Mapping the mind's landscape: Common neural encoding for spatial and morality concepts

Abstract concepts such as justice are not directly tied to our sensory or motor experiences, yet they constitute an essential part of our knowledge. A longstanding question is how the brain, shaped by survival pressures, encodes these abstract concepts. This study investigated how vertical spatial representations relate to moral concept encoding in the brain (“good is up; bad is down”). We found that vertical positional processing and moral semantics elicited characteristic activation patterns, which enabled the learned neural distinctions between up and down to be generalized to decode the neural signatures of moral and immoral concepts, and vice versa, suggesting shared neural signatures between the two concept domains. Most of the vertical metaphorical representations of morality were independent of the encoding of pleasant vs. unpleasant affect, indicating the specificity of the vertical spatial representation that could not be attributed to the generic representation of arbitrary magnitude or polarity. Nonetheless, morality encoding did not rely solely on vertical spatial information, in that the morality of a word could also be decoded from neural signatures in non-spatial areas. These findings highlight both the spatial metaphorical associations and the domain-specific information in the neural representation of moral concepts.