Date Published: April 12, 2019
Publisher: Public Library of Science
Author(s): Józef Maciuszek, Mateusz Polak, Martyna Sekulak, Barbara Dritschel.
When talking about absence, we may express it in a negative statement (using explicit negation e.g. I was not) or in a positive statement (using implicit negation e.g. I wished I were). Previous research has shown that explicitly negated statements may cause false recall–negated items may paradoxically be remembered as present. The current study compares false recall caused by implicit and explicit negation. Participants listened to a recording in which some objects were mentioned as present, some as absent, and some not mentioned at all. The absence of objects was expressed using explicit or implicit negation. Participants’ recall of the recording was measured either five minutes or one week after exposure to the recording. Results indicate that implicit and explicit negation lead to a nearly identical false recall of negated items. However, items not mentioned in the recording (i.e. neither mentioned nor negated) were more often recognized as present by participants exposed to implicit, rather than explicit negation. We postulate that false recall of negated items could be explained by participants remembering the item itself, but forgetting the context in which it was present (an affirmative or a negative statement), hence objects would be recalled as present just because they were spoken of.
In everyday communication, one of the main functions of negation is to inform about the absence of objects (e.g. There is no fireplace in the living room), as well as to deny events (e.g. Yesterday, the last flight from Washington was not late) and behavior (e.g. John did not stop at a red light). How negation influences the memory of negated objects or behavior is of interest both from a scientific (e.g. memory and language theories) and practical standpoint (e.g. forensic psychology). Many psycholinguistic studies have found that negatives are harder to process than affirmatives [1, 2, 3] Negative statements impede memory (e.g. ) and can have unintended, paradoxical effects for the recipients of the communication [5, 6, 7]. Results of many previous studies (e.g. [4, 8, 9]) showed that people remember affirmative sentences better than negative ones. The research question investigated in a paper by Maciuszek & Polczyk  was whether recalling negated objects and actions can have adverse effects on memory, namely result in a higher rate of false recognition as compared to when the items are not mentioned at all. The aforementioned study  demonstrated that after a one-week delay, negated items (i.e. items that the source material stated were not present) were more often reported as ‘Present’ than items not mentioned at all. These results were similar when objects and actions were negated.
The presented study is a continuation of earlier research by Maciuszek & Polczyk , in which the NRFM (Negation Related False Memories) effect was shown. NRFM led to a significantly higher number of false alarms regarding negated than not mentioned items (after a one-week delay). This finding raised a question whether the NRFM effect is to be explained by cognitive processing of explicit negation (i.e. negative statements) or whether it can be accounted for within a broader theoretical scope. It is possible that recalling an item mentioned in a given source is easier than recalling whether the item was mentioned within an affirmative or negative statement (especially after a weeklong delay). In other words, it may be easier to recall individual words within statements than the syntactic structure of these statements.