Encoding touch and the orbitofrontal cortex

Abstract

During value-based decision making, we often evaluate the value of each option sequentially by shifting our attention, even when the options are presented simultaneously. The orbitofrontal cortex (OFC) has been suggested to encode value during value-based decision making. Yet it is not known how its activity is modulated by attention shifts. We investigated this question by employing a passive viewing task that allowed us to disentangle effects of attention, value, choice and eye movement. We found that the attention modulated OFC activity through a winner-take-all mechanism. When we attracted the monkeys' attention covertly, the OFC neuronal activity reflected the reward value of the newly attended cue. The shift of attention could be explained by a normalization model. Our results strongly argue for the hypothesis that the OFC neuronal activity represents the value of the attended item. They provide important insights toward understanding the OFC's role in value-based decision making.

From finger friction and induced vibrations to brain activation: Tactile comparison between real and virtual textile fabrics

“…For instance, these authors showed a peak of increased activity in the orbitofrontal cortex when comparing (with positron emission tomography methods) the tactile exploration of novel stimuli from a related set of textures with familiar tactile stimuli in normal human subjects. The present findings in this study, together with results of Frey et al [39], demonstrate that the orbitofrontal cortex is involved in the active encoding of novel tactile information. Together with the orbitofrontal activity, in the virtual tactile encoding condition, there was a selective increase of activity of the dl-PFC within the left hemisphere and in the right hemisphere as well.…”

“…Indeed, Frey et al [39] demonstrated a strong relationship between the orbitofrontal cortex and the attempt to encode tactile information which is consistent with the role of the orbitofrontal cortex for recognition memory. For instance, these authors showed a peak of increased activity in the orbitofrontal cortex when comparing (with positron emission tomography methods) the tactile exploration of novel stimuli from a related set of textures with familiar tactile stimuli in normal human subjects.…”

Prediction, cognition and the brain

“…Neurons in different brain structures have been shown to code prediction errors stemming from different sources, e.g., rewards, punishment, external stimuli and own behavior, a process which in some contexts may be mediated through the dopaminergic and norepinergic pathways (Schultz and Dickinson, 2000 ). In addition to this direct link between prediction errors and learning, a somewhat more indirect one may be mediated through increased attentional resources being diverted towards the perceived prediction error (Wills et al, 2007 ) or their high emotional significance (Frey et al, 2009 ). On a somewhat different note, although it has previously been suggested that errors in behavior could be organized hierarchically (Krigolson and Holroyd, 2007 ), it is not clear what such hierarchical structure includes and whether different levels of hierarchy may somehow interact.…”

Cortical Local Field Potential Power Is Associated with Behavioral Detection of Near-threshold Stimuli in the Rat Whisker System: Dissociation between Orbitofrontal and Somatosensory Cortices

“…Thus ongoing cortical activity modulates behavioral performance presumably by optimizing the representations of behaviorally relevant perceptual parameters (e.g., detection vs. processing of finer stimulus detail). Adding to these previous findings, we now link such modulation specifically to orbitofrontal cortex, a structure previously implicated in sensory integration and attention (Ongur and Price, 2000;Frey et al, 2009). It should be noted that OFC has been implicated in a variety of behavioural functions in addition to attentional control.…”

“…This region thus appears to be involved in sensory integration. In humans, active as opposed to passive exploration of tactile stimuli is associated with increased OFC activity; in primates, OFC lesions produce deficits in tactile discrimination (Frey et al, 2009;Passingham and Ettlinger, 1972) . Behaviorally, OFC has a critical role in associative learning and decision-making through its representation of the rewardand punishment-value of sensory cues.…”