{'fraction_non_alphanumeric': 0.015841584158415842, 'fraction_numerical': 0.007920792079207921, 'mean_word_length': 5.657894736842105, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Acquisition, generalization, and discrimination reversal of a natural concept.

Pigeons rapidly acquired a discrimination between 40 pictures containing trees and 40 not containing trees. Differential reinforcement did not affect the discriminability of individual instances of trees. Generalization to new instances of tree pictures was better than to new instances of non-tree pictures. The level of discrimination did not depend on whether trees constituted the reinforced or the unreinforced category.