Table 1.

Summary of studies that examined the impact of cochlear implantation on cognition in older adults

Study	N	Age range	Cochlear implant	Pre-implant cognitive measures	Cognitive outcome measures	Outcome
Vega (1977) [24]	13	23-67 years	Single-electrode	None	No tests depended on auditory functioning. Duration of implant use not reported. Used sub-tests of Halsted-Reitan neuropsychological test battery (spatial & symbolic abilities, visual temporal acuity, speed of response, attention and test motivation, and intellectual and conceptual functioning), Continuous reaction time test, Purdue pegboard, Trails test, Weschler-Bellvue Form II test	Average scores were within range of general population. 11 CI recipients with normal to superior cognitive functioining; 2 CI recipients with impaired cognitive and conceptual functioning
Crary, Wexler, Berliner, & Miller (1982) [25]	46	19-75 years	Single-electrode	WAIS; MFD; Trlmk; BNDR; BIP	Same as pre-implant measures. Tested one-year post-CI (n = 23) and at two years or more post-CI (n = 16).	As a group, scores in low range of normal intelligence and results stable over time. Process of CI candidacy screened out individuals with cognitive/psychological disorder.
Aplin (1993) [26]		14-80 years	Nucleus 22-channel	WAIS-R or WISC-R	Details not reported.	No adverse effects reported. Described following subjects at intervals post-implant to monitor for improvements in functioning; however, methods and results not reported.

Note. CI = Cochlear implant; WAIS = Wechsler Adult Intelligence Scale; MFD = Graham-Kendall Memory for Designs; Trlmk = Trail Making Test; BNDR = Bender Visual Motor Gestalt; BIP = Bender Visual Motor Interference; WAIS-R = Wechsler Adult Intelligence Scale- Revised; WISC-R = Wechsler Intelligence Scale for Children.