How do people grasp the abstract concept of time? It has been argued that abstract concepts, such as future and past, are grounded in sensorimotor experience. When responses to words that refer to ...the past or the future are either spatially compatible or incompatible with a left-to-right timeline, a space-time congruency effect is observed. In the present study, we investigated whether reading expertise determines the strength of the space-time congruency effect, which would suggest that learning to read and write drives the effect. Using a temporal categorization task, we compared two types of space-time congruency effects, one where spatial incongruency was generated by the location of the stimuli on the screen and one where it was generated by the location of the responses on the keyboard. While the first type of incongruency was visuo-spatial only, the second involved the motor system. Results showed stronger space-time congruency effects for the second type of incongruency (i.e., when the motor system was involved) than for the first type (visuo-spatial). Crucially, reading expertise, as measured by a standardized reading test, predicted the size of the space-time congruency effects. Altogether, these results reinforce the claim that the spatial representation of time is partially mediated by the motor system and partially grounded in spatially-directed movement, such as reading or writing.
Blood oxygen level-dependent functional MRI (fMRI) constitutes a powerful neuroimaging technology to map brain-wide functions in response to specific sensory or cognitive tasks. However, fMRI mapping ...of the vestibular system, which is pivotal for our sense of balance, poses significant challenges. Physical constraints limit a subject’s ability to perform motion- and balance-related tasks inside the scanner, and current stimulation techniques within the scanner are nonspecific to delineate complex vestibular nucleus (VN) pathways. Using fMRI, we examined brain-wide neural activity patterns elicited by optogenetically stimulating excitatory neurons of a major vestibular nucleus, the ipsilateral medial VN (MVN). We demonstrated robust optogenetically evoked fMRI activations bilaterally at sensorimotor cortices and their associated thalamic nuclei (auditory, visual, somatosensory, and motor), high-order cortices (cingulate, retrosplenial, temporal association, and parietal), and hippocampal formations (dentate gyrus, entorhinal cortex, and subiculum). We then examined the modulatory effects of the vestibular system on sensory processing using auditory and visual stimulation in combination with optogenetic excitation of the MVN. We found enhanced responses to sound in the auditory cortex, thalamus, and inferior colliculus ipsilateral to the stimulated MVN. In the visual pathway, we observed enhanced responses to visual stimuli in the ipsilateral visual cortex, thalamus, and contralateral superior colliculus. Taken together, our imaging findings reveal multiple brain-wide central vestibular pathways. We demonstrate large-scale modulatory effects of the vestibular system on sensory processing.
The concept of affordance refers to the opportunities for action provided by the environment, often conveyed through visual information. It has been applied to explain visuomotor processing and ...movement planning. As emotion modulates both visual perception and the motor system, it is reasonable to ask whether emotion can influence affordance judgments. If present, this relationship can have important ontological implications for affordances. Thus, we investigated whether the emotional value of manipulable objects affected the judgment of the appropriate grasping that could be used to interact with them (i.e., their affordance).
Volunteers were instructed to use a numerical scale to report their judgment on how an observed object should be grasped. We compared these judgments across emotional categories of objects (pleasant, unpleasant and neutral), while also considering the expected effect of object size.
We found that unpleasant objects were rated as more appropriately graspable by a precision grip than pleasant and neutral objects. Simultaneously, smaller object size also favored this judgment. This effect was seen in all emotional categories examined in equal magnitude.
Our findings suggest that the emotional value of objects modulates affordance judgments in a way that favors careful manipulation and minimal physical contact with aversive stimuli. Finally, we discuss how this affective aspect of our experience of objects overlaps with what affordances are conceptualized to be, calling for further reexamination of the relationship between affordances and emotions.
•The thalamus has extensive functional connectivity to nine cortical resting state networks.•Thalamo-cortical connectivity strength decreases from childhood to early adulthood (5–25 ...y/o).•Thalamo-cortical connectivity strength is associated with cognitive abilities.
The thalamus has complex connections with the cortex and is involved in various cognitive processes. However, little is known about the age-related changes of thalamo-cortical connections and their relation to cognitive abilities. The present study analyzed resting-state functional connectivity between the thalamus and nine cortical functional networks (default mode network (DMN), posterior DMN, left/right executive, dorsal attention, salience, motor, visual and auditory network) in a healthy human sample (N = 95, aged 5–25 years). Cognitive abilities, including processing speed, selective attention, and cognitive flexibility were assessed using neuropsychological tests. All nine cortical resting-state networks showed functional connections to the thalamus at rest, with no effect for sex (p > 0.05). For the motor, visual, auditory, DMN, posterior DMN, salience and dorsal attention network, we found mainly bilateral thalamic projections in the mediodorsal nucleus, pulvinar and in nuclei of the lateral group. For the right and left lateralized executive network, corresponding lateralized thalamic projections were found. Thalamo-cortical connectivity strength showed significant age-related changes from distinct sub-nuclei of the thalamus to different cortical networks including the visual, DMN, salience and dorsal attention network. Further, connectivity strength of thalamo-cortical networks was associated with cognitive abilities, including processing speed, selective attention and cognitive flexibility. Better cognitive abilities were associated with increased thalamo-cortical connectivity in the pulvinar, mediodorsal nucleus, intralaminar nucleus, and nuclei from the lateral group. Alterations in the integrity of the thalamo-cortical system seem to be crucial for the development of cognitive abilities during brain maturation.
Abstract
Mitochondrial calcium (Ca
2+
mito
) dynamics plays vital roles in regulating fundamental cellular and organellar functions including bioenergetics. However, neuronal Ca
2+
mito
dynamics in ...vivo and its regulation by brain activity are largely unknown. By performing two-photon Ca
2+
imaging in the primary motor (M1) and visual cortexes (V1) of awake behaving mice, we find that discrete Ca
2+
mito
transients occur synchronously over somatic and dendritic mitochondrial network, and couple with cytosolic calcium (Ca
2+
cyto
) transients in a probabilistic, rather than deterministic manner. The amplitude, duration, and frequency of Ca
2+
cyto
transients constitute important determinants of the coupling, and the coupling fidelity is greatly increased during treadmill running (in M1 neurons) and visual stimulation (in V1 neurons). Moreover, Ca
2+
/calmodulin kinase II is mechanistically involved in modulating the dynamic coupling process. Thus, activity-dependent dynamic Ca
2+
mito
-to-Ca
2+
cyto
coupling affords an important mechanism whereby Ca
2+
mito
decodes brain activity for the regulation of mitochondrial bioenergetics to meet fluctuating neuronal energy demands as well as for neuronal information processing.
Virtual realities are powerful tools to analyze and manipulate interactions between animals and their environment and to enable measurements of neuronal activity during behavior. In many species, ...however, optical access to the brain and/or the behavioral repertoire are limited. We developed a high-resolution virtual reality for head-restrained adult zebrafish, which exhibit cognitive behaviors not shown by larvae. We noninvasively measured activity throughout the dorsal telencephalon by multiphoton calcium imaging. Fish in the virtual reality showed regular swimming patterns and were attracted to animations of conspecifics. Manipulations of visuo-motor feedback revealed neurons that responded selectively to the mismatch between the expected and the actual visual consequences of motor output. Such error signals were prominent in multiple telencephalic areas, consistent with models of predictive processing. A virtual reality system for adult zebrafish therefore provides opportunities to analyze neuronal processing mechanisms underlying higher brain functions including decision making, associative learning, and social interactions.
To date, interlimb transfer following visuomotor adaptation has been mainly investigated through discrete reaching movements. Here we explored this issue in the context of continuous manual tracking, ...a task in which the contribution of online feedback mechanisms is crucial, and in which there is a well-established right (dominant) hand advantage under baseline conditions. We had two objectives (1) to determine whether this preexisting hand asymmetry would persist under visuomotor rotation, (2) to examine interlimb transfer by assessing whether prior experience with the rotation by one hand benefit to the other hand. To address these, 44 right-handed participants were asked to move a joystick and to track a visual target following a rather unpredictable trajectory. Visuomotor adaptation was elicited by introducing a 90° rotation between the joystick motion and the cursor motion. Half of the participants adapted to the rotation first with the right hand, and then with the left, while the other half performed the opposite protocol. As expected during baseline trials, the left hand was less accurate while also exhibiting more variable and exploratory behavior. However, participants exhibited a left hand advantage during first exposure to the rotation. Moreover, interlimb transfer was observed albeit more strongly from the left to the right hand. We suggest that the less effective and more variable/exploratory control strategy of the left hand promoted its adaptation, which incidentally favored transfer from left to right hand. Altogether, this study speaks for further attention to the dominant/non-dominant asymmetry during baseline before examining interlimb transfer of adaptation.
Wine flavour has been methodically studied since the beginning of sensory research, with various purposes relating to product quality and consumer preferences. Recent advances in neuroscience have ...provided a deeper insight into how the perceptions elicited by flavour-active molecules are processed by the brain. In particular, the implications of the synthetic, emotional and mental imagery features of olfaction, together with the cross-modal influences on flavour perception, should be properly acknowledged in tasting methods.
The purpose of this review is to present a critical appraisal of current tasting methods, with focus on those that are most frequently applied to assess fine wine. The remarkable ability to distinguish odours, and the emotional nature of the sense of smell, are the basis for the development of alternative tasting approaches that have lead to recent advances. The limitations of aroma and flavour descriptive analysis resulting from the synthetic nature of olfaction will be discussed and, in particular, those limitations that relate to the holistic evaluation of quality that constitutes the core of aesthetic judgements.
We argue that the conventional tasting sequence and the dominance given to descriptive analysis contributes to the subordination of the holistic nature of wine assessment. Further, expert quality judgements may be strongly biased by cognitive factors and wine preferences. Hence, the highest level of expertise may be attained when individuals are able to recognise a fine wine's synthetic properties (e.g. complexity, harmony, persistence) in association with socio-cultural aspects (e.g. origin, winemaking traditions), and then produce aesthetic judgements independently from wine enjoyment.
Overall, fine wines may be defined as those characterized by superior synthetic or holistic properties that are perceived and appreciated by individuals who understand, and in the context of, their cultural meaning.
•Wine aroma is dependent on a few number of key odourants.•In experts cognition affects sensory perception.•Fine wines may be regarded as aesthetic objects.•The core of expertise corresponds to the ability to separate preference from aesthetic evaluation.•Tasting learning should include emotional responses.
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