7 research outputs found
Reward devaluation disrupts latent inhibition in fear conditioning
Three experiments explored the link between
reward shifts and latent inhibition (LI). Using consummatory
procedures, rewards were either downshifted
from 32% to 4% sucrose (Experiments 1–2), or
upshifted from 4% to 32% sucrose (Experiment 3). In
both cases, appropriate unshifted controls were also included.
LI was implemented in terms of fear conditioning
involving a single tone-shock pairing after extensive
tone-only preexposure. Nonpreexposed controls were also
included. Experiment 1 demonstrated a typical LI effect
(i.e., disruption of fear conditioning after preexposure to the
tone) in animals previously exposed only to 4% sucrose.
However, the LI effect was eliminated by preexposure to a
32%-to-4% sucrose devaluation. Experiment 2 replicated
this effect when the LI protocol was administered immediately
after the reward devaluation event. However, LI was
restored when preexposure was administered after a 60-
min retention interval. Finally, Experiment 3 showed that
a reward upshift did not affect LI. These results point to a
significant role of negative emotion related to reward devaluation
in the enhancement of stimulus processing despite
extensive nonreinforced preexposure experience
Behavioural responses to unexpected changes in reward quality
Successive negative contrast (SNC) effects are changes in anticipatory or consummatory behaviour
when animals unexpectedly receive a lower value reward than they have received previously. SNC
effects are often assumed to reflect frustration and appear to be influenced by background affective
state. However, alternative explanations of SNC, such as the functional-search hypothesis, do not
necessarily imply an aversive affective state. We tested 18 dogs in a SNC paradigm using a patch
foraging task. Dogs were tested in two conditions, once with the low value reward in all of five trials
(unshifted) and once when reward value was altered between high and low (shifted). Following a
reward downshift, subjects showed a SNC effect by switching significantly more often between
patches compared to the unshifted condition. However, approach latency, foraging time and quantity
consumed did not differ between conditions, suggesting non-affective functional search behaviour
rather than frustration. There was no relationship between strength of SNC and anxiety-related
behaviours as measured in a novel object test and a personality questionnaire (C-BARQ). However,
associations with the C-BARQ scores for Trainability and Stranger directed aggression suggest a
possible link with behavioural flexibility and coping style. While reward quality clearly affects incentive
motivation, the relationship between SNC, frustration and background affective state requires further
exploration
Effects of housing on consummatory successive negative contrast in rats: wire-bottom cages versus polycarbonate tubs
A reappraisal of successive negative contrast in two populations of domestic dogs
When an anticipated food reward is unexpectedly
reduced in quality or quantity, many mammals show a
successive negative contrast (SNC) effect, i.e. a reduction
in instrumental or consummatory responses below the level
shown by control animals that have only ever received the
lower-value reward. SNC effects are believed to reflect an
aversive emotional state, caused by the discrepancy
between the expected and the actual reward. Furthermore,
how animals respond to such discrepancy has been suggested
to be a sign of animals’ background mood state.
However, the occurrence and interpretation of SNC effects
are not unequivocal, and there is a relative lack of studies
conducted outside of laboratory conditions. Here, we tested
two populations of domestic dogs (24 owned pet dogs and
21 dogs from rescue kennels) in a SNC paradigm following
the methodology by Bentosela et al. (J Comp Psychol
123:125–130, 2009), using a design that allowed a within-,
as well as a between-, subjects analysis. We found no
evidence of a SNC effect in either population using a
within- or between-subjects design. Indeed, the withinsubjects
analysis revealed a reverse SNC effect, with subjects
in the shifted condition showing a significantly higher
level of response, even after they received an unexpected
reduction in reward quality. Using a within-, rather than a
between-, subjects design may be beneficial in studies of
SNC due to higher sensitivity and statistical power; however,
order effects on subject performance need to be
considered. These results suggest that this particular SNC
paradigm may not be sufficiently robust to replicate easily
in a range of environmental contexts and populations
Positive Emotions in Children: Current Research and Future Directions
Current studies indicate that positive emotions contribute to the development of social, affective, and cognitive resources that promote psychosocial well-being. However, most research has focused on adolescents and adults rather than children, although the basis for emotional development is established during childhood and affects the emergence of social and cognitive processes during this period. This chapter reviews Latin American studies that have examined how children's positive emotions are related to other variables as well as proposed models for assessing and fostering these emotions. It concludes with suggestions for future research.Fil: Oros, Laura Beatriz. Universidad de la Cuenca del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentin