The role of response-reward correlation in stimulus-response overshadowing

Rats pressed levers for food reward which was delivered, when appropriate, 0·4 s after the response. For one group, the delay interval was filled by a light cue; for the other group, the same number of lights was given but they were not correlated with food delivery. In Experiment I, all lever presses were reinforced and there were no differences in response rate between groups. In Experiments II and III, lever pressing was rewarded according to a VI and VR schedule respectively. Group differences were observed in Experiment II but they disappeared in Experiment III. The results of Experiments I and II show that a reward-related stimulus does not overshadow a lever response unless the stimulus is a better predictor of reward. Differences in salience or competition from sign-tracking behaviors were ruled out as causes of this phenomenon. Experiment III demonstrated, however, that a weak response-reward correlation is not a sufficient condition for the overshadowing effect. A fourth experiment replicated the results of Experiment III using naive animals. The results of these last two experiments are not consistent with an information theory approach unless (a) a response-units concept is adopted or (b) the cue involved in overshadowing is not the pre-food light but the end of a temporal interval, whose salience is enhanced by the light.     

The Building of Epistemic Trust: An Adoptive Family’s Experience of Mentalization-Based Therapy

ABSTRACT

Recently, theorists have posited the development of epistemic trust – the trust in others as reliable sources of information – as an essential aspect of the therapeutic relationship and a mechanism of therapeutic change. Epistemic trust is likely to be disrupted in adoptive children and families and Mentalization Based Treatment (MBT) aims to explicitly promote its development. Therefore, this study aims to investigate how epistemic mistrust is addressed and how epistemic trust is established within the MBT framework. This single-case, exploratory study reports data from in-depth interviews with one adoptive family, which were analyzed qualitatively using Interpretative Phenomenological Analysis. Two superordinate themes are reported: pre-therapy factors contributing to epistemic mistrust and factors contributing to the development of epistemic trust. The findings highlight two critical elements in establishing epistemic trust: the use of certain clinical skills that help build a secure base within therapy and the possibility of trust being transferred from and to other professionals/systems beyond therapy. Hence, this study informs a deeper understanding of how epistemic trust may be built in therapeutic work with adopted children and identifies possible clinical approaches that may be used by clinicians working with this client group.