Potentiation rather than distraction in a trace fear conditioning procedure

Abstract

HighlightsDistractors should increase attentional load in trace conditioning procedures.Instead a light ‘distractor’ cue improved conditioning, irrespective of trace.This finding depended on the relative salience of the additional cue.There was no evidence that the distractor stimuli acquired associative strength.The findings are consistent with arousal-mediated effects on associative leaning.

Competition and facilitation in compound conditioning.

“…With a 20-s trace, increased responding to X was observed after AX-O; that is, facilitated learning (potentiation) was seen with the same cues that produced competition in the absence of a trace between X and O. This interaction has been replicated in another fear conditioning experiment (Pezze, Marshall, & Cassaday, 2016) and in a flavor aversion preparation by Batsell and colleagues (Batsell et al, 2012). In the flavor aversion experiments, two taste cues (denatonium and saccharide) were used as X and A and LiCl-induced illness served as O.…”

Age-related differences in appetitive trace conditioning and novel object recognition procedures

“…A further consideration arises in that age-related differences in the sensitivity to distracting stimuli could have confounded interpretation of the rats’ responding to the flashing light background stimulus or the target CS. Distractors have been found to interfere with trace conditioning (Han et al, 2003; but see Pezze, Marshall, & Cassaday, 2016). However, as trace conditioning showed improvement with repeated testing we would have to assume that distractibility decreased with age.…”

Ratios and effect size.

“…When a is nonnegative and b is greater than zero, the ratio will vary between 0 and 1.0 with 0.5 corresponding to a and b having equivalent values. In a conditioned suppression experiment, a represents the instrumental response rate (e.g., Bonardi & Jennings, 2009 ; Robinson, Whitt, Horsley, & Jones, 2010 ) or lick rate (e.g., Pezze, Marshall, & Cassaday, 2016 ) during a conditioned stimulus for shock (conditional stimulus [CS] rate); and b represents a baseline response rate (e.g., the instrumental or lick rate immediately before the presentation of the conditioned stimulus; Pre-CS rate). Here, similar CS and Pre-CS rates will yield ratios that approximate 0.5.…”

“…Skewed data sets could benefit from the distorting influence of some of these ratios. Consider lick-suppression, latency data (e.g., Miller et al, 2015 ; Pezze et al, 2016 ) that will often be negatively skewed: They will be relatively diffuse at long latencies and compressed at short latencies, as they approach the floor of zero seconds. This pattern of compression and expansion is the complement of the distortions appreciable in Figure 3 seen for the Kamin, Redhead, and Ennaceur ratios.…”