Biomedical subjects

Tom Beckers

Publications and source records attributed to Tom Beckers.

6 recordsLinked to original sources

PubMed2003

Secondary task difficulty modulates forward blocking in human contingency learning.

The influence of a secondary task on forward blocking of human contingency ratings was examined. A smaller blocking effect was found when participants performed a highly demanding secondary task than when they performed a less demanding secondary task. The modulatory effect of secondary task difficulty was significant only when the secondary task was administered during both the learning and the test phase of the contingency judgement task. The results suggest that forward blocking in human contingency learning cannot be fully accounted for by associative processes. Instead, forward blocking seems to depend at least partially on deliberate deductive reasoning processes.

Cognition↗

PubMed2002

Automatic integration of non-perceptual action effect features: the case of the associative affective Simon effect.

In the first phase of Experiment 1, participants were instructed to move a response key up or down in response to a go signal. One of both responses was consistently followed by an aversive stimulus, whereas the other response was never followed by the aversive stimulus. In a subsequent test phase, the same responses had to be emitted according to the grammatical category (noun or adjective) of positive and negative target words. Results showed that the level of affective correspondence between the task-irrelevant positive or negative connotation of the target and the motivational significance of the effect of the correct response influenced performance. The results of Experiment 2 replicated those of Experiment 1, using alternating target-response assignment. These findings point to the integration of affective action effect feature codes in the cognitive representation of actions.

Association Learning↗

PubMed2002

Second-order backward blocking and unovershadowing in human causal learning.

De Houwer and Beckers (in press, Experiment 1) recently demonstrated that ratings about the relation between a target cue T2 and an outcome are higher when training involves CT1+ and T1T2+ followed by C+ trials than when training involves CT1+ and T1T2+ followed by C- trials. We replicated this study but now explicitly asked participants to rate the causal status of the cues both before and after the C+ or C- trials. Results showed that causal ratings for T2 were significantly higher after C+ trials than before C+ trials and that T2 received significantly lower ratings after C- trials than before C- trials. The results thus provide the first evidence for higher-order unovershadowing and higher-order backward blocking. In addition, the ratings for T1 revealed that first-order backward blocking (i.e., decrease in ratings for T1 as the result of C+ trials) was stronger than first-order unovershadowing (i.e., increase in ratings for T1 as the result of C- trials).

Adult↗

PubMed2002

Outcome and cue properties modulate blocking.

Participants saw a series of situations in which a cue (a light appearing at a certain position) could be followed by an outcome (a drawing of a tank that exploded) and were afterwards asked to rate the likelihood of the outcome in the presence of the cue. In Experiments 1 and 2, the compound cues AT and KL were always followed by the outcome (AT+, KL+). During an elemental phase that either preceded or followed the compound phase, Cue A was also paired with the outcome (A+). Cue T elicited a lower rating than Cues K and L when cues were described as being weapons but not when the cues were said to be indicators. The magnitude of this blocking effect was also influenced by whether the outcome occurred to a maximal or submaximal extent. Experiment 3 replicated the effect of cue instructions on blocking (A+, AT+) but showed that cue instructions had no impact on reduced overshadowing (B-, BT+). The results shed new light on previous findings and support probabilistic contrast models of human contingency judgements.

Cues↗

PubMed2002

Higher-order retrospective revaluation in human causal learning.

Previous studies demonstrated that participants will retrospectively adjust their ratings about the relation between a target cue and an outcome on the basis of information about the causal status of a competing cue that was previously paired with the target cue. We demonstrate that such retrospective revaluation effects occur not only for target cues with which the competing cue was associated directly, but also for target cues that were associated indirectly with the competing cue. These second-order and third-order retrospective revaluation effects are compatible with certain implementations of the probabilistic contrast model and with a modified, extended comparator model, but cannot be explained on the basis of a revised Rescorla-Wagner model or a revised SOP model.

Adult↗

PubMed2002

A review of recent developments in research and theories on human contingency learning.

Over the past 20 years, human contingency learning has resurfaced as an important topic within experimental psychology. This renewed interest was sparked mainly by the proposal that associative models of Pavlovian conditioning might also apply to human contingency learning--a proposal that has led to many new empirical findings and theoretical developments. We provide a brief review of these recent developments and try to point to issues that need to be addressed in future research.

Association Learning↗