The brain modulates spatial-hearing responses into a steady-state following response to periodic IPD switches

Evidence

Evoked responses to the intermediate IPM rate (6.8 Hz; Fig. 2 ) became steady state at the same rate as the IPM, and so we term this response the IPM-FR. In the time domain (left-middle), the peak amplitude of the IPM-FR is broadly the same as that for the slowest IPM rate (3.2 Hz), but responses were more steady state than those at the low rate, being more consistent in phase and amplitude across epochs (evidenced by a more favourable SNR). This is confirmed by comparing the variability of the individual responses in the time domain as well as the frequency domain (Fig. 2 ), where the spectral magnitude was almost twice larger than that the largest magnitude obtained at the lowest IPM rate. Moreover, the average spectral magnitude of the next harmonics was almost twice smaller than those obtained at the lowest IPM rate. Finally, the IPM-FR is observed at the most rapid IPM rate (13.7 Hz, bottom panels of Fig. 3 ). As for the intermediate IPM rate, responses show a steady-state pattern in the time domain, albeit with a reduced amplitude. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2975

Categorization

Category: Definitional Content

• DEFINE: Defines the IPM-FR as a steady-state EEG following response to periodic interaural phase modulation.

Related

• Abrupt interaural phase changes evoke P1-N1-P2 cortical responses (similarity 0.89)
• Slow IPD transitions evoke a classic P1-N1-P2 auditory evoked response in the EEG (similarity 0.87)
• Slow IPM sweeps evoke transient P1-N1-P2 responses while faster rates evoke steady-state following responses. (similarity 0.85)
• Slow interaural-phase modulation evokes transient P1-N1-P2 waves while faster rates produce steadier following responses (similarity 0.85)
• The best interaural phase deviation for evoking neural responses depends on modulation rate (similarity 0.84)
• Steady-state interaural phase following responses were more robust than responses to slow sweeps. (similarity 0.81)
• Low- and high-frequency binaural brainstem pathways prefer opposite interaural phase ranges (similarity 0.80)
• Optimal interaural phase difference for cortical following responses depends on the IPM rate (similarity 0.80)
• Phase transitions hidden at envelope minima decrease monaural detection of interaural cues (similarity 0.79)
• EEG phase-modulation response amplitude depends jointly on rate and phase size (similarity 0.79)

Broader Connections

• Diotic phase-shift controls rule out monaural sources of interaural-phase responses #corroborates (0.82) — Dijk, Pim van, Physiology, Psychoacoustics and…, 2949