Top-down modulation of sensory processing allows the animal to select inputs most relevant to current tasks. We found that the cingulate (Cg) region of the mouse frontal cortex powerfully influences ...sensory processing in the primary visual cortex (V1) through long-range projections that activate local γ-aminobutyric acid–ergic (GABAergic) circuits. Optogenetic activation of Cg neurons enhanced V1 neuron responses and improved visual discrimination. Focal activation of Cg axons in V1 caused a response increase at the activation site but a decrease at nearby locations (center-surround modulation). Whereas somatostatin-positive GABAergic interneurons contributed preferentially to surround suppression, vasoactive intestinal peptide-positive interneurons were crucial for center facilitation. Long-range corticocortical projections thus act through local microcircuits to exert spatially specific top-down modulation of sensory processing.
Rethinking Food Reward de Araujo, Ivan E; Schatzker, Mark; Small, Dana M
Annual review of psychology,
01/2020, Letnik:
71, Številka:
1
Journal Article
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The conscious perception of the hedonic sensory properties of caloric foods is commonly believed to guide our dietary choices. Current and traditional models implicate the consciously perceived ...hedonic qualities of food as driving overeating, whereas subliminal signals arising from the gut would curb our uncontrolled desire for calories. Here we review recent animal and human studies that support a markedly different model for food reward. These findings reveal in particular the existence of subcortical body-to-brain neural pathways linking gastrointestinal nutrient sensors to the brain's reward regions. Unexpectedly, consciously perceptible hedonic qualities appear to play a less relevant, and mostly transient, role in food reinforcement. In this model, gut-brain reward pathways bypass cranial taste and aroma sensory receptors and the cortical networks that give rise to flavor perception. They instead reinforce behaviors independently of the cognitive processes that support overt insights into the nature of our dietary decisions.
Can what we know change what we see? Does language affect cognition and perception? The last few years have seen increased attention to these seemingly disparate questions, but with little ...theoretical advance. We argue that substantial clarity can be gained by considering these questions through the lens of predictive processing, a framework in which mental representations—from the perceptual to the cognitive—reflect an interplay between downwardflowing predictions and upward-flowing sensory signals. This framework provides a parsimonious account of how (and when) what we know ought to change what we see and helps us understand how a putatively high-level trait such as language can impact putatively low-level processes such as perception. Within this framework, language begins to take on a surprisingly central role in cognition by providing a uniquely focused and flexible means of constructing predictions against which sensory signals can be evaluated. Predictive processing thus provides a plausible mechanism for many of the reported effects of language on perception, thought, and action, and new insights on how and when speakers of different languages construct the same "reality" in alternate ways.
The Self-Evidencing Brain Hohwy, Jakob
Noûs (Bloomington, Indiana),
June 2016, Letnik:
50, Številka:
2
Journal Article
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An exciting theory in neuroscience is that the brain is an organ for prediction error minimization (PEM). This theory is rapidly gaining influence and is set to dominate the science of mind and brain ...in the years to come. PEM has extreme explanatory ambition, and profound philosophical implications. Here, I assume the theory, briefly explain it, and then I argue that PEM implies that the brain is essentially self-evidencing. This means it is imperative to identify an evidentiary boundary between the brain and its environment. This boundary defines the mindworld relation, opens the door to skepticism, and makes the mind transpire as more inferentially secluded and neurocentrically skull-bound than many would nowadays think. Therefore, PEM somewhat deflates contemporary hypotheses that cognition is extended, embodied and enactive; however, it can nevertheless accommodate the kinds of cases that fuel these hypotheses.
This is a review of the proprioceptive senses generated as a result of our own actions. They include the senses of position and movement of our limbs and trunk, the sense of effort, the sense of ...force, and the sense of heaviness. Receptors involved in proprioception are located in skin, muscles, and joints. Information about limb position and movement is not generated by individual receptors, but by populations of afferents. Afferent signals generated during a movement are processed to code for endpoint position of a limb. The afferent input is referred to a central body map to determine the location of the limbs in space. Experimental phantom limbs, produced by blocking peripheral nerves, have shown that motor areas in the brain are able to generate conscious sensations of limb displacement and movement in the absence of any sensory input. In the normal limb tendon organs and possibly also muscle spindles contribute to the senses of force and heaviness. Exercise can disturb proprioception, and this has implications for musculoskeletal injuries. Proprioceptive senses, particularly of limb position and movement, deteriorate with age and are associated with an increased risk of falls in the elderly. The more recent information available on proprioception has given a better understanding of the mechanisms underlying these senses as well as providing new insight into a range of clinical conditions.
The objective of this study was to explore the production of an expanded snack entirely based on pea- and oat-rich fractions using the extrusion technology. The effect of the die temperature, HZ6 ...(146–175 °C) and blend moisture content, MC (11.2 and 16.8% dry basis) were investigated aiming at maximizing expansion, while obtaining a good texture and pleasant sensory perception. The best response was obtained with a HZ6 of 160 °C and MC of 11.2%. MC was the parameter that most influenced final extrudate properties/responses. The gross composition of the raw-material was not modified by extrusion processing apart from a decrease in glucose and fructose content attributed to Maillard reactions. The snacks contained 3.5 g of β-glucan per portion. This is high enough for both approved EFSA health claims: lowers cholesterol and reduces post-prandial glucose response.
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•Successful production of expanded extrudates based on pea- and oat-fractions.•Blend moisture content had the greatest impact of extrudate properties.•Higher porosity and brownish color were obtained for highly expanded extrudates.•Sensory attributes highly correlated with those determined by texture analysis.•β-glucan molecular weight slightly reduced at highest Specific Mechanical Energy.
Visual illusion susceptibility in autism: A neural model Park, Sangwook; Zikopoulos, Basilis; Yazdanbakhsh, Arash
European journal of neuroscience/EJN. European journal of neuroscience,
August 2022, Letnik:
56, Številka:
3
Journal Article
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While atypical sensory perception is reported among individuals with autism spectrum disorder (ASD), the underlying neural mechanisms of autism that give rise to disruptions in sensory perception ...remain unclear. We developed a neural model with key physiological, functional and neuroanatomical parameters to investigate mechanisms underlying the range of representations of visual illusions related to orientation perception in typically developed subjects compared to individuals with ASD. Our results showed that two theorized autistic traits, excitation/inhibition imbalance and weakening of top‐down modulation, could be potential candidates for reduced susceptibility to some visual illusions. Parametric correlation between cortical suppression, balance of excitation/inhibition, feedback from higher visual areas on one hand and susceptibility to a class of visual illusions related to orientation perception on the other hand provide the opportunity to investigate the contribution and complex interactions of distinct sensory processing mechanisms in ASD. The novel approach used in this study can be used to link behavioural, functional and neuropathological studies; estimate and predict perceptual and cognitive heterogeneity in ASD; and form a basis for the development of novel diagnostics and therapeutics.
Individuals with autism perceive the external world, including visual scenes, differently. To better understand potential brain changes in autism, we developed a neural model that can mimic our brain's visual system and showed that people with autism are less susceptible to some visual illusions, because of potential changes in brain wiring. This work can form a framework for the study of autism heterogeneity and the development of new diagnostics.
Advertising needs to capture consumers' attention in likable ways, and the visual complexity of advertising plays a central role in this regard. Yet ideas about visual complexity effects conflict, ...and objective measures of complexity are rare. The authors distinguish two types of visual complexity, differentiate them from the difficulty of comprehending advertising, and propose objective measures for each. Advertisements are visually complex when they contain dense perceptual features ("feature complexity") and/or when they have an elaborate creative design ("design complexity"). An analysis of 249 advertisements that were tested with eye-tracking shows that, as the authors hypothesize, feature complexity hurts attention to the brand and attitude toward the ad, whereas design complexity helps attention to both the pictorial and the advertisement as a whole, its comprehensibility, and attitude toward the ad. This is important because design complexity is under direct control of the advertiser. The proposed measures can be readily adopted to assess the visual complexity of advertising, and the findings can be used to improve the stopping power of advertisements. PUBLICATION ABSTRACT
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