Imagine you’re trying to pinpoint the source of a sound in a crowded room. You can use your keen hearing to gather clues, but it’s not always easy to identify the exact location. Similarly, in the field of auditory cognitive neuroscience, researchers use a technique called electroencephalography (EEG) to investigate brain activity related to hearing. However, accurately localizing brain activity poses a challenge. To overcome this, scientists have developed individualized models based on factors like subject anatomy and electrode positions. This study compared the results of using template anatomies and electrode positions versus subject-specific ones, as well as combinations of both. The researchers focused on the primary auditory cortex, a small region within the brain that is notoriously difficult to pinpoint. They found that both electrode locations and subject anatomies had an impact on the analysis outcomes. Interestingly, one inverse solution called dSPM consistently benefited from individualizing subject morphologies compared to another solution called sLORETA. These findings shed light on the importance of considering individual differences when studying auditory brain activity. To dive deeper into this fascinating research, check out the full article!

Due to its high temporal resolution and non-invasive nature, electroencephalography (EEG) is considered a method of great value for the field of auditory cognitive neuroscience. In performing source space analyses, localization accuracy poses a bottleneck, which precise forward models based on individualized attributes such as subject anatomy or electrode locations aim to overcome. Yet acquiring anatomical images or localizing EEG electrodes requires significant additional funds and processing time, making it an oftentimes inaccessible asset. Neuroscientific software offers template solutions, on which analyses can be based. For localizing the source of auditory evoked responses, we here compared the results of employing such template anatomies and electrode positions versus the subject-specific ones, as well as combinations of the two. All considered cases represented approaches commonly used in electrophysiological studies. We considered differences between two commonly used inverse solutions (dSPM, sLORETA) and targeted the primary auditory cortex; a notoriously small cortical region that is located within the lateral sulcus, thus particularly prone to errors in localization. Through systematical comparison of early evoked component metrics and spatial leakage, we assessed how the individualization steps impacted the analyses outcomes. Both electrode locations as well as subject anatomies were found to have an effect, which though varied based on the configuration considered. When comparing the inverse solutions, we moreover found that dSPM more consistently benefited from individualization of subject morphologies compared to sLORETA, suggesting it to be the better choice for auditory cortex localization.

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