TY - JOUR T1 - Cortical Tonotopic Map Changes in Humans are Larger in Hearing Loss than in additional Tinnitus JF - The Journal of Neuroscience JO - J. Neurosci. DO - 10.1523/JNEUROSCI.2083-19.2020 SP - JN-RM-2083-19 AU - E.A. Koops AU - R.J. Renken AU - C.P. Lanting AU - P. van Dijk Y1 - 2020/03/19 UR - http://www.jneurosci.org/content/early/2020/03/13/JNEUROSCI.2083-19.2020.abstract N2 - Neural plasticity due to hearing loss results in tonotopic map changes. Several studies have suggested a relation between hearing-loss-induced tonotopic reorganization and tinnitus. This large functional magnetic resonance imaging (fMRI) study on humans intended to clarify the relations between hearing loss, tinnitus and tonotopic reorganization. To determine the differential effect of hearing loss and tinnitus, both male and female participants with bilateral high frequency hearing loss, with and without tinnitus, and a control group were included. In a total of 90 participants, bilateral cortical responses to sound stimulation were measured with loudness matched pure-tone stimuli (0.25 - 8 kHz). In the bilateral auditory cortices, the high frequency sound-evoked activation level was higher in both hearing-impaired participant groups, compared to the control group. This was most prominent in the hearing loss group without tinnitus. Similarly, the tonotopic maps for the hearing loss without tinnitus group were significantly different from the controls, whereas the maps of those with tinnitus were not. These results show that higher response amplitudes and map reorganization are a characteristic of hearing loss, not of tinnitus. Both tonotopic maps and response amplitudes of tinnitus participants appear intermediate to the controls and hearing loss without tinnitus group. This observation suggests a connection between tinnitus and an incomplete form of central compensation to hearing loss, rather than excessive adaptation. One implication of this may be that treatments for tinnitus shift their focus towards enhancing the cortical plasticity on track, instead of reversing it.Significance Statement: Tinnitus, a common and potentially devastating condition, is the presence of a ‘phantom’ sound that often accompanies hearing loss. Hearing loss is known to induce plastic changes in cortical and sub-cortical areas. Although plasticity is a valuable trait that allows the human brain to rewire and recover from injury and sensory deprivation, it can lead to tinnitus as an unwanted side effect. In this large fMRI study, we provide evidence that tinnitus is related to a more conservative form of reorganization than in hearing loss without tinnitus. This result contrasts with the previous notion that tinnitus is related to excessive reorganization. As a consequence, treatments for tinnitus may need to enhance the cortical plasticity, rather than reversing it. ER -