Nonconscious fear conditioning, visceral perception, and the development of gut feelings

Social and motivational functioning is not critically dependent on feedback of autonomic responses: neuropsychological evidence from patients with pure autonomic failure

Social, emotional and motivational behaviours are associated with production of automatic bodily responses. Re-representation in the brain through feedback of autonomic and skeletomuscular arousal is proposed to underlie "feeling states". These influence emotional judgments and bias motivational decision-making and guide social interactions. Consistent with this hypothesis, dissocial behaviour and deficits on emotional and motivation tasks are associated with blunted bodily responses in patients with orbitofrontal brain lesions or developmental psychopathy. To determine the critical dependence of social and emotional behaviours on bodily responses mediated by the autonomic nervous system, we examined patients with pure autonomic failure (PAF), a peripheral denervation of autonomic neurons with onset in middle age. Compared to healthy subjects, PAF patients were unimpaired on tests of motivational decision-making (Iowa Gambling Task), recognition of emotional facial expressions, Theory of Mind Tasks and tests of social cognition. Only on a test of emotional attribution, which is perhaps more sensitive to subjective feeling states, did PAF patients score worse than the comparison group, though there was no evidence that this deficit was specific to a discrete emotion and requires further validation. These findings suggest that emotional and social functioning is not critically tied to on-going experience of autonomic arousal state, Acquisition of autonomic failure late in life may protect against maladaptive social behaviour through established behavioural responses that may be associated with central "as if" representations.

Expression of conditional fear with and without awareness

Conditional responding during simple Pavlovian conditioning is often characterized as a form of implicit memory. The extent to which this type of associative learning is independent of awareness is an issue of continuing debate. Previous studies have demonstrated conditioning in the absence of awareness. However, their results have been questioned based on methodological concerns with postexperimental questionnaires. In the present study, skin conductance response (SCR) and unconditioned stimulus (UCS) expectancy were measured concurrently as participants were exposed to a differential delay fear conditioning procedure in which one tone (CS+) predicted a loud white noise, whereas a second tone (CS-) was presented alone. UCS predictability was varied on a trial-by-trial basis by presenting conditioned stimuli (CSs) at volumes just above or below the perceptual threshold. Differential UCS expectancy (awareness) was observed only on perceived trials, whereas differential SCR developed on both perceived and unperceived trials. Although perceived stimuli elicited larger SCRs, the magnitude of conditioning, indexed by differential conditioned response expression (conditioned SCR to CS+ minus the SCR to CS-), was not influenced by stimulus perception. These data indicate that conditional fear can be expressed when individuals are unaware of fear-eliciting stimuli and suggest that the degree of conditioning is independent of awareness during differential Pavlovian fear conditioning.

Effects of trial order and differential conditioning on acquisition of differential shock expectancy and skin conductance conditioning to masked stimuli

Research suggests that when people are fear conditioned to masked spiders and snakes (electric shocks are contingent on only spiders or snakes), they acquire a conditional skin conductance response and can predict the occurrence of shocks even though they are unable to identify the masked spiders and snakes. Because in prior studies trial order was not completely random, it is unclear if findings were due to the contingencies from differential conditioning or a restricted trial order or both. When participants were assigned to four groups to disentangle effects of trial order and differential conditioning to masked pictures in acquisition, effects were obtained only for trial order. These findings demonstrate that trial order can result in conditioning. However, because effects were observed even for participants who reported unawareness of the contingency from trial order, results are consistent with the notion of hunches or gut feelings.

How the Self Controls Its “Automatic Pilot” when Processing Subliminal Information

Human performance may be primed by information not consciously available. Can such priming become so overwhelming that observers cannot help but act accordingly? In the present study, well-visible stimuli were preceded by whole series of unidentifiable stimuli. These series had strong, additive priming effects on behavior. However, their effect depended on the frequency with which they provided information conflicting to the visible main stimuli. Thus, effects of subliminal priming are under observers' strategic control, with the criterion presumably set as a function of the openly observable error frequency. Electrical brain potentials show that this criterion acts simultaneously at the level of visual discrimination of the primes and at motor activation evoked by the primes, thereby shielding observers from unwanted information.

Phobias and preparedness: the selective, automatic, and encapsulated nature of fear

We describe evidence for an evolved module for fear elicitation and fear learning with four primary characteristics. First, it is preferentially activated by stimuli related to survival threats in evolutionary history. Thus, fear-relevant stimuli lead to superior conditioning of aversive associations compared with fear-irrelevant stimuli. Second, the module is automatically activated by fear-relevant stimuli, meaning that fear activation occurs before conscious cognitive analysis of the stimulus can occur. Third, the fear module is relatively impenetrable to conscious cognitive control, and fear conditioning with fear-relevant stimuli can occur even with subliminal conditioned stimuli. Fourth, the amygdala seems to be the central brain area dedicated to the fear module. Finally, we propose that there are two levels of fear conditioning, with an emotional level that is relatively independent of the cognitive contingency level, each mediated by different brain areas.

Emotion, cognition, and behavior

Emotion is central to the quality and range of everyday human experience. The neurobiological substrates of human emotion are now attracting increasing interest within the neurosciences motivated, to a considerable extent, by advances in functional neuroimaging techniques. An emerging theme is the question of how emotion interacts with and influences other domains of cognition, in particular attention, memory, and reasoning. The psychological consequences and mechanisms underlying the emotional modulation of cognition provide the focus of this article.

Quadratic trend analysis and heartbeat detection

In heartbeat detection tasks based on the Method of Constant Stimuli (MCS), subjects judge the simultaneity between their heartbeats and stimuli presented at six intervals ranging from 0 to 500 ms after the R-waves on an electrocardiogram. Because research suggests that subjects do not perceive stimuli at 0 or 500 ms as simultaneous, individual performance was indexed with quadratic trend analysis to test for distributions of simultaneity judgments across intervals that peak between 0 and 500 ms. Further, because some tasks use only two intervals, performance was also indexed using intervals of either 0 and 200 ms or 200 and 500 ms. Continuous performance scores from quadratic trend and two-interval analysis tended to correlate more highly with variables previously shown to correlate with heartbeat detection than scores from the commonly-used chi(2) analysis. These findings support the use of both quadratic trend analysis and two-interval tasks for assessing heartbeat detection ability.