarre cognitive estimates.

Bringing the Cognitive Estimation Task into the 21st Century: Normative Data on Two New Parallel Forms

“…For example, to provide a fitting estimate for the item, “How many strings are there on a harp?”, one needs to access semantic knowledge about musical instruments. Indeed, both the current and previous findings in the literature have reported significant associations between CET performance and semantic knowledge [6], [11], [14], [25].…”

“…The CET appears to be multidimensional in nature with different cognitive functions operating in concert to achieve the overall goal. These findings also suggest that impairments in distinct cognitive abilities might underlie the CET impairments reported in individuals with syndromes such as Alzheimer’s disease [6]–[13], Korsakoff’s disease [11], [14], [15], frontotemporal dementia [12], subcortical vascular dementia [16] and post-encephalitis amnesia [17].…”

“…Thus, it is not surprising that frontal lobe damage produces deficits in estimation. Since this original study, a number of researchers have demonstrated deficits in cognitive estimation in patients with frontal lobe lesions compared to patients with temporal or diencephalic lesions and healthy controls [3]–[6]. However, it should be noted that Taylor and O’Carroll [7] did not find a significant difference between patients with anterior and posterior lesions in terms of cognitive estimation in a large group of patients with different neurological conditions.…”

“…However, it should be noted that Taylor and O’Carroll [7] did not find a significant difference between patients with anterior and posterior lesions in terms of cognitive estimation in a large group of patients with different neurological conditions. Deficits in CET performance have also been reported in Alzheimer’s disease [6]–[13], Korsakoff’s disease [11], [14], [15], frontotemporal dementia [12], subcortical vascular dementia [16], post-encephalitis amnesia [17], major depressive disorder [18], traumatic brain injury [19] and in some cases of non-demented Parkinson’s disease [20] but see [21].…”

Assessing Cognitive Estimation and Its Effects on Community Integration in People with Acquired Brain Injury Undergoing Rehabilitation

“…For example, he estimated the height of the highest building in London as between 18,000 and 20,000 feet and that the largest fish in the world was a trout which was over 3 metres long. Estimation difficulties are not solely limited to individuals with such discrete frontal lobe injury, and problems in estimation abilities have been reported in adults with Alzheimer's disease [ 6 – 9 ], viral encephalitis [ 10 ], frontotemporal dementia [ 9 , 11 ], Huntington's disease [ 12 ], Korsakoff's syndrome [ 13 , 14 ], Parkinson's disease [ 15 – 17 ] (however, see Scarpina et al [ 18 ] for a recent finding of no difference between PD patients and controls), vascular dementia [ 19 , 20 ], traumatic brain injury [ 21 – 23 ], major depressive disorder [ 24 ], and schizophrenia [ 25 – 27 ]. This breadth of effect across a broad number of conditions would suggest that investigation of estimation abilities in terms of measurement and possible effects on outcome is worthy of investigation.…”