Evaluation of different cochlear implants in unilateral hearing patients during word listening tasks: A brain connectivity study

Abstract

Advanced methodologies used for the biomedical signal interpretation allow using cerebral signals to assess important cognitive functions in humans. In the present study, as parameter of cerebral effort, has been employed the isolated effective coherence, in order to estimate the effective connectivity and network organization. The hypothesis was that the lower the number of inter-connections engaged, the lower the cerebral effort induced by the experimental condition. In the present research this index has been applied to test the reaction to the use of different cochlear implant processors (Freedom, CP810 and CP910 - Cochlear Ltd), with the aim to identify the most performing device during a word in noise recognition task. Results support the capability of identifying the device eliciting less brain area connections. In particular, the CP910 was the processor inducing the lower number of inter-connections among the tested ones. This investigation appeared to be worthy, since representing a tool to identify devices that would make available user's cognitive resources for additional tasks, a matter susceptible of generalization to various fields of application. The employment of the cerebral signals therefore open the way to the evaluation of the impact of different sensors and prosthetic devices, also using connectivity measures.

The Dry Revolution: Evaluation of Three Different EEG Dry Electrode Types in Terms of Signal Spectral Features, Mental States Classification and Usability

“…Therefore, if in the 60s an EEG device required a room and meters of cables, modern EEG devices are no larger than a smartphone and equipped with storage support, long-life batteries and wireless communication. These great improvements are at the basis of the recent successes of cognitive and behavioral neuroscience research, since it is now possible to investigate human brain physiological dynamics while working or performing everydayness activities, such as driving the car [7,8,9] or piloting an aircraft [10,11,12], working in control rooms [13,14,15,16], watching the TV [17,18], doing sport [19], eating [20], listening music [21,22] or smelling fragrances [23,24]. EEG devices are now wearable and they are considered the key tool to bring research about Brain-Computer Interfaces (BCI, i.e., those system aimed to adapt the objects behavior on the basis of current human mental states) from the laboratory to the applicative fields [25,26].…”

Gamma-Band Modulation in Parietal Area as the Electroencephalographic Signature for Performance in Auditory–Verbal Working Memory: An Exploratory Pilot Study in Hearing and Unilateral Cochlear Implant Children

“…Few recent studies have investigated cortical activations through electroencephalography (EEG), a powerful, accessible and versatile neuroimaging tool for investigating human brain physiology, cognition and behavior [ 42 , 43 ] in CIs children during cognitive tasks. For example, researchers used theta and alpha connectivity to differentiate performance across different implant processors [ 44 ] or hemispheric gamma activation to suggest the occurrence of a sensitive period for CI surgery for best emotion recognition skills development [ 45 ]. Moreover, during a listening task in the noise, a higher workload index (theta/alpha) in over-demanding situations is recorded [ 46 ], as well as displaying lower parietal alpha power levels in the most challenging listening condition [ 47 ].…”