The role of beak shape in octopodid taxonomy

Beak shapes in nine species of Southern Ocean octopodids were measured using seven size-standardized ratios. The results were analysed using principal component analysis and discriminant function analysis and showthat beak shape may be used as a taxonomic character to distinguish between genera, but not between species. Stepwise discriminant function analysis indicated that all seven ratios were required to maximize discrimination between beaks. A phenogram constructed from a matrix of Mahalanobis distances differed from a dendrogram produced from genetic data. This suggests that, although useful for discrimination, beak morphology is probably not suitable for constructing phylogenies

Filled-duration illusions

Data relevant to the “filled duration illusion”, the claim that filled intervals appear to last longer than unfilled ones of the same real duration, are reviewed. A distinction is made between divided-time studies (where an empty interval has one or more than one brief dividing stimulus inside it) and filled-duration studies (where the filled intervals are filled with some continuous event). Divided durations appear to last longer than empty ones, and the effect grows with the number of dividers, although it may be restricted to short durations. The best current explanation appears to involve the weighted summation of the different sub-intervals of which the total duration is composed. When intervals with simple fillers are contrasted with empty ones, they are usually judged as longer, and the effect may grow as the intervals lengthen, at least over short duration ranges. When complex fillers are used, fillers usually have no effect on perceived duration or shorten it. A pacemaker-counter approach can account for some simple filler effects, and division of attention for complex filler effects. Although there are some exceptions, “filled interval illusions” of all these types are normally found, but some problems, such as questions about the relative perceived variability of filled and unfilled intervals, or stimulus order effects, merit further research

The influence of recreational drug use on experiences of the passage of time

Background: Laboratory research suggests that alcohol, marijuana, cocaine and MDMA influence the processing of time. Anecdotal reports of recreational drug use also often include descriptions of changes in the speed of the passage of time. Despite this, little is known about how and why recreational drug use influences the passage of time. Aim: To examine retrospective self-reports of the passage of time during a previous instance of alcohol, cannabis, cocaine or MDMA use. To establish the effect of substance use frequency, substance dose, anxiety, depression and stress on the passage of time. Method: Using an online questionnaire, passage of time judgments were collected for the current day as well as recent instances of alcohol, cocaine, marijuana or MDMA use. Measures of affect, typical substance use frequency and substance use amount were taken. Results: Time was remembered as passing significantly more quickly than normal during alcohol, cocaine and MDMA use. Marijuana was associated with time passing more slowly than normal. Regression analysis revealed that drug induced distortions to the passage of time use were not predicted by drug use frequency, dose, depression, anxiety or stress. Furthermore, comparison of recreational drug users and non-users did not indicate any long-term effects of drug use on the passage of time. Conclusions: The results suggest that whilst distortions to the passage of time are a common feature of drug use, their causes are complex

How long was it for you? Memories of the duration of the UK covid-19 lockdown

The covid-19 global pandemic has significantly impacted on the daily lives of people across the world. One consequence of this has been significant distortion to the speed at which time feels like it is passing during day-to-day life in comparison with prior to the pandemic. The current study sought to further understanding of the impact of the pandemic on temporal experience by exploring individual differences in the subjective length of the first 12 months of the pandemic in the UK. Using an online questionnaire, subjective judgments of the perceived length of the preceding 12 months were taken. In addition, measures of affect, task load and satisfaction with current levels of social interaction, physical activity, conformity with regulations, perceived covid risk and shielding status were taken. The results showed that only 9% of participants reported that the preceding 12 months felt like 12 months. The majority of participants (57%) reported that it felt like the pandemic had lasted for longer than 12 months, and this feeling was stronger for those who indicated greater levels of depression and anxiety, reduced physical activity, reduced satisfaction with social interaction and being advised to shield

Time distortion under threat: Sympathetic arousal predicts time distortion only in the context of negative, highly arousing stimuli

Theoretical models of time perception suggest a simple bottom-up relationship between physiological arousal and perceived duration. Increases in physiological arousal lengthen the perceived duration of events whereas decreases in physiological arousal reduce them. Whilst this relationship has been demonstrated for highly arousing negatively valenced stimuli, it has not been demonstrated for other classes of distorting stimuli (e.g. positively valenced or low arousal stimuli). The current study tested the effect of valence (positive and negative) and arousal level (high and low) on the relationship between physiological arousal and perceived duration. Sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) activity was measured during a verbal estimation task in which participants judged the duration of high and low arousal, positive, negative and neutrally valenced IAPS images. SNS and PSNS activity were indexed by measuring Pre-Ejection Period (PEP) and High Frequency Heart-rate Variability (HF-HRV) respectively. SNS reactivity was predicative of perceived duration, but only for high arousal negatively valenced stimuli, with decreases in PEP being associated with longer duration estimates. SNS and PSNS activity was not predictive of perceived duration for the low arousal negative stimuli or the low and high arousal positive stimuli. We therefore propose a new model suggesting that emotional distortions to time result from a combination of bottom-up (physiological arousal) and topdown (threat detection) factors

The impact of a bariatric rehabilitation service on weight loss and psychological adjustment - study protocol

Bariatric surgery is currently the most effective form of obesity management for those whose BMI is greater than 40 (or 35 with co morbidities). A minority of patients, however, either do not show the desired loss of excess weight or show weight regain by follow up. Research highlights some of the reasons for this variability, most of which centres on the absence of any psychological support with patients describing how although surgery fixes their body, psychological issues relating to dietary control, self esteem, coping and emotional eating remain neglected.The present study aims to evaluate the impact of a health psychology led bariatric rehabilitation service (BRS) on patient health outcomes. The bariatric rehabilitation service will provide information, support and mentoring pre and post surgery and will address psychological issues such as dietary control, self esteem, coping and emotional eating. The package reflects the rehabilitation services now common place for patients post heart attack and stroke which have been shown to improve patient health outcomes

Chronic bilateral heel pain in a child with Sever disease: case report and review of literature

We are presenting a case report of a 10-year-old male with a 1 year history of bilateral heel pain. Sever disease is self limiting condition of calcaneal apophysis. It is the most common cause of heel pain in the growing child. There is no documented case of this condition in this region. This case highlights the clinical features of this self limiting disorder as seen in this patient and reviews the current literature

Trait impulsivity influences behavioural and physiological responses to threat in a virtual environment

Trait impulsivity represents a tendency to take action without forethought or consideration of consequences. This trait is multifaceted and can be decomposed into attentional, motor and non-planning subtypes of impulsivity. The purpose of the current study was to investigate how subtypes of trait impulsivity responded to different degrees of threat within room-scale virtual reality (VR) with respect to behaviour and level of physiological activation. Thirty-four participants were required to negotiate a virtual environment (VE) where they walked at height with the continuous threat of a virtual ‘fall.’ Behavioural measures related to the speed of movement, interaction frequency and risk were collected. Participants also wore ambulatory sensors to collect data from electrocardiogram (ECG) and electrodermal activity (EDA). Our results indicated that participants who scored highly on non-planning impulsivity exhibited riskier behaviour and higher skin conductance level (SCL). Participants with higher motor impulsivity interacted with more objects in the VE when threat was high, they also exhibited contradictory indicators of physiological activation. Attentional impulsivity was associated with a greater number of falls across the VE. The results demonstrate that subtypes of trait impulsivity respond to threats via different patterns of behaviour and levels of physiological activation, reinforcing the multifaceted nature of the trait