scholarly journals Brain mechanisms underlying flavour and appetite

2006 ◽  
Vol 361 (1471) ◽  
pp. 1123-1136 ◽  
Author(s):  
Edmund T Rolls
Keyword(s):  
Orbitofrontal Cortex ◽  
Functional Neuroimaging ◽  
Cognitive Factors ◽  
Subjective Ratings ◽  
Visual Inputs ◽  
Independent Information ◽  
Frontal Operculum ◽  
Affective Value ◽  
Taste And Smell ◽  
The Brain

Complementary neurophysiological recordings in macaques and functional neuroimaging in humans show that the primary taste cortex in the rostral insula and adjoining frontal operculum provides separate and combined representations of the taste, temperature and texture (including viscosity and fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex, these sensory inputs are for some neurons combined by learning with olfactory and visual inputs. Different neurons respond to different combinations, providing a rich representation of the sensory properties of food. In the orbitofrontal cortex, feeding to satiety with one food decreases the responses of these neurons to that food, but not to other foods, showing that sensory-specific satiety is computed in the primate (including human) orbitofrontal cortex. Consistently, activation of parts of the human orbitofrontal cortex correlates with subjective ratings of the pleasantness of the taste and smell of food. Cognitive factors, such as a word label presented with an odour, influence the pleasantness of the odour and the activation produced by the odour in the orbitofrontal cortex. These findings provide a basis for understanding how what is in the mouth is represented by independent information channels in the brain; how the information from these channels is combined; and how and where the reward and subjective affective value of food is represented and is influenced by satiety signals. Activation of these representations in the orbitofrontal cortex may provide the goal for eating, and understanding them helps to provide a basis for understanding appetite and its disorders.

scholarly journals Sensory processing in the brain related to the control of food intake

2007 ◽  
Vol 66 (1) ◽  
pp. 96-112 ◽  
Author(s):  
Edmund T. Rolls
Keyword(s):  
Food Intake ◽  
Orbitofrontal Cortex ◽  
Functional Neuroimaging ◽  
Rhesus Macaques ◽  
Human Subjects ◽  
Sensory Properties ◽  
Visual Inputs ◽  
Reward Value ◽  
Frontal Operculum ◽  
Taste And Smell

Complementary neurophysiological recordings in rhesus macaques (Macaca mulatta) and functional neuroimaging in human subjects show that the primary taste cortex in the rostral insula and adjoining frontal operculum provides separate and combined representations of the taste, temperature and texture (including viscosity and fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex, these sensory inputs are for some neurons combined by learning with olfactory and visual inputs. Different neurons respond to different combinations, providing a rich representation of the sensory properties of food. In the orbitofrontal cortex feeding to satiety with one food decreases the responses of these neurons to that food, but not to other foods, showing that sensory-specific satiety is computed in the primate (including the human) orbitofrontal cortex. Consistently, activation of parts of the human orbitofrontal cortex correlates with subjective ratings of the pleasantness of the taste and smell of food. Cognitive factors, such as a word label presented with an odour, influence the pleasantness of the odour, and the activation produced by the odour in the orbitofrontal cortex. Food intake is thus controlled by building a multimodal representation of the sensory properties of food in the orbitofrontal cortex and gating this representation by satiety signals to produce a representation of the pleasantness or reward value of food that drives food intake. Factors that lead this system to become unbalanced and contribute to overeating and obesity are described.

scholarly journals The Orbitofrontal Cortex, Food Reward, Body Weight, and Obesity

2021 ◽  
Author(s):  
Edmund T Rolls
Keyword(s):  
Individual Differences ◽  
Orbitofrontal Cortex ◽  
Food Reward ◽  
Cognitive Factors ◽  
Reward Systems ◽  
Reward Value ◽  
Inferior Temporal Visual Cortex ◽  
Affective Value ◽  
The Brain ◽  
Great Development

Abstract In primates including humans, the orbitofrontal cortex is the key brain region representing the reward value and subjective pleasantness of the sight, smell, taste and texture of food. At stages of processing before this, in the insular taste cortex and inferior temporal visual cortex, the identity of the food is represented, but not its affective value. In rodents, the whole organisation of reward systems appears to be different, with reward value reflected earlier in processing systems. In primates and humans, the amygdala is overshadowed by the great development of the orbitofrontal cortex. Social and cognitive factors exert a top-down influence on the orbitofrontal cortex, to modulate the reward value of food that is represented in the orbitofrontal cortex. Recent evidence shows that even in the resting state, with no food present as a stimulus, the liking for food, and probably as a consequence of that body mass index, is correlated with the functional connectivity of the orbitofrontal cortex and ventromedial prefrontal cortex. This suggests that individual differences in these orbitofrontal cortex reward systems contribute to individual differences in food pleasantness, and obesity. Implications of how these reward systems in the brain operate for understanding, preventing, and treating obesity are described.

Information processing in the taste system of primates

1989 ◽  
Vol 146 (1) ◽  
pp. 141-164
Author(s):  
E. T. Rolls
Keyword(s):  
Orbitofrontal Cortex ◽  
Discrimination Task ◽  
Fruit Juice ◽  
Sweet Taste ◽  
Solitary Tract ◽  
Taste System ◽  
Visual Inputs ◽  
Close Proximity ◽  
Frontal Operculum ◽  
Single Neurones

1. Analysis of the activity of single neurones in the gustatory pathways in primates (cynomolgus monkeys) shows that the tuning of neurones to the four prototypical stimuli 1.0 mol l-1 glucose, 1.0 mol l-1 NaCl, 0.001 mol l-1 quinine-HCl and 0.01 mol l-1 HCl becomes sharper as information progresses through the taste system from the first central relay in the brainstem, the nucleus of the solitary tract, via the thalamus to the primary taste cortex in the frontal operculum and insula to reach a secondary cortical taste area in the caudolateral orbitofrontal cortex. 2. Feeding monkeys to satiety with glucose has no effect on the gustatory responses of neurones in the nucleus of the solitary tract, the frontal opercular taste cortex or the insular taste cortex, but decreases the magnitude of the neuronal responses of orbitofrontal cortex taste neurones which respond to glucose to zero. 3. The responses of orbitofrontal cortex taste neurones decrease to foods on which the monkey is fed to satiety, but continue to foods which have not just been eaten, that is, they reflect sensory-specific satiety, the phenomenon in which the pleasantness of the taste of a food and its acceptability, but not those of of other foods, is decreased by eating that food to satiety. 4. It has been found that the orbitofrontal cortex taste area or areas receives inputs from different modalities: single neurones with unimodal responses to taste (47%), olfactory (12%) and visual (10%) stimuli are found in close proximity to each other. Moreover, some single neurones show multimodal convergence, responding, for example, to taste and visual inputs (17%), taste and olfactory inputs (10%), and olfactory and visual inputs (4%). Some of these multimodal single neurones have corresponding sensitivities in the two modalities: they respond best to sweet tastes (e.g. 1 mol l-1 glucose), and respond more in a visual discrimination task to the visual stimulus which signifies sweet fruit juice than to that which signifies saline; or they respond to sweet taste and, in an olfactory discrimination task, to fruit juice odour. These results suggest that multimodal representations are formed in the orbitofrontal cortex secondary and related taste areas.(ABSTRACT TRUNCATED AT 400 WORDS)

What Has Direct Cortical and Subcortical Electrostimulation Taught Us about Neurolinguistics?

2019 ◽  
pp. 185-211
Author(s):  
Hugues Duffau
Keyword(s):  
White Matter ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Great Accuracy ◽  
Subcortical White Matter ◽  
Cerebral Lesions ◽  
Physiological Basis ◽  
Postoperative Mri ◽  
The Brain

Investigating the neural and physiological basis of language is one of the most important challenges in neurosciences. Direct electrical stimulation (DES), usually performed in awake patients during surgery for cerebral lesions, is a reliable tool for detecting both cortical and subcortical (white matter and deep grey nuclei) regions crucial for cognitive functions, especially language. DES transiently interacts locally with a small cortical or axonal site, but also nonlocally, as the focal perturbation will disrupt the entire subnetwork sustaining a given function. Thus, in contrast to functional neuroimaging, DES represents a unique opportunity to identify with great accuracy and reproducibility, in vivo in humans, the structures that are actually indispensable to the function, by inducing a transient virtual lesion based on the inhibition of a subcircuit lasting a few seconds. Currently, this is the sole technique that is able to directly investigate the functional role of white matter tracts in humans. Thus, combining transient disturbances elicited by DES with the anatomical data provided by pre- and postoperative MRI enables to achieve reliable anatomo-functional correlations, supporting a network organization of the brain, and leading to the reappraisal of models of language representation. Finally, combining serial peri-operative functional neuroimaging and online intraoperative DES allows the study of mechanisms underlying neuroplasticity. This chapter critically reviews the basic principles of DES, its advantages and limitations, and what DES can reveal about the neural foundations of language, that is, the large-scale distribution of language areas in the brain, their connectivity, and their ability to reorganize.

Childhood trauma moderates morphometric associations between orbitofrontal cortex and amygdala: implications for pathological personality traits

2020 ◽  
pp. 1-10
Author(s):  
Nadia Bounoua ◽  
Rickie Miglin ◽  
Jeffrey M. Spielberg ◽  
Curtis L. Johnson ◽  
Naomi Sadeh
Keyword(s):  
Personality Traits ◽  
Childhood Trauma ◽  
Orbitofrontal Cortex ◽  
Functional Neuroimaging ◽  
Trauma Exposure ◽  
Diagnostic Interview ◽  
Emotional Dysregulation ◽  
Self Report ◽  
Traumatic Experiences ◽  
Pathological Personality Traits

Abstract Background Research has demonstrated that chronic stress exposure early in development can lead to detrimental alterations in the orbitofrontal cortex (OFC)–amygdala circuit. However, the majority of this research uses functional neuroimaging methods, and thus the extent to which childhood trauma corresponds to morphometric alterations in this limbic-cortical network has not yet been investigated. This study had two primary objectives: (i) to test whether anatomical associations between OFC–amygdala differed between adults as a function of exposure to chronic childhood assaultive trauma and (ii) to test how these environment-by-neurobiological effects relate to pathological personality traits. Methods Participants were 137 ethnically diverse adults (48.1% female) recruited from the community who completed a clinical diagnostic interview, a self-report measure of pathological personality traits, and anatomical MRI scans. Results Findings revealed that childhood trauma moderated bilateral OFC–amygdala volumetric associations. Specifically, adults with childhood trauma exposure showed a positive association between medial OFC volume and amygdalar volume, whereas adults with no childhood exposure showed the negative OFC–amygdala structural association observed in prior research with healthy samples. Examination of the translational relevance of trauma-related alterations in OFC–amygdala volumetric associations for disordered personality traits revealed that trauma exposure moderated the association of OFC volume with antagonistic and disinhibited phenotypes, traits characteristic of Cluster B personality disorders. Conclusions The OFC–amygdala circuit is a potential anatomical pathway through which early traumatic experiences perpetuate emotional dysregulation into adulthood and confer risk for personality pathology. Results provide novel evidence of divergent neuroanatomical pathways to similar personality phenotypes depending on early trauma exposure.

scholarly journals Perceiving actions before they happen: psychological dimensions scaffold neural action prediction

2020 ◽  
Author(s):  
Mark A Thornton ◽  
Diana I Tamir
Keyword(s):  
Magnetic Resonance Imaging ◽  
Functional Neuroimaging ◽  
Social World ◽  
Action Space ◽  
Action Prediction ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
The Social ◽  
Psychological Dimensions ◽  
The Brain

Abstract The social world buzzes with action. People constantly walk, talk, eat, work, play, snooze and so on. To interact with others successfully, we need to both understand their current actions and predict their future actions. Here we used functional neuroimaging to test the hypothesis that people do both at the same time: when the brain perceives an action, it simultaneously encodes likely future actions. Specifically, we hypothesized that the brain represents perceived actions using a map that encodes which actions will occur next: the six-dimensional Abstraction, Creation, Tradition, Food(-relevance), Animacy and Spiritualism Taxonomy (ACT-FAST) action space. Within this space, the closer two actions are, the more likely they are to precede or follow each other. To test this hypothesis, participants watched a video featuring naturalistic sequences of actions while undergoing functional magnetic resonance imaging (fMRI) scanning. We first use a decoding model to demonstrate that the brain uses ACT-FAST to represent current actions. We then successfully predicted as-yet unseen actions, up to three actions into the future, based on their proximity to the current action’s coordinates in ACT-FAST space. This finding suggests that the brain represents actions using a six-dimensional action space that gives people an automatic glimpse of future actions.

scholarly journals Cultural variation in the gray matter volume of the prefrontal cortex is moderated by the dopamine D4 receptor gene (DRD4)

2018 ◽  
Vol 29 (9) ◽  
pp. 3922-3931 ◽  
Author(s):  
Qinggang Yu ◽  
Nobuhito Abe ◽  
Anthony King ◽  
Carolyn Yoon ◽  
Israel Liberzon ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Orbitofrontal Cortex ◽  
Receptor Gene ◽  
Cultural Influences ◽  
Dopamine D4 Receptor ◽  
East Asians ◽  
European Americans ◽  
The Difference ◽  
D4 Receptor ◽  
The Brain

Abstract Recent evidence suggests a systematic cultural difference in the volume/thickness of prefrontal regions of the brain. However, origins of this difference remain unclear. Here, we addressed this gap by adopting a unique genetic approach. People who carry the 7- or 2-repeat (7/2-R) allele of the dopamine D4 receptor gene (DRD4) are more sensitive to environmental influences, including cultural influences. Therefore, if the difference in brain structure is due to cultural influences, it should be moderated by DRD4. We recruited 132 young adults (both European Americans and Asian-born East Asians). Voxel-based morphometry showed that gray matter (GM) volume of the medial prefrontal cortex and the orbitofrontal cortex was significantly greater among European Americans than among East Asians. Moreover, the difference in GM volume was significantly more pronounced among carriers of the 7/2-R allele of DRD4 than among non-carriers. This pattern was robust in an alternative measure assessing cortical thickness. A further exploratory analysis showed that among East Asian carriers, the number of years spent in the U.S. predicted increased GM volume in the orbitofrontal cortex. The present evidence is consistent with a view that culture shapes the brain by mobilizing epigenetic pathways that are gradually established through socialization and enculturation.

scholarly journals I know that I don’t know: Structural and functional connectivity underlying meta-ignorance in pre-schoolers

2018 ◽  
Author(s):  
Elisa Filevich ◽  
Caroline Garcia Forlim ◽  
Carmen Fehrman ◽  
Carina Forster ◽  
Markus Paulus ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Orbitofrontal Cortex ◽  
Cingulate Gyrus ◽  
Partial Knowledge ◽  
Metacognitive Monitoring ◽  
Default Mode ◽  
Posterior Cingulate Gyrus ◽  
Knowledge Condition ◽  
The Brain

Research Highlights[1] Children develop the ability to report that they do not know something at around five years of age.[2] Children who could correctly report their own ignorance in a partial-knowledge task showed thicker cortices within medial orbitofrontal cortex.[3] This region was functionally connected to parts of the default-mode network.[4] The default-mode network might support the development of correct metacognitive monitoring.AbstractMetacognition plays a pivotal role in human development. The ability to realize that we do not know something, or meta-ignorance, emerges after approximately five years of age. We aimed at identifying the brain systems that underlie the developmental emergence of this ability in a preschool sample.Twenty-four children aged between five and six years answered questions under three conditions of a meta-ignorance task twice. In the critical partial knowledge condition, an experimenter first showed two toys to a child, then announced that she would place one of them in a box behind a screen, out of sight from the child. The experimenter then asked the child whether or not she knew which toy was in the box.Children who answered correctly both times to the metacognitive question in the partial knowledge condition (n=9) showed greater cortical thickness in a cluster within left medial orbitofrontal cortex than children who did not (n=15). Further, seed-based functional connectivity analyses of the brain during resting state revealed that this region is functionally connected to the medial orbitofrontal gyrus, posterior cingulate gyrus and precuneus, and mid- and inferior temporal gyri.This finding suggests that the default mode network, critically through its prefrontal regions, supports introspective processing. It leads to the emergence of metacognitive monitoring allowing children to explicitly report their own ignorance.

scholarly journals Values Encoded in Orbitofrontal Cortex Are Causally Related to Economic Choices

2020 ◽  
Author(s):  
Sébastien Ballesta ◽  
Weikang Shi ◽  
Katherine E. Conen ◽  
Camillo Padoa-Schioppa
Keyword(s):  
Electrical Stimulation ◽  
Neuronal Activity ◽  
Orbitofrontal Cortex ◽  
Rhesus Monkeys ◽  
Fundamental Issue ◽  
High Current ◽  
Neural Processes ◽  
Economic Choices ◽  
The Brain

AbstractIt has long been hypothesized that economic choices rely on the assignment and comparison of subjective values. Indeed, when agents make decisions, neurons in orbitofrontal cortex encode the values of offered and chosen goods. Moreover, neuronal activity in this area suggests the formation of a decision. However, it is unclear whether these neural processes are causally related to choices. More generally, the evidence linking economic choices to value signals in the brain remains correlational. We address this fundamental issue using electrical stimulation in rhesus monkeys. We show that suitable currents bias choices by increasing the value of individual offers. Furthermore, high-current stimulation disrupts both the computation and the comparison of subjective values. These results demonstrate that values encoded in orbitofrontal cortex are causal to economic choices.

Sign in / Sign up

Export Citation Format

Share Document