Fear conditioning is preserved in very preterm-born young adults despite increased anxiety levels

Abstract

Very preterm birth is associated with an increased risk for anxiety disorders. Abnormal brain development may result in disordered fear learning processes, which may be exacerbated by environmental risk factors and persist in adulthood. We tested the hypotheses that very preterm-born young adults displayed higher levels of fear conditioning, less differentiation between threat, CS+, and safety, CS-, signals and stronger resistance to extinction relative to term-born controls. A group of 37 very preterm-born young adults and 31 age- and sex-matched term-born controls performed a differential fear conditioning paradigm on two consecutive days. Acquisition and extinction training were performed on day 1. Recall and reinstatement were tested on day 2. Preterm-born participants showed significantly higher levels of anxiety in the Depression-Anxiety-Stress-Scale-21 questionnaire. The fear conditioning outcome measures, skin conductance response amplitudes and anxiety ratings, were overall higher in the preterm-born group compared to controls. Acquisition, extinction, recall and reinstatement of differential conditioned fear responses, CS+ > CS-, however, were not significantly different between the groups. There were no significant group by stimulus type interactions. The finding of preserved associative fear learning in very preterm-born young adults was unexpected and needs to be confirmed in future studies.

Mild Deficits in Fear Learning: Evidence from Humans and Mice with Cerebellar Cortical Degeneration

“…This may have hampered a clear differentiation between the two CS+. While the age of our study population may be a factor, it's worth noting that a recent behavioral study in young and healthy participants employing a similar paradigm (Albayrak et al, 2023) also reported no differentiation between the CS+E and CS+U in early recall.…”

“…Habituation, fear acquisition and extinction training were performed on day 1 and recall was tested on day 2. The experimental method closely resembled the one described in Albayrak et al (2023), which was based on the earlier study by Milad et al (2007). To focus on conditioning to the cue rather than the context, fear acquisition and extinction training were performed in two separate contexts (acquisition context and extinction context) represented by pictures of two different office rooms: one with a desk ("office") and one with a bookshelf ("library").…”

“…The conditioning stimuli (CSs) were represented by the same desk lamp, which emitted light in either blue, red or yellow colors. The experimental paradigm closely followed the one described inAlbayrak et al (2023), which was based on the earlier study conducted byMilad et al (2007).…”