SPATIAL REPRESENTATION, MODIFIED BY ECOLOGY - FROM HUNTER-GATHERERS TO CITY DWELLERS IN INDONESIA

Performance with the Kohs Block Design and Face Drawing Tests were ass essed in two ecologically distinct groups of healthy Indonesians: 196 urbanized subjects and 130 near ''hunter-gatherers'' (Dani and Asmat f rom inland West New Guinea). Analysis of subjects' error patterns on t he block design construction tasks revealed disproportionally and sign ificantly higher percentages of ''nonrandom'' configuration-preserving errors by Dani and Asmat subjects (22.18%) than by urbanized subjects , whose errors were fewer but significantly more random and unrelated to the target design. Relations, ratios, and orientation among feature s within a design pattern tended to be neglected by the Dani and Asmat but rarely by the urbanized subjects (9.78%). On the face drawing tas k, 81% of Asmat and Dani subjects drew schematized versions (the ''neo lithic'' face pattern), whereas only 39% of urbanized subjects did so. Results suggest that the impact of ecological context on neuropsychol ogic functioning is profound, influencing even basic visuospatial cogn itive processing.