Nonparametric permutation tests for functional neuroimaging: A primer with examples

Neuroimaging studies have indicated involvement of left prefrontal cortex and temporal areas in verbal memory processes. The current study used event-related functional neuroimaging to compare encoding of subsequently recalled and not recalled words in high and low memory performers. Fifteen healthy volunteers were given lists of words to learn with immediate recall and to read as a control condition. High performers reported to have visualized the words whereas low performers used a rehearsal strategy. Compared to reading, unsuccessful encoding was associated with thalamic and left premotor area (BA 6) activity. Comparing successful with unsuccessful learning yielded widespread activity of the left prefrontal and posterior temporal gyrus as well as the left superior parietal lobe in the whole group. Low performers showed activation of the left premotor area throughout learning and additionally of the left middle temporal and parahippocampal gyrus during successful encoding. High performers showed increased activation in the extrastriate cortex throughout learning and additionally in the left parietal post- and paracentral areas as well as in the right precuneus during successful encoding. The results suggest that high verbal memory performance is the result of spatiovisual activation concomitant to imagery and low performance of hippocampal and motor activation, the latter being associated with rehearsal, with a common memory circuit subserving both groups.

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Behavior in the Brain

Journal of Psychophysiology ◽

10.1027/0269-8803/a000016 ◽

2010 ◽

Vol 24 (2) ◽

pp. 76-82 ◽

Cited By ~ 15

Author(s):

Martin M. Monti ◽

Adrian M. Owen

Keyword(s):

Motor Behavior ◽

Functional Neuroimaging ◽

Brain Activity ◽

Motor Output ◽

The Unconscious ◽

Ethical Implications ◽

Brain Responses ◽

Minimally Conscious ◽

Brain Insults ◽

Brain Behavior

Recent evidence has suggested that functional neuroimaging may play a crucial role in assessing residual cognition and awareness in brain injury survivors. In particular, brain insults that compromise the patient’s ability to produce motor output may render standard clinical testing ineffective. Indeed, if patients were aware but unable to signal so via motor behavior, they would be impossible to distinguish, at the bedside, from vegetative patients. Considering the alarming rate with which minimally conscious patients are misdiagnosed as vegetative, and the severe medical, legal, and ethical implications of such decisions, novel tools are urgently required to complement current clinical-assessment protocols. Functional neuroimaging may be particularly suited to this aim by providing a window on brain function without requiring patients to produce any motor output. Specifically, the possibility of detecting signs of willful behavior by directly observing brain activity (i.e., “brain behavior”), rather than motoric output, allows this approach to reach beyond what is observable at the bedside with standard clinical assessments. In addition, several neuroimaging studies have already highlighted neuroimaging protocols that can distinguish automatic brain responses from willful brain activity, making it possible to employ willful brain activations as an index of awareness. Certainly, neuroimaging in patient populations faces some theoretical and experimental difficulties, but willful, task-dependent, brain activation may be the only way to discriminate the conscious, but immobile, patient from the unconscious one.

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What Is Left Is Right

European Psychologist ◽

10.1027/1016-9040.14.1.78 ◽

2009 ◽

Vol 14 (1) ◽

pp. 78-89 ◽

Cited By ~ 8

Author(s):

Kenneth Hugdahl ◽

René Westerhausen

Keyword(s):

Speech Processing ◽

Information Transfer ◽

Hemispheric Asymmetry ◽

Functional Neuroimaging ◽

Gray Matter Volume ◽

Functional Anatomy ◽

Posterior Part ◽

Functional Asymmetry ◽

Planum Temporale ◽

Evolution Of Speech

The present paper is based on a talk on hemispheric asymmetry given by Kenneth Hugdahl at the Xth European Congress of Psychology, Praha July 2007. Here, we propose that hemispheric asymmetry evolved because of a left hemisphere speech processing specialization. The evolution of speech and the need for air-based communication necessitated division of labor between the hemispheres in order to avoid having duplicate copies in both hemispheres that would increase processing redundancy. It is argued that the neuronal basis of this labor division is the structural asymmetry observed in the peri-Sylvian region in the posterior part of the temporal lobe, with a left larger than right planum temporale area. This is the only example where a structural, or anatomical, asymmetry matches a corresponding functional asymmetry. The increase in gray matter volume in the left planum temporale area corresponds to a functional asymmetry of speech processing, as indexed from both behavioral, dichotic listening, and functional neuroimaging studies. The functional anatomy of the corpus callosum also supports such a view, with regional specificity of information transfer between the hemispheres.

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Effects of Psychotherapy on Brain Activation Patterns in Anxiety Disorders

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000240 ◽

2016 ◽

Vol 224 (2) ◽

pp. 62-70 ◽

Cited By ~ 2

Author(s):

Thomas Straube

Keyword(s):

Anxiety Disorders ◽

Neuronal Plasticity ◽

Functional Neuroimaging ◽

State Of The Art ◽

Methodological Issues ◽

Future Directions ◽

Activation Patterns ◽

New Learning ◽

Analytical Strategies ◽

Sample Characteristics

Abstract. Psychotherapy is an effective treatment for most mental disorders, including anxiety disorders. Successful psychotherapy implies new learning experiences and therefore neural alterations. With the increasing availability of functional neuroimaging methods, it has become possible to investigate psychotherapeutically induced neuronal plasticity across the whole brain in controlled studies. However, the detectable effects strongly depend on neuroscientific methods, experimental paradigms, analytical strategies, and sample characteristics. This article summarizes the state of the art, discusses current theoretical and methodological issues, and suggests future directions of the research on the neurobiology of psychotherapy in anxiety disorders.

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