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Cognitive reserve (CR) theory suggests that individual differences in general intelligence (IQ), occupational attainment or participation in leisure/recreational activities protect against cognitive decline. However the relationship between CR and cognitive functioning in patients with brain tumours has been very rarely investigated in past research. The present study systematically assesses whether CR concept can also be applied to cognitive functions of neurosurgical patients affected by brain tumours. We investigated the role of different CR proxies (education level, premorbid IQ, current IQ, working and leisure activity) in protecting language against brain tumours and surgery effects, considering interactions with demographic (sex/age), anatomical (hemisphere/lobe location of lesion) and clinical/biological variables (tumour type: High/Low Grade Glioma or Meningioma; lesion volume; lesion aggressiveness). One-hundred patients undergoing neuropsychological assessment before and immediately after surgery participated. A "Language Score" summarizing performance on all language tests was derived with Principal Component Analysis. Data were then analyzed with Multiple Regression and Classification and Regression Tree analyses to investigate possible relationships between predictors (CR proxies and clinical variables) and Language Score. We found that premorbid IQ was the best predictor of pre-operatory language integrity, above and beyond all clinical variables considered, also moderating lesion volume effects. Moreover, patients with lower pre-operatory language integrity and low-to-moderately aggressive tumours showed a mitigating effect of current IQ over surgery consequences. Results thus suggest that different CR proxies play a role in moderating cognitive decline following brain tumours and surgery., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The ability to flexibly switch between fast and accurate decisions is crucial in everyday life. Recent neuroimaging evidence suggested that left lateral prefrontal cortex plays a role in switching from a quick response strategy to an accurate one. However, the causal role of the left prefrontal cortex in this particular, non-verbal, strategy switch has never been demonstrated. To fill this gap, we administered a perceptual decision-making task to neuro-oncological prefrontal patients, in which the requirement to be quick or accurate changed randomly on a trial-by-trial basis. To directly assess hemispheric asymmetries in speed-accuracy regulation, patients were tested a few days before and a few days after surgical excision of a brain tumor involving either the left (N=13) or the right (N=12) lateral frontal brain region. A group of age- and education-matched healthy controls was also recruited. To gain more insight on the component processes implied in the task, performance data (accuracy and speed) were not only analyzed separately but also submitted to a diffusion model analysis. The main findings indicated that the left prefrontal patients were impaired in appropriately adopting stricter response criteria in speed-to-accuracy switching trials with respect to healthy controls and right prefrontal patients, who were not impaired in this condition. This study demonstrates that the prefrontal cortex in the left hemisphere is necessary for flexible behavioral regulations, in particular when setting stricter response criteria is required in order to successfully switch from a speedy strategy to an accurate one., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Whether semantic knowledge is categorically organized or is based in an undifferentiated distributed network within the temporal lobes or it is at least partially organized in property-based networks is still an open issue. With a naming task involving living and nonliving entities, the latter divided according to degree of manipulability, we studied a group of 30 tumour patients with either right, left anterior or left posterior temporal lobes' lesions and a herpes simplex encephalitis patient (MU). Both cross-subject and cross-stimulus analyses were conducted. Left hemisphere patients were overall worse than both right hemisphere patients and controls in the naming task. They moreover named nonliving items worse than living. This effect was larger in left posterior temporal than both right temporal and also left anterior temporal patients and significant both at a cross-subject and cross-stimulus levels of analysis. In addition the left posterior temporal group had more difficulties with highly manipulable objects than left anterior temporal patients, but the effect was significant only on a cross-subject analysis. VLSM lesion analysis revealed that the area most critically associated with the larger naming deficit for manipulable objects was the posterior superior portion of the left temporal lobe, particularly the posterior middle temporal gyrus. These results support a 'property-based networks' account of semantic knowledge rather than an 'undifferentiated network' account. For manipulable objects, this would be a posterior-temporal/inferior-parietal left hemisphere "action/manipulation-property-based" network related to the dorsal pathways which is thought to be important in action control, as suggested by neuroimaging results., (2010 Elsevier Ltd. All rights reserved.)