Aging and Sex Influence Cortical Auditory-Motor Integration for Speech Control

It is well known that acoustic change in speech production is subject to age-related declines. How aging alters cortical sensorimotor integration in speech control, however, remains poorly understood. The present event-related potential study examined the behavioral and neural effects of aging and sex on the auditory-motor processing of voice pitch errors. Behaviorally, older adults produced significantly larger vocal compensations for pitch perturbations than young adults across the sexes, while the effects of sex on vocal compensation did not exist for both young and older adults. At the cortical level, there was a significant interaction between aging and sex on the N1-P2 complex. Older males produced significantly smaller P2 amplitudes than young males, while young males produced significantly larger N1 and P2 amplitudes than young females. In addition, females produced faster N1 responses than males regardless of age, while young adults produced faster P2 responses than older adults across the sexes. These findings provide the first neurobehavioral evidence that demonstrates the aging influence on auditory feedback control of speech production, and highlight the importance of sex in understanding the aging of the neuromotor control of speech production

Can High-Quality Jobs Help Workers Learn New Tricks? A Multi-Disciplinary Review of Work Design For Cognition

Understanding whether and how work design affects human cognition is important because: (1) cognition is necessary for job performance, (2) digital technologies increase the need for cognition, and (3) it is vital to maintain cognitive functioning in the mature workforce. We synthesize research from work design, human factors, learning, occupational health, and lifespan perspectives. Defining cognition in terms of both knowledge and cognitive processes/fluid abilities, we show that five types of work characteristics (job complexity, job autonomy, relational work design, job feedback, and psychosocial demands) affect employees’ cognition via multiple pathways. In the short-to-medium term, we identify three cognitively-enriching pathways (opportunity for use of cognition, accelerated knowledge acquisition, motivated exploratory learning) and two cognitively-harmful pathways (strain-impaired cognition, depleted cognitive capacity). We also identify three longer-term pathways: cognitive preservation, accumulated knowledge, and ill-health impairment). Based on the emerging evidence for the role of work design in promoting cognition, we propose an integrative model suggesting that short-to-medium term processes between work design and cognition accumulate to affect longer-term cognitive outcomes, such as the prevention of cognitive decline as one ages. We also identify further directions for research and methodological improvements

Exploring the Aetiology and Effects of Pharmacological Cognitive Enhancement use in UK University Students.

Media claims suggest that use of pharmacological cognitive enhancers (PCE) in UK universities is significant and is increasing, though academic research has come to less consistent conclusions. While there has been expansion of research in this area, the public health impact of long-term PCE use, including the potential for adverse effects to cognitive, neurological and physiological functioning remains unclear. Consequently, this thesis aimed to investigate the aetiology and long-term effects of PCE use in some UK universities. Study 1 aimed to investigate CE use in four UK universities, including: which substances are commonly used, the reasons for use and which factors relate to consumption. Here, caffeinated products were the most popular, followed by modafinil. Furthermore, several sociodemographic and personality variables were part of a statistical model to predict CE use, although only gender, age and moral perceptions of modafinil use were found to be significant. Study 2 focussed on modafinil as the most popular PCE aiming to assess the long-term impact (> 3 months) of use on executive functioning by administering various cognitive performance measures. Despite no behavioural differences on the 2-back (working memory) and the continuous performance task (sustained attention), modafinil users responded to both horizontal and vertical cues more quickly than nonusers on the cued go/no-go task (inhibitory control) without experiencing an accuracy trade-off or performance decrement. To investigate the neural substrates of any potential cognitive deficits, Study 3 assessed cognitive and neurophysiological processes by using functional near-infrared spectroscopy, electrocardiogram and a digital sphygmomanometer alongside cognitive performance measures designed to increase cognitive workload. It was found that there were no behavioural performance differences on easy and difficult variants of the multitasking framework (stressor) or 3-back (working memory) between groups, but users experienced significantly lower systolic blood pressure across the tasks and greater haemodynamic change during the 3-back. Blood pressure indicated that users appeared 11 | P a g e less physiologically aroused during performance measures, but increased haemodynamic response compared with controls revealed possible underlying cognitive deficits. Taken as a whole, modafinil appears to be the most popular PCE in the UK for university students, and long-term use unexpectedly revealed enhanced inhibitory control but possible deficits to working memory performance. This research consolidates previous claims about modafinil as the most popular PCE among UK university students. Furthermore, this is the first study to investigate long-term modafinil use and establish behavioural and neurophysiological differences with nonusers

The context of behavioural flexibility in chimpanzees (Pan troglodytes) : implications for the evolution of cumulative culture

Cumulative culture is rare, if not altogether absent in non-human species. At the foundation of cumulative learning is the ability to flexibly modify, relinquish or build upon prior behaviours to make them more productive or efficient. Within the primate literature, a failure to optimise solutions in this way is often proposed to derive from low-fidelity copying of witnessed behaviours, sub-optimal social learning heuristics, or a lack of relevant socio-cognitive adaptations. However, humans can also be markedly inflexible in their behaviours, perseverating with, or becoming fixated on outdated or inappropriate responses. Humans show differential patterns of flexibility as a function of cognitive load, exhibiting difficulties with inhibiting suboptimal behaviours when there are high demands on working memory. Here I present a series of studies on captive chimpanzees which show that not only is inhibitory control compromised in chimpanzees, but indicate ape behavioural conservatism may be underlain by similar constraints as in humans; chimpanzees show relatively little conservatism when behavioural optimisation involves the inhibition of a well-established but simple solution, or the addition of a simple modification to a well-established but complex solution. In contrast, when behavioural optimisation involves the inhibition of a well-established but complex solution, and especially when the alternative solution is also complex, chimpanzees show evidence of behavioural conservatism. I propose that conservatism is linked to behavioural complexity, potentially mediated by cognitive resource availability, and may be an important factor in the evolution of cumulative culture