Beta band oscillations as a correlate of alertness — Changes in aging Mateusz Gola a, ⁎, Jan Kamiński b , Aneta Brzezicka c , Andrzej Wróbel b a Department of Psychophysiology of Cognitive Processes, Warsaw School of Social Sciences and Humanities, Poland b Laboratory of Visual System, Department of Neurophysiology, Nencki Institute of Experimental Biology, Poland c Interdisciplinary Center for Applied Cognitive Studies, Warsaw School of Social Sciences and Humanities, Poland abstract article info Article history: Received 25 February 2011 Received in revised form 29 July 2011 Accepted 1 September 2011 Available online 14 September 2011 Keywords: Attention Beta band Aging Human EEG Older adults (N 60 years) show attentional deficits in comparison to younger people (18–30 years). As beta-band EEG activity has been previously postulated to indicate attentional modulation in the visual system, we searched for possible deficits in beta power in elderly subjects performing an attentional task with spatial differentiation between visual stimuli. We found that in older adults a lower level of beta activity correlated with decreased be- havioral performance. As compared to young subjects, older adults expressed decreased activation in beta band during an attentional task, which displayed two different dynamics during the anticipatory period. Those dy- namics were accompanied by one of two different behavioral pattern deficits. We hypothesize that one group of elderly participants suffered from difficulty in the activation of attentional processes (alertness deficits), while the other — from difficulty in sustaining those processes (vigilance deficits). © 2011 Elsevier B.V. All rights reserved. 1. Introduction More than a hundred years of electrophysiological research have shown that activity in different frequency bands can be attributed to spe- cific psychophysiological states. The first observations referred to a de- crease in alpha band power (8–12 Hz) during general physiological arousal (Berger, 1930). More sophisticated analytical methods have gradually uncovered the complex, still not well understood relation be- tween activities in specific EEG frequencies and their behavioral corre- lates. Childers and Perry (1970), for example, have shown that the transition from sleep to waking state was accompanied by a decrease in the amplitude of the delta rhythm (0.5–4 Hz). Recent studies related changes in theta (4–7 Hz) activity to memory processes (Rutishauser et al., 2010), emotional arousal and fear conditioning (Knyazev et al., 2009). The role of the alpha band, traditionally recorded in resting corti- cal states (Bastiaansen and Brunia, 2001; Thut et al., 2006; Sauseng et al., 2005) was observed to be a correlate of active inhibition within the cor- tex (Snyder and Foxe, 2010). Cortical activation, on the other hand, was shown to be accompanied by an increase of beta (12–30 Hz; Bekisz and Wróbel, 1993; 1999;) and gamma power (30–60 Hz; Herculano-Houzel et al., 1999; von Stein et al., 2000; von Stein and Sarnthein, 2000). Fur- thermore, it became widely accepted that synchronization of gamma band activity served as a mechanism for local integration of cortical in- formation (Roskies, 1999; Uhlhaas et al., 2009). The physiological mech- anisms related to beta band activity have remained relatively less studied (see Engel and Fries, 2010, for a review). Initial reports of beta band signal synchronization were published by Mundy-Castle (1951), who observed significantly more 12–30 Hz activity in people with good visual imagination skills compared to less skilled subjects. Subsequently, Townsend and Johnson (1979) and Belyavin and Wright (1987) found positive correlation between accuracy level in visual vigilance tasks and beta band power in occi- pito-parietal brain areas. Recent studies are in line with these early observations. Our experiments on cats (Bekisz and Wróbel, 1993, 1999, 2003; Wróbel et al., 1994a,b, 2007; reviewed in Wróbel, 2000) provided data supporting the hypothesis that beta band activ- ity plays an important role in attention processes in numerous tha- lamic and cortical centers of visual system. This hypothesis was based on the finding that beta band power increased during the pre- paratory time period of a visual spatial differentiation task only in tri- als resulting in correct responses. Similar data were supplied by Buschman and Miller (2007), who also noticed positive correlation between beta band power and visual attention in occipito-parietal cortex of the monkey. An increase of beta band EEG activity during stimulus expectancy period was also found in humans (Basile et al., 2007). Hanslmayer et al. (2007) demonstrated that brief visual stim- uli were perceived by subjects only when preceded by periods of in- creased phase coupling in EEG beta band. In a MEG study, Gross et al. (2004) showed that low long range beta band phase synchroniza- tion was a significant indicator of performance in an attentional blink task. Motivated by the hitherto findings relating EEG beta band activ- ity to attentional processes, we examined whether attentional deteri- oration in aging is reflected in changes in beta band power. Although the deterioration of behavioral functioning in elderly people is common knowledge, its validation under laboratory condi- tions is not trivial because of various brain compensatory International Journal of Psychophysiology 85 (2012) 62–67 ⁎ Corresponding author. Tel./fax: + 48 729 030 030. E-mail address: mateusz.gola@swps.edu.pl (M. Gola). 0167-8760/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.ijpsycho.2011.09.001 Contents lists available at SciVerse ScienceDirect International Journal of Psychophysiology journal homepage: www.elsevier.com/locate/ijpsycho