- Email: [email protected]
State anxiety and nonlinear heart rate variability
IOP 2016
Methods: visual eye-tracking while reading words versus pseudohomophones (one letter substituted; e.g. corasón instead of corazón: heart) was studied in two conditions: explicit (participants had to detect a misspelling error) and implicit orthographic recognition (they were instructed to respond if a letter “e” was included in the word). 32 healthy, right-handed participants within an age range from 17 to 19 years old, were selected from a wider screening study and divided into three equal groups of 14, according to their performance on a 5-test battery of orthographic competence (HSS: High Spelling Skills, ASS: Average Spelling Skills, and LSS: Low Spelling Skills). Results: LSS showed a significantly minor number and less prolonged fixations than HSS in the area of interest (AOI), located around the letter substituted in misspelled words for both explicit and implicit recognition tasks. HSS showed similar eye-patterns when pseudohomophones appeared, regardless of their relevance to task performance. Conclusions: Lower levels of orthographic efficiency may reflect difficulties automatizing the word recognition processes and/or problems with the storage and rapid access to the orthographic lexicon, even during advanced stages of reading development. doi:10.1016/j.ijpsycho.2016.07.333
75 Heavy alcohol use is not associated with disinhibition in young males Janette L. Smith, Jaimi M. Iredale, Richard P. Mattick University of NSW, Sydney, Australia Background: We investigated the possibility of sex differences in the relationship between heavy alcohol use and deficits in behavioural control in a sample of males, with identical recruitment criteria and protocol to our previously published sample of females. Methods: Participants were 41 males aged 18-21, who either drank heavily regularly (i.e., four standard drinks on one occasion, at least once a month, n = 20) or drank heavily less often than this (including never, n = 21). Previous history of alcohol use was assessed before completion of a stop-signal task while EEG was recorded. Results: Male heavy drinkers showed no differences to controls for any behavioural performance (probability of inhibition, stopsignal reaction time, Go accuracy or Go RT) or event-related potential measure (P3 to failed and successful inhibition trials, and ERN amplitudes). There were no significant relationships between these measures and questionnaire scores indicating hazardous and harmful drinking. Discussion: Despite identical recruitment criteria and similar significant increases in alcohol use, the males in this study showed none of the deficits in inhibition or performance monitoring identified in the female sample. Possible reasons for this difference will be discussed. Future research may determine whether this sex difference is also apparent for other substances of abuse, and when the inhibitory process, intact in young male heavy drinkers, becomes damaged, as is typically observed in older male alcohol dependent participants. Conclusion: Deficits in inhibitory processing associated with heavy drinking, previously established in females, appear to be absent in males. doi:10.1016/j.ijpsycho.2016.07.334
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76 State anxiety and nonlinear heart rate variability Elena Saperova, Dmitry Dimitriev Ekaterina Koltzova Chuvash State Pedagogical University, Cheboksary, Russia Background: Anxiety is a negative emotional response to threatening circumstances. Clinical and experimental research has demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. Nonlinear techniques are able to describe heart rate variability in a more effective manner. The purpose of the present study was to investigate the possible application of nonlinear analysis of heart rate variability to the study of state anxiety. Methods: The sample consisted of 96 students volunteered to participate in the study. For each student, two 10-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger’s State-Trait Anxiety Inventory was used to assess the level of state anxiety. Results: Before adjusting for heart rate, a Wilcoxon matched pairs test showed a significant decreasing of Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), pointwise correlation dimension (PD2) and increasing of the short-term fractal-like scaling exponent of detrended fluctuation analysis during the exam session, compared to the rest period. Applying Pearson analysis indicated significant negative correlations between the dynamics of state anxiety and SD1/SD2, and between changes in state anxiety and changes of entropy measures. There was a strong negative correlation between the dynamics of SA and LLE (r = -0.45, p b0.05). A significant positive correlation was found between the dynamics of SA and α1 (r = 0.22, p b0.05). Declines of SD1, Complex Correlation measure (CCM), SampEn and LLE were still significant after adjusting for heart rate. Corrected short-term fractal scaling exponent (α1) was also increased during the exam session. As before, dynamics of adjusted LLE were significantly correlated with the dynamics of SA. Conclusions: This study shows that state anxiety is associated with increasing in state anxiety during academic examination is related to the decrease in complexity and decrease in size of the Poincaré plot through reduction of both the interbeat interval and its variation. doi:10.1016/j.ijpsycho.2016.07.335
86 Individual differences in working memory precision based on selective attention Anne-Katrin Vellage, Notger G. Müller German Centre of Neurodegenerative Diseases (DZNE) Magdeburg, Magdeburg, Germany The idea of a concrete item limit in working memory has been challenged in the past years by studies investigating the precision of memories. However, the influence of irrelevant information on precision of memories and memory limits is less investigated and was subject of the present study. Is there an individual tradeoff between memory precision and memory capacity? Do subjects with a high working memory capacity (WMC) memorize information with less precision, but are also less prone to distractors?
Methods: visual eye-tracking while reading words versus pseudohomophones (one letter substituted; e.g. corasón instead of corazón: heart) was studied in two conditions: explicit (participants had to detect a misspelling error) and implicit orthographic recognition (they were instructed to respond if a letter “e” was included in the word). 32 healthy, right-handed participants within an age range from 17 to 19 years old, were selected from a wider screening study and divided into three equal groups of 14, according to their performance on a 5-test battery of orthographic competence (HSS: High Spelling Skills, ASS: Average Spelling Skills, and LSS: Low Spelling Skills). Results: LSS showed a significantly minor number and less prolonged fixations than HSS in the area of interest (AOI), located around the letter substituted in misspelled words for both explicit and implicit recognition tasks. HSS showed similar eye-patterns when pseudohomophones appeared, regardless of their relevance to task performance. Conclusions: Lower levels of orthographic efficiency may reflect difficulties automatizing the word recognition processes and/or problems with the storage and rapid access to the orthographic lexicon, even during advanced stages of reading development. doi:10.1016/j.ijpsycho.2016.07.333
75 Heavy alcohol use is not associated with disinhibition in young males Janette L. Smith, Jaimi M. Iredale, Richard P. Mattick University of NSW, Sydney, Australia Background: We investigated the possibility of sex differences in the relationship between heavy alcohol use and deficits in behavioural control in a sample of males, with identical recruitment criteria and protocol to our previously published sample of females. Methods: Participants were 41 males aged 18-21, who either drank heavily regularly (i.e., four standard drinks on one occasion, at least once a month, n = 20) or drank heavily less often than this (including never, n = 21). Previous history of alcohol use was assessed before completion of a stop-signal task while EEG was recorded. Results: Male heavy drinkers showed no differences to controls for any behavioural performance (probability of inhibition, stopsignal reaction time, Go accuracy or Go RT) or event-related potential measure (P3 to failed and successful inhibition trials, and ERN amplitudes). There were no significant relationships between these measures and questionnaire scores indicating hazardous and harmful drinking. Discussion: Despite identical recruitment criteria and similar significant increases in alcohol use, the males in this study showed none of the deficits in inhibition or performance monitoring identified in the female sample. Possible reasons for this difference will be discussed. Future research may determine whether this sex difference is also apparent for other substances of abuse, and when the inhibitory process, intact in young male heavy drinkers, becomes damaged, as is typically observed in older male alcohol dependent participants. Conclusion: Deficits in inhibitory processing associated with heavy drinking, previously established in females, appear to be absent in males. doi:10.1016/j.ijpsycho.2016.07.334
111
76 State anxiety and nonlinear heart rate variability Elena Saperova, Dmitry Dimitriev Ekaterina Koltzova Chuvash State Pedagogical University, Cheboksary, Russia Background: Anxiety is a negative emotional response to threatening circumstances. Clinical and experimental research has demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. Nonlinear techniques are able to describe heart rate variability in a more effective manner. The purpose of the present study was to investigate the possible application of nonlinear analysis of heart rate variability to the study of state anxiety. Methods: The sample consisted of 96 students volunteered to participate in the study. For each student, two 10-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger’s State-Trait Anxiety Inventory was used to assess the level of state anxiety. Results: Before adjusting for heart rate, a Wilcoxon matched pairs test showed a significant decreasing of Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), pointwise correlation dimension (PD2) and increasing of the short-term fractal-like scaling exponent of detrended fluctuation analysis during the exam session, compared to the rest period. Applying Pearson analysis indicated significant negative correlations between the dynamics of state anxiety and SD1/SD2, and between changes in state anxiety and changes of entropy measures. There was a strong negative correlation between the dynamics of SA and LLE (r = -0.45, p b0.05). A significant positive correlation was found between the dynamics of SA and α1 (r = 0.22, p b0.05). Declines of SD1, Complex Correlation measure (CCM), SampEn and LLE were still significant after adjusting for heart rate. Corrected short-term fractal scaling exponent (α1) was also increased during the exam session. As before, dynamics of adjusted LLE were significantly correlated with the dynamics of SA. Conclusions: This study shows that state anxiety is associated with increasing in state anxiety during academic examination is related to the decrease in complexity and decrease in size of the Poincaré plot through reduction of both the interbeat interval and its variation. doi:10.1016/j.ijpsycho.2016.07.335
86 Individual differences in working memory precision based on selective attention Anne-Katrin Vellage, Notger G. Müller German Centre of Neurodegenerative Diseases (DZNE) Magdeburg, Magdeburg, Germany The idea of a concrete item limit in working memory has been challenged in the past years by studies investigating the precision of memories. However, the influence of irrelevant information on precision of memories and memory limits is less investigated and was subject of the present study. Is there an individual tradeoff between memory precision and memory capacity? Do subjects with a high working memory capacity (WMC) memorize information with less precision, but are also less prone to distractors?