Visual short-term memory load affects sensory processing of irrelevant sounds in human auditory cortex

Apperception Cortical Dynamics (ACD), Department of Psychology, P.O. Box 9, University of Helsinki, FIN-00014 Helsinki, Finland.
Cognitive Brain Research (Impact Factor: 3.77). 08/2003; 17(2):358-67. DOI: 10.1016/S0926-6410(03)00137-X
Source: PubMed


We used whole-head magnetoencephalography (MEG) to investigate neural activity in human auditory cortex elicited by irrelevant tones while the subjects were engaged in a short-term memory task presented in the visual modality. As compared to a no-memory-task condition, memory load enhanced the amplitude of the auditory N1m response. In addition, the N1m amplitude depended on the phase of the memory task, with larger response amplitudes observed during encoding than retention. Further, these amplitude modulations were accompanied by anterior-posterior shifts in N1m source locations. The results show that a memory task for visually presented stimuli alters sensory processing in human auditory cortex, even when subjects are explicitly instructed to ignore any auditory stimuli. Thus, it appears that task demands requiring attentional allocation and short-term memory result in interaction across visual and auditory brain areas carrying out the processing of stimulus features.

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Available from: Jussi Valtonen
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    • "also Weisz & Schlittmeier, 2006). In other neurophysiological ISE experiments, distractor presentation continued during retention (Bell et al., 2010; Campbell et al., 2007; Valtonen et al., 2003) or was even restricted to retention (Campbell et al., 2003, 2007; Kopp et al., 2004, 2006). A question arises as to whether the observed ISE depends on the timing of irrelevant sound presentation. "
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    • "statistical significance. Support for the independence between visual and auditory resource cannot be based on support of the null hypothesis as in the current experiment, as it is always possible that an effect in audition could be observed by further increasing the difficulty of the visual task (Valtonen et al., 2003). As above, it is perhaps worth considering what a more detailed analysis might reveal in terms of the interactions between auditory and visual stimulation. "
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    • "This, in turn, results in a clear dissociation between the sensory magnitude and the N1 amplitude (Picton, Goodman, & Bryce, 1970; Picton, Woods, & Proulx, 1978; Pratt & Sohmer, 1977). In a similar vein, Woods and Elmasian (1986) observed that the strong attenuation of the N1 amplitude at the beginning of a stimulus block is not directly related to loudness (see also Donald, 1979), but rather to its attention-catching properties or disruptiveness (Campbell, 2005; Campbell et al., 2003, 2005; Rinne et al., 2006; Valtonen et al., 2003). For the same reason, the N1 generator process does not seem to be involved in feature integration. "
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