The Distribution of Attention Across Auditory Input Channels: An Assessment Using the Human Evoked Potential

Abstract

In order to determine the extent to which distraction disrupts performance when attention is divided, the distribution of attention across five auditory input channels was assessed using the N1 component of the human auditory evoked potential. In addition, the possibility that methylphenidate (Ritalin) affects the distribution of attention across input channels was tested. Sixteen subjects performed a tone discrimination task under conditions of focused attention and divided attention, both with and without the presence of stimuli interposed between the points to be attended. The subjects performed in two sessions during which they received either methylphenidate (10 mg) or a placebo in a double‐blind design. The results showed that the interposed stimuli were receiving some attention resulting in a disruption of performance. Methylphenidate did not affect the distribution of attention as reflected in the N1 wave. The data are interpreted as showing that: 1) distraction plays a major role in producing performance deficits observed with divided attention; and 2) methylphenidate does not appreciably affect the distribution of attention across input channels.

The gradient of spatial auditory attention in free field: An event-related potential study

“…A narrow focus of attention indexed by Nl/Nd was also reported by Schwent, Snyder, and Hillyard (1976) in a three-channel design. However, in a similar type of study that presented tones over five channels distinguished by location and pitch, Hink et al (1978) found that NIlNd amplitudes were enhanced not only by the attended-channel tones but also by the tones in adjacent channels. Possible factors that might account for these differing patterns of results among studies include differences in stimulus presentation rate, spatial separation between auditory channels, frequency separation between channels, and type of attention-directing task.…”

“…The identification of such targets is associated with a longer latency positive ERP component (the "P3" or "P300") wave having a peak latency of 300-400 msec. A number of studies have shown that the P3 is specifically elicited by targets in the attended channel and not by comparable deviant stimuli in an unattended channel (e.g., Hillyard et al, 1973;Hink, Fenton, Pfefferbaum, Tinklenberg, & Kopell, 1978). These findings have suggested that the NIlNd and P3 waves are indices of two hierarchically organized levels of selection, with the NIlNd reflecting an initial between-channel selection based on easily discriminable cues and the P3 indexing a subsequent withinchannel target selection following a more elaborated and detailed processing of the relevant stimulus properties.…”

Selectively attending to auditory objects

“…The attention-related changes in ERPs occur when participants attend to a particular stream of sounds in the presence of one or more different streams of distracting stimuli and when stimulus sequences are easily discriminated, whether they are distinguished by spatial position, frequency, or both spatial position and frequency (58)(59)(60). Although there is one report of the habituation of the Nde (61), performance and Nde amplitude are usually maintained over long sessions (59,62,63). The Nde amplitudes and latencies are also little affected by repeated testing (34, 64).…”

“…When the task-relevant and task-irrelevant tones are highly distinctive and presented at short ISIs (e.g., 200-400 msec), the selective attention effects on ERPs can occur at latencies as short as 30 msec following stimulus onset (56,57). The attention-related changes in ERPs occur when participants attend to a particular stream of sounds in the presence of one or more different streams of distracting stimuli and when stimulus sequences are easily discriminated, whether they are distinguished by spatial position, frequency, or both spatial position and frequency (58)(59)(60). Although there is one report of the habituation of the Nde (61), performance and Nde amplitude are usually maintained over long sessions (59,62,63).…”

Effect of methylphenidate on visual responses in the superior colliculus in the anaesthetised rat: Role of cortical activation

“…It is well documented that methlphenidate (MPH) improves vigilance (Coons et al, 1981;Strauss et al, 1984;Peloquin & Klorman, 1986;Camp-Bruno & Herting, 1994;Hermens et al, 2007) and divided/focused attention (Hink et al, 1978) in normal humans and attentional performance in rats (Bizarro et al, 2004). Methylphenidate is also particularly effective at ameliorating the attentional difficulties in children and adults with Attention Deficit Hyperactivity Disorder (ADHD; Brown et al, 2005;Tucha et al, 2006).…”