Publications by authors named "Tor I Hansen"

Web-based testing of cognitive abilities allows for large-scale assessments without geographical constraints. Yet, the extent to which it can reach populations beyond the typical demographic groups recruited for cognitive studies is unclear. This study focused on comparing the characteristics of individuals from a general population study (HUNT4) who chose to participate in a cognitive study (HUNT4-Hjernetrim) with those who did not.

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This study explores the synchronization of multimodal physiological data streams, in particular, the integration of electroencephalography (EEG) with a virtual reality (VR) headset featuring eye-tracking capabilities. A potential use case for the synchronized data streams is demonstrated by implementing a hybrid steady-state visually evoked potential (SSVEP) based brain-computer interface (BCI) speller within a fully immersive VR environment. The hardware latency analysis reveals an average offset of 36 ms between EEG and eye-tracking data streams and a mean jitter of 5.

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Background: Patients with substance use disorders (SUDs) are at increased risk for symptom deterioration following treatment, with up to 60% resuming substance use within the first year posttreatment. Substance use craving together with cognitive and mental health variables play important roles in the understanding of the trajectories from abstinence to substance use.

Objective: This prospective observational feasibility study aims to improve our understanding of specific profiles of variables explaining SUD symptom deterioration, in particular, how individual variability in mental health, cognitive functioning, and smartphone use is associated with craving and substance use in a young adult clinical population.

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Aim: To investigate visual function and neurodevelopment in a geographically defined population cohort of school-aged children born extremely preterm.

Methods: All children born extremely preterm in Central Norway between 2006 and 2011 (n=65) were identified, and 36 (median age, min/max: 13, 10/16) were included. Best-corrected visual acuity (BCVA), contrast sensitivity (four spatial frequencies), parent-reported challenges and neuropsychological testing in learning, executive functions, motor skills, perception, reaction time, working and visual memory, processing speed, and pattern separation were measured.

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Purpose: Risk of cancer has been associated with body or organ size in several studies. We sought to investigate the relationship between intracranial volume (ICV) (as a proxy for lifetime maximum brain size) and risk of IDH-mutant low-grade glioma.

Methods: In a multicenter case-control study based on population-based data, we included 154 patients with IDH-mutant WHO grade 2 glioma and 995 healthy controls.

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Background: Little is known about the extent to which glioma patients experience subjective changes in cognitive function following surgery. We sought to assess patient-reported cognitive function before and after glioma surgery and explore potential factors associated with cognitive change.

Methods: In a prospective population-based study, patient-reported cognitive function was measured in 182 patients undergoing primary surgery for diffuse glioma (141 high-grade gliomas (HGG) and 41 low-grade gliomas (LGG)) by using the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 cognitive function subscale preoperatively and at 1 and 6 months postoperatively.

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Aerobic exercise is proposed to attenuate cognitive decline in aging. We investigated the effect of different aerobic exercise interventions and cardiorespiratory fitness (CRF) upon cognition throughout a 5-year exercise intervention in older adults. 106 older adults (52 women, age 70-77 years) were randomized into high-intensity interval training (HIIT; ∼90% peak heart rate), moderate-intensity continuous training (MICT; ∼70% peak heart rate), or control for 5 years.

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The hippocampus and the entorhinal cortex are considered the main brain structures for allocentric representation of the external environment. Here, we show that the amygdala and the ventral visual stream are involved in allocentric representation. Thirty-one young men explored 35 virtual environments during high-resolution functional magnetic resonance imaging (fMRI) of the medial temporal lobe (MTL) and were subsequently tested on recall of the allocentric pattern of the objects in each environment-in other words, the positions of the objects relative to each other and to the outer perimeter.

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Background: Glioma is the most common primary brain tumor and is believed to arise from glial stem cells. Despite large efforts, there are limited established risk factors. It has been suggested that tissue with more stem cell divisions may exhibit higher risk of cancer due to chance alone.

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Aims/hypothesis: The aim of this study was to compare cognitive function in adults with type 1 diabetes who have impaired awareness of hypoglycaemia with those who have normal awareness of hypoglycaemia. A putative association was sought between cognitive test scores and a history of severe hypoglycaemia.

Methods: A total of 68 adults with type 1 diabetes were included: 33 had impaired and 35 had normal awareness of hypoglycaemia, as confirmed by formal testing.

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To date, there is no consensus whether sexual dimorphism in the size of neuroanatomical structures exists, or if such differences are caused by choice of intracranial volume (ICV) correction method. When investigating volume differences in neuroanatomical structures, corrections for variation in ICV are used. Commonly applied methods are the ICV-proportions, ICV-residuals and ICV as a covariate of no interest, ANCOVA.

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Introduction: Computerized neuropsychological tests are effective in assessing different cognitive domains, but are often limited by the need of proprietary hardware and technical staff. Web-based tests can be more accessible and flexible. We aimed to investigate validity, effects of computer familiarity, education, and age, and the feasibility of a new web-based self-administered neuropsychological test battery (Memoro) in older adults and seniors.

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In rodents representations of environmental positions follow a granularity gradient along the hippocampal and entorhinal anterior-posterior axis; with fine-grained representations most posteriorly. To investigate if such a gradient exists in humans, functional magnetic resonance imaging data were acquired during virtual environmental learning of the objects' positions and the association between the objects and room geometry. The Objects-room geometry binding led to increased activation throughout the hippocampus and in the posterior entorhinal cortex.

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The objective of the current study was to determine long-term test-retest reliability of the P3 NoGo wave as well as two independent components (IC P3 NoGo early and IC P3 NoGo late) decomposed from this wave by independent component analysis (ICA). For this purpose 19-channel EEG was recorded during a cued visual Go/NoGo task. First, spatial filters of the two independent components (ICs) were obtained by application of ICA to ERPs of 102 healthy adults.

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