An electrophysiological investigation of glucose effects in the Flanker task
Seiss, E, Hope, C, Dean, PJA and Sterr, A (2010) An electrophysiological investigation of glucose effects in the Flanker task In: Warwick Workshop on Motor Priming and Cognitive Control, 17-19 August, 2010. University of Warwick, Coventry , UK.
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Behavioural studies have indicated that response times on complex reaction time tasks are faster if blood glucose concentrations are slightly elevated above normal (Donohoe & Benton, 2000). Such tasks involve several cognitive processing stages but it is not clear which of these stages are speeded after glucose administration. In order to investigate this problem we have used a double blind repeated measures design for the administration of glucose and placebo drinks. Participants performed a Flanker task while EEG was recorded as a physiological measure. More specifically, we used a Flanker task that required participants to respond to either left or right pointing central arrows by pressing a left or a right button, respectively. In addition on each trial there are extra arrows surrounding the central arrow which all either pointed in the same (congruent condition) or opposite (incongruent condition) direction as the central arrow or they were lines without an arrow head (neutral condition) All condition were presented equiprobably. No significant differences between the glucose and placebo condition were observed in mean reaction times and errors rates. However the ERP data showed that the N1 amplitude was significantly increased after glucose administration. This could indicate that stimulus identification is influenced by glucose administration, as previous researchers have found an increased N1 amplitude during discriminative feature processing compared to simple detection tasks (Hopf et al., 2002). In addition, mean reaction times and error rates were analysed separately for each of the 8 blocks. Differences between drink types were only found for the reaction times of the first block. Participants who had received glucose during their 1st session and placebo during the 2nd session, had longer reaction times after glucose administration compared to placebo. However this effect was not found for participants who received placebo before glucose drinks. These findings might be linked to task difficulty effects. Previous research has shown that high task difficulty is necessary to find glucose enhancement effects on the Hick task (sensorimotor function; Donohoe & Benton, 2000), working memory (Kennedy & Scholey, 2001) and episodic memory (Sünram-Lea et al., 2002). Our results conflict directly with Donohoe and Benton’s (2000), potentially caused by methodological or task differences. It might be also possible that separate cognitive processes might be differently affected by glucose; which should be explored in future studies.
|Item Type:||Conference or Workshop Item (Conference Poster)|
|Divisions :||Faculty of Health and Medical Sciences > School of Psychology|
|Date :||18 August 2010|
|Related URLs :|
|Depositing User :||Symplectic Elements|
|Date Deposited :||13 Nov 2013 14:49|
|Last Modified :||09 Jun 2014 13:42|
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