81 research outputs found
Toward a model-based cognitive neuroscience of mind wandering
Published version also available at http://dx.doi.org/10.1016/j.neuroscience.2015.09.053People often ââmind wanderâ during everyday
tasks, temporarily losing track of time, place, or current task
goals. In laboratory-based tasks, mind wandering is often
associated with performance decrements in behavioral
variables and changes in neural recordings. Such empirical
associations provide descriptive accounts of mind
wandering â howit affects ongoing task performance â but fail
to provide true explanatory accounts â why it affects task
performance. In this perspectives paper, we consider mind
wandering as a neural state or process that affects the
parameters of quantitative cognitive process models, which
in turn affect observed behavioral performance. Our
approach thus uses cognitive process models to bridge
the explanatory divide between neural and behavioral data.
We provide an overview of two general frameworks for
developing a model-based cognitive neuroscience of mind
wandering. The first approach uses neural data to segment
observed performance into a discrete mixture of latent
task-related and task-unrelated states, and the second
regresses single-trial measures of neural activity onto
structured trial-by-trial variation in the parameters of
cognitive process models. We discuss the relative merits of
the two approaches, and the research questions they can
answer, and highlight that both approaches allow neural data
to provide additional constraint on the parameters of cognitive
models, which will lead to a more precise account of the
effect of mind wandering on brain and behavior. We conclude
by summarizing prospects for mind wandering as conceived
within a model-based cognitive neuroscience framework,
highlighting the opportunities for its continued study and
the benefits that arise from using well-developed quantitative techniques to study abstract theoretical constructs
Arctic Aerosol at the Svalbard Island in Year 2010. Modal Structure, Elemental Composition and Time Dependence of the Crustal Aerosol Component
Commentary:Transcranial stimulation of the frontal lobes increases propensity of mind-wandering without changing meta-awareness
Commentary:Transcranial stimulation of the frontal lobes increases propensity of mind-wandering without changing meta-awareness
Blinding is compromised for transcranial direct current stimulation at 1Â mA for 20Â min in young healthy adults
Trace metals in aerosol at Terra Nova Bay, Antarctica.
Atmospheric particulate with an aerodynamic diameter o10 mm (PM10) was sampled continuously during the austral summers of 2000â2001 and 2001â2002 at a coastal site near to the Italian base of Terra Nova, Antarctica. Li, Pb, Cd, U, Ba, Bi, Cs, Rb, Tl, Sr, Al, V, Fe, Cu, Mn, Zn, Co, Ag were determined by inductively coupled sector field mass spectroscopy (ICP-SFMS) after sample digestion by a combination of HF, HNO3, and H2O2 in ultraclean conditions. Quality control of the analytical procedure was carried out by blank control, by evaluating the limits of detection, recoveries and repeatability. Concentrations found are extremely low for most metals, confirming the high purity of Antarctic aerosol. Principal Component Analysis (PCA) highlights high correlations among Pb, Cr, Bi, Cu and Zn concentration values and among Li, U, Ba, Cs, Rb, Al, V, Fe, Mn, Co concentration values permitting the identification of two principal source groups, namely crustal dust and human emission activities. Elements of anthropogenic origins (Pb, Cr, Cu, Zn) were highly enriched with respect to their crustal composition
On the efficiency of neurally-informed cognitive models to identify latent cognitive states
Placebo Intervention Enhances Reward Learning in Healthy Individuals
According to the placebo-reward hypothesis, placebo is a reward-anticipation process that increases
midbrain dopamine (DA) levels. Reward-based learning processes, such as reinforcement learning,
involves a large part of the DA-ergic network that is also activated by the placebo intervention. Given
the neurochemical overlap between placebo and reward learning, we investigated whether verbal
instructions in conjunction with a placebo intervention are capable of enhancing reward learning
in healthy individuals by using a monetary reward-based reinforcement-learning task. Placebo
intervention was performed with non-invasive brain stimulation techniques. In a randomized,
triple-blind, cross-over study we investigated this cognitive placebo effect in healthy individuals by
manipulating the participantsâ perceived uncertainty about the interventionâs efficacy. Volunteers in the
purportedly low- and high-uncertainty conditions earned more money, responded more quickly and had
a higher learning rate from monetary rewards relative to baseline. Participants in the purportedly high-
uncertainty conditions showed enhanced reward learning, and a model-free computational analysis
revealed a higher learning rate from monetary rewards compared to the purportedly low-uncertainty
and baseline conditions. Our results indicate that the placebo response is able to enhance reward
learning in healthy individuals, opening up exciting avenues for future research in placebo effects on
other cognitive functions
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