Using neuroimaging to understand the cortical mechanisms of auditory selective attention

Abstract

Over the last four decades, a range of different neuroimaging tools have been used to study human auditory attention, spanning from classic event-related potential studies using electroencephalography to modern multimodal imaging approaches (e.g., combining anatomical information based on magnetic resonance imaging with magneto- and electroencephalography). This review begins by exploring the different strengths and limitations inherent to different neuroimaging methods, and then outlines some common behavioral paradigms that have been adopted to study auditory attention. We argue that in order to design a neuroimaging experiment that produces interpretable, unambiguous results, the experimenter must not only have a deep appreciation of the imaging technique employed, but also a sophisticated understanding of perception and behavior. Only with the proper caveats in mind can one begin to infer how the cortex supports a human in solving the “cocktail party” problem.

Auditory Processing Disorder (APD): Progress in Diagnostics So Far. A Mini-Review on Imaging Techniques

“…This is also true for NIRS [17] . Diffusion tensor imaging is a magnetic resonance technique that is powerful for investigating the microstructure of white matter in vivo.…”

“…The main techniques that have revolutionized the way in which we visualize the brain and how it functions are the positron emission tomography (PET) scan, structural and functional magnetic resonance imaging (sMRI and fMRI, respectively) with the diffusion tensor imaging (DTI) technique, magnetoencephalography (MEG), and electroencephalography (EEG) [17] . Near infrared spectroscopy (NIRS) is another technique that may be used, but it is not popular because fMRI and MEG provide superior information [17] .…”

“…Near infrared spectroscopy (NIRS) is another technique that may be used, but it is not popular because fMRI and MEG provide superior information [17] .…”

“…Compared with EEG, MEG produces less distortion. Because MEG records the magnetic field, which is not affected by bone, separate recordings from both hemispheres can be collected more conveniently [17,27] . Four reasons that have been suggested as to why this neuroimaging technique is useful include the following: it can provide evidence of the mechanisms of cortical neural activity that occur in central APD (CAPD) and what kind of compensation occurs; it enables visualization of the link between patient performance and neural structures in clinical testing; if neural pathologies are identified, there can be new, better management of the condition based on the indicated neural abnormalities; and it can be used to determine how much restoration of normal neural activity in CAPD occurs via interventional management of CAPD patients [25] .…”

“…MEG in combination with ABR can track neural activity at the start of a neural signal from the structures just below the midbrain up to the higher auditory cortex [26] . MEG and EEG can assess selective attention because it has been shown that attention causes a significant change in the M100 and N100 potentials, respectively, in normal listeners when attending to a particular signal when two signals are presented at the same time [17] . This is expected to be abnormal in APD, with delayed or absent signals.…”