Richard J. Stevenson’s research while affiliated with Macquarie University and other places

The psychological states of hunger and satiety play an important role in regulating human food intake. Several lines of evidence suggest that these states rely upon declarative learning and memory processes, which are based primarily in the medial temporal lobes (MTL). The MTL, and particularly the hippocampus, is unusual in that it is especially vulnerable to insult. Consequently, we examine here the impact on hunger and satiety of conditions that: (1) are central to ingestive behaviour and where there is evidence of MTL pathology (i.e., habitual consumption of a Western-style diet, obesity, and anorexia nervosa); and (2) where there is overwhelming evidence of MTL pathology, but where ingestive behaviour is not thought central (i.e., temporal lobe epilepsy and post-traumatic stress disorder). While for some of these conditions the evidence base is currently limited, the general conclusion is that MTL impairment is linked, sometimes strongly, to dysfunctional hunger and satiety. This focus on the MTL, and declarative learning and memory processes, has implications for the development of alternative treatment approaches for the regulation of appetite.

Trypophobia is a relatively common aversion to clusters of holes. There is no consensus yet on which emotions are involved in Trypophobia nor in its functional utility. This report investigates the role of disgust using contamination tasks in two studies, which contrast people with an aversion to trypophobic stimuli to those without. In Study 1, participants reported their emotional reactions to imagined contamination of trypophobic images. In Study 2, participants evaluated physically present trypophobic, disgust, fear, and control stimuli. The capacity of these stimuli to contaminate other objects was established using a chain of contagion task. Across both studies, contamination was present, however, only those with an aversion to trypophobic stimuli evidenced contamination on the chain of contagion task, a hallmark of disgust responding. Elevated levels were not only reported for disgust, but also alongside fear/anxiety. Participant reports suggest an underlying disease avoidance mechanism in Trypophobia, with trypophobic participants demonstrating an exaggerated response to such stimuli involving disgust and fear/anxiety, which is also seen in small animal phobia, BII, and C-OCD. Implications, particularly for treatment are discussed.

People can use their internal state to determine if they are hungry or thirsty. Although the meaning of some interoceptive cues may be innate (e.g., pain), it is possible that others—including those for hunger and thirst—are acquired. There has been little exploration of this idea in humans. Consequently, we conducted a survey among child caregivers to determine if the basic conditions necessary for interoceptive learning were present. Two‐hundred and thirty‐five caregivers of children aged 1–12 years were asked if they had recently noticed stomach rumbling, hunger‐related irritability, and a dry mouth in their child. They were also asked how they would respond. The impact of several moderating variables, especially caregiver beliefs about the causes of hunger, fullness, and thirst, was also explored. Fifteen percent of caregivers had recently noticed stomach rumbling in their child, 28% hunger‐related irritability, and 14% a dry mouth. Forty‐four percent of caregivers had noticed at least one of these three cues. Noticing hunger cues was significantly moderated by caregiver beliefs about their cause, by child age, and in one case by temporal context (around vs. outside mealtimes). Key caregiver responses were providing the need (e.g., offer food) and/or asking the child if they had a need (e.g., hungry?). Each type of response could potentially support a different form of interoceptive learning. In conclusion, we suggest the necessary conditions for children to learn interoceptive hunger and thirst cues, are present in many caregiver–offspring dyads.

There appears to be no attempt to categorize the specific classes of behavior that the tactile system underpins. Awareness of how an organism uses touch in their environment informs understanding of its versatility in non-verbal communication and tactile perception. This review categorizes the behavioral functions underpinned by the tactile sense, by using three sources of data: (1) Animal data, to assess if an identified function is conserved across species; (2) Human capacity data, indicating whether the tactile sense can support a proposed function; and (3) Human impaired data, documenting the impacts of impaired tactile functioning (e.g., reduced tactile sensitivity) for humans. From these data, three main functions pertinent to the tactile sense were identified: Ingestive Behavior; Environmental Hazard Detection and Management; and Social Communication. These functions are reviewed in detail and future directions are discussed with focus on social psychology, non-verbal behavior and multisensory perception.

There are two main forms of hunger (i.e. desire to eat): appetitive (food cues lead to hunger) and interoceptive/temporal (internal bodily/time cues lead to hunger). The focus here is to examine how these hungers relate to the chemical and non-chemical senses. Appetitive hunger arises from perceiving food cues via vision, olfaction and audition. This results in memory retrieval about the perceived food, both of its flavour/affect during eating and its consequences. The processes that take place when a visual/auditory food cue is perceived are different to those that occur when an olfactory food cue is perceived. An olfactory food cue automatically generates a mental image of its associated flavour (sensation and affect) while visual or auditory food cues require more controlled processing, and if a mental image is formed, they may draw more upon the affective nature of the eating experience. For interoceptive/temporal hunger, this involves a wide variety of internal bodily sensations and time, but how these translate into hunger is not so well understood. However, when hunger does occur it may be more akin to that resulting from visual/auditory food cues. Differences in hunger processing between olfaction and the other senses are discussed.

One prediction derived from the disease avoidance account of disgust is that proximal disgust cues (smells, tastes and touches) should elicit this emotion more intensely than distal disgust cues (sights and sounds). If correct, then memories of disgusting experiences should involve smelling, tasting or touching to a greater degree than seeing or hearing. Two surveys were conducted on university students to test this idea, drawing upon their naturalistic experiences. Survey 1 (N = 127) asked participants to detail their most memorable disgusting, fear-provoking, morally repulsive and yucky/gross experience, with each recollection self-rated for sensory involvement. Survey 2 (N = 89) employed the same task, but this time, participants recollected their most common disgusting, fear-provoking, morally repulsive and yucky/gross experience in the preceding week. The majority of disgusting experiences were core disgusts—i.e. related to disease/pathogen presence or stimuli. The proximal and distal sensory cues contributed equally to individuals’ most memorable core disgust experiences, but the proximal senses were more involved than the distal senses in individuals’ most common core disgust experiences. Further, the proximal sensory cues, as compared with the distal sensory cues, were signficantly more involved in core disgust experiences than in morally repulsive and fear-provoking experiences. The implications of these findings for a disease avoidance account of disgust, for multi-sensory disgust research, and core disgust’s classification as an emotion or a drive, are discussed.