Can cognitive training capitalise on near transfer effects? Limited evidence of transfer following online inhibition training in a randomised-controlled trial.

Despite early promise, cognitive training research has failed to deliver consistent real-world benefits and questions have been raised about the experimental rigour of many studies. Several meta-analyses have suggested that there is little to no evidence for transfer of training from computerised tasks to real-world skills. More targeted training approaches that aim to optimise performance on specific tasks have, however, shown more promising effects. In particular, the use of inhibition training for improving shoot/don't-shoot decision-making has returned positive far transfer effects. In the present work, we tested whether an online inhibition training task could generate near and mid-transfer effects in the context of response inhibition tasks. As there has been relatively little testing of retention effects in the literature to date, we also examined whether any benefits would persist over a 1-month interval. In a pre-registered, randomised-controlled trial, participants (n = 73) were allocated to either an inhibition training programme (six training sessions of a visual search task with singleton distractor) or a closely matched active control task (that omitted the distractor element). We assessed near transfer to a Flanker task, and mid-transfer to a computerised shoot/don't-shoot task. There was evidence for a near transfer effect, but no evidence for mid-transfer. There was also no evidence that the magnitude of training improvement was related to transfer task performance. This finding adds to the growing body of literature questioning the effectiveness of cognitive training. Given previous positive findings, however, there may still be value in continuing to explore the extent to which cognitive training can capitalise on near or mid-transfer effects for performance optimisation.

A preliminary study of the thermal strain experienced by dive support boat personnel.

Anecdotal evidence indicated some British military dive support boat personnel suffer from uncomfortably cold hands and feet, which could impair their performance and be associated with reductions in core body temperature. This study collected preliminary data on thermal stress and cognitive performance of personnel taking part in a cold-weather training exercise. Six men were monitored during four boat transits in a range of climatic conditions (air temperature +1.2°C to -10.5°C, wind chill -4.5°C to 19.3°C). Core body temperature was measured with a radio pill and 12 skin sites (ISO 9886 plus hand, finger, foot and toe) with iButtons or thermistors. Self-reported thermal comfort and thermal sensation was also recorded. Reaction time and selective attention were measured pre- and post-transit. Participants' physical characteristics and personal clothing ensembles were recorded. No participant became hypothermic. Most participants' hand, foot and digit temperatures fell to below 15°C, indicating a risk of impaired dexterity, in addition to that arising from gloves. During the trial, hand and digit temperatures occasionally fell below 10°C. The limited data collected showed personal clothing choices could provide adequate thermal protection for these conditions and temperatures, and highlighted inter-individual variation and the need to allow for significant variation of day-to-day environmental conditions.

Feasibility and acceptability of transcranial stimulation in obsessive-compulsive symptoms (FEATSOCS): study protocol for a randomised controlled trial of transcranial direct current stimulation (tDCS) in obsessive-compulsive disorder (OCD).

BACKGROUND: Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder which often proves refractory to current treatment approaches. Transcranial direct current stimulation (tDCS), a noninvasive form of neurostimulation, with potential for development as a self-administered intervention, has shown potential as a safe and efficacious treatment for OCD in a small number of trials. The two most promising stimulation sites are located above the orbitofrontal cortex (OFC) and the supplementary motor area (SMA). METHODS: The aim of this feasibility study is to inform the development of a definitive trial, focussing on the acceptability, safety of the intervention, feasibility of recruitment, adherence and tolerability to tDCS and study assessments and the size of the treatment effect. To this end, we will deliver a double-blind, sham-controlled, crossover randomised multicentre study in 25 adults with OCD. Each participant will receive three courses of tDCS (SMA, OFC and sham), randomly allocated and given in counterbalanced order. Each course comprises four 20-min stimulations, delivered over two consecutive days, separated by at least 4 weeks' washout period. We will collect information about recruitment, study conduct and tDCS delivery. Blinded raters will assess clinical outcomes before, during and up to 4 weeks after stimulation using validated scales. We will include relevant objective neurocognitive tasks, testing cognitive flexibility, motor disinhibition, cooperation and habit learning. DISCUSSION: We will analyse the magnitude of the effect of the interventions on OCD symptoms alongside the standard deviation of the outcome measure, to estimate effect size and determine the optimal stimulation target. We will also measure the duration of the effect of stimulation, to provide information on spacing treatments efficiently. We will evaluate the usefulness and limitations of specific neurocognitive tests to determine a definitive test battery. Additionally, qualitative data will be collected from participants to better understand their experience of taking part in a tDCS intervention, as well as the impact on their overall quality of life. These clinical outcomes will enable the project team to further refine the methodology to ensure optimal efficiency in terms of both delivering and assessing the treatment in a full-scale trial. TRIAL REGISTRATION: ISRCTN17937049 . (date applied 08/07/2019). Recruitment (ongoing) began 23rd July 2019 and is anticipated to complete 30th April 2021.