Biomedical subjects

F Baeyens

Publications and source records attributed to F Baeyens.

At least 19 recordsLinked to original sources

PubMed2001

Food likes and their relative importance in human eating behavior: review and preliminary suggestions for health promotion.

The present article reviews research about the psychological determinants of human eating behavior. A hypothetical model of food choice and intake is introduced, presenting various factors influencing eating behavior. Internal factors include sensory food aspects. Among the external factors are information, the social context and the physical environment. Processes such as mere exposure, Pavlovian conditioning and social learning shape the relationships between these factors, food liking and eating behavior. The relative contribution of the various determinants is discussed. In spite of a scarcity of studies, liking for the sensory aspects of food seems to be at the center of the development, maintenance and change of dietary patterns. Consequently, efforts for promoting healthy eating behavior might benefit from an increased attention towards learning principles and food likes in the development of interventions. Existing intervention strategies are criticized and preliminary suggestions are formulated to enhance their effectiveness.

Feeding Behavior↗

PubMed2001

Sequential and simultaneous feature positive discriminations: occasion setting and configural learning in human Pavlovian conditioning.

Using a conditioned suppression preparation, the authors investigated sequential (X --> A+/A-) versus simultaneous (XA+/A-) feature positive (FP) discrimination learning in humans. The sequential discrimination was expected to be resolved by means of a Feature X Modulated Target A-US association and the simultaneous discrimination by a feature X-US association. After sequential FP training, extinction of Feature X did not affect discriminative X --> A/A responding (Experiment 1), and X transferred its modulatory ability only to new targets, B, that had also been modulated (Experiment 2). This suggests that the sequential FP discrimination indeed resulted in occasion setting. Unlike expected, Feature X Extinction did not affect discriminative XA/A responding after simultaneous FP training (Experiment 3), while at the same time Feature X did show the predicted nonselective transfer to new targets, B (Experiment 4). J. M. Pearce's (1987) configural learning theory can account for most but not all findings of Experiments 3 and 4.

Adolescent↗

PubMed2000

Evaluative conditioning in the picture-picture paradigm with random assignment of conditioned stimuli to unconditioned stimuli.

Human participants were allocated to 1 of 3 groups. In the conditioning group, each conditioned stimulus (CS)-unconditioned stimulus (US) pair was presented 7 times during the acquisition phase. Participants who were assigned to the extinction group saw 5 additional presentations of each CS in isolation after the 7 presentations of each CS-US pair. In the latent inhibition group, the CS-only trials were presented before the CS-US trials. Overall, a significant evaluative conditioning effect was observed. This effect cannot be dismissed on the basis of the arguments developed by A. P. Field and G. C. L. Davey (1997, 1998, 1999), and the results thus provide strong evidence for the associative nature of evaluative conditioning. The results are also in line with other findings, which showed that evaluative conditioning is resistant to extinction.

Conditioning, Classical↗

PubMed2000

Pre-extinction of sensory preconditioned electrodermal activity.

In the present study, sensory preconditioning of human electrodermal activity was demonstrated. In the first phase of the experiment, two pairs of neutral pictures of human faces were presented (A/B and C/D) sequentially. In the second phase, one picture of one pair was immediately followed by an electrocutaneous stimulus (B+), and one picture of the other pair was not (D-). In the third phase the other picture of each pair (A and C) was tested. The effect of A and C alone presentations (pre-extinction) between the first and the second phase was investigated. When only those participants that showed reliable B+/D- differentiation were considered, the extinction group did not show stronger conditioned electrodermal activity to A than to C, whereas the control group did. These findings suggest that sensory preconditioning of anticipatory/preparatory responding only occurs when the pre-conditioned stimulus (A) actually predicts the conditioned stimulus (B).

Adult↗

PubMed1999

Attention to chronic pain is dependent upon pain-related fear.

Pain interrupts, distracts, and is difficult to disengage from. In this study, the role of pain-related fear in moderating attentional interference produced by chronic pain was investigated. Forty chronic pain patients completed a list of questionnaires assessing pain severity, pain-related fear (Tampa Scale for Kinesiophobia), and negative affect (Negative Emotionality scale). Attentional interference was measured by a numerical interference test. Multiple regression analysis revealed that the attentional interference was best predicted by the interaction between pain severity and pain-related fear. These results are discussed in terms of how pain-related fear creates a hypervigilance to pain.

Adult↗

PubMed1998

Neither extended sequential nor simultaneous feature positive training result in modulation of evaluative flavor-flavor conditioning in humans.

In previous attempts to induce Pavlovian modulation of human evaluative flavor-flavor associations, the recurrent finding was that exposure to a Feature Positive (FP) schedule (XA+/A-), in which flavor A was reinforced by the aversive flavor Tween20 if and only if it was accompanied by a feature stimulus X, did not result in the expected X-modulated dislike for target A, but in simple unconditional A-US associations. The first experiment reported here investigated if more extended training results in a shift from simple A-US learning to the development of X-modulated A-US associations. Participants were exposed to a 32-trial, 4-session sequential FP schedule using flavors both for feature and target stimuli. The modulatory and/or excitatory power of the stimuli was assessed after each training session. After initial training, participants again acquired a simple unmodulated target A-US association. Contrary to expectations, the additional training sessions did not result in participants gradually learning the XA+/A- discrimination, but rather seemed to corroborate the already established A-US association. This was true whether or not participants acquired valid explicit knowledge about the conditional X-->(A-US) relation. The second experiment tested the hypothesis that what can be described as conditional flavor preferences may actually be based on a configural learning process. Participants were exposed to a single-session, eight-trial XA+/A- simultaneous discrimination schedule, the parameters of which were selected so as to enhance the probability of configuring XA, while simultaneously making it likely to observe a pattern of evaluations similar to an X-modulated dislike for A (X was less salient than A). Even though there was good evidence that participants noticed flavor X, they again failed to solve the XA+/A- discrimination and most probably acquired an association between the more salient flavor A and the US. The possibility is discussed that evaluative learning, unlike expectancy learning, might ultimately prove not to be subject to modulation.

Adult↗

PubMed1998

Attentional disruption is enhanced by the threat of pain.

Using a primary task paradigm this study investigated whether attentional disruption to a low-intensity electrocutaneous pain stimulus is enhanced by the threat of intense pain. Healthy volunteers (n = 38) performed a tone discrimination task in the presence of two types of distractors (a low-intensity electrocutaneous stimulus and a control stimulus) which they were instructed to ignore. In some trials, tone probes were presented immediately (250 ms) after distractor onset, further on (750 ms) during the distractor, and immediately (250 ms) after distractor offset. In a threat condition half of the participants were informed that a high-intensity painful stimulus would occur. As predicted, those participants who received the threat instructions, displayed a specific larger disruption of task performance immediately after the onset of the low-intensity pain stimulus in comparison with the control group.

Adolescent↗

PubMed1998

When somatic information threatens, catastrophic thinking enhances attentional interference.

Styles of catastrophic thinking about pain have been related to an inability to divert attention away from pain. We investigated whether pain catastrophizers displayed high attentional interference during a threatening low-intensity electrocutaneous stimulus (ES). In Experiment 1, 44 undergraduates performed a tone discrimination task whilst experiencing several times an ES on the left or right arms. Tones were also presented 250 ms and 750 ms after ES onset. Participants were threatened that a high-intensity painful stimulus would occur at one site. As predicted, pain catastrophizers displayed pronounced task interference immediately after threat stimulus onset. In Experiment 2, threat was induced in 36 undergraduates by informing them that an ES excites pain fibres. Again, catastrophizers had marked interference immediately after onset. The results are discussed in terms of how catastrophizing amplifies somatosensory information and primes fear mechanisms.

Adolescent↗

PubMed1998

Avoidance and confrontation of painful, back-straining movements in chronic back pain patients.

Avoidance of painful activities has been proposed to be an important risk factor for the initiation and maintenance of chronic low back suffering, whereas exposure to these activities has been suggested to be beneficial for recovery. In a cross-sectional study, the differences between chronic patients with avoidant and confrontational styles were investigated using self-report measures and a behavioral test. Participants were first classified as avoiders or confronters. In comparison with confronters, avoiders reported greater frequency and duration of pain, higher fear of pain and injury, more disability in daily living, and more attention to back sensations. Finally, avoiders reported more fear of (re)injury during the behavioral test and had a worse performance than confronters. The results suggest a close link between the fear of pain/(re)injury on one hand and avoidance behavior and physical deconditioning on the other hand.

Activities of Daily Living↗

PubMed1998

Extinction in fear conditioning: effects on startle modulation and evaluative self-reports.

A basic feature of human evaluative conditioning is that the reported acquired valence of a previously neutral conditioned stimulus (CS) that has been paired with a valenced unconditioned stimulus (US), is resistant to extinction. The present study investigated whether startle modulation, sometimes presented as an index of acquired valence, reflected this basic feature. In a differential fear conditioning paradigm (n = 38) with an electrocutaneous stimulus as the US, a strong extinction manipulation was conducted by removing the US-electrodes and by extended extinction trials. At the end of extinction, the results corroborated previous findings of evaluative conditioning in that the reported valence for CS+ was still more negative than for CS-, despite disappearance of the differential skin conductance responses. However, startle modulation did not show resistance-to-extinction. Results were discussed in terms of recent conceptualizations of extinction.

Adolescent↗

PubMed1997

Evaluative learning with "subliminally" presented stimuli.

Evaluative learning refers to the change in the affective evaluation of a previously neutral stimulus (NS) that occurs after the stimulus has been associated with a second, positive or negative, affective stimulus (AS). Four experiments are reported in which the AS was presented very briefly. Significant evaluative learning was observed in participants who did not notice the presentation of the affective stimuli (ASi) (Experiment 2) or could not discriminate between the briefly presented positive and negative ASi when asked to do so (Experiment 3). In two other experiments (Experiments 1 and 4), no significant learning effect was obtained. A meta-analysis performed on the present and previously reported results (De Houwer, Baeyens, & Eelen, 1994) gave evidence for a small, though statistically reliable evaluative learning effect when ASi are presented "subliminally." This finding supports the hypothesis that evaluative associations can be learned implicitly.

Adult↗

PubMed1997

Habituation and the interference of pain with task performance.

Pain interrupts, distracts and is difficult to disengage from. In this experiment the attentional interference during pain is studied with a primary task paradigm. We were interested in the strength of attentional interference with repeated presentations of pain. Healthy volunteers (n = 24) performed a tone discrimination task in the presence of two types of distractors (an electrical pain stimulus and a control stimulus) which they were instructed to ignore. On some trials, tone probes were presented immediately (250 ms) after distractor onset, further on (750 ms) during the distractor, and immediately (250 ms) after distractor offset. Habituation of the task interference during the early processing of both the pain and the control stimulus was observed. It was also found that the attentional interference during pain did not completely disappear with repeated presentations. Finally, results clearly showed a more prolonged processing time of the tones during pain trials than during control trials. These results are discussed in terms of cognitive theories of habituation.

Acoustic Stimulation↗

PubMed1996

Observational conditioning of food valence in humans.

It has been suggested that the observation of a model consuming a food (CS) and facially expressing either to like or to dislike (US') the food, may be a sufficient condition to bring about a change in the valence of the food for the observer. Unfortunately, up to now this hypothesis has not been investigated in a straightforward manner. In this study, during acquisition, children consumed a series of evaluatively neutral colored and flavored drinks, while simultaneously they watched a videotaped model synchronically drinking identical drinks and facially expressing his evaluation (neutral or dislike) of the liquids. In one condition, the presence of a particular flavor in the drinks was designated to function as the CS+ or the CS-, whereas in the other condition it was the color of the drinks which was the critical CS+ or CS-. Next, the children evaluated a series of drinks containing the critical CSs. A clear evaluative learning effect was obtained when the flavor but not when the color of the drinks was systematically paired with the model's facial expression of dislike. Moreover, the flavor conditioning effect was dependent on the presence in the test drinks of the local context cues (c.q. the colors of the drinks) which were used during acquisition. Finally a double dissociation was observed between explicit beliefs and the "evaluative knowledge" expressed in the ratings of the drinks, in that none of the children in the CS = Flavor groups evidenced any explicit knowledge about the crucial CS-US' contingency but showed evaluative conditioning, whereas the majority of the children in CS = Color groups were aware of the CS-US' relation but failed to demonstrate an evaluative CS-/CS-differentiation.

Attitude↗

PubMed1995

Respiratory learning and somatic complaints: a conditioning approach using CO2-enriched air inhalation.

In a differential respiratory conditioning paradigm with normal Ss two odors (fresh smelling niaouli and bad smelling ammonia) were used as conditioned stimuli (CS+ or CS-) and 7.4% CO2-enriched air was used as the unconditioned stimulus (US). Three CS+ and three CS- trials were run during acquisition, followed on the next day by the same number of CS+ and CS- only trials. Respiratory frequency, minute ventilation, end-tidal fractional concentration of CO2 and subjective complaints were measured throughout the experiment. While during acquisition all measures were affected, the conditioning effects included only respiratory frequency and subjective complaints. A selective association effect appeared in that the conditioning effects were confined to ammonia as CS+: respiratory frequency increased and more somatic complaints were presented when compared to the CS- condition. The conditioning effect on complaints was not confined to complaints of general arousal, but included respiratory complaints as well. Correlational analyses showed that increases in complaints as caused by the conditioning procedure were predicted by changes in somatic variables, but not by individual differences in Negative Affectivity.

Adolescent↗

PubMed1995

Evaluative conditioning is a qualitatively distinct form of classical conditioning: a reply to Davey (1994).

Based on a critical review of the literature, Davey (1994) [Behaviour Research and Therapy, 32, 291-299] concludes that there is no sufficient evidence to support the theoretical position that evaluative conditioning is a qualitatively different form of classical conditioning. In the present manuscript, we will try to show that Davey's conclusion is biased by: (a) an overemphasis on what he believes to be problematic procedural aspects of previous evaluative conditioning studies; and (b) a selective reading of the available evidence. Finally, an attempt is made to characterize evaluative conditioning phenomena as the output of a Referential Learning System, which can be distinguished from an Expectancy Learning System.

Association Learning↗

PubMed1994

Sensory and temporal information about impending pain: the influence of predictability on pain.

Theories disagree about whether a verbal warning for pain has a detrimental or beneficial effect on the impact of an actual pain stimulus. Scheme-based theories predict a detrimental effect, whereas more representation-based, stimulus-comparator theories propose a beneficial effect. In this study, the influence of sensory predictability and temporal predictability is investigated. To control for attentional processes and to obtain a behavioral measure of the intrusive character of pain, an auditory discrimination task was introduced. This study firmly demonstrates that information about the painful nature of a heat stimulus does not a priori have detrimental effects on the impact of the stimulus. In fact, conditions in which a pain warning was given displayed a diminished impact in the SCR amplitude as well as in the subjectively reported intensity of the heat stimulus. Informing Ss about the exact time of administration did not add to the impact modulation, but instead resulted in a less-anxious state between signals. Although an overall behavioral disruption, particularly at onset, was observed, the behavioral data did not parallel the results of the two other response systems. Results are discussed in terms of scheme-based models, stimulus-comparator theories and the safety-signal hypothesis.

Adolescent↗

PubMed1994

Verbal evaluative conditioning with undetected US presentations.

In evaluative conditioning research it has been shown that a neutral stimulus (CS) acquires the valence of a positive or negative stimulus (US) with which it is presented contingently. An experiment is reported in which it is examined whether evaluative shifts can also be observed in the complete absence of contingency-awareness. Neutral words were either followed by a briefly presented positive or negative word. Results showed that neutral words which were presented contingently with a positive word, were afterwards liked more than words which were paired with negative words. This result was obtained despite the fact that Ss were not aware of the presentation of the briefly presented USs.

Adult↗

PubMed1993

The role of CS-US contingency in human evaluative conditioning.

Recent studies suggest that in Pavlovian conditioning, two different processes may be operative: signal learning and evaluative learning, resulting in two qualitatively different associative structures. Signal-learning is hypothesized to be responsible for providing us with genuine predictors (CS) for significant events (US). This proposition logically entails that the statistical-correlational relation, i.e. the contingency between CS and US should be a crucial determinant of signal learning. Evaluative conditioning, on the other hand, refers to the observation that the mere pairing of neutral with (dis)liked stimuli changes the valence of the originally neutral stimuli in a (negative) positive direction. As argued elsewhere, evaluative conditioning is probably based on the CS acquiring a mere referential value to the US, without any genuine CS-US expectancy being involved. From this, it was hypothesized that evaluative conditioning might not be dependent on CS-US contingency. Using the standard evaluative conditioning paradigm, four different levels of CS-US contingency were created on a between-subject base. The overall effect of evaluative conditioning was strongly significant, and was not mediated by awareness of the CS-US relation. Of crucial importance, this conditioning effect did not interact with the level of contingency, supporting the hypothesis that CS-US contingency is not a crucial determinant of evaluative conditioning. Moreover, this effect was obtained in a situation in which Ss simultaneously evidence to have consciously registered quite accurately the different levels of CS-US contingency.

Adult↗