42 research outputs found
Effects of mixed versus blocked design on stimulus evaluation: combining underaddative effects.
(from the journal abstract) According to the asynchronous discrete coding model of Miller, two manipulations should display underadditive effects on reaction time if they slow down noncontingent stages associated with the processing of two separable dimensions of a stimulus. Underadditive effects are also predicted by a dual route model when a task variable is factorially varied with design type (mixed vs blocked). Interpretations of both underadditive effects and their combination were evaluated. Intact and degraded stimuli were presented to 18 young adults either in a single block (mixed) or in separate blocks (blocked). Spatial stimulus-response (S-R) compatibility was manipulated in all conditions. Stimulus degradation and S-R compatibility interacted underadditively, but only in blocked presentations. Both interpretations of underadditive effects were supported. Eye-movement registrations provided additional support for the alternative routes model
Waterstof in de gebouwde omgeving:Synthese Thematiek WaterstofLab
Er ligt een gemeenschappelijke uitdaging om de warmtevoorziening van de gebouwde omgeving CO2-neutraal te maken. In de meeste huishoudens is aardgas nu nog een vanzelfsprekende keuze voor verwarmen en koken. Daar komt de komende 30 jaar verandering in. Niet in één keer, maar geleidelijk en gefaseerd. In het Klimaatakkoord is afgesproken dat iedere gemeente voor eind 2021 een transitievisie warmte heeft. Waterstof kan hier als klimaatneutraal gas mogelijk een rol in spelen, maar er zijn ook nog veel vragen. Het WaterstofLab, gestart in 2020, beoogt door het organiseren van dialoog tussen een breed scala aan betrokkenen en belanghebbenden op zoek te gaan naar een meer eenduidig beeld omtrent de rol die waterstof kan spelen als onderdeel van de oplossing voor een CO2-neutrale gebouwde omgeving, de huidige stand van zaken rond waterstof, en de termijn waarop een bijdrage verwacht zou kunnen worden. Dit document is het resultaat van de voorbeschouwing. Het geeft weer waar de regiegroep van het WaterstofLab het in grote lijnen over eens is en waar nog de grote vraagtekens zitten. Dit is nadrukkelijk geen eindconclusie, maar een tussenstand op basis van huidige inzichten in de groep. Het is bedoeld als start van een bredere dialoog
The beat goes on: Rhythmic modulation of cortical potentials by imagined tapping
A frequency analysis was used to tag cortical activity from imagined rhythmic movements. Participants synchronized overt and imagined taps with brief visual stimuli presented at a constant rate, alternating between left and right index fingers. Brain potentials were recorded from across the scalp and topographic maps made of their power at the alternation frequency between left and right taps. Two prominent power foci occurred in each hemisphere for both overt and imagined taps, one over sensorimotor cortex and the other over posterior parietal cortex, with homologous foci in opposite hemispheres arising from oscillations 180° out of phase. These findings demonstrate temporal isomorphism at a neural level between overt and imagined movements and illustrate a new approach to studying covert actions
A computational account of altered error processing in older age: dopamine and the error-related negativity
When participants commit errors or receive feedback signaling that they havemade an error, a negative brain potential is elicited. According to Holroyd and Coles's (in press) neurocomputational model of error processing, this error-related negativity (ERN) is elicited when the brain first detects that the consequences of an action are worse than expected. To study age-related changes in error processing, we obtained performance and ERN measures of younger and high-functioning older adults. Experiment 1 demonstrated reduced ERN amplitudes in older adults in the context of otherwise intact brain potentials. This result could not be attributed to uncertainty about the required response in older adults. Experiment 2 revealed impaired performance and reduced response-and feedback-related ERNs of older adults in a probabilistic learning task. These age changes could be simulated by manipulation of a single parameter of the neurocomputational model, this manipulation corresponding to weakened phasic activity of the mesencephalic dopamine system
A computational account of altered error processing in older age: Dopamine and the error-related negativity
When participants commit errors or receive feedback signaling that they have made an error, a negative brain potential is elicited. According to Holroyd and Coles’s (in press) neurocomputational model of error processing, this error-related negativity (ERN) is elicited when the brain first detects that the consequences of an action are worse than expected. To study age-related changes in error processing, we obtained performance and ERN measures of younger and high-functioning older adults. Experiment 1 demonstrated reduced ERN amplitudes in older adults in the context of otherwise intact brain potentials. This result could not be attributed to uncertainty about the required response in older adults. Experiment 2 revealed impaired performance and reduced response- and feedback-related ERNs of older adults in a probabilistic learning task. These age changes could be simulated by manipulation of a single parameter of the neurocomputational model, this manipulation corresponding to weakened phasic activity of the mesencephalic dopamine syste