A boundedness subspace causally shifts Russian aspect predictions
measured in 1 paperKatinskaia & Yangarber train m mutually-orthogonal INLP classifiers per layer to locate the "boundedness" subspace in masked-verb representations of Russian BERT-base, BERT-large and RoBERTa-large [katinskaia-yangarber-2024] Behavioral probing shows aspect becomes decodable mainly in final layers (BERT-large 85-88% in the last 8 layers) [katinskaia-yangarber-2024] AlterRep pushing hidden vectors toward unboundedness raises imperfective predictions +21%/+10.3% and lowers perfective -26%/-18.3% at BERT-large layer 24; pushing toward boundedness has the opposite, smaller effect [katinskaia-yangarber-2024] Twenty random-subspace placebos and an unaffected number-agreement control confirm specificity to the boundedness subspace [katinskaia-yangarber-2024]