2,990 research outputs found
Glucose modulates event-related potential components of recollection and familiarity in healthy adolescents.
No full textIntroduction Behavioural evidence supports the notion that oral glucose ingestion enhances recognition memory judgements based on recollection, but not familiarity. The present study sought to clarify and extend upon these behavioural findings by investigating the influence of glucose administration on event-related potential (ERP) components that are thought to be differentially mediated by recollection and familiarity processes in healthy adolescents. Methods In a within-subjects design, participants performed a recognition memory task, during which time electroencephalogram (EEG) was recorded, subsequent to ingestion of either (a) glucose or (b) placebo in a counterbalanced order. Results Response times during the recognition memory task were observed to be faster for the glucose condition, relative to a placebo control. Further, glucose ingestion was associated with an enhanced left parietal old/new ERP effect (a marker of recollection) and an enhanced mid-frontal old/new ERP effect (known to be mediated by familiarity). Discussion These findings (a) support the results of previous research that the ‘glucose memory facilitation effect’ can be extended to healthy adolescents, but (b) suggest that glucose enhances both the recollection and familiarity components of recognition memory. The observed ERP profile has important implications for the proposal that glucose specifically targets the hippocampus in modulating cognitive performance
Lifestyle, glucose regulation and the cognitive effects of glucose load in middle-aged adults
No full textInterventions aimed at improving glucose regulatory mechanisms have been suggested as a possible source of cognitive enhancement in the elderly. In particular, previous research has identified episodic memory as a target for facilitation after either moderate increases in glycaemia (after a glucose drink) or after improvements in glucose regulation. The present study aimed to extend this research by examining the joint effects of glucose ingestion and glucose regulation on cognition. In addition, risk factors associated with the development of poor glucose regulation in middle-aged adults were considered. In a repeated measures design, thirty-three middle-aged adults (aged 35–55 years) performed a battery of memory and non-memory tasks after either 25 g or 50 g glucose or a sweetness matched placebo drink. To assess the impact of individual differences in glucose regulation, blood glucose measurements were taken on four occasions during testing. A lifestyle and diet questionnaire was also administered. Consistent with previous research, episodic memory ability benefited from glucose ingestion when task demands were high. Blood glucose concentration was also found to predict performance across a number of cognitive domains. Interestingly, the risk factors associated with poor glucose regulation were linked to dietary impacts traditionally associated with poor health, e.g. the consumption of high-sugar sweets and drinks. The research replicates earlier work suggesting that task demands are critical to the glucose facilitation effect. Importantly, the data demonstrate clear associations between elevated glycaemia and relatively poor cognitive performance, which may be partly due to the effect of dietary and lifestyle factors
Spontaneous and cued gaze-following in autism and Williams syndrome
No full textBackground: From a young age the typical development of social functioning relies upon the allocation of attention to socially relevant information, which in turn allows experience at processing such information and thus enhances social cognition. As such, research has attempted to identify the developmental processes that are derailed in some neuro-developmental disorders that impact upon social functioning. Williams syndrome (WS) and Autism are disorders of development that are characterized by atypical yet divergent social phenotypes and atypicalities of attention to people. Methods: We used eye tracking to explore how individuals with WS and Autism attended to, and subsequently interpreted, an actor’s eye gaze cue within a social scene. Images were presented for three seconds, initially with an instruction simply to look at the picture. The images were then shown again, with the participant asked to identify the object being looked at. Allocation of eye-gaze in each condition was analyzed by ANOVA and accuracy of identification was compared with t-tests. Results: Participants with WS allocated more gaze time to face and eyes than their matched controls both with and without being asked to identify the item being looked at; while participants with Autism spent less time on face and eyes in both conditions. When cued to follow gaze, participants with WS increased gaze to the correct targets, while those with Autism looked more at the face and eyes but did not increase gaze to the correct targets, while continuing to look much more than their controls at implausible targets. Both groups identified fewer objects than their controls. Conclusions: The atypicalities found are likely to be entwined with the deficits shown in interpreting social cognitive cues from the images. WS and Autism are characterised by atypicalities of social attention that impact upon socio-cognitive expertise but importantly the type of atypicality is syndrome-specific
Colección: Perfil #3
No full textThis board-book version of LM turns out to be quite creative. Ratoncete comes from school every afternoon and goes through the forest looking for adventures. He apparently blasts a horn into the ear of the sleeping lion. Don Leon wants to spank him as a result, but Ratoncete offers an apology, not an offer of help. Later, he happens upon the lion in his trap of ropes. 8 pages, counting both covers. 6½" x 9".Language note: SpanishNo Autho
Glucose enhancement of event-related potentials associated with episodic memory and attention
No full textPrevious studies have reported that increasing glycaemia by a glucose-containing drink enhances memory functioning. The aim of the present study was to extend this literature by examining the effects of glucose on episodic memory as well as attention processes, and to investigate associated event-related potential (ERP) markers. Fifteen minutes after treatment (25 g glucose or placebo drink), 35 participants performed an old/new recognition memory task and a Stroop colour naming task. Consistent with previous research, when controlling for glucose regulation, cognitive facilitation was observed behaviourally for verbal memory, but there was also a trend towards attentional facilitation. Furthermore, across both domains, it was the most demanding task conditions that exhibited glucose sensitivity. In support of the behavioural results, the analysis of ERPs across treatment groups revealed an enhanced left-parietal old/new effect related to recollection, and also suggested modulation of attentional processes. The results suggest that glucose may facilitate attention as well as memory
The effects of age and task domain on dual task performance: A meta-analysis
No full textRecent research has argued against a general dual-tasking impairment in older adults, and suggests that task domain may be an important moderator variable (e.g. Riby, Perfect & Stollery, 2003). Here, meta-analyses were conducted on the results of studies between 1981 and 2003 to examine the conditions where older adults are impaired. A strong overall effect size indicated a clear age-related dual tasking impairment. However, this effect size was not representative of all the individual studies reported. Consequently, an analysis of variance analogue (Hedges & Olkin, 1985) was used to investigate potential moderators responsible for the variability in the effect sizes across studies. These secondary analyses included a comparision of dependant measure used (reaction time versus accuracy), whether baseline differences in performance had been controlled for and importantly the task domain. The key finding found task domain to be the crucial mediator, and those tasks with a substantial central processing component (e.g. episodic memory tasks) or motor component (e.g. tracking tasks) show greater age differences in dual tasking compared to those tasks that are data driven or rely on relatively automatic processing (e.g. simple perceptual or implicit memory tasks).Recent research has argued against a general dual-tasking impairment in older adults, and suggests that task domain may be an important moderator variable (e.g. Riby, Perfect & Stollery, 2003). Here, meta-analyses were conducted on the results of studies between 1981 and 2003 to examine the conditions where older adults are impaired. A strong overall effect size indicated a clear age-related dual tasking impairment. However, this effect size was not representative of all the individual studies reported. Consequently, an analysis of variance analogue (Hedges & Olkin, 1985) was used to investigate potential moderators responsible for the variability in the effect sizes across studies. These secondary analyses included a comparision of dependant measure used (reaction time versus accuracy), whether baseline differences in performance had been controlled for and importantly the task domain. The key finding found task domain to be the crucial mediator, and those tasks with a substantial central processing component (e.g. episodic memory tasks) or motor component (e.g. tracking tasks) show greater age differences in dual tasking compared to those tasks that are data driven or rely on relatively automatic processing (e.g. simple perceptual or implicit memory tasks)
Hippocampal involvement in glucose facilitation of recognition memory: Event-related potential components in a dual-task paradigm
No full textBackground - Glucose administration may facilitate hippocampus-mediated recognition memory (‘remember’ rather than familiarity ‘know’ responses).
Objective - This study aimed to investigate the electrophysiological correlates of this phenomenon in a cohort of older individuals.
Methods - In this double-blind placebo-controlled cross-over study, 12 older participants (mean age = 69.33 ± 1.69 years) completed the remember-know paradigm both with and without a concurrent tracking task while recording event-related potentials (ERPs).
Results - Counter to predictions, glucose reduced overall accuracy. No treatment effects were found for proportion of Remember, Know and Guess responses, although there was a trend towards greater accuracy for ‘Remember’ responses following glucose. There was weak evidence for dissociation of drink effects on tracking with glucose being associated with preferential allocation of resources to ‘Remember’ over ‘Know’ responses. At P3 and F3 electrode sites, a significantly greater left parietal (LP) recollection effect and greater FN400 effect respectively were found for glucose.
Conclusions - These findings do not support task effort modulation of the memory-enhancing effects of glucose. There was evidence of a greater glucose facilitatory effect for hippocampus-mediated LP recollection
The facilitative effects of glucose ingestion on memory retrieval in younger and older adults: is task difficulty or task domain critical?
No full textMarkets Equilibrium: The Is-Lm Model
No full text. The purpose of this study is to analyze how the concept of markets equilibrium: the IS-LM Model. This research uses library research method by using reference sources from books and journals according to the theme. The author uses a qualitative method which is explained graphically, namely the market balance of the IS-LM model where the focus is on money and goods markets associated with macroeconomics where researchers take the side of investors. The results of this study are that the balance in the economy is the point where the IS and LM curves intersect. This point provides an interest rate (r) and income level (Y) that satisfies the equilibrium conditions that occur in the goods market and money market. In other words, planned spending equals actual spending, and the demand for real money balances equals the supply. So that the IS-LM balance, it is stated that IS=LM
Type 2 Diabetes and Memory: Using Neuroimaging to Understand the Mechanisms
No full textThe most robust and frequently reported cognitive deficits in type 2 diabetes (DM2) are those that relate to memory. Behavioural research has identified a number of potential contributory physiological factors, including abnormalities in glucose metabolism, such as hyperglycaemia and hypoglycaemia. The impact of these mechanisms on memory has been further investigated through the use of both structural and functional neuroimaging. Structural brain imaging has indicated that memory impairments in DM2 are associated with global atrophy of the brain. Further data suggest that localised atrophy in the hippocampal area, a brain region critical to memory formation and consolidation, may be primarily responsible for the memory deficits seen in this population. Functional imaging data has corroborates these findings, with functional magnetic resonance imaging (fMRI) suggesting reduced connectivity between the hippocampus and surrounding brain regions, particularly the frontal and temporal gyri. Despite this, little functional neuroimaging research has directly investigated differences in regional brain activity between healthy and DM2 participants whilst memory tasks are being performed. By using neuroimaging techniques to their full potential, we can acquire a fuller, more comprehensive picture of the impact that DM2 has on memory
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