The world’s 8 billion people speak about 7000 languages; 3.2 billion of those people natively speak the top 10 languages. Currently neuropsychology is moderately well-developed in 6 of the top 10 languages, serving roughly 2.5 billion. Developing robust neuropsychology in all 7000 languages to serve everyone equitably in their native language seems impractical within the next few decades. However, 1-2 billion people speak a major language as their second language so a pragmatic strategy may be to develop an alternative approach of second-language neuropsychology (SLN) to serve clients who speak rare languages natively but widely-diffused languages as their second language. This strategy involves adapting all levels of neuropsychological services to the second language user.

Intended participants are those who speak a language of limited (e.g., <1 million speakers) diffusion as their first language and a language of wider diffusion (historically-colonial languages such as English, Russian, Mandarin, or Arabic; regional trade languages such as Swahili or Lingala; or nationalized languages such as Indonesian or Tagalog) as their second or more language. Intended participants are those with Basic Interpersonal Communication Skills (BICS) in their second language, but not necessarily Cognitive and Academic Language Proficiency (CALP). SLN will adapt current neuropsychology techniques in the following domains:

1. 1. Oral language: interview, feedback, treatment, and communication among professionals;

2. 2. Detailed language use evaluation;

3. 3. testing and norms;

4. 4. written materials: reports, client education materials, treatment materials, professional education materials, etc.

The language style for such communication will use standard versions of such traditional or national languages, as commonly taught as a second language. It will use basic vocabulary, simple grammatical structures, and broadly-understood cultural referents. It will minimize grammatical complexity, slang, regionalisms, figures of speech, and metaphor. Materials will be available in the specified language both for those who are literate and for those with inadequate literacy. The development of such language style will require both written materials and training of neuropsychologists and allies. Once core SLN materials are developed, these may be further localized for specific communities to contribute to acceptance and effectiveness. These general strategies will need modification to the specifics of each major language, writing system, and population. This will be particularly true for testing language functioning itself, a particular challenge for the SLN strategy. The SLN strategy will require empirical verification of its viability in each major language and population. Some may perceive SLN as neo-colonialist and culturally insensitive; this may be mitigated in part through diversifying the neuropsychology workforce, community-based research, piloting, focus groups, and localization of materials.

Because this is a proposal and not yet a research project, prototype neuropsychological screening protocols for English-as-a-Second-Language and Spanish-as-a-Second-Language will be presented as examples.

Cultural and linguistic diversity present major challenges to providing equitable neuropsychological services to the world’s population. Current neuropsychology resources are least accessible to major populations that may be most in need. The SLN strategy is not perfect or universal but may reach the next 1-2 billion underserved population