An fMRI study of canonical and noncanonical word order in German

Understanding a complex sentence requires the processing of information at different (e.g., phonological, semantic, and syntactic) levels, the intermediate storage of this information and the unification of this information to compute the meaning of the sentence information. The present investigation homed in on two aspects of sentence processing: working memory and reanalysis. Event-related functional MRI was used in 12 healthy native speakers of German, while they read sentences. Half of the sentences had unambiguous initial noun-phrases (masculine nominative, masculine accusative) and thus signaled subject-first (canonical) or object-first (noncanonical) sentences. Noncanonical unambiguous sentences were supposed to entail greater demand on working memory, because of their more complex syntactic structure. The other half of the sentences had case-ambiguous initial noun-phrases (feminine gender). Only the second unambiguous noun-phrase (eighth position in the sentences) revealed, whether a canonical or noncanonical word order was present. Based on previous data it was hypothesized that ambiguous noncanonical sentences required a recomputation of the sentence, as subjects would initially commit to a subject first reading. In the respective contrasts two main areas of brain activation were observed. Unambiguous noncanonical sentences elicited more activation in left inferior frontal cortex relative unambiguous canonical sentences. This was interpreted in conjunction with the greater demands on working memory in the former condition. For noncanonical ambiguous relative to canonical ambiguous sentences, an activation of the left supramarginal gyrus was revealed, which was interpreted as a reflection of the reanalysis-requirements induced by this condition.     

Auditory stroop and absolute pitch: An fMRI study

To date, the underlying cognitive and neural mechanisms of absolute pitch (AP) have remained elusive. In the present fMRI study, we investigated verbal and tonal perception and working memory in musicians with and without absolute pitch. Stimuli were sine wave tones and syllables (names of the scale tones) presented simultaneously. Participants listened to sequences of five stimuli, and then rehearsed internally either the syllables or the tones. Finally participants indicated whether a test stimulus had been presented during the sequence. For an auditory stroop task, half of the tonal sequences were congruent (frequencies of tones corresponded to syllables which were the names of the scale tones) and half were incongruent (frequencies of tones did not correspond to syllables). Results indicate that first, verbal and tonal perception overlap strongly in the left superior temporal gyrus/sulcus (STG/STS) in AP musicians only. Second, AP is associated with the categorical perception of tones. Third, the left STG/STS is activated in AP musicians only for the detection of verbal‐tonal incongruencies in the auditory stroop task. Finally, verbal labelling of tones in AP musicians seems to be automatic. Overall, a unique feature of AP appears to be the similarity between verbal and tonal perception. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.     

Common deactivation patterns during working memory and visual attention tasks: an intra-subject fMRI study at 4 Tesla

This parametric functional magnetic resonance imaging (fMRI) study investigates the balance of negative and positive fMRI signals in the brain. A set of visual attention (VA) and working memory (WM) tasks with graded levels of difficulty was used to deactivate separate but overlapping networks that include the frontal, temporal, occipital, and limbic lobes; regions commonly associated with auditory and emotional processing. Brain activation (% signal change and volume) was larger for VA tasks than for WM tasks, but deactivation was larger for WM tasks. Load-related increases of blood oxygenation level-dependent (BOLD) responses for different levels of task difficulty cross-correlated strongly in the deactivated network during VA but less so during WM. The variability of the deactivated network across different cognitive tasks supports the hypothesis that global cerebral blood flow vary across different tasks, but not between different levels of task difficulty of the same task. The task-dependent balance of activation and deactivation might allow maximization of resources for the activated network.     

Differences and commonalities in the judgment of causality in physical and social contexts: An fMRI study

Understanding cause and effect is a fundamental aspect of human cognition. When shown videos of simple two-dimensional shapes colliding, humans experience one object causing the other to move, e.g., one billiard-like ball seeming to hit and move the other. The impression of causality can also occur when people attribute social interactions to moving objects. Whether the judgment of social and physical causality engages distinct or shared neural networks is not known. In a functional magnetic imaging (fMRI) study, participants were presented with two types of dynamic videos: a blue ball colliding with a red ball (P; physical condition) and a blue ball (“Mr. Blue”) passing a red ball (“Mrs. Red”) without making contact (S; social condition). Participants judged causal relationships (C) or movement direction (D; control task) in both video types, resulting in four conditions (PC; SC; PD; SD). We found common neural activations for physical and social causality judgments (SC>SD)∩(PC>PD) in the right middle/inferior frontal gyrus, right inferior parietal lobule, the right supplementary motor area, and bilateral insulae. For social causal judgments (SC>PC), we found distinct neural activity in the right temporo-parietal junction (rTPJ). These results provide evidence for a common neural network underlying judgments of causality that apply to both physical and social situations. The results also indicate that social causality judgments recruit additional neural resources in an area critical for determining animacy and intentionality.     

Neural mechanisms underlying urgent and evaluative behaviors: An fMRI study on the interaction of automatic and controlled processes

Dual‐process theories have dominated the study of risk perception and risk‐taking over the last two decades. However, there is a lack of objective brain‐level evidence supporting the two systems of processing in every‐day risky behavior. To address this issue, we propose the dissociation between evaluative and urgent behaviors as evidence of dual processing in risky driving situations. Our findings show a dissociation of evaluative and urgent behavior both at the behavioral and neural level. fMRI data showed an increase of activation in areas implicated in motor programming, emotional processing, and visuomotor integration in urgent behavior compared to evaluative behavior. These results support a more automatic processing of risk in urgent tasks, relying mainly on heuristics and experiential appraisal. The urgent task, which is characterized by strong time pressure and the possibility for negative consequences among others factors, creates a suitable context for the experiential‐affective system to guide the decision‐making process. Moreover, we observed greater frontal activation in the urgent task, suggesting the participation of cognitive control in safe behaviors. The findings of this research are relevant for the study of the neural mechanisms underlying dual process models in risky perception and decision‐making, especially because of their proximity to everyday activities. Hum Brain Mapp 36:2853–2864, 2015. © 2015 Wiley Periodicals, Inc.     

Top‐down and bottom‐up influences on the left ventral occipito‐temporal cortex during visual word recognition: An analysis of effective connectivity

The functional role of the left ventral occipito‐temporal cortex (vOT) in visual word processing has been studied extensively. A prominent observation is higher activation for unfamiliar but pronounceable letter strings compared to regular words in this region. Some functional accounts have interpreted this finding as driven by top‐down influences (e.g., Dehaene and Cohen [ 2011 ]: Trends Cogn Sci 15:254–262; Price and Devlin [ 2011 ]: Trends Cogn Sci 15:246–253), while others have suggested a difference in bottom‐up processing (e.g., Glezer et al. [ 2009 ]: Neuron 62:199–204; Kronbichler et al. [ 2007 ]: J Cogn Neurosci 19:1584–1594). We used dynamic causal modeling for fMRI data to test bottom‐up and top‐down influences on the left vOT during visual processing of regular words and unfamiliar letter strings. Regular words (e.g., taxi) and unfamiliar letter strings of pseudohomophones (e.g., taksi) were presented in the context of a phonological lexical decision task (i.e., “Does the item sound like a word?”). We found no differences in top‐down signaling, but a strong increase in bottom‐up signaling from the occipital cortex to the left vOT for pseudohomophones compared to words. This finding can be linked to functional accounts which assume that the left vOT contains neurons tuned to complex orthographic features such as morphemes or words [e.g., Dehaene and Cohen [ 2011 ]: Trends Cogn Sci 15:254‐262; Kronbichler et al. [ 2007 ]: J Cogn Neurosci 19:1584–1594]: For words, bottom‐up signals converge onto a matching orthographic representation in the left vOT. For pseudohomophones, the propagated signals do not converge, but (partially) activate multiple orthographic word representations, reflected in increased effective connectivity. Hum Brain Mapp 35:1668–1680, 2014. © 2013 Wiley Periodicals, Inc.     

Vicariously touching products through observing others' hand actions increases purchasing intention,and the effect of visual perspective in this process: An fMRI study

The growth of online shopping increases consumers' dependence on vicarious sensory experiences, such as observing others touching products in commercials. However, empirical evidence on whether observing others' sensory experiences increases purchasing intention is still scarce. In the present study, participants observed others interacting with products in the first‐ or third‐person perspective in video clips, and their neural responses were measured with functional magnetic resonance imaging (fMRI). We investigated (1) whether and how vicariously touching certain products affected purchasing intention, and the neural correlates of this process; and (2) how visual perspective interacts with vicarious tactility. Vicarious tactile experiences were manipulated by hand actions touching or not touching the products, while the visual perspective was manipulated by showing the hand actions either in first‐ or third‐person perspective. During the fMRI scanning, participants watched the video clips and rated their purchasing intention for each product. The results showed that, observing others touching (vs. not touching) the products increased purchasing intention, with vicarious neural responses found in mirror neuron systems (MNS) and lateral occipital complex (LOC). Moreover, the stronger neural activities in MNS was associated with higher purchasing intention. The effects of visual perspectives were found in left superior parietal lobule (SPL), while the interaction of tactility and visual perspective was shown in precuneus and precuneus‐LOC connectivity. The present study provides the first evidence that vicariously touching a given product increased purchasing intention and the neural activities in bilateral MNS, LOC, left SPL and precuneus are involved in this process. Hum Brain Mapp 39:332–343, 2018. © 2017 Wiley Periodicals, Inc.     

Neural adaptation to thin and fat bodies in the fusiform body area and middle occipital gyrus: An fMRI adaptation study

Visual perception can be strongly biased due to exposure to specific stimuli in the environment, often causing neural adaptation and visual aftereffects. In this study, we investigated whether adaptation to certain body shapes biases the perception of the own body shape. Furthermore, we aimed to evoke neural adaptation to certain body shapes. Participants completed a behavioral experiment (n = 14) to rate manipulated pictures of their own bodies after adaptation to demonstratively thin or fat pictures of their own bodies. The same stimuli were used in a second experiment (n = 16) using functional magnetic resonance imaging (fMRI) adaptation. In the behavioral experiment, after adapting to a thin picture of the own body participants also judged a thinner than actual body picture to be the most realistic and vice versa, resembling a typical aftereffect. The fusiform body area (FBA) and the right middle occipital gyrus (rMOG) show neural adaptation to specific body shapes while the extrastriate body area (EBA) bilaterally does not. The rMOG cluster is highly selective for bodies and perhaps body parts. The findings of the behavioral experiment support the existence of a perceptual body shape aftereffect, resulting from a specific adaptation to thin and fat pictures of one's own body. The fMRI results imply that body shape adaptation occurs in the FBA and the rMOG. The role of the EBA in body shape processing remains unclear. The results are also discussed in the light of clinical body image disturbances. Hum Brain Mapp 34:3233–3246, 2013. © 2012 Wiley Periodicals, Inc.