http://apsychoserver.psychofizz.psych.arizona.edu/JJBAReprints/PSYC501A/Readings/Polich_2007_Clin_Neurophys_Review_P3s.pdf

Updating P300: An Integrative Theory of P3a and P3b

This article examines the role of attention and automaticity in auditory processing as revealed by event-related potential (ERP) research. An ERP component called the mismatch negativity , generated by the brain's automatic response to changes in repetitive auditory input, reveals that physical features of auditory stimuli are fully processed whether or not they are attended. It also suggests that there exist precise neuronal representations of the physical features of recent auditory stimuli, perhaps the traces underlying acoustic sensory (“echoic”) memory. A mechanism of passive attention switching in response to changes in repetitive input is also implicated. Conscious perception of discrete acoustic stimuli might be mediated by some of the mechanisms underlying another ERP component (NI), one sensitive to stimulus onset and offset. Frequent passive attentional shifts might accountforthe effect cognitive psychologists describe as “the breakthrough of the unattended” (Broadbent 1982), that is, that even unattended stimuli may be semantically processed, without assuming automatic semantic processing or late selection in selective attention. The processing negativity supports the early-selection theory and may arise from a mechanism for selectively attending to stimuli defined by certain features. This stimulus selection occurs in the form ofa matching process in which each input is compared with the “attentional trace,” a voluntarily maintained representation of the task-relevant features of the stimulus to be attended. The attentional mechanism described might underlie the stimulus-set mode of attention proposed by Broadbent. Finally, a model of automatic and attentional processing in audition is proposed that is based mainly on the aforementioned ERP components and some other physiological measures.

The role of attention in auditory information processing as revealed by event-related potentials and other brain measures of cognitive function

Effects of crossmodal divided attention on late ERP components. II. Error processing in choice reaction tasks.

THE ability to respond to unexpected stimuli (the 'orienting response') is a fundamental characteristic of mammalian behaviour1, but the brain mechanisms by which novelty is detected remain poorly defined. Electrophysiological recordings of scalp and intracranial event-related potentials (ERPs) have shown that novel stimuli activate a distributed network involving prefrontal and posterior association cortex2–6. In addition, ERP7,8 and single-neuron9,10 recordings, as well as neuroimaging11 and modelling12 studies, have suggested that temporal cortical regions, including the hippocampus, are also involved. To examine further the role of the medial temporal lobe in novelty processing, I measured physiological responses to novel auditory and tactile stimuli in patients with damage to the posterior hippocampal region. In normal control subjects, unexpected novel stimuli produce a characteristic ERP signal, accompanied by an autonomic skin response. Both responses are reduced in hippocampal lesion patients, whereas the response to expected control stimuli is unaffected. Thus the hippocampal region, in addition to its known role in memory formation, is an essential component of the distributed limbic–cortical network that detects and responds to novel stimuli.

Contribution of human hippocampal region to novelty detection.

The neurophysiological mechanisms underlying mismatch negativity (MMN) can be inferred from an examination of some of the brain generators involved in the process of this event-related potential (ERP) component. ERPs were recorded in two studies in which the subjects were involved in a selective dichotic listening task. Subjects were required to silently count rare stimuli deviating in pitch from a sequence of standard stimuli in one ear, while ignoring all the stimuli (standards and deviants) delivered randomly to the other ear. The results showed that, in all cases, the negative wave elicited by the deviant stimuli showed the highest amplitudes over the right hemiscalp irrespective of the ear of stimulation or the direction of attention. Scalp radial current density analysis showed that this asymmetric potential distribution could be attributed to the sum of activities of two sets of neural generators: one temporal, located in the vicinity of the primary auditory cortex, predominantly activated in the hemisphere contralateral to the ear of stimulation, and the other frontal, involving mainly the right hemisphere.



The results are discussed in light of Naatanen's model: we suggest the dissociation of two functional processes on the basis of activity of distinct brain areas: a sensory memory mechanism related to the temporal generators, and an automatic attention-switching process related to the frontal generators.

Brain generators implicated in the processing of auditory stimulus deviance: a topographic event-related potential study.

Analysis of single-trial electroencephalogram waveforms in a reaction time task demonstrated that the onset and offset values of event-related potentials can be used as indices of the duration of information processing. Two negative waves have been identified which peak at different times in different regions of the scalp, with the second overlapping the last part of the first. These waves are related in different ways to the duration of perceptual processing.

https://science.sciencemag.org/content/sci/215/4538/1413.full.pdf

Onset and offset of brain events as indices of mental chronometry

Attention impairment and psychomotor retardation in depressed patients: an event-related potential study

Potentiels evoques par l'apparition de patterns: effets de la dimension du pattern et de la densite des contrastes

Publisher Summary This chapter discusses correct and incorrect responses in a choice reaction time task and the endogenous components of the evoked potential. The results clearly demonstrate that, when the subject has to deal successively with auditory and visual stimuli within one same run, an endogenous negative wave develops and peaks at the same location as that of the modality-specific potential obtained in response to relevant stimuli. These modality-specific negative potentials (MSNPs) are the only ones to be highly correlated with RTs. Some more points must be emphasized that may contribute to the interpretation of the vertex non-specific negative wave observed for visual stimuli: (1) this wave is followed by a P300 and looks like the N2-P3a complex in response to novel irrelevant stimuli, (2) its amplitude increases for unexpected stimuli whatever the modality (P= 0.01 across modalities, sign test), and (3) in the case of incorrect responses, some preliminary results obtained from a trial-by-trial analysis showed two kinds of vertex activity in response to auditory stimuli: the first one looked like the usual AEmP and the second one, of much higher amplitude, is similar to the K-complex described long ago as representing a surprise effect.

Nicole Lesevre

Papers

Onset and offset of brain events as indices of mental chronometry

Attention impairment and psychomotor retardation in depressed patients: an event-related potential study

Potentiels evoques par l'apparition de patterns: effets de la dimension du pattern et de la densite des contrastes

Correct and Incorrect Responses in a Choice Reaction Time Task and the Endogenous Components of the Evoked Potential

Electrophysiological changes elicited by auditory stimuli given a positive or negative value: a study comparing anhedonic with hedonic subjects.