Adaptive behavior is optimized in organisms that maintain flexible representations of the value sensory-predictive cues. To identify central predictive reward humans, we used reinforcer devaluation while measuring neural activity with functional magnetic resonance imaging. We presented two arbitrary visual stimuli, both before and after olfactory devaluation, a paradigm appetitive conditioning. In amygdala orbitofrontal cortex, responses evoked by target stimulus were decreased whereas to...

We combined event-related functional magnetic resonance imaging (fMRI) with olfactory classical conditioning to differentiate the neural responses evoked during appetitive and aversive learning. Three neutral faces [the conditioned stimuli (CS+)] were repetitively paired pleasant, neutral, or unpleasant odors unconditioned (UCS)] in a partial reinforcement schedule. A fourth face was never odor nonconditioned stimulus (CS−)]. Learning-related activity, comparing unpaired (face only) CS+ CS−,...

The need to breathe links the mammalian olfactory system inextricably respiratory rhythms that draw air through nose. In rodents and other small animals, slow oscillations of local field potential activity are driven at rate breathing (∼2–12 Hz) in bulb cortex, faster oscillatory bursts coupled specific phases cycle. These dynamic thought regulate cortical excitability coordinate network interactions, helping shape coding, memory, behavior. However, while a ubiquitous hallmark function...

Learning to associate sensory cues with threats is critical for minimizing aversive experience. The ecological benefit of associative learning relies on accurate perception predictive cues, but how enhances perceptual acuity signals, particularly in humans, unclear. We combined multivariate functional magnetic resonance imaging olfactory psychophysics show that initially indistinguishable odor enantiomers (mirror-image molecules) become discriminable after conditioning, paralleling the...

Significance To make adaptive choices based on reward-predicting stimuli, organisms must take into account information about both the value and specific identity of reward to be obtained. Using appetizing food odors pattern-based functional magnetic resonance imaging, we show that human orbitofrontal cortex encodes future rewards in form identity-specific codes. That is, even if valued same, different expected rewards, such as pizza chocolate cake, are differently encoded this region. We...

Studies of patients with focal brain injury indicate that smell perception involves caudal orbitofrontal and medial temporal cortices, but a more precise functional organization has not been characterized. In addition, although it is believed odors are potent triggers emotion, support for an anatomical association scant. We sought to define the neural substrates human olfactory information processing determine how these modulated by affective properties odors. used event-related magnetic...

Arousal and valence are proposed to represent fundamental dimensions of emotion. The neural substrates for processing these aspects stimuli studied widely, with recent studies chemosensory suggesting the amygdala processes intensity (a surrogate arousal) rather than valence. However, investigations have assumed that a effect in is linear such testing extremes sufficient infer responses across space. In this study, we tested an alternative hypothesis, namely nonlinear. Using event-related...

It is widely accepted that unconscious processes can modulate judgments and behavior, but do such influences affect one's daily interactions with other people? Given olfactory information has relatively direct access to cortical subcortical emotional circuits, we tested whether the affective content of subliminal odors alters social preferences. Participants rated likeability neutral faces after smelling pleasant, neutral, or unpleasant delivered below detection thresholds. Odor...

It is widely assumed that the thalamus functionally irrelevant for sense of smell. Although animal studies suggest mediodorsal (MD) links primary olfactory (piriform) cortex to neocortical projection sites in orbitofrontal (OFC), this transthalamic route regarded be inconsequential, particularly compared with a direct monosynaptic pathway linking piriform and OFC. In study, we combined functional magnetic resonance imaging novel effective connectivity techniques measure attention-dependent...