1,721,672 research outputs found
Walsh, V H, NX67371
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/423766Surname: WALSH. Given Name(s) or Initials: V H. Military Service Number or Last Known Location: NX67371. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 23928.251271
Item: [2016.0049.56027] "Walsh, V H, NX67371
Encoding of temporal probabilities in the human brain
No full textAnticipating the timing of future events is a necessary precursor to preparing actions and allocating resources to sensory processing. This requires elapsed time to be represented in the brain and used to predict the temporal probability of upcoming events. While neuropsychological, imaging, magnetic stimulation studies, and single-unit recordings implicate the role of higher parietal and motor-related areas in temporal estimation, the role of earlier, purely sensory structures remains more controversial. Here we demonstrate that the temporal probability of expected visual events is encoded not by a single area but by a wide network that importantly includes neuronal populations at the very earliest cortical stages of visual processing. Moreover, we show that activity in those areas changes dynamically in a manner that closely accords with temporal expectations
Walsh v Lonsdale (1882) 21 Ch D 9, Court of Appeal
No full textEssential Cases: Land Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in Walsh v Lonsdale (1882) 21 Ch D 9, Court of Appeal. The document also includes supporting commentary from author Aruna Nair.</p
The parietal cortex and the representation of time, space, number and other magnitudes
No full textThe development of sub-disciplines within cognitive neuroscience follows common sense categories such as language, audition, action, memory, emotion and perception among others. There are also well-established research programmes into temporal perception, spatial perception and mathematical cognition that also reflect the subjective impression of how experience is constructed. There is of course no reason why the brain should respect these common sense, text book divisions and, here, we discuss the contention that generalized magnitude processing is a more accurate conceptual description of how the brain deals with information about time, space, number and other dimensions. The roots of the case for linking magnitudes are based on the use to which magnitude information is put (action), the way in which we learn about magnitudes (ontogeny), shared properties and locations of magnitude processing neurons, the effects of brain lesions and behavioural interference studies. Here, we assess this idea in the context of a theory of magnitude, which proposed common processing mechanisms of time, space, number and other dimensions
Different brain circuits underlie motor and perceptual representations of temporal intervals
Full text linkIn everyday life, temporal information is used for both perception and action, but whether these two functions reflect the operation of similar or different neural circuits is unclear. We used functional magnetic resonance imaging to investigate the neural correlates of processing temporal information when either a motor or a perceptual representation is used. Participants viewed two identical sequences of visual stimuli and used the information differently to perform either a temporal reproduction or a temporal estimation task. By comparing brain activity evoked by these tasks and control conditions, we explored commonalities and differences in brain areas involved in reproduction and estimation of temporal intervals. The basal ganglia and the cerebellum were commonly active in both temporal tasks, consistent with suggestions that perception and production of time are subserved by the same mechanisms. However, only in the reproduction task was activity observed in a wider cortical network including the right pre-SMA, left middle frontal gyrus, left premotor cortex, with a more reliable activity in the right inferior parietal cortex, left fusiform gyrus, and the right extrastriate visual area V5/MT. Our findings point to a role for the parietal cortex as an interface between sensory and motor processes and suggest that it may be a key node in translation of temporal information into action. Furthermore, we discuss the potential importance of the extrastriate cortex in processing visual time in the context of recent findings
Chapter 17 - Gunslingers, poker players, and chickens 3: Decision making under mental performance pressure in junior elite athletes
No full textBackground: Having investigated the decision making of world class elite and subelite athletes (see Parkin and Walsh, 2017; Parkin et al., 2017), here the abilities of those at the earliest stage of entry to elite sport are examined. Junior elite athletes have undergone initial national selection and are younger than athletes examined previously (mean age 13 years). Decision making under mental pressure is explored in this sample. During performance an athlete encounters a wide array of mental pressures; these include the psychological impact of errors, negative feedback, and requirements for sustained attention in a dynamic environment (Anshel and Wells, 2000; Mellalieu et al., 2009). Such factors increase the cognitive demands of the athletes, inducing distracting anxiety-related thoughts known as rumination (Beilock and Gray, 2007). Mental pressure has been shown to reduce performance of decision-making tasks where reward and loss contingencies are explicit, with a shift toward increased risk taking (Pabst et al., 2013; Starcke et al., 2011). Mental pressure has been shown to be detrimental to decision-making speed in comparison to physical stress, highlighting the importance of considering a range of different pressures encountered by athletes (Hepler, 2015). / Objective: To investigate the influence of mental pressure on key indicators of decision making in junior elite athletes. This chapter concludes a wider project examining decision making across developmental stages in elite sport. The work further explores how psychological insights can be applied in an elite sporting environment and in particular tailored to the requirements of junior athletes. / Methods: Seventeen junior elite athletes (10 males, mean age: 13.80 years) enrolled on a national youth athletic development program participated in the study. Performance across three categories of decision making was assessed under conditions of low and high mental pressure. Decision making under risk was measured via the Cambridge Gambling Task (CGT; Rogers et al., 1999), decision making under uncertainty via the Balloon Analogue Risk Task (BART; Lejuez et al., 2002), and fast reactive responses to perceptual stimuli via the Visual Search Task (Treisman, 1982). Mental pressure was induced with the addition of a concurrent verbal memory task, used to increase cognitive load and mimic the distracting effects of anxiety-related rumination. / Results: In junior elite athletes, fast reactive responses to perceptual stimuli (on the Visual Search Task) were slower under conditions of mental pressure. For decision making under risk there was an interaction of mental pressure and gender on the amount of points gambled, under pressure there was a higher level of risk taking in male athletes compared to females. There was no influence of mental pressure on decision making under uncertainity. There were no significant correlations in the degree to which individual's responses changed under pressure across the three measures of decision making. When assessing the applicability of results based on group averages there were no junior elite athletes who showed an “average” response (within 1SD of the mean) to mental pressure across all the three decision-making tasks. / Conclusion: Mental pressure affects decision making in a sample of junior elite athletes, with a slowing of response times, and modulations to performance of decision making under risk that have a high requirement for working memory. In relation to sport, these findings suggest that novel situations that place high cognitive demands on the athlete may be particularly influenced by mental pressure. The application of this work in junior elite athletes included the feedback of individual results and the implementation of a decision-making taxonomy
Chapter 16 - Gunslingers, poker players, and chickens 2: Decision-making under physical performance pressure in subelite athletes
No full textBackground: Having investigated the influence of acute physical exhaustion on decision-making in world-class elite athletes in Parkin et al. (2017), here a similar method is applied to subelite athletes. These subelite athletes were enrolled on a Team GB talent development program and were undergoing training for possible Olympic competition in 4–8 years. They differ from elite athletes examined previously according to expertise and age. While considered elite (Swann et al., 2015), the subelite athletes had approximately 8 years fewer sporting experience and were yet to obtain sustained success on the international stage. Additionally, the average age of the subelite sample is 20 years; thus, they are still undergoing the behavioral, cognitive, and neuronal changes that occur during the transition from late adolescence to young adulthood (Blakemore and Robbins, 2012). Previous work has used broad definitions of elite status in sport, and as such overlooked different categories within the spectrum of elite athletes (Swann et al., 2015). Therefore it is important to consider subelite athletes as a discrete point on the developmental trajectory of elite sporting expertise. / Objective: This work aims to investigate the influence of physical pressure on key indicators of decision-making in subelite athletes. It forms part of a wider project examining decision-making across different stages of the developmental trajectory in elite sport. In doing so, it aims to examine how to apply and develop psychological insights useful to an elite sporting environment. / Methods: 32 subelite athletes (18 males, mean age: 20 years) participated in the study. Performance across three categories of decision-making was assessed under conditions of low and high physical pressure. Decision-making under risk was measured with performance of the Cambridge Gambling Task (CGT; Rogers et al., 1999), decision-making under uncertainty with the Balloon Analogue Risk Task (BART; Lejuez et al., 2002), and fast reactive responses and inhibition via the Stop Signal Reaction Time Task (SSRT; Logan, 1994). Physical exhaustion was induced via intervals of maximal exertion exercise on a wattbike. / Results: Under pressure subelite athletes showed increased risk taking for both decisions where probability outcomes were explicit (on the CGT), and those where probability outcomes were unknown (on the BART). Despite making quicker decisions under pressure, with fewer errors, on the CGT, subelite athletes showed a reduced ability to optimally adjust betting behavior according to reward and loss contingencies. Fast reactive responses to perceptual stimuli and response inhibition did not change as a result of physical pressure. Individual responses to pressure showed a negative correlation in that a decrease in reaction times on the SSRT Task under pressure was associated with an increase in risk taking on the BART. When assessing the applicability of results based on group averages to individual athletes, 17% of the sample showed an “average” response (within 1 SD of the mean) to pressure across all three decision-making tasks. / Conclusion: Indicators of decision-making in a sample of subelite athletes are influenced by physical pressure, with a shift toward increased indiscriminate risk taking. The influence that physical pressure has on decision-making was different to that observed in world-class elite athletes; this highlights the importance of distinguishing between athletes at the elite level (Swann et al., 2015). The application of this work to a novel subgroup of elite athletes, including the implementation of a decision-making taxonomy, is discussed
Memory for time distinguishes between perception and action
No full textOur experience of time is unlike that of other features of the sensory world such as colour, movement, touch, or sound because there is no unique receptor system through which it is received. However, since time call be perceived, remembered, estimated, and compared in a way analogous to other sensory experiences, it should perhaps be Subject to some of the same architectures or principles that have advanced understanding in these other domains. By adapting a task designed to test visual memory within a perception/action framework we investigated whether memory for time is affected by the use to which temporal information is put. When remembering a visual or auditory duration for subsequent motor production, storage is biased by a delay of up to 8 s. When the same duration is remembered for subsequent perception, however, there is no such effect of delay on memory. The results suggest a distinction in temporal memory that parallels the perception/action dichotomy in vision
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