Functional MRI at the crossroads.

Since the observation of the blood oxygenation level dependent (BOLD) effect on measured MR signal in the brain, functional magnetic resonance imaging (fMRI) has rapidly become the tool of choice for exploring brain function in cognitive neuroscience. Although fMRI is an exciting and powerful means to examining the brain in vivo, the field has sometimes permitted itself to believe that patterns of BOLD activity reveal more than it is possible to measure given the method's spatial and temporal sampling, while concurrently not fully exploring the amount of information it provides. In this article, we examine some of the constraints on the kinds of inferences that can be supported by fMRI.

CNTRICS final task selection: executive control.

The third meeting of the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) was focused on selecting promising measures for each of the cognitive constructs selected in the first CNTRICS meeting. In the domain of executive control, the 2 constructs of interest were "rule generation and selection" and "dynamic adjustments in control." CNTRICS received 4 task nominations for each of these constructs, and the breakout group for executive control evaluated the degree to which each of these tasks met prespecified criteria.

Modeling group fMRI data.

The analysis of group fMRI data requires a statistical model known as the mixed effects model. This article motivates the need for a mixed effects model and outlines the different stages of the mixed model used to analyze group fMRI data. Different modeling options and their impact on analysis results are also described.

Region of interest analysis for fMRI.

A common approach to the analysis of fMRI data involves the extraction of signal from specified regions of interest (or ROI's). Three approaches to ROI analysis are described, and the strengths and assumptions of each method are outlined.

Neural substrates for reversing stimulus-outcome and stimulus-response associations.

Adaptive goal-directed actions require the ability to quickly relearn behaviors in a changing environment, yet how the brain supports this ability is barely understood. Using functional magnetic resonance imaging and a novel reversal learning paradigm, the present study examined the neural mechanisms associated with reversal learning for outcomes versus motor responses. Participants were extensively trained to classify novel visual symbols (Japanese Hiraganas) into two arbitrary classes ("male" or "female"), in which subjects could acquire both stimulus-outcome associations and stimulus-response associations.

Challenge-driven attention: interacting frontal and brainstem systems.

The world is an unpredictable place, presenting challenges that fluctuate from moment to moment. However, the neural systems for responding to such challenges are far from fully understood. Using fMRI, we studied an audiovisual task in which the trials' difficulty and onset times varied unpredictably.

The role of fMRI in cognitive neuroscience: where do we stand?

Functional magnetic resonance imaging (fMRI) has quickly become the most prominent tool in cognitive neuroscience. In this article, I outline some of the limits on the kinds of inferences that can be supported by fMRI, focusing particularly on reverse inference, in which the engagement of specific mental processes is inferred from patterns of brain activation. Although this form of inference is weak, newly developed methods from the field of machine learning offer the potential to formalize and strengthen reverse inferences.

Automaticity in motor sequence learning does not impair response inhibition.

We examined the relationship between automaticity and response inhibition in the serial reaction time (SRT) task to test the common assertion that automatic behavior is ballistic. Participants trained for 3 h on the SRT, using blocks of a second-order conditional sequence interleaved with random blocks. Automaticity was measured using a concurrent secondary letter-counting task.

The neural substrates of visual perceptual learning of words: implications for the visual word form area hypothesis.

Abstract It remains under debate whether the fusiform visual word form area (VWFA) is specific to visual word form and whether visual expertise increases its sensitivity (Xue et al., 2006; Cohen et al., 2002).

Common neural substrates for inhibition of spoken and manual responses.

The inhibition of speech acts is a critical aspect of human executive control over thought and action, but its neural underpinnings are poorly understood. Using functional magnetic resonance imaging and the stop-signal paradigm, we examined the neural correlates of speech control in comparison to manual motor control. Initiation of a verbal response activated left inferior frontal cortex (IFC: Broca's area).

Selective corticostriatal dysfunction in schizophrenia: examination of motor and cognitive skill learning.

It has been suggested that patients with schizophrenia have corticostriatal circuit dysfunction (Carlsson & Carlsson, 1990). Skill learning is thought to rely on corticostriatal circuitry and different types of skill learning may be related to separable corticostriatal loops (Grafton, Hazeltine, & Ivry, 1995; Poldrack, Prabhakaran, Seger, & Gabrieli, 1999). The authors examined motor (Serial Reaction Time task, SRT) and cognitive (Probabilistic Classification task, PCT) skill learning in patients with schizophrenia and normal controls.

Guidelines for reporting an fMRI study.

In this editorial, we outline a set of guidelines for the reporting of methods and results in functional magnetic resonance imaging studies and provide a checklist to assist authors in preparing manuscripts that meet these guidelines.

Automatic independent component labeling for artifact removal in fMRI.

Blood oxygenation level dependent (BOLD) signals in functional magnetic resonance imaging (fMRI) are often small compared to the level of noise in the data. The sources of noise are numerous including different kinds of motion artifacts and physiological noise with complex patterns. This complicates the statistical analysis of the fMRI data.

Construction of a 3D probabilistic atlas of human cortical structures.

We describe the construction of a digital brain atlas composed of data from manually delineated MRI data. A total of 56 structures were labeled in MRI of 40 healthy, normal volunteers. This labeling was performed according to a set of protocols developed for this project.

Selective amplification of stimulus differences during categorical processing of speech.

The brain's perceptual stimuli are constantly changing: some of these changes are treated as invariances and are suppressed, whereas others are selectively amplified, giving emphasis to the distinctions that matter most. The starkest form of such amplification is categorical perception. In speech, for example, a continuum of phonetic stimuli gets carved into perceptually distinct categories.

Secondary-task effects on classification learning.

Probabilistic classification learning can be supported by implicit knowledge of cue-response associations. We investigated whether forming these associations depends on attention by assessing the effect of performing a secondary task on learning in the probabilistic classification task (PCT). Experiment I showed that concurrent task performance significantly interfered with performance of the PCT.

In praise of tedious anatomy.

Functional neuroimaging is fundamentally a tool for mapping function to structure, and its success consequently requires neuroanatomical precision and accuracy. Here we review the various means by which functional activation can be localised to neuroanatomy and suggest that the gold standard should be localisation to the individual's or group's own anatomy through the use of neuroanatomical knowledge and atlases of neuroanatomy. While automated means of localisation may be useful, they cannot provide the necessary accuracy, given variability between individuals.

Category learning and the memory systems debate.

A substantial and growing body of evidence from cognitive neuroscience supports the concept of multiple memory systems (MMS). However, the existence of multiple systems has been questioned by theorists who instead propose that dissociations can be accounted for within a single memory system. We present convergent evidence from neuroimaging and neuropsychological studies of category learning in favor of the existence of MMS for category learning and declarative knowledge.

Diffusion tensor imaging of the superior longitudinal fasciculus and working memory in recent-onset schizophrenia.

Background: Structural and functional abnormalities in frontal-parietal circuitry are thought to be associated with working memory (WM) deficits in patients with schizophrenia. This study examines whether recent-onset schizophrenia is associated with anatomical changes in the superior longitudinal fasciculus (SLF), the main frontal-parietal white matter connection, and whether the integrity of the SLF is related to WM performance.

Methods: We applied a novel registration approach (Tract-Based Spatial Statistics [TBSS]) to diffusion tensor imaging data to examine fractional anisotropy (FA) in the left and right SLF in 12 young adult patients with recent-onset schizophrenia and 17 matched control subjects.

Neural systems for perceptual skill learning.

Recent studies have begun to use functional neuroimaging techniques to examine the changes in brain activity that occur as humans learn new skills. This review outlines results from a number of imaging studies examining visual perceptual skill learning. Although the regions engaged during skill learning differ across tasks, a common finding has been increasing activation in the inferior temporal and fusiform gyri as skill is acquired and activation of the caudate nucleus in association with learning.

Triangulating a cognitive control network using diffusion-weighted magnetic resonance imaging (MRI) and functional MRI.

The ability to stop motor responses depends critically on the right inferior frontal cortex (IFC) and also engages a midbrain region consistent with the subthalamic nucleus (STN). Here we used diffusion-weighted imaging (DWI) tractography to show that the IFC and the STN region are connected via a white matter tract, which could underlie a "hyperdirect" pathway for basal ganglia control. Using a novel method of "triangulation" analysis of tractography data, we also found that both the IFC and the STN region are connected with the presupplementary motor area (preSMA).

Elaborative verbal encoding and altered anterior parahippocampal activation in adolescents and young adults at genetic risk for schizophrenia using FMRI.

Background: First-degree relatives of persons with schizophrenia are at elevated risk for the illness, demonstrate deficits in verbal memory, and exhibit structural abnormalities in the medial temporal lobe (MTL). We used functional magnetic resonance imaging (fMRI) to assess brain activity in the MTL during novel and repeated word-pair encoding.

Methods: Participants were 21 non-psychotic, first-degree relatives of persons with schizophrenia and 26 matched healthy controls (ages 13-28).

The neural basis of loss aversion in decision-making under risk.

People typically exhibit greater sensitivity to losses than to equivalent gains when making decisions. We investigated neural correlates of loss aversion while individuals decided whether to accept or reject gambles that offered a 50/50 chance of gaining or losing money. A broad set of areas (including midbrain dopaminergic regions and their targets) showed increasing activity as potential gains increased.