Publications by authors named "Marcus J Naumer"

Background: Standardized neuropsychological testing serves to quantify cognitive impairment in multiple sclerosis (MS) patients. However, the exact mechanism underlying the translation of cognitive dysfunction into difficulties in everyday tasks has remained unclear. To answer this question, we tested if MS patients with intact vs.

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Aging is accompanied by unisensory decline. To compensate for this, two complementary strategies are potentially relied upon increasingly: first, older adults integrate more information from different sensory organs. Second, according to the predictive coding (PC) model, we form "templates" (internal models or "priors") of the environment through our experiences.

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In Autism Spectrum Disorders (ASD), impaired response inhibition and lack of adaptation are hypothesized to underlie core ASD symptoms, such as social communication and repetitive, stereotyped behavior. Thus, the aim of the present study was to compare neural correlates of inhibition, post-error adaptation, and reaction time variability in ASD and neuro-typical control (NTC) participants by investigating possible differences in error-related changes of oscillatory MEG activity. Twelve male NTC (mean age 20.

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Multisensory integration strongly depends on the temporal proximity between two inputs. In the audio-visual domain, stimulus pairs with delays up to a few hundred milliseconds can be perceived as simultaneous and integrated into a unified percept. Previous research has shown that the size of this temporal window of integration can be narrowed by feedback-guided training on an audio-visual simultaneity judgment task.

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To determine whether the performance of multiple sclerosis (MS) patients in the sound-induced flash illusion (SiFi), a multisensory perceptual illusion, would reflect their cognitive impairment. We performed the SiFi task as well as an extensive neuropsychological testing in 95 subjects [39 patients with relapse-remitting MS (RRMS), 16 subjects with progressive multiple sclerosis (PMS) and 40 healthy control subjects (HC)]. MS patients reported more frequently the multisensory SiFi than HC.

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Our ability to select relevant information from the environment is limited by the resolution of attention - i.e., the minimum size of the region that can be selected.

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The neurophysiological underpinnings of the nonsocial symptoms of autism spectrum disorder (ASD) which include sensory and perceptual atypicalities remain poorly understood. Well-known accounts of less dominant top-down influences and more dominant bottom-up processes compete to explain these characteristics. These accounts have been recently embedded in the popular framework of predictive coding theory.

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In the later stages of addiction, automatized processes play a prominent role in guiding drug-seeking and drug-taking behavior. However, little is known about the neural correlates of automatized drug-taking skills and drug-related action knowledge in humans. We employed functional magnetic resonance imaging (fMRI) while smokers and non-smokers performed an orientation affordance task, where compatibility between the hand used for a behavioral response and the spatial orientation of a priming stimulus leads to shorter reaction times resulting from activation of the corresponding motor representations.

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Visuo-haptic integration contributes essentially to object shape recognition. Although there has been a considerable advance in elucidating the neural underpinnings of multisensory perception, it is still unclear whether seeing an object and exploring it with the dominant hand elicits the same brain response as compared to the non-dominant hand. Using fMRI to measure brain activation in right-handed participants, we found that for both left- and right-hand stimulation the left lateral occipital complex (LOC) and anterior cerebellum (aCER) were involved in visuo-haptic integration of familiar objects.

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Article Synopsis
  • The study focuses on a unique case of synaesthesia experienced by an individual (LJ) who perceives specific smells when shown certain visual images, unlike typical synaesthesia which often involves colors.
  • LJ consistently associates congruent olfactory sensations with visual stimuli, such as smelling leather when viewing dress shoes.
  • In an fMRI experiment, LJ showed increased activity in the brain region responsible for processing smells (piriform cortex) when exposed to these visual stimuli, while control participants did not show this response, indicating his experiences may not just be vivid imagery.
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Previous studies investigating mild cognitive impairment (MCI) have focused primarily on cognitive, memory, attention, and executive function deficits. There has been relatively little research on the perceptual deficits people with MCI may exhibit. This is surprising given that it has been suggested that sensory and cognitive functions share a common cortical framework [1].

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In this article, we review a recent paper by Stevenson et al. (J Neurosci 34: 691-697, 2014). This paper illustrates the need to present different forms of stimuli in order to characterize the perceptual abilities of people with autism spectrum disorder (ASD).

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The car dependence of people living in contemporary cities is a major concern for policy makers, who often find it difficult to persuade people into more sustainable transport modes. By contrast, recent insights from neuroscience have shown that a broad spectrum of behaviors can become habitual and, thus, resistant to change. Here, we outline the potential of collaboration between neuroscience and human geography aiming at a better understanding of habits that determine everyday commuting routines.

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Human neuroimaging studies suggest that neural cue reactivity is strongly associated with indices of drug use, including addiction severity and treatment success. However, little is known about factors that modulate cue reactivity. The goal of this review, in which we survey published fMRI and PET studies on drug cue reactivity in cocaine, alcohol, and tobacco cigarette users, is to highlight major factors that modulate brain reactivity to drug cues.

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Rationale: Behavioral experiments have demonstrated that the sensory modality of presentation modulates drug cue reactivity.

Objectives: The present study on nicotine addiction tested whether neural responses to smoking cues are modulated by the sensory modality of stimulus presentation.

Methods: We measured brain activation using functional magnetic resonance imaging (fMRI) in 15 smokers and 15 nonsmokers while they viewed images of smoking paraphernalia and control objects and while they touched the same objects without seeing them.

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Neuroimaging studies on cue reactivity have substantially contributed to the understanding of addiction. In the majority of studies drug cues were presented in the visual modality. However, exposure to conditioned cues in real life occurs often simultaneously in more than one sensory modality.

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Human neuroplasticity of multisensory integration has been studied mainly in the context of natural or artificial training situations in healthy subjects. However, regular smokers also offer the opportunity to assess the impact of intensive daily multisensory interactions with smoking-related objects on the neural correlates of crossmodal object processing. The present functional magnetic resonance imaging study revealed that smokers show a comparable visuo-haptic integration pattern for both smoking paraphernalia and control objects in the left lateral occipital complex, a region playing a crucial role in crossmodal object recognition.

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The study of Wagner et al. (J Neurosci 31: 894-898, 2011) reveals the neural correlates of spontaneously activated action representations in smokers when subjects watch movie characters smoke. We stress the importance of differentiating how these representations are activated: while the anterior intraparietal sulcus and inferior frontal gyrus are part of the mirror neuron system of smokers, the middle frontal gyrus, premotor cortex, and superior parietal lobule represent the smoking-related tool use skills and action knowledge activated by smoking paraphernalia.

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Primate multisensory object perception involves distributed brain regions. To investigate the network character of these regions of the human brain, we applied data-driven group spatial independent component analysis (ICA) to a functional magnetic resonance imaging (fMRI) data set acquired during a passive audio-visual (AV) experiment with common object stimuli. We labeled three group-level independent component (IC) maps as auditory (A), visual (V), and AV, based on their spatial layouts and activation time courses.

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The processing of visual and haptic inputs, occurring either separately or jointly, is crucial for everyday-life object recognition, and has been a focus of recent neuroimaging research. Previously, visuohaptic convergence has been mostly investigated with matching-task paradigms. However, much less is known about visuohaptic convergence in the absence of additional task demands.

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Information integration across different sensory modalities contributes to object recognition, the generation of associations and long-term memory representations. Here, we used functional magnetic resonance imaging adaptation to investigate the presence of sensory integrative effects at cortical levels as early as nonprimary auditory and extrastriate visual cortices, which are implicated in intermediate stages of object processing. Stimulation consisted of an adapting audiovisual stimulus S(1) and a subsequent stimulus S(2) from the same basic-level category (e.

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Research on the psychological and neuronal underpinnings of addiction has concentrated mostly on affective, motivational, learning, and executive processes and the brain regions subserving these functions. In contrast, sensory and motor aspects of addiction have largely been neglected even though they may be highly relevant for the development and preservation of addiction. The aim of the present review is to emphasize the significance of sensory and motor processes for the better understanding and treatment of addiction.

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In mammals smooth retinotopic maps of the visual field are formed along the visual processing pathway whereby the left visual field is represented in the right hemisphere and vice versa. The reorganization of retinotopic maps in the lateral geniculate nucleus (LGN) of the thalamus and early visual areas (V1-V3) is studied in a patient who was born with only one cerebral hemisphere. Before the seventh week of embryonic gestation, the development of the patient's right cerebral hemisphere terminated.

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To date, noninvasive neuroimaging research on multisensory perception has focused on cortical activations. In a series of elegant functional magnetic resonance imaging experiments, Beauchamp and Ro recently investigated altered cortical activations associated with acquired sound-touch synesthesia resulting from a thalamic lesion. Their findings highlight the important role of intact thalamocortical projections for preventing illusory crossmodal perception and for underlying reliable multisensory integration.

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In addition to reward- and craving-related processes, habitual mechanisms play an important role in addiction. While the dorsal striatum has been proposed to code for the motivational state of habitual drug-seeking actions, the neural underpinnings of the corresponding drug-taking skills and action knowledge remain poorly understood. We used functional magnetic resonance imaging (fMRI) and a behavioral orientation affordance paradigm to investigate the neural and behavioral correlates of automatized drug-taking actions in nicotine dependence.

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