This heterogeneity results in some part from the relatively small number of conducted studies. However, the major part is explained by the huge diversity of used paradigms and auditory stimuli (Guerreiro et al. 2010). Electroencephalogram (EEG) and scalp-recorded event-related brain potentials (ERPs) are established methods in the field of cognitive neuroscience. This measurement Inhibitors,research,lifescience,medical enables researchers to gain an objective measure of neural activation patterns released by the activation of a sum of tens of thousands of synchronous firing

neural cells. Moreover, this approach convinces with an excellent temporal resolution in the range of milliseconds. Therefore, ERPs are sensitive measures of the temporal dynamics and the intensity of stimulus-induced electrocortical activity during information processing (Mueller et al.

2008). These factors make EEG the method Inhibitors,research,lifescience,medical of choice when focusing on very transient patterns as can be found in speech processing and attention modulation. The most prominent auditory evoked potential (AEP) components in the context of auditory cognition are N1 and P2, with peak amplitudes at about 100 ms and 200 ms after stimulus onset, respectively. These components are associated with early attention and orienting processes, as well as cortical arousal response (Näätänen and Picton 1987). Previous studies on age-related Inhibitors,research,lifescience,medical differences in the waveform Inhibitors,research,lifescience,medical of auditory evoked N1 and P2 components during selective attention tasks have shown

inconsistent findings. Whereas several studies indicated an enhanced N1 peak amplitude in older adults compared to younger adults (Amenedo and Diaz 1999), others do not find such differences (Brown et al. 1983; Picton et al. 1984; Barrett et al. 1987; Woods 1992; LEE011 Iragui et al. 1993). The same inconsistency can be found concerning the P2 Inhibitors,research,lifescience,medical component. Whereas some authors found increased peak amplitudes in older adults (Pfefferbaum et al. 1984; Ford and Pfefferbaum 1991; Friedman et al. 1993; Anderer et al. 1998), others do not confirm such an altered AEP pattern (Brown et al. 1983; Picton et al. 1984; Barrett et al. 1987). This study aims to investigate age-related differences in the neural processing also of spoken language during different modulations of the subject’s selective attention. By comparing early AEP components (N1/P2 complex) between young adults (YA) and older adults (OA), we hypothesize to find task-related as well as age-related differences reflected as modulations of neurophysiological parameters (latency and amplitude). By using natural speech stimuli instead of the less complex sine-wave tones, CV syllables, or monosyllabic words, we aim to achieve a stronger generalization and comparability to real-life speech processing of our results.