Consistent witness responses: The effects of age and negative feedback

Memory performance predicts interrogative suggestibility better than global cognition in older adults with subjective cognitive complaints

The present study aims to investigate to which extent global cognition and verbal memory can estimate interrogative suggestibility (IS) in elderly people with subjective cognitive complaints (SCCs). We used the Gudjonsson Suggestibility Scale (GSS 2) subscales (i.e., Yield 1, Yield 2 and Shift) as measures of IS. Data from a sample of consecutive patients (N = 94) who referred to neuropsychology units for the first time were collected. Our results showed that verbal memory is a better predictor of IS than global cognition. Moreover, memory impairment led to significantly higher IS independently of global cognitive status. These findings suggest that the assessment of verbal memory allows to estimate individual levels of IS better than global cognition, even in elders with objective cognitive deficits. Implications for forensic assessment of senior witnesses are discussed.

Reducing interrogative suggestibility: The role of self-affirmation and positive feedback

Interrogative suggestibility, as measured with Gudjonsson Suggestibility Scales, consists of an individual's tendency to yield to misleading questions (Yield) and to change answers after negative feedback (Shift). This study aimed to determine whether reinforced self-affirmation (RSA), a technique that aims to boost self-confidence in order to increase the tendency to rely on one's own memory instead of external cues, can reduce interrogative suggestibility. RSA consists of self-affirmation induced by means of writing down one's greatest achievements in life and of manipulated positive feedback. The efficacy of two kinds of positive feedback was explored. Shift was reduced by positive feedback relating both to memory and to the feeling that a person is very independent in their judgements, while only feedback related to memory reduced Yield. The results are discussed in terms of the different mechanisms underlying Yield and Shift. Inducing independence of judgements might not have been effective in the case of Yield because to some extent it taps opinions but not the quality of a cognitive process such as memory. An individual may believe in their own opinions and views but still be unsure about the quality of their own memory.

Sleep does not cause false memories on a story-based test of suggestibility

Sleep contributes to the consolidation of memories. This process may involve extracting the gist of learned material at the expense of details. It has thus been proposed that sleep might lead to false memory formation. Previous research examined the effect of sleep on false memory using the Deese-Roediger-McDermott (DRM) paradigm. Mixed results were found, including increases and decreases in false memory after sleep relative to wake. It has been questioned whether DRM false memories occur by the same processes as real-world false memories. Here, the effect of sleep on false memory was investigated using the Gudjonsson Suggestibility Scale. Veridical memory deteriorated after a 12-h period of wake, but not after a 12-h period including a night's sleep. No difference in false memory was found between conditions. Although the literature supports sleep-dependent memory consolidation, the results here call into question extending this to a gist-based false memory effect.