The Interplay of Bottom-Up Arousal and Attentional Capture during Auditory Scene Analysis: Evidence from Ocular Dynamics The auditory system plays a crucial role as the brain’s early warning system. Previous work has shown that the brain automatically monitors unfolding auditory scenes and rapidly detects new events. Here, we focus on understanding how automatic change detection interfaces with the networks that regulate arousal and attention, measuring pupil dilation (PD) as an indicator of listener arousal and microsaccades (MS) as an index of attentional sampling. Naive participants (N = 36, both sexes) were exposed to artificial “scenes” comprising multiple concurrent streams of pure tones while their ocular activity was monitored. The scenes were categorized as REG or RND, featuring isochronous (regular) or random temporal structures in the tone streams. Previous work showed that listeners are sensitive to predictable scene structure and use this information to facilitate change processing. Scene changes were introduced by either adding or removing a single tone stream. Results revealed distinct patterns in the recruitment of arousal and attention during auditory scene analysis. Sustained PD was reduced in REG scenes compared with RND, indicating reduced arousal in predictable contexts. However, no differences in sustained MS activity were observed between scene types, suggesting no differences in attentional engagement. Scene changes, though task-irrelevant, elicited PD as well as MS suppression, consistent with automatic attentional capture and increased arousal. Notably, only MS responses were modulated by scene regularity. This suggests that changes within predictable environments more effectively recruit attentional resources. Together, these findings offer novel insights into how automatic auditory scene analysis interacts with neural systems governing arousal and attention.
The possibilities of conscious experience in light of the dual origin hypothesis of the neocortex According to contemporary psycho- and physiological perspectives, the brain supports our experience of the world by constantly anticipating what may happen next. In this context, limbic mesocortical areas have been proposed to play a key domain-general role in cortical processing, holding highly abstract content that may be efficiently broadcasted to virtually the whole brain, ultimately integrating interoception into a unified field of experience from the point of view of someone who has a body. Here we ground the evolutionary basis of such structural and functional organization in the hypothesis of the dual origin of the neocortex, suggesting that the addition of phylogenetically newer cortical types with modality-specific processing may have enabled the primitive polysensory role of limbic mesocortical areas to evolve into a multimodal coordinator within an ever more complex brain, favoring the possibilities of conscious experience. Moreover, two fundamental functional axes with relevance for allostasis emerge: (i) a navigation/spatial versus exchange/contact axis; and (ii) a sensing versus acting axis. The former summarizes a fundamental distinction between spatial navigation and musculoskeletal control versus close interactions in the intimate and internal spheres; the latter reflects a functional (although intimately linked) distinction between sensory and motor aspects. These axes define a conceptual bidimensional space across cortical types where virtually all cortical areas may be placed according to their functional relevance, with limbic mesocortices ultimately integrating experience across sensory-motor function and navigation-exchange. These notions have important implications for our understanding of allostasis and human experience.
The sense of agency in near and far space: where do we stand? Modern technology frequently places the consequences of our actions at a distance (e.g. remote surgery, smart-home control, virtual reality). Does spatial distance between an action and its outcome weaken the sense of agency (SoA) – the feeling of control over one’s actions and consequences? Two recent studies, by Jenkins and Obhi and Mariano et al., answered “yes,” reporting stronger temporal binding (TB) in near than far space and interpreting this as greater implicit agency. A third study – our own work with a similar paradigm – found no distance effect. Here we (i) provide a rigorous side-by-side methodological comparison of the three studies, (ii) argue why a direct test to establish a distance modulation of TB (the Near – Far difference of the Active – Passive delta) should be performed in order to reach meaningful conclusions, and (iii) report new reanalyses of our data and direct tests on the two target studies. Overall, current evidence does not support a distance effect on SoA. Our reassessment provides alternative explanations that converge with available evidence suggesting that distance may influence temporal interval perception, but that effect is independent of action intention and therefore of agency.
Poetry of coordinated motion: The beauty of dance lies in the physics of the movement What is perceived as beautiful movement in dance? We investigated quantitative relations between the subjective experience of observing dance and objective physical variables. By integrating datasets from perceptual psychophysics and movement biomechanics, we explored how the control, coordination and energetics of dance movements, which represent dance skill, related to perceptual judgements of a naïve audience. Multidimensional perceptual ratings of dance were found to distil statistically into a single Gestalt, ‘aesthetic value’ (or beauty), which was systematically related to multiple physical variables. Higher aesthetic value was attributed to more-skilled dancers demonstrating greater amplitude and speed of motion, with coordinated and economical execution. These findings thus are consistent with the Romantic conception of beauty being related to vitality. Moreover, the enhanced coordination and economy of these skilled movements align with the Classical conception, endorsed by Plato, Aristotle and Leibniz, that beauty is measurable (quantifiable), proportionate (mathematical) and encompasses harmony and symmetry. Historically, the lack of technology to measure the dynamic qualities of dance movement in three-dimensional space meant that it was not possible to corroborate empirically this classical perspective, which is substantiated here for the first time. Overall, the findings support an evolutionary framework, whereby a dancer’s aesthetic value to observers reflects the quality of their vigour and neuromuscular function, the dominant perceptual factor influencing mate selection thus being the beauty of dance performance, driven by dancer skill.
A forebrain hub for cautious actions via the midbrain Adaptive goal-directed behavior requires dynamic coordination of movement, motivation, and environmental cues. Among these, cautious actions, where animals adjust their behavior in anticipation of predictable threats, are essential for survival. Yet, their underlying neural mechanisms remain less well understood than those of appetitive behaviors, where caution plays little role. Using calcium imaging in freely moving mice, we show that glutamatergic neurons in the subthalamic nucleus (STN) are robustly engaged by contraversive movement during cue-evoked avoidance and exploratory behavior. Model-based analyses controlling for movement and other covariates revealed that STN neurons additionally encode salient sensory cues, punished errors, and especially cautious responding, where their activity anticipates avoidance actions. Targeted lesions and optogenetic manipulations reveal that STN projections to the midbrain are necessary for executing cued avoidance. These findings identify a critical role for the STN in orchestrating adaptive goal-directed behavior by integrating sensory, motor, and punitive signals to guide timely, cautious actions via its midbrain projections.
Instrumental learning enhances the intrinsic excitability of basal amygdala projection neurons The basolateral amygdala (BLA) is critical for Pavlovian and instrumental emotional association learning. Pavlovian fear conditioning is accompanied by increased excitability of BLA neurons. Here we tested whether instrumental learning similarly enhances BLA excitability. Electrophysiological recordings were taken from BLA neurons in brain slices prepared from instrumentally trained Long–Evans rats. Both reward and punishment training increased intrinsic excitability. Moreover, excitability positively correlated with performance on the punishment task, suggesting a functional link between neuronal excitability and learning. These findings support the idea that enhanced excitability facilitates synaptic plasticity and circuit integration during instrumental learning.
Increased Baseline Pupil Size Linked to Uncertainty Avoidance in Decision Making Uncertainty is a key contributor to decision making, and humans show inconsistent attitudes towards it. Although excessive uncertainty-avoidance or uncertainty-seeking are hallmark symptoms of several mental conditions, the neural mechanism underlying uncertainty seeking and avoidance remains unclear. Here, we probed whether changes in pupil-linked arousal are indicative of uncertainty avoidance in humans. Investigating baseline pupil size to capture endogenous fluctuations across two experiments (N1 = 24, N2 = 21), we found that pretrial pupillary responses (as early as 700 ms prior to the onset of a trial) were closely related to uncertainty attitudes during multiarmed bandit tasks. Although increased baseline pupil size signalled avoidance in uncertainty-related decisions, it did not foreshadow value processing per se. The specificity of our results suggests that uncertainty processing is dynamic and depends on (potentially noradrenergic) endogenous pupil fluctuations.
Experience-driven Predictability Does Not Influence Neural Entrainment to the Beat Humans spontaneously synchronize movements to a perceived underlying pulse, or beat, in music. Beat perception may be indexed by the synchronization of neural oscillations to the beat, marked by increases in EEG amplitude at the beat frequency [Nozaradan, S., Peretz, I., Missal, M., & Mouraux, A. Tagging the neuronal entrainment to beat and meter. Journal of Neuroscience, 31, 10234–10240, 2011]. Indeed, neural synchronization to the beat appears stronger for strong-beat than non-beat rhythms [Tal, I., Large, E. W., Rabinovitch, E., Wei, Y., Schroeder, C. E., Poeppel, D., et al. Neural entrainment to the beat: The “missing-pulse” phenomenon. Journal of Neuroscience, 37, 6331–6341, 2017] and may underlie the generation of an internal representation of beat. However, because we are exposed disproportionately to strong-beat rhythms (e.g., most Western music) in the environment, comparisons of neural responses to strong-beat and non-beat rhythms may be confounded by relative differences in familiarity. Here, we dissociated beat-related and familiarity-related neural responses by comparing EEG amplitudes during the perception of strong-beat and non-beat rhythms that were either novel or made familiar through training. First, we recorded EEG from participants while they listened to a set of strong-beat, weak-beat, and non-beat rhythms. Then, they were trained on half of the rhythms over four behavioral sessions by listening to and tapping along with them, such that half of the rhythms were familiar by the end of training. Finally, EEG responses to the full rhythm set (half now familiar, half still unfamiliar) were recorded posttraining. Results show no effect of training on EEG amplitude at beat or stimulus-related frequencies and little evidence of familiarity-driven changes in EEG amplitude for weak- and non-beat rhythms. This suggests that oscillatory entrainment to the beat is not driven by familiarity and therefore likely reflects beat processing.