Auditory processing in absolute pitch possessors

Abstract

Absolute pitch is associated with a large auditory digit span: A clue to its genesis The Journal of the Acoustical Society of America 133, 1859 (2013) Abstract. Absolute pitch (AP) is a rare ability in classifying a musical pitch without a reference standard. It has been of great interest to researchers studying auditory processing and music cognition since it is seldom expressed and sheds light on influences pertaining to neurodevelopmental biological predispositions and the onset of musical training. We investigated the smallest frequency that could be detected or just noticeable difference (JND) between two pitches. Here, we report significant differences in JND thresholds in AP musicians and non-AP musicians compared to non-musician control groups at both 1000 Hz and 987.76 Hz testing frequencies. Although the AP-musicians did better than non-AP musicians, the difference was not significant. In addition, we looked at neuro-anatomical correlates of musicianship and AP using structural MRI. We report increased cortical thickness of the left Heschl's Gyrus (HG) and decreased cortical thickness of the inferior frontal opercular gyrus (IFO) and circular insular sulcus volume (CIS) in AP compared to non-AP musicians and controls. These structures may therefore be optimally enhanced and reduced to form the most efficient network for AP to emerge.

Superior pitch identification ability revealed by cortical complexity measures in nonmusicians

“…Interestingly, in an investigation of epileptic patients, Kim and Knosche (2017) have suggested a role for the insula when engaged in verbal labeling, a process hypothesized to assisted AP performance. McKetton and Schneider (2018) found less cortical thickness of the insula in AP compared to non-AP musicians and nonmusician controls, suggesting that the insula may be a critical component of the network underlying AP ability. Also worth mentioning are the findings of the decrease in the precuneus which is thought to be important for music-related visual perception and imagery (Demorest et al, 2010; Schmithorst, 2005) as well as the supramarginal gyrus, a region of the dorsal auditory pathway (i.e., from the Heschl’s gyrus to the PT, supramarginal gyrus, and dorsolateral prefrontal cortex) thought to be important for processing auditory-related spatial properties (Kim & Knosche, 2017).…”

“…Additionally, superior PI participants showed more fractal dimensionality on the left middle and transverse temporal gyri. AP musicians, compared to non-AP musicians and non-musicians, exhibit a similar leftward white matter tract comprising the middle temporal gyrus (Loui et al, 2011), which is important for identifying pitch (Loui et al, 2011;Wilson et al, 2006Wilson et al, , 2009 The transverse template gyrus (a region of Herschel's gyrus and belonging to primary auditory cortex) may also serve as a central hub for auditory processing (Briley et al, 2012;McKetton & Schneider, 2018;Wengenroth et al, 2014) and, together with more left cortical thickness, may comprise a network that is responsible for the superior pitch perception and discrimination of AP musicians compared to non-AP musicians (McKetton & Schneider, 2018;Wengenroth et al, 2014). Of course the question remains: Is the asymmetry a consequence or a cause of AP?…”