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Aging and error processing: age related increase in the variability of the error-negativity is not accompanied by increase in response variability.

Hoffmann S, Falkenstein M - PLoS ONE (2011)

Bottom Line: In the present study we aimed to investigate whether the Ne reduction usually found in older subjects is due to an altered component structure, i.e., a true alteration in response monitoring in older subjects.The results show a genuine reduction as well as a different component structure of the Ne in older compared to young subjects.Hence, the results indicate that older subjects can compensate the reduction in control reflected in the reduced Ne, at least in simple tasks that induce reaction slips.

View Article: PubMed Central - PubMed

Affiliation: Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany. shoffmann@ifado.de

ABSTRACT

Background: Several studies report an amplitude reduction of the error negativity (Ne or ERN), an event-related potential occurring after erroneous responses, in older participants. In earlier studies it was shown that the Ne can be explained by a single independent component. In the present study we aimed to investigate whether the Ne reduction usually found in older subjects is due to an altered component structure, i.e., a true alteration in response monitoring in older subjects.

Methodology/principal findings: Two age groups conducted two tasks with different stimulus response mappings and task difficulty. Both groups received fully balanced speed or accuracy instructions and an individually adapted deadline in both tasks. Event-related potentials, Independent Component analysis of EEG-data and between trial variability of the Ne were combined with analysis of error rates, coefficients of variation of RT-data and ex-Gaussian fittings to reaction times. The Ne was examined by means of ICA and PCA, yielding a prominent independent component on error trials, the Ne-IC. The Ne-IC was smaller in the older than the younger subjects for both speed and accuracy instructions. Also, the Ne-IC contributed to a much lesser extent to the Ne in older than in younger subjects. RT distribution parameters were not related to Ne/ERP-variability.

Conclusions/significance: The results show a genuine reduction as well as a different component structure of the Ne in older compared to young subjects. This reduction is not reflected in behaviour, apart from a general slowing of older participants. Also, the Ne decline in the elderly is not due to speed accuracy trade-off. Hence, the results indicate that older subjects can compensate the reduction in control reflected in the reduced Ne, at least in simple tasks that induce reaction slips.

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Topographic distribution of the average number of principle components accounting for 90% of variance.Estimation of the variability between trials in the Ne-time window for both tasks. Blue indicates less variability between trials; red indicates more variability between trials. Beside each topography a colour legend is provided indicating the number of principle components (PCs) explaining at least 90% of variance between trials. For example having a look at the topography of the young subjects in the flanker task, one can see that at FCz about three principle components explain at least 90% of variance between trials. In older participants (left) about five principle components explain at least 90% of variance between trials. Note that in general the signal is least variable at fronto-central positions and reflects the typical Ne-topography.
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pone-0017482-g002: Topographic distribution of the average number of principle components accounting for 90% of variance.Estimation of the variability between trials in the Ne-time window for both tasks. Blue indicates less variability between trials; red indicates more variability between trials. Beside each topography a colour legend is provided indicating the number of principle components (PCs) explaining at least 90% of variance between trials. For example having a look at the topography of the young subjects in the flanker task, one can see that at FCz about three principle components explain at least 90% of variance between trials. In older participants (left) about five principle components explain at least 90% of variance between trials. Note that in general the signal is least variable at fronto-central positions and reflects the typical Ne-topography.

Mentions: With respect to the estimation of the trial-to-trial variability of the Ne at FCz by means of PCA the results show that the Ne of older participants showed more variability between trials than the Ne of younger subjects [F(1,34) = 28.55, p<.001, η2 = .46] and in the rotation task compared to the flanker task [F(1,34) = 11.3, p<.01, η2 = .25]: In younger subjects, fewer principle components account for 90% of the variance between the trials than for older subjects. This was true for the flanker task as well as for the rotation task. Figure 2 shows the scalp distributions of the variability, which was calculated by estimating the number of components which explain at least 90% of variance for the erroneous trials with respect to the Ne-time window.


Aging and error processing: age related increase in the variability of the error-negativity is not accompanied by increase in response variability.

Hoffmann S, Falkenstein M - PLoS ONE (2011)

Topographic distribution of the average number of principle components accounting for 90% of variance.Estimation of the variability between trials in the Ne-time window for both tasks. Blue indicates less variability between trials; red indicates more variability between trials. Beside each topography a colour legend is provided indicating the number of principle components (PCs) explaining at least 90% of variance between trials. For example having a look at the topography of the young subjects in the flanker task, one can see that at FCz about three principle components explain at least 90% of variance between trials. In older participants (left) about five principle components explain at least 90% of variance between trials. Note that in general the signal is least variable at fronto-central positions and reflects the typical Ne-topography.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3046248&req=5

pone-0017482-g002: Topographic distribution of the average number of principle components accounting for 90% of variance.Estimation of the variability between trials in the Ne-time window for both tasks. Blue indicates less variability between trials; red indicates more variability between trials. Beside each topography a colour legend is provided indicating the number of principle components (PCs) explaining at least 90% of variance between trials. For example having a look at the topography of the young subjects in the flanker task, one can see that at FCz about three principle components explain at least 90% of variance between trials. In older participants (left) about five principle components explain at least 90% of variance between trials. Note that in general the signal is least variable at fronto-central positions and reflects the typical Ne-topography.
Mentions: With respect to the estimation of the trial-to-trial variability of the Ne at FCz by means of PCA the results show that the Ne of older participants showed more variability between trials than the Ne of younger subjects [F(1,34) = 28.55, p<.001, η2 = .46] and in the rotation task compared to the flanker task [F(1,34) = 11.3, p<.01, η2 = .25]: In younger subjects, fewer principle components account for 90% of the variance between the trials than for older subjects. This was true for the flanker task as well as for the rotation task. Figure 2 shows the scalp distributions of the variability, which was calculated by estimating the number of components which explain at least 90% of variance for the erroneous trials with respect to the Ne-time window.

Bottom Line: In the present study we aimed to investigate whether the Ne reduction usually found in older subjects is due to an altered component structure, i.e., a true alteration in response monitoring in older subjects.The results show a genuine reduction as well as a different component structure of the Ne in older compared to young subjects.Hence, the results indicate that older subjects can compensate the reduction in control reflected in the reduced Ne, at least in simple tasks that induce reaction slips.

View Article: PubMed Central - PubMed

Affiliation: Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany. shoffmann@ifado.de

ABSTRACT

Background: Several studies report an amplitude reduction of the error negativity (Ne or ERN), an event-related potential occurring after erroneous responses, in older participants. In earlier studies it was shown that the Ne can be explained by a single independent component. In the present study we aimed to investigate whether the Ne reduction usually found in older subjects is due to an altered component structure, i.e., a true alteration in response monitoring in older subjects.

Methodology/principal findings: Two age groups conducted two tasks with different stimulus response mappings and task difficulty. Both groups received fully balanced speed or accuracy instructions and an individually adapted deadline in both tasks. Event-related potentials, Independent Component analysis of EEG-data and between trial variability of the Ne were combined with analysis of error rates, coefficients of variation of RT-data and ex-Gaussian fittings to reaction times. The Ne was examined by means of ICA and PCA, yielding a prominent independent component on error trials, the Ne-IC. The Ne-IC was smaller in the older than the younger subjects for both speed and accuracy instructions. Also, the Ne-IC contributed to a much lesser extent to the Ne in older than in younger subjects. RT distribution parameters were not related to Ne/ERP-variability.

Conclusions/significance: The results show a genuine reduction as well as a different component structure of the Ne in older compared to young subjects. This reduction is not reflected in behaviour, apart from a general slowing of older participants. Also, the Ne decline in the elderly is not due to speed accuracy trade-off. Hence, the results indicate that older subjects can compensate the reduction in control reflected in the reduced Ne, at least in simple tasks that induce reaction slips.

Show MeSH
Related in: MedlinePlus