Browsing by Subject "executive functions"

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  • Elsilä, Lauri V.; Korhonen, Nuppu; Hyytiä, Petri; Korpi, Esa R. (2020)
    While interest in psychedelic drugs in the fields of psychiatry and neuroscience has re-emerged in recent last decades, the general understanding of the effects of these drugs remains deficient. In particular, there are gaps in knowledge on executive functions and goal-directed behaviors both in humans and in commonly used animal models. The effects of acute doses of psychedelic lysergic acid diethylamide (LSD) on reward-driven decision making were explored using the mouse version of the Iowa Gambling Task. A total of 15 mice were trained to perform in a touch-screen adaptation of the rodent version of the Iowa Gambling Task, after which single acute doses of LSD (0.025, 0.1, 0.2, 0.4 mg/kg), serotonin 2A receptor-selective agonist 25CN-NBOH (1.5 mg/kg), d-amphetamine (2.0 mg/kg), and saline were administered before the trial. 25CN-NBOH and the three lowest doses of LSD showed no statistically significant changes in option selection or in general functioning during the gambling task trials. The highest dose of LSD (0.4 mg/kg) significantly decreased premature responding and increased the omission rate, but had no effect on option selection in comparison with the saline control. Amphetamine significantly decreased the correct responses and premature responding while increasing the omission rate. In conclusion, mice can perform previously learned, reward-driven decision-making tasks while under the acute influence of LSD at a commonly used dose range.
  • Laakso, Hanna (Helsingin yliopisto, 2015)
    Objective: Cognitive impairment as a consequence of a stroke is common. Advanced age increases the frequency of poststroke cognitive deficits. Particularly executive dysfunction has an important role in poststroke disability. Complex by their nature, however, measuring executive function is difficult. The Hayling test, Design fluency task and Questioning task are some of the less common assessment methods of executive functions, and thus, they are not widely studied. The aim of the present study was to assess the feasibility of these tests in elderly patients three months after ischemic stroke. Performances on these tests were compared to conventional assessment methods of executive functions, and their predictive value on functional disability in follow-up was examined. Methods: 62 stroke patients and 39 control subjects, aged 55-85, underwent comprehensive neurological and neuropsychological examinations three months after the index stroke. Executive functions were studied with the Trail Making test, Stroop test, Wisconsin card sorting test, Verbal fluency task as well as with the Hayling test, Design fluency task and Questioning task. The modified Rankin Scale (mRS) and the Lawton's Instrumental activities of daily living -scale (IADL) were used to assess functional abilities at three months, and the mRS after 15 months follow-up. Results and conclusions: The Hayling test and Questioning task and the four conventional tests of executive functions differentiated stroke patients from healthy controls. Furthermore, the executive functions predicted functional dependence in the elderly stroke patients. The Hayling test was most consistently associated with functional disability as evaluated with mRS and IADL three months after the stroke, and predicted functional disability as evaluated with mRS at 15 months follow-up. Of all executive functions tests, the Hayling test proved to be the most constant predictor of functional abilities in elderly stroke patients. However, there is no golden standard for measuring executive functions, and in the future, more sensitive methods are needed. Nevertheless, the present study confirms the importance of assessing executive functions in clinical populations, when predicting functional disability even in the long-term.
  • Mikkola, Katri (Helsingfors universitet, 2016)
    Attention-deficit/hyperactivity disorder (ADHD) is a pervasive neurodevelopmental disorder of executive functions, which affects the social, occupational, educational, and personal life of the individuals concerned. The main characteristics of this disorder are age inappropriate inattention, impulsivity and hyperactivity. The research on adult ADHD is still scarce, especially concerning the neural networks of attention. Childhood ADHD has been associated with impairment in two of the attentional network subsystems alerting and executive control, leaving the third subsystem, orienting of attention, intact. Research on adult ADHD and the subsystems of attentional network is contradicting. The aim of this study was to investigate neural activation of these attentional networks during highly demanding attentional tasks in adults with ADHD. The first hypothesis was that the ADHD group have decreased activity in the frontoparietal network during orienting of attention in contrast to the control group. The second hypothesis was that the ADHD group have decreased activity in the dorsolateral prefrontal cortex, anterior cingulate gyrus, and precuneus during divided attention in contrast to the control group. Both the ADHD group and the control group included 16 participants, aged 25 – 56 across all participants, whose brain activation was measured with functional magnetic resonance imaging during the attentional tasks. The tasks included divided and selective attention. Both conditions included task-irrelevant novel distractors. The results supported both hypotheses. The ADHD group had decreased brain activity in the frontoparietal network during top-down controlled and bottom-up triggered attention. Decreased activation in the dorsolateral prefrontal cortex, anterior cingulate gyrus and precuneus was observed during divided attention in the ADHD group. Furthermore, the default-mode network was hyperactivated in the ADHD group. Activation of this network has been related to increasing task demands and failure of maintaining an alert state. Thus, adult ADHD seems to associate with abnormally functioning attention networks. Moreover, the results indicated that in addition to dysfunctional alerting and executive control, adults with ADHD have also impaired orienting of attention. These dysfunctional attentional networks may have a connection with the inattentive symptoms of adult ADHD.
  • Jokinen, Hanna; Goncalves, Nicolau; Vigario, Ricardo; Lipsanen, Jari; Fazekas, Franz; Schmidt, Reinhold; Barkhof, Frederik; Madureira, Sofia; Verdelho, Ana; Inzitari, Domenico; Pantoni, Leonardo; Erkinjuntti, Timo; LADIS Study Grp (2015)
    White matter lesions (WML) are the main brain imaging surrogate of cerebral small-vessel disease. A new MRI tissue segmentation method, based on a discriminative clustering approach without explicit model based added prior, detects partial WML volumes, likely representing very early-stage changes in normal-appearing brain tissue. This study investigated how the different stages of WML, from a "pre-visible" stage to fully developed lesions, predict future cognitive decline. MRI scans of 78 subjects, aged 65-84 years, from the Leukoaraiosis and Disability (LADIS) study were analyzed using a self supervised multispectral segmentation algorithm to identify tissue types and partial VVML volumes. Each lesion voxel was classified as having a small (33%), intermediate (66%), or high (100%) proportion of lesion tissue. The subjects were evaluated with detailed clinical and neuropsychological assessments at baseline and at three annual follow-up visits. We found that voxels with small partial WML predicted lower executive function compound scores at baseline, and steeper decline of executive scores in follow-up, independently of the demographics and the conventionally estimated hyperintensity volume on fluid-attenuated inversion recovery images. The intermediate and fully developed lesions were related to impairments in multiple cognitive domains including executive functions, processing speed, memory, and global cognitive function. In conclusion, early-stage partial WML, still too faint to be clearly detectable on conventional MRI, already predict executive dysfunction and progressive cognitive decline regardless of the conventionally evaluated WML load. These findings advance early recognition of small vessel disease and incipient vascular cognitive impairment.
  • Laakso, H. M.; Hietanen, M.; Melkas, S.; Sibolt, G.; Curtze, S.; Virta, M.; Ylikoski, R.; Pohjasvaara, T.; Kaste, M.; Erkinjuntti, T.; Jokinen, H. (2019)
    Background and purposeImpairment of executive functions (EFs) is a common cognitive symptom post-stroke and affects independence in daily activities. Previous studies have often relied on brief cognitive tests not fully considering the wide spectrum of EF subdomains. A detailed assessment of EFs was used to examine which of the subdomains and tests have the strongest predictive value on post-stroke functional outcome and institutionalization in long-term follow-up. MethodsA subsample of 62 patients from the Helsinki Stroke Aging Memory Study was evaluated with a battery of seven neuropsychological EF tests 3 months post-stroke and compared to 39 healthy control subjects. Functional impairment was evaluated with the modified Rankin Scale (mRS) and Instrumental Activities of Daily Living (IADL) scale at 3 months, and with the mRS at 15 months post-stroke. Institutionalization was reviewed from the national registers of permanent hospital admissions in up to 21-year follow-up. ResultsThe stroke group performed more poorly than the control group in multiple EF tests. Tests of inhibition, set shifting, initiation, strategy formation and processing speed were associated with the mRS and IADL scale in stroke patients. EF subdomain scores of inhibition, set shifting and processing speed were associated with functional outcome. In addition, inhibition was associated with the risk for earlier institutionalization. ConclusionsExecutive function was strongly associated with post-stroke functional impairment. In follow-up, poor inhibition was related to earlier permanent institutionalization. The results suggest the prognostic value of EF subdomains after stroke.
  • Hartikka, Roosa (Helsingin yliopisto, 2019)
    Objectives. One of the key factors responsible for one’s self-regulatory skills are considered to be temperament-based effortful control (EC) and higher-order executive functions (EFs). These have been shown to share some mutual neural networks and brain regions, but little is known about the connections between them. In particular, there is a lack of longer-term follow-up studies. This study examined the association between parental-assessed EC in childhood and test performance based EFs in early adolescence. In addition, the aim was to investigate the connections between sub-features of EC and EFs, and whether gender affects the relationship between them. Methods. This study consisted of 183 children and adolescents who had participated at the age of 5,5 and 12 years in the follow-up phases of the cohort study, which began in 1998. EC was assessed by The Children’s Behavior Questionnaire (CBQ) and EFs were evaluated with subtests from Developmental Neuropsychological Assessment for Children II (NEPSY-II), Trail Making Test (TMT), Conners’ Continuous Performance Test II (CPT) and Wisconsin Card Sorting Test (WCST). Results and conclusions. Higher parental-rated EC at 5,5 years of age was associated EFs at age 12, especially in tasks measuring linguistic and non-linguistic fluency and inhibitory skills (verbal and design fluency subtests from NEPSY-II). Looking at the individual subfactors of EC, the ability to maintain attentional focus (attentional focusing), the tendency to enjoy low intensity stimuli (low intensity pleasure), and the ability to suppress inappropriate responses (inhibitory control) were found to be associated with higher EFs (better performance in verbal and design fluency subtests from NEPSY-II, less perseveration errors in WCST and lower response time in CPT). In addition, some gender specific connections were found: boys’ ability to shift attention was associated with higher stimulus resolution (higher D Prime score in CPT). The results suggest that childhood temperament could be used to identify potential challenges in EFs later in early adolescence.
  • Moisala, Mona; Salmela, Viljami; Carlson, Synnöve; Salmela-Aro, Katariina; Lonka, Kirsti; Hakkarainen, Kai; Alho, Kimmo (2018)
    Background: Adolescence is a time of ongoing neural maturation and cognitive development, especially regarding executive functions. In the current study, age-related differences in the neural correlates of different executive functions were tracked by comparing three age groups consisting of adolescents and young adults. Methods: Brain activity was measured with functional magnetic resonance imaging (fMRI) from 167 human participants (13- to 14-year-old middle adolescents, 16- to 17-year-old late adolescents and 20-to 24-year-old young adults; 80 female, 87 male) while they performed attention and working memory tasks. The tasks were designed to tap into four putative sub-processes of executive function: division of attention, inhibition of distractors, working memory, and attention switching. Results: Behaviorally, our results demonstrated superior task performance in older participants across all task types. When brain activity was examined, young adult participants demonstrated a greater degree of overlap between brain regions recruited by the different executive tasks than adolescent participants. Similarly, functional connectivity between frontoparietal cortical regions was less task specific in the young adult participants than in adolescent participants. Conclusions: Together, these results demonstrate that the similarity between different executive processes in terms of both neural recruitment and functional connectivity increases with age from middle adolescence to early adulthood, possibly contributing to age-related behavioral improvements in executive functioning. These developmental changes in brain recruitment may reflect a more homogenous morphological organization between process-specific neural networks, increased reliance on a more domain-general network involved in executive processing, or developmental changes in cognitive strategy.
  • Putkinen, Vesa; Saarikivi, Katri (2018)
    Musical training has been associated with superior performance in various executive function tasks. To date, only a few neuroimaging studies have investigated the neural substrates of the supposed "musician advantage" in executive functions, precluding definite conclusions about its neural basis. Here, we provide a selective review of neuroimaging studies on plasticity and typical maturation of executive functions, with the aim of investigating how proficient performance in executive function tasks is reflected in brain activity. Specifically, we examine the evidence for the hypothesis that enhanced or mature executive functions are manifested as efficient use of neural systems supporting those functions. We also present preliminary results from a functional magnetic resonance imaging study suggesting-in line with this hypothesis-that musically trained adolescents recruit frontoparietal regions less strongly during executive functions tasks than untrained peers.
  • Criscuolo, Antonio; Bonetti, Leonardo; Särkämö, Teppo; Kliuchko, Marina; Brattico, Elvira (2019)
    Converging evidence has demonstrated that musical training is associated with improved perceptual and cognitive skills, including executive functions and general intelligence, particularly in childhood. In contrast, in adults the relationship between cognitive performance and musicianship is less clear and seems to be modulated by a number of background factors, such as personality and socio-economic status. Aiming to shed new light on this topic, we administered the Wechsler Adult Intelligence Scale III (WAIS-III), the Wechsler Memory Scale III (WMS-III), and the Stroop Test to 101 Finnish healthy adults grouped according to their musical expertise (non-musicians, amateurs, and musicians). After being matched for socio-economic status, personality traits and other demographic variables, adult musicians exhibited higher cognitive performance than non-musicians in all the mentioned measures. Moreover, linear regression models showed significant positive relationships between executive functions (working memory and attention) and the duration of musical practice, even after controlling for intelligence and background variables, such as personality traits. Hence, our study offers further support for the association between cognitive abilities and musical training, even in adulthood.
  • Jylkka, Jussi; Soveri, Anna; Wahlstrom, Jenny; Lehtonen, Minna; Rodriguez-Fornells, Antoni; Laine, Matti (2017)
    We examined the relationship between self-reported everyday language switching experience and the performance of early bilinguals in tasks measuring different executive functions. Our participants were Finnish-Swedish early bilinguals, aged 16-41 years (N=66, Experiment 1) and 18-69 years (N=111, Experiment 2). An earlier study using a sample from a similar population discovered a negative relationship between self-reported language switching and a mixing cost in error rates in a number-letter task. This finding was not replicated. Instead, we found that a higher rate of reported contextual language switching predicted larger switching cost reaction times in the number-letter task, and that a higher rate of reported unintended language switches predicted larger error rates in a spatial n-back task. We conclude that these results likely reflect individual differences in executive skills, and do not provide evidence for the hypothesis that language switching trains executive functions.