Neuropsychologia最新文献

Language is a key part of human cognition, essential for our well-being at all stages of our lives. Whereas many neurocognitive abilities decline with age, for language the picture is much less clear, and how exactly speech comprehension changes with ageing is still unknown. To investigate this, we employed magnetoencephalography (MEG) and recorded neuromagnetic brain responses to auditory linguistic stimuli in healthy participants of younger and older age using a passive task-free paradigm and a range of different linguistic stimulus contrasts, which enabled us to assess neural processing of spoken language at multiple levels (lexical, semantic, morphosyntactic). Using machine learning-based classification algorithms to scrutinise intertrial phase coherence of MEG responses in cortical source space, we found that patterns of oscillatory neural activity diverged between younger and older participants across several frequency bands (alpha, beta, gamma) for all tested linguistic information types. The results suggest multiple age-related changes in the brain's neurolinguistic circuits, which may be due to both healthy ageing in general and compensatory processes in particular.

The recognition of objects is strongly facilitated when they are presented in the context of other objects (Biederman, 1972). Such contexts facilitate perception and induce expectations of context-congruent objects (Trapp and Bar, 2015). The neural mechanisms underlying these facilitatory effects of context on object processing, however, are not yet fully understood. In the present study, we investigate how context-induced expectations affect subsequent object processing. We used functional magnetic resonance imaging and measured repetition suppression as a proxy for prediction error processing. Participants viewed pairs of alternating or repeated object images which were preceded by context-congruent, context-incongruent or neutral cues. We found a stronger repetition suppression in congruent as compared to incongruent or neutral cues in the object sensitive lateral occipital cortex. Interestingly, this stronger effect was driven by enhanced responses to alternating stimulus pairs in the congruent contexts, rather than by suppressed responses to repeated stimulus pairs, which emphasizes the contribution of surprise-related response enhancement for the context modulation on RS when expectations are violated. In addition, in the congruent condition, we discovered significant functional connectivity between object-responsive and frontal cortical regions, as well as between object-responsive regions and the fusiform gyrus. Our findings indicate that prediction errors, reflected in enhanced brain responses to violated contextual expectations, underlie the facilitating effect of context during object perception.

The aspiration for insight into human cognitive processing has traditionally driven research in cognitive science. With methods such as the Hidden semi-Markov Model-Electroencephalography (HsMM-EEG) method, new approaches have been developed that help to understand the temporal structure of cognition by identifying temporally discrete processing stages. However, it remains challenging to assign concrete functional contributions by specific processing stages to the overall cognitive process. In this paper, we address this challenge by linking HsMM-EEG³ with cognitive modelling, with the aim of further validating the HsMM-EEG³ method and demonstrating the potential of cognitive models to facilitate functional interpretation of processing stages. For this purpose, we applied HsMM-EEG³ to data from a mental rotation task and developed an ACT-R cognitive model that is able to closely replicate human performance in this task. Applying HsMM-EEG³ to the mental rotation experiment data revealed a strong likelihood for 6 distinct stages of cognitive processing during trials, with an additional stage for non-rotated conditions. The cognitive model predicted intra-trial mental activity patterns that project well onto the processing stages, while explaining the additional stage as a marker of non-spatial shortcut use. Thereby, this combined methodology provided substantially more information than either method by itself and suggests conclusions for cognitive processing in general.

Non-arbitrary mapping between the sound of a word and its meaning, termed sound symbolism, is commonly studied through crossmodal correspondences between sounds and visual shapes, e.g., auditory pseudowords, like ‘mohloh’ and ‘kehteh’, are matched to rounded and pointed visual shapes, respectively. Here, we used functional magnetic resonance imaging (fMRI) during a crossmodal matching task to investigate the hypotheses that sound symbolism (1) involves language processing; (2) depends on multisensory integration; (3) reflects embodiment of speech in hand movements. These hypotheses lead to corresponding neuroanatomical predictions of crossmodal congruency effects in (1) the language network; (2) areas mediating multisensory processing, including visual and auditory cortex; (3) regions responsible for sensorimotor control of the hand and mouth. Right-handed participants (n = 22) encountered audiovisual stimuli comprising a simultaneously presented visual shape (rounded or pointed) and an auditory pseudoword (‘mohloh’ or ‘kehteh’) and indicated via a right-hand keypress whether the stimuli matched or not. Reaction times were faster for congruent than incongruent stimuli. Univariate analysis showed that activity was greater for the congruent compared to the incongruent condition in the left primary and association auditory cortex, and left anterior fusiform/parahippocampal gyri. Multivoxel pattern analysis revealed higher classification accuracy for the audiovisual stimuli when congruent than when incongruent, in the pars opercularis of the left inferior frontal (Broca's area), the left supramarginal, and the right mid-occipital gyri. These findings, considered in relation to the neuroanatomical predictions, support the first two hypotheses and suggest that sound symbolism involves both language processing and multisensory integration.

Objective

Openness to experience has been consistently associated with better cognitive functioning in older people, but its association with cognitive decline is less clear. Cognitive reserve has been proposed as a mechanism underlying this relationship, but previous studies have reported mixed findings, possibly due to the different ways of conceptualizing cognitive reserve. We aimed to analyze the potential mediating role of cognitive reserve in the association between openness and cognitive functioning and decline in healthy older people.

Method

In Wave 1 and at the four-year follow-up (Wave 2), 87 healthy older people (49.4% women; M age = 65.08, SD = 4.54) completed a neuropsychological battery to assess cognitive functioning and a questionnaire to assess cognitive reserve. Openness was measured with the NEO- Five-Factor Inventory. Mediation models were proposed to investigate the relationship between openness and cognitive function or decline through cognitive reserve or its change.

Results

Cognitive reserve mediated the openness-cognitive functioning association. Thus, individuals with higher openness showed greater cognitive reserve, and this greater cognitive reserve was associated with better cognitive functioning. Moreover, greater cognitive reserve at baseline also mediated the association between higher openness and slower cognitive decline. However, change in cognitive reserve did not mediate the association between openness and change in cognitive functioning.

Conclusions

Cognitive reserve is a mechanism underlying the association between openness and cognitive functioning and decline. These findings support the differential preservation hypothesis, suggesting that healthy older adults who engage in more cognitively stimulating activities would show less age-related cognitive decline.

Faces and Chinese characters are both objects of perceptual expertise. In this study, we investigated the characteristics of interhemispheric transmission times (IHTTs) in both transmission direction and transmission efficiency during the processing of objects of perceptual expertise. A total of 112 participants engaged in a divided visual field paradigm for faces, Chinese characters, and houses in both upright and inverted orientations. The N170 amplitudes elicited by the objects of perceptual expertise (faces and Chinese characters) involved in this study were larger than those elicited by the non-perceptual expertise objects (houses). We used the latencies of the N170 component of the event-related potential (ERP) recorded in the left and right hemispheres to calculate the IHTTs. For all objects, the N170-related IHTTs from the right to the left hemispheres were shorter than those in the opposite direction. Essentially, the N170-related IHTTs for faces were shorter, that is, more efficient than those for Chinese characters and houses. This result indicates that the IHTTs during perceptual expertise and non-perceptual expertise object processing share a common transmission direction advantage, but transmission efficiency is face-specific.

In earlier work with adults, we showed that long-term phonemic representations are audiovisual, meaning that they contain information on typical mouth shape during articulation. Many aspects of audiovisual processing have a prolonged developmental course, often not reaching maturity until late adolescence. In this study, we examined the status of phonemic representations in two groups of children – 8-9-year-olds and 11-12-year-olds. We used the same audiovisual oddball paradigm as in the earlier study with adults (Kaganovich and Christ, 2021). On each trial, participants saw a face and heard one of two vowels. One vowel occurred frequently (standard), while another occurred rarely (deviant). In one condition (neutral), the face had a closed, non-articulating mouth. In the other condition (audiovisual violation), the mouth shape matched the frequent vowel. Although stimuli were audiovisual in both conditions, we hypothesized that identical auditory changes would be perceived differently by participants. Namely, in the neutral condition, deviants violated only the audiovisual pattern specific to each experimental block. By contrast, in the audiovisual violation condition, deviants additionally violated long-term representations for how a speaker's mouth looks during articulation. We compared the amplitude of MMN and P3 components elicited by deviants in the two conditions. In the 11-12-year-old group, the pattern of neural responses was similar to that in adults – namely, they had a larger MMN component in the audiovisual compared to neutral condition, with no major difference in the P3 amplitude. In contrast, in the 8-9-year-old group, we saw a posterior MMN in the neutral condition only and a larger P3 in the audiovisual violation compared to the neutral condition. The larger P3 in the audiovisual violation condition suggests that younger children did perceive deviants as being more attention-grabbing when they violated the typical combination of sound and mouth shape. Yet, at this age, the earlier, more automatic stages of phonemic processing indexed by the MMN component may not yet encode visual speech elements the same way they do in older children and adults. We conclude that phonemic representations do not become audiovisual until 11–12 years of age.

Narratives may be regarded as simulations of everyday social situations. They are key to studying the human mind in socio-culturally determined contexts as they allow anchoring to the common ground of embodied and environmentally-engaged cognition. Here we review recent findings from naturalistic neuroscience on neural functions in conditions that mimic lifelike situations. We will focus particularly on neurocinematics, a research field that applies mediated narratives as stimuli for neuroimaging experiments. During the last two decades, this paradigm has contributed to an accumulation of insights about the neural underpinnings of behavior and sense-making in various narratively contextualized situations particularly pertaining to socio-emotional encounters. One of the key questions in neurocinematics is, how do intersubjectively synchronized brain activations relate to subjective experiences? Another question we address is how to bring natural contexts into experimental studies. Seeking to respond to both questions, we suggest neurocinematic studies to examine three manifestations of the same phenomenon side-by-side: subjective experiences of narrative situations, unfolding of narrative stimulus structure, and neural processes that co-constitute the experience. This approach facilitates identifying experientially meaningful activity patterns in the brain and points out what they may mean in relation to shared and communicable contents. Via rich-featured and temporally contextualized narrative stimuli, neurocinematics attempts to contribute to emerging holistic theories of neural dynamics and connectomics explaining typical and atypical interindividual variability.

A major issue concerning inflectional encoding in spoken word production is whether or not regular forms (e.g., past tense walked) are encoded by rule application and irregular forms (e.g., swam) by retrieval from associative memory and inhibition of the regular rule. We used functional magnetic resonance imaging (fMRI) to examine the involvement of domain-general inhibition, thought to be underpinned by right inferior frontal gyrus (IFG), right pre-supplementary motor area (SMA), and right basal ganglia. Participants were presented with infinitive verbs that take either regular or irregular past tense. They switched between producing the past tense of these regular and irregular verbs in one block, and between inflecting or reading these infinitive verbs aloud in another block. As concerns corticobasal areas, compared to reading, inflecting activated left IFG and left preSMA/SMA. Regulars yielded higher activation than irregulars in these frontal areas, both on switch and repeat trials, which did not differ in activation. Switching between inflecting and reading activated left preSMA/SMA. These results indicate that inflectional encoding, and switching between inflecting and reading, engage frontal areas in the left hemisphere, including left preSMA/SMA for both and left IFG for inflecting, without recruiting the domain-general inhibition circuitry in the right hemisphere. We advance an account of inflectional encoding in spoken word production that assumes a distinction between regulars and irregulars, but without engaging domain-general inhibition.

Background

The hemispheric contributions toward interoception, the perception of internal bodily cues, and emotion recognition remains unclear. Semantic dementia cases with either left-dominant (i.e., left-SD) or right-dominant (i.e., right-SD) anterior temporal lobe atrophy experience emotion recognition difficulties, however, little is known about interoception in these syndromes. Here, we hypothesised that right-SD would show worse interoception and emotion recognition due to right-dominant atrophy.

Methods

Thirty-five participants (8 left-SD; 6 right-SD; 21 controls) completed a monitoring task. Participants pressed a button when they: (1) felt their heartbeat, without pulse measurement (Interoception); or (2) heard a recorded heartbeat (Exteroception-control). Simultaneous ECG was recorded. Accuracy was calculated by comparing the event frequency (i.e., heartbeat or sound) to response frequency. Emotion recognition was assessed via the Facial Affect Selection Task. Voxel-based morphometry analyses identified neural correlates of interoception and emotion recognition.

Results

Right-SD showed worse interoception than controls and left-SD (both p's < 0.001). Both patient groups showed worse emotion recognition than controls (right-SD: p < .001; left-SD: p = .018), and right-SD showed worse emotion recognition than left-SD (p = .003). Regression analyses revealed that worse emotion recognition was predicted by right-SD (p = .002), left-SD (p = .005), and impaired interoception (p = .004). Interoception and emotion were associated with the integrity of right-lateralised structures including the insula, temporal pole, thalamus, superior temporal gyrus, and hippocampus.

Conclusion

Our study provides the first evidence for impaired interoception in right-SD, suggesting that impaired emotion recognition in this syndrome is driven by inaccurate internal monitoring. Further we identified a common neurobiological basis for interoception and emotion in the right hemisphere.