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. Awareness of CS-US contingencies was mildly reduced in preterms. 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 largely preserved associative fear learning in very preterm-born young adults was unexpected and needs to be confirmed in future studies.

Absence of modulatory effects of 6Hz cerebellar transcranial alternating current stimulation on fear learning in men

“…Moreover, the complexity of our paradigm involving two distinct images of office spaces as contexts, varied-colored lights as CSs could have affected the strength of learned associations. Similar absence of group differences has also been observed in a recent behavioral study of our group with a comparable paradigm ( Albayrak et al, 2023 ). For a clearer understanding of ctACS effects on fear learning processes, future studies should consider simpler fear conditioning paradigms.…”

“…To account for the observed group differences in habituation rates during the acquisition training phase, we calculated the differential SCR (SCR diff ) by subtracting the SCR to CS+ low from the SCR to CS+ high for each respective trial presented in the same context ( Ganella et al, 2017 ; Albayrak et al, 2023 ). This allowed us to quantify the differential response to the conditioned stimuli.…”

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 is 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.…”

“…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, we performed fear acquisition and extinction training 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 in Albayrak et al (2023) , which was based on the earlier study conducted by Milad et al (2007) .…”