StopWatch: The Preliminary Evaluation of a Smartwatch-Based System for Passive Detection of Cigarette Smoking.

Introduction: Recent developments in smoking cessation support systems and interventions have highlighted the requirement for unobtrusive, passive ways to measure smoking behavior. A number of systems have been developed for this that either use bespoke sensing technology, or expensive combinations of wearables and smartphones. Here, we present StopWatch, a system for passive detection of cigarette smoking that runs on a low-cost smartwatch and does not require additional sensing or a connected smartphone. Methods: Our system uses motion data from the accelerometer and gyroscope in an Android smartwatch to detect the signature hand movements of cigarette smoking. It uses machine learning techniques to transform raw motion data into motion features, and in turn into individual drags and instances of smoking. These processes run on the smartwatch, and do not require a smartphone. Results: We conducted preliminary validations of the system in daily smokers (n = 13) in laboratory and free-living conditions running on an Android LG G-Watch. In free-living conditions, over a 24-h period, the system achieved precision of 86% and recall of 71%. Conclusions: StopWatch is a system for passive measurement of cigarette smoking that runs entirely on a commercially available Android smartwatch. It requires no smartphone so the cost is low, and needs no bespoke sensing equipment so participant burden is also low. Performance is currently lower than other more expensive and complex systems, though adequate for some applications. Future developments will focus on enhancing performance, validation on a range of smartwatches, and detection of electronic cigarette use. Implications: We present a low-cost, smartwatch-based system for passive detection of cigarette smoking. It uses data from the motion sensors in the watch to identify the signature hand movements of cigarette smoking. The system will provide the detailed measures of individual smoking behavior needed for context-triggered just-in-time smoking cessation support systems, and to enable just-in-time adaptive interventions. More broadly, the system will enable researchers to obtain detailed measures of individual smoking behavior in free-living conditions that are free from the recall errors and reporting biases associated with self-report of smoking.

Severity and susceptibility: measuring the perceived effectiveness and believability of tobacco health warnings.

BACKGROUND: Pictorial tobacco health warning labels (HWLs) have been shown to be more effective than text-only HWLs in changing smoking attitudes and intentions. However, there is contradictory evidence regarding how the severity of the content of HWLs influences responses to them. METHODS: We examined the perceived believability and effectiveness of HWLs in an online study using a convenience sample of non-smokers (N = 437) and smokers (N = 436). HWLs were in one of three presentation formats: (text-only, a moderately severe image or highly severe image) and focussed on three disease outcomes (lung cancer, blindness or tooth and gum disease). Participants rated the effectiveness and believability of each HWL and also rated their perceived susceptibility to each disease. RESULTS: A 2 (smoking status) × 3 (presentation format) × 3 (disease outcome) ANOVA was run for both believability and effectiveness ratings. The most severe pictorial HWLs received the highest believability and effectiveness ratings and as expected, the text-only HWLs received the lowest. Lung cancer HWLs were rated most believable and effective, with the blindness HWLs receiving the lowest scores. A 2 (smoking status) × 3 (disease outcome) ANOVA was conducted on the ratings of perceived susceptibility to the three diseases. Smokers considered themselves to be more susceptible to all three diseases, and among smokers, perceived susceptibility to the diseases was positively correlated with effectiveness and believability ratings of the HWLs. CONCLUSION: Our findings support previous evidence that pictorial HWLs are rated as more effective and believable than text-only warnings, and provide some support for the use of severe or 'grotesque' HWLs on tobacco products. Our data also suggest that HWLs should aim to increase perceived susceptibility to disease, as this was positively related to perceived message effectiveness and believability.

Correction to 'Smoking status and attractiveness among exemplar and prototypical identical twins discordant for smoking'.

[This corrects the article DOI: 10.1098/rsos.161076.].

Evaluating clinical stop-smoking services globally: towards a minimum data set.

BACKGROUND AND AIMS: Behavioural and pharmacological support for smoking cessation improves the chances of success and represents a highly cost-effective way of preventing chronic disease and premature death. There is a large number of clinical stop-smoking services throughout the world. These could be connected into a global network to provide data to assess what treatment components are most effective, for what populations and in what settings. To enable this, a minimum data set (MDS) is required to standardize the data captured from smoking cessation services globally. METHODS: We describe some of the key steps involved in developing a global MDS for smoking cessation services and methodologies to be considered for their implementation, including approaches for reaching consensus on data items to include in a MDS and for its robust validation. We use informal approximations of these methods to produce an example global MDS for smoking cessation. Our aim with this is to stimulate further discussion around the development of a global MDS for smoking cessation services. RESULTS: Our example MDS comprises three sections. The first is a set of data items characterizing treatments offered by a service. The second is a small core set of data items describing clients' characteristics, engagement with the service and outcomes. The third is an extended set of client data items to be captured in addition to the core data items wherever resources permit. CONCLUSIONS: There would be benefit in establishing a minimum data set (MDS) to standardize data captured for smoking cessation services globally. Once implemented, a formal MDS could provide a basis for meaningful evaluations of different smoking cessation treatments in different populations in a variety of settings across many countries.

State anxiety and emotional face recognition in healthy volunteers.

High trait anxiety has been associated with detriments in emotional face processing. By contrast, relatively little is known about the effects of state anxiety on emotional face processing. We investigated the effects of state anxiety on recognition of emotional expressions (anger, sadness, surprise, disgust, fear and happiness) experimentally, using the 7.5% carbon dioxide (CO2) model to induce state anxiety, and in a large observational study. The experimental studies indicated reduced global (rather than emotion-specific) emotion recognition accuracy and increased interpretation bias (a tendency to perceive anger over happiness) when state anxiety was heightened. The observational study confirmed that higher state anxiety is associated with poorer emotion recognition, and indicated that negative effects of trait anxiety are negated when controlling for state anxiety, suggesting a mediating effect of state anxiety. These findings may have implications for anxiety disorders, which are characterized by increased frequency, intensity or duration of state anxious episodes.

Aftereffects support opponent coding of expression.

We used aftereffects to investigate the coding mechanisms underlying perception of facial expression. Recent evidence that some dimensions are common to the coding of both expression and identity suggests that the same type of coding system could be used for both attributes. Identity is adaptively opponent coded by pairs of neural populations tuned to opposite extremes of relevant dimensions. Therefore, the authors hypothesized that expression would also be opponent coded. An important line of support for opponent coding is that aftereffects increase with adaptor extremity (distance from an average test face) over the full natural range of possible faces. Previous studies have reported that expression aftereffects increase with adaptor extremity. Critically, however, they did not establish the extent of the natural range and so have not ruled out a decrease within that range that could indicate narrowband, multichannel coding. Here the authors show that expression aftereffects, like identity aftereffects, increase linearly over the full natural range of possible faces and remain high even for impossibly distorted adaptors. These results suggest that facial expression, like face identity, is opponent coded. (PsycINFO Database Record

Smoking status and attractiveness among exemplar and prototypical identical twins discordant for smoking.

Smoking is associated with negative health of skin and increased signs of facial ageing. We aimed to address two questions about smoking and appearance: (1) does facial appearance alone provide an indication of smoking status, and (2) how does smoking affect the attractiveness of faces? We used faces of identical twins discordant for smoking, and prototypes made by averaging the faces of the twins. In Task 1, we presented exemplar twin sets and same sex prototypes side-by-side and participants (n = 590) indicated which face was the smoker. Participants were blind to smoking status. In Task 2 a separate sample (n = 580) indicated which face was more attractive. For the exemplar twin sets, there was inconclusive evidence participants selected the smoking twin as the smoker more often, or selected the non-smoking twin as the more attractive more often. For the prototypes, however, participants clearly selected the smoking prototypes as the smoker more often, and the non-smoking prototypes as the more attractive. Prototypical faces of non-smokers are judged more attractive, and prototypical faces of smokers are correctly identified as smokers more often than prototypical faces of matched smokers/non-smokers [corrected]. We discuss the possible use of these findings in smoking behaviour change interventions.

Association of Alcohol Consumption with Perception of Attractiveness in a Naturalistic Environment.

AIMS: To investigate the relationship between objectively-assessed alcohol consumption and perception of attractiveness in naturalistic drinking environments, and to determine the feasibility and acceptability of conducting a large-scale study in these environments. METHODS: Observational study conducted simultaneously across three public houses in Bristol, UK. Participants were required to rate the attractiveness of male and female face stimuli and landscape stimuli administered via an Android tablet computer application, after which their expired breath alcohol concentration (BrAC) was measured. RESULTS: Linear regression revealed no clear evidence for relationships between alcohol consumption and either overall perception of attractiveness for stimuli, for faces specifically, or for opposite-sex faces. The naturalistic research methodology was feasible, with high levels of participant engagement and enjoyment. CONCLUSIONS: We found no evidence for a relationship between alcohol consumption and perception of attractiveness in our large-scale naturalistic study. Our study is important given the large sample size, the successful translation of an experimental, laboratory-based paradigm to a naturalistic drinking environment and the high level of public engagement with the study. Future studies should use similarly ecologically-valid methodologies to further explore the conditions under which this effect may be observed and identify the mechanisms underlying any relationships.

Deciding on race: a diffusion model analysis of race-categorisation.

It has long been known that a person's race can affect their decisions about people of another race; an observation that clearly taps into some deep societal issues. However, in order to behave differently in response to someone else's race, you must first categorise that person as other-race. The current study investigates the process of race-categorisation. Two groups of participants, Asian and Caucasian, rapidly classified facial images that varied from strongly Asian, through racially intermediate, to strongly Caucasian. In agreement with previous findings, there was a difference in category boundary between the two groups. Asian participants more frequently judged intermediate images as Caucasian and vice versa. We fitted a decision model, the Ratcliff diffusion model, to our two choice reaction time data. This model provides an account of the processes thought to underlie binary choice decisions. Within its architecture it has two components that could reasonably lead to a difference in race category boundary, these being evidence accumulation rate and a priori bias. The latter is the expectation or prior belief that a participant brings to the task, whilst the former indexes sensitivity to race-dependent perceptual cues. Whilst we find no good evidence for a difference in a priori bias between our two groups, we do find evidence for a difference in evidence accumulation rate. Our Asian participants were more sensitive to Caucasian cues within the images than were our Caucasian participants (and vice versa). These results support the idea that differences in perceptual sensitivity to race-defining visual characteristics drive differences in race categorisation. We propose that our findings fit with a wider view in which perceptual adaptation plays a central role in the visual processing of own and other race.

Nine-year-old children use norm-based coding to visually represent facial expression.

Children are less skilled than adults at making judgments about facial expression. This could be because they have not yet developed adult-like mechanisms for visually representing faces. Adults are thought to represent faces in a multidimensional face-space, and have been shown to code the expression of a face relative to the norm or average face in face-space. Norm-based coding is economical and adaptive, and may be what makes adults more sensitive to facial expression than children. This study investigated the coding system that children use to represent facial expression. An adaptation aftereffect paradigm was used to test 24 adults and 18 children (9 years 2 months to 9 years 11 months old). Participants adapted to weak and strong antiexpressions. They then judged the expression of an average expression. Adaptation created aftereffects that made the test face look like the expression opposite that of the adaptor. Consistent with the predictions of norm-based but not exemplar-based coding, aftereffects were larger for strong than weak adaptors for both age groups. Results indicate that, like adults, children's coding of facial expressions is norm-based.

The expressions of strangers: our identity-independent representation of facial expression.

Evidence suggests that underlying the human system processing facial expressions are two types of representation of expression: one dependent on identity and the other independent of identity. We recently presented findings indicating that identity-dependent representations are encoded using a prototype-referenced scheme, in a manner notably similar to that proposed for facial identity. Could it be that identity-independent representations are encoded this way too? We investigated this by adapting participant to anti-expressions and asking them to categorize the expression aftereffect in a prototype probe that was either the same (congruent) or different (incongruent) identity to that of the adapter. To distinguish between encoding schemes, we measured how aftereffect magnitude changed in response to variations in the strength of adapters. The increase in aftereffect magnitude with adapter strength characteristic of prototype-referenced encoding was observed in both congruent and, crucially, incongruent conditions. We conclude that identity-independent representations of expression are indeed encoded using a prototype-referenced scheme. The striking similarity between the encoding of facial identity and both representations of expression raises the possibility that prototype-referenced encoding might be a common scheme for encoding the many types of information in faces needed to enable our complex social interactions.

Anti-expression aftereffects reveal prototype-referenced coding of facial expressions.

Adaptation is a powerful experimental technique that has recently provided insights into how people encode representations of facial identity. Here, we used this approach to explore the visual representation of facial expressions of emotion. Participants were adapted to anti-expressions of six facial expressions. The participants were then shown an average face and asked to classify the face's expression using one of six basic emotion descriptors. Participants chose the emotion matching the anti-expression they were adapted to significantly more often than they chose any other emotion (e.g., if they were adapted to antifear, they classified the emotion on the average face as fear). The strength of this aftereffect of adaptation decreased as the strength of the anti-expression adapter decreased. These findings provide evidence that visual representations of facial expressions of emotion are coded with reference to a prototype within a multidimensional framework.