A key challenge for cognitive neuroscience is to decipher therepresentational schemes of the brain. A recent class of decodingalgorithms for fMRI data, stimulus-feature-based encodingmodels, is becoming increasingly popular for inferring thedimensions of neural representational spaces from stimulus-feature spaces. We argue that such inferences are not always valid,because decoding can occur even if the neural representationalspace and the stimulus-feature space use different representationalschemes. This can happen when there is a systematic mappingbetween them. In a simulation, we successfully decoded the binaryrepresentation of numbers from their decimal features. Sincebinary and decimal number systems use different representations,we cannot conclude that the binary representation encodes decimalfeatures. The same argument applies to the decoding of neuralpatterns from stimulus-feature spaces and we urge caution ininferring the nature of the neural code from such methods. Wediscuss ways to overcome these inferential limitations.

Is language unique in how it evokes conceptual content, and if so, why? In an influential study, Lupyan & Thompson-Schill (2012) report that labels (nouns like “dog”) have a stronger cuing effect in picture verification tasks than “equally informative and predictive nonverbal cues”, like the sound of a barking dog. Here we sought to better understand the factors that lead to a label advantage. First, while we replicate the label advantage itself, our data do not support the assumption that labels and environmental sounds are equally informative. Instead, we show that different cue types are associated with target images to different degrees, and that labels show the strongest association. Moreover, the degree of association is a better predictor of reaction times than cue type. Thus, we conclude that labels are not more effective at activating the same semantic content than non-verbal cues, but rather activate different semantic content.

The Action-sentence Compatibility Effect (ACE) is a well-known demonstration of the role of motor activity in the comprehension of language. Participants are asked to make sensibility judgments on sentences by producing movements toward the body or away from the body. The ACE is the finding that movements are faster when the direction of the movement (e.g., toward) matches the direction of the action in the to-be-judged sentence (e.g., Art gave you the pen describes action toward you). We report on a pre-registered, multi-lab replication of one version of the ACE. The results show that none of the 18 labs involved in the study observed a reliable ACE, and that the meta-analytic estimate of the size of the ACE was essentially zero.