Feedback in hypothesis testing: An ERP study

We used event-related potentials (ERPs) to probe the effects of feedback in a hypothesis testing (HT) paradigm. Thirteen college students serially tested hypotheses concerning a hidden rule by judging its presence or absence in triplets of digits and revised them on the basis of an exogenous performance feedback. ERPs time-locked to performance feedback were then examined. The results showed differences between responses to positive and negative feedback at all cortical sites. Negative feedback, indicating incorrect performance, was associated to a negative deflection preceding a P300-like wave. Spatiotemporal principal component analysis (PCA) showed the interplay between early frontal components and later central and posterior ones. Lateralization of activity was selectively detectable at frontal sites, with a left frontal dominance for both positive and negative feedback. These results are discussed in terms of a proposed computational model of trial-to-trial feedback in HT in which the cognitive and emotive aspects of feedback are explicitly linked to putative mediating brain mechanisms. The properties of different feedback types and feedback-related deficits in depression are also discussed

Time-varying spectral entropy differentiates between positive and negative feed back-related EEG activity in a hypothesis testing paradigm

Positive and negative performance feedbacks have been shown to differentially modulate amplitudes of the associated electroencephalographic (EEG) brain activity. In the present study, we tested whether feedback also modulates the organization of neuronal oscillations. Ten college students serially tested hypotheses concerning a hidden rule by judging its presence or absence in triplets of digits and revised them on the basis of an exogenous performance feedback. The EEG signal time-locked to feedback was convolved with a family of complex wavelets. The time-varying spectral entropy of the resulting time-frequency representation was then computed. The results showed that feedback differentially modulated spectral organization at frontal and posterior scalp regions around 200 ms and in the 300-500 ms range. Spatio-temporal principal component analysis (PCA) indicated that feedback-specific modulations essentially resulted from the interplay between fronto-polar, fronto-central, and parieto-occipital components. Functional and methodological implications were discussed. © 2007 Elsevier B.V. All rights reserved

Modulation of late alpha band oscillations by feedback in a hypothesis testing paradigm

We used the electroencephalogram (EEG) to investigate whether positive and negative performance feedbacks differentially modulate late time-locked oscillatory brain activity in hypothesis testing. Ten college students serially tested hypotheses concerning a hidden rule by judging its presence or absence in triplets of digits, and revised them on the basis of an exogenous performance feedback. The EEG signal was convolved with a family of complex wavelets and induced brain potentials were extracted in the alpha range (8-13 Hz). The time-varying modulation of alpha activity time-locked to positive and negative feedback was analyzed in the 350-700 ms time-window. The results showed differential feedback-induced modulations of upper-alpha rhythms (≥ 10 Hz) between 450 and 700 ms in parieto-occipital and central regions, and of lower-alpha rhythms (< 10 Hz) between 350 and 450 ms in central regions. These results were interpreted in terms of differential functional roles of feedback in short-term memory and active inhibition/disinhibition of resources for subsequent hypothesis testing. Some implications for cognitive models of feedback are discussed. © 2006 Elsevier B.V. All rights reserved

Feedback modulates gamma oscillations in a hypothesis testing paradigm

We analyzed the time-varying modulation of gamma (> 30 Hz) electroencephalographic (EEG) activity exerted by positive and negative feedback in a hypothesis testing paradigm. Ten college students serially tested hypotheses concerning a hidden rule by judging its presence or absence in triplets of digits and revised them on the basis of an exogenous performance feedback. The EEG signal was convolved with a family of complex wavelets and brain potentials were extracted in the gamma range. Feedback-related modulations were found as early as 100 ms after feedback onset, as well as in the 300-600 ms time-window. The results were discussed in terms of functional and neurophysiological models of feedback. © 2007 Elsevier B.V. All rights reserved

Time-frequency intracranial source localization of feedback-related EEG activity in hypothesis testing

The neural correlates of the response to performance feedback have been the object of numerous neuroimaging studies. However, the precise timing and functional meaning of the resulting activations are poorly understood. We studied the electroencephalographic response time locked to positive and negative performance feedback in a hypothesis testing paradigm. The signal was convoluted with a family of complex wavelets. Intracranial sources of activity at various narrow-band frequencies were estimated in the 100- to 400-ms time window following feedback onset. Positive and negative feedback were associated to 1) early parahippocampo-cingular sources of alpha oscillations, more posteriorly located and long lasting for negative feedback and to 2) late partially overlapping neural circuits comprising regions in prefrontal, cingular, and temporal cortices but operating at feedback-specific latencies and frequencies. The results were interpreted in the light of neurophysiological models of feedback and were used to discuss methodological issues in the study of high-level cognitive functions, including reasoning and decision making. © The Author 2006. Published by Oxford University Press. All rights reserved