Verbalization of Decision Strategies in Multiple‐Cue Probabilistic Inference

In multiple‐cue probabilistic inference, people choose between alternatives based on several cues, each of which is differentially associated with an alternative's overall value. Various strategies have been proposed for probabilistic inference (e.g., weighted additive, tally, and take‐the‐best). These strategies differ in how many cue values they require to enact and in how they weight each cue. Do decision makers actually use any of these strategies? Ways to investigate this question include analyzing people's choices and the cues that they reveal. However, different strategies often predict the same decisions, and search behavior says nothing about whether or how people use the information that they acquire. In this research, we attempt to elucidate which strategies participants use in a multiple‐cue probabilistic inference task by examining verbal protocols, a high‐density source of process data. The promise of verbal data is in their utility for testing detailed information processing models. To that end, we apply protocol analysis in conjunction with computational simulations. We find converging evidence across outcome measures, search measures, and verbal reports that most participants use simplifying heuristics, namely take‐the‐best. Copyright © 2015 John Wiley & Sons, Ltd.     

Optimal cue aggregation in the absence of criterion knowledge

The study of multi‐cue judgment investigates how decision makers aggregate cues to predict the value of a criterion variable. We consider a multi‐cue judgment task in which decision makers have prior knowledge of inter‐cue relationships but are ignorant of how the cues correlate with the criterion. In this setting, a naive judgment strategy prescribes weighting the cues equally. Although many participants are well described via an equal weighting scheme, we find that a substantial minority of participants make predictions consistent with a weighting scheme based on a low‐dimensional projection of the cue space that optimally takes into account inter‐cue correlations. The use of such a weighting scheme is consistent with minimizing maximal error in prediction when the cue‐criterion relationships are unknown.     

Illusory contour figures are perceived as occluding surfaces by 8‐month‐old infants

Infants have been demonstrated to be able to perceive illusory contours in Kanizsa figures. This study tested whether they also perceive these illusory figures as having the properties of real objects, such as depth and capability of occluding other objects. Eight‐ and five‐month‐old infants were presented with scenes that included a Kanizsa square and further depth cues provided by the deletion and accretion pattern of a moving duck. The 8‐month‐old infants looked significantly longer at the scene when the two types of occlusion cues were inconsistent than when they were consistent with each other, which provides evidence that they interpreted the Kanizsa square as a depth cue. In contrast, 5‐month‐olds did not show this difference. This finding demonstrates that 8‐month‐olds perceive the figure formed by the illusory contours as having properties of a real object that can act as an occluder.     

Illusory and spurious correlations: distinct phenomena or joint outcomes of exemplar‐based category learning?

Stereotype formation about novel groups was analyzed with trivariate stimulus distributions that were generated by group membership, valence of behavior, and a context variable. Within this stimulus setting, we manipulated the confounding role of the context variable and the distinctiveness of events in terms of their relative infrequency. The experimental procedure allowed us to analyze illusory and spurious correlations in a joint framework, to conduct focused tests for memory effects of relative infrequency and to investigate the detection of covariations with the context variable. The results revealed that illusory and spurious correlations were formed without enhanced memory for infrequent events and with existing covariations of the confounding context factor being well extracted. These observations suggest that illusory and spurious correlations can be understood without assuming specific cognitive processes that are tied to the particular characteristics of a given stimulus distribution, such as enhanced memory in the case of relative infrequency and neglect of a context variable in the case of a confounding factor. Instead, computer simulations with an exemplar‐based learning model demonstrated that exemplar‐based category learning may provide a coherent and integrative theoretical framework for illusory correlations, spurious correlations and true contingency learning in social cognition. Copyright © 2006 John Wiley & Sons, Ltd.     

Do People Order Cues by Retrieval Fluency when Making Probabilistic Inferences?

In multiple‐cue probabilistic inferences, people infer alternatives' unknown values on decision criteria, using alternatives' attributes as cues. Some inferential strategies, like take‐the‐best, assume that people consider relevant cues sequentially in order of decreasing validity. This assumption has been deemed cognitively implausible by some, who suggest memory retrieval principles to guide cue order. We test whether memory‐based inferences are better described by a model considering cues in order of validity or in order of memory retrieval. In an experiment, we manipulated the frequency with which cues appeared in a learning phase, increasing retrieval fluency of cue values related to the more frequently appearing cue. In a subsequent decision phase, participants made a series of two‐alternative decisions based on the learned cue values. We compared two sequential sampling models, which differed in whether cues are sampled in order of subjective cue validity or in order of retrieval fluency. To model retrieval order of cues in the fluency sampling model, we used the declarative memory theory embedded in the ACT‐R cognitive architecture. Most participants' decisions were best described by the model sampling cues in order of memory retrieval. Only a minority of participants were classified as sampling cues by validity. Our result suggests that retrieval fluency is the primary driver of cue order in inferences from memory, irrespective of the cues' validities. Copyright © 2017 John Wiley & Sons, Ltd.     

Using source cues and familiarity cues to resist imagination inflation

To investigate whether people can resist imagination inflation--the imagination-induced increased confidence that fictitious childhood events really happened--we gave them different types of cues. In a three-stage procedure, participants: (1) rated their confidence that a list of childhood events had happened to them, (2) imagined some of these events, and (3) made confidence ratings a second time. Subjects received either no cues about the source of the imagined event, an additional source cue (perspective), an additional familiarity cue (a plausibility questionnaire), or both cues. Only subjects who had both types of cues resisted imagination inflation. These results suggest that additional cues can sometimes safeguard people from becoming more confident that fictitious events were genuine experiences.     

Learning concepts and categories: is spacing the "enemy of induction"?

Inductive learning -- that is, learning a new concept or category by observing exemplars -- happens constantly, for example, when a baby learns a new word or a doctor classifies x-rays. What influence does the spacing of exemplars have on induction? Compared with massing, spacing enhances long-term recall, but we expected spacing to hamper induction by making the commonalities that define a concept or category less apparent. We asked participants to study multiple paintings by different artists, with a given artist's paintings presented consecutively (massed) or interleaved with other artists' paintings (spaced). We then tested induction by asking participants to indicate which studied artist (Experiments 1a and 1b) or whether any studied artist (Experiment 2) painted each of a series of new paintings. Surprisingly, induction profited from spacing, even though massing apparently created a sense of fluent learning: Participants rated massing as more effective than spacing, even after their own test performance had demonstrated the opposite.     

Forward blocking in human learning sometimes reflects the failure to encode a cue-outcome relationship

In two “allergist” causal judgement experiments, participants were trained with a blocking design (A + |AB+). The procedure allowed different food cues to be paired with different fictitious allergic reactions. On test, participants were asked to rate the causal efficacy of the target cues and to recall the particular allergic reaction (outcome) that had followed each cue during training. Forward blocking was observed on the causal judgement measure and on the outcome recall measure in both Experiment 1 and Experiment 2. A backward blocking contingency was also trained in Experiment 2 (AB + |A+). Backward blocking was not observed either on the causal judgement or on the outcome recall measure. The evidence from the recall measure suggests that forward blocking in this task results from a failure to encode the B-outcome relationship during training. Associative and nonassociative mechanisms of forward blocking are discussed.     

Forward blocking in human learning sometimes reflects the failure to encode a cue–outcome relationship

In two “allergist” causal judgement experiments, participants were trained with a blocking design (A?+?|AB+). The procedure allowed different food cues to be paired with different fictitious allergic reactions. On test, participants were asked to rate the causal efficacy of the target cues and to recall the particular allergic reaction (outcome) that had followed each cue during training. Forward blocking was observed on the causal judgement measure and on the outcome recall measure in both Experiment 1 and Experiment 2. A backward blocking contingency was also trained in Experiment 2 (AB?+?|A+). Backward blocking was not observed either on the causal judgement or on the outcome recall measure. The evidence from the recall measure suggests that forward blocking in this task results from a failure to encode the B–outcome relationship during training. Associative and nonassociative mechanisms of forward blocking are discussed.     

The Role of Interruptions and Contextual Associations in Delayed‐Execute Prospective Memory

We conducted three experiments to examine the dynamics of a delayed‐execute prospective memory task involving task interruptions. In the delayed‐execute paradigm, participants must delay a response until some future condition is met. After an intention was formed to a salient cue, an interruption reduced prospective memory relative to a no‐interruption condition. Prospective memory for cues encountered during an interrupting task was worse than for cues occurring before an interruption, but the location of the cue in either the ongoing task or the interruption did not affect prospective memory. Importantly, reinstating the prevailing context after the interruption alleviated the negative influence of the interruption. Providing participants with information about the future context for making the delayed‐execute response also alleviated some of these deficits presumably because participants could encode more specific features of the performance context. These results highlight the potential importance of contextual associations and reminders in completing everyday intentions successfully. Copyright © 2013 John Wiley & Sons, Ltd.     

Partial reinforcement and context switch effects in human predictive learning

Human participants were trained in a trial-by-trial contingency judgements task in which they had to predict the probability of an outcome (diarrhoea) following different cues (food names) in different contexts (restaurants). Cue P was paired with the outcome on half of the trials (partial reinforcement), while cue C was paired with the outcome on all the trials (continuous reinforcement), both cues in Context A. Test was conducted in both Context A and a different but equally familiar context (B). Context change decreased judgements to C, but not to P (Experiment 1). This effect was found only in the cue trained in the context where a different cue was partially reinforced (Experiment 2). Context switch effects disappeared when different cues received partial reinforcement in both contexts of training (Experiment 3). The implications of these results for an explanation of context switch effects in terms of ambiguity in the meaning of the cues prompting attention to the context (e.g., Bouton, 1997) are discussed.     

Partial reinforcement and context switch effects in human predictive learning

Human participants were trained in a trial-by-trial contingency judgements task in which they had to predict the probability of an outcome (diarrhoea) following different cues (food names) in different contexts (restaurants). Cue P was paired with the outcome on half of the trials (partial reinforcement), while cue C was paired with the outcome on all the trials (continuous reinforcement), both cues in Context A. Test was conducted in both Context A and a different but equally familiar context (B). Context change decreased judgements to C, but not to P (Experiment 1). This effect was found only in the cue trained in the context where a different cue was partially reinforced (Experiment 2). Context switch effects disappeared when different cues received partial reinforcement in both contexts of training (Experiment 3). The implications of these results for an explanation of context switch effects in terms of ambiguity in the meaning of the cues prompting attention to the context (e.g., Bouton, 1997) are discussed.     

The role of expectation and memory‐retrieval techniques in the construction of beliefs about past events

This study assessed social factors affecting the elicitation of false reports for events occurring the day after birth. High, medium and low hypnotizable participants (N=170) were randomly assigned to hypnotic, guided imagery (non‐hypnotic), expectancy or control conditions. Participants were led to believe that they had experienced a specific event on the day after birth. Hypnotic and guided imagery participants were age regressed, while participants in the expectancy condition were provided with cues suggesting access to this memory was feasible. Relative to controls, these participants recalled higher levels of day‐after‐birth reports, although age‐regressed participants reported significantly more event specific details than expectancy participants. Furthermore, high and medium hypnotizables were more likely than low hypnotizables to recall events occurring the day after birth. Implications of this study within the therapeutic setting are discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Processing of probabilistic information in weight perception and motor prediction

We studied the effects of probabilistic cues, i.e., of information of limited certainty, in the context of an action task (GL: grip-lift) and of a perceptual task (WP: weight perception). Normal subjects (n = 22) saw four different probabilistic visual cues, each of which announced the likely weight of an object. In the GL task, the object was grasped and lifted with a pinch grip, and the peak force rates indicated that the grip and load forces were scaled predictively according to the probabilistic information. The WP task provided the expected heaviness related to each probabilistic cue; the participants gradually adjusted the object’s weight until its heaviness matched the expected weight for a given cue. Subjects were randomly assigned to two groups: one started with the GL task and the other one with the WP task. The four different probabilistic cues influenced weight adjustments in the WP task and peak force rates in the GL task in a similar manner. The interpretation and utilization of the probabilistic information was critically influenced by the initial task. Participants who started with the WP task classified the four probabilistic cues into four distinct categories and applied these categories to the subsequent GL task. On the other side, participants who started with the GL task applied three distinct categories to the four cues and retained this classification in the following WP task. The initial strategy, once established, determined the way how the probabilistic information was interpreted and implemented.     

Traces of the artist: Sensitivity to the role of the artist in children's pictorial reasoning

In three studies we investigated the question of whether children consider the attributes of the artist (sentience, age level, affective style, emotion) when making judgments about the traces (drawings) made by that artist. In Study 1, 2–5‐year‐old children were asked to find pictures drawn by a machine, an adult, an older and a younger child. Results indicated that children younger than 4 years do not consider the artists' attributes when making judgments, but 4‐ and 5‐year‐olds do. Furthermore, whereas the oldest children were adept at both machine‐person (sentience) and person‐person (age) contrasts, 4‐year‐olds succeeded only with person‐person contrasts. In Study 2, videotaped artists displayed differences in degree of agitation (affective style) while drawing, and this attribute was manipulated in the drawing by varying line density, asymmetry, line overlap and line gap, or all four features, across stimuli. Three‐ and five‐year‐old children judged whether a calm or agitated person drew the stimuli. Findings showed that five‐year‐old, but not 3‐year‐old, children easily completed the task. In Study 3, 3‐, 5‐ and 7‐year‐old children judged whether happy or sad artists made paintings of matching emotional tone. Performance on this picture judgment task was contrasted with performance on three theory of mind tasks (false belief, emotion and interpretative). The results indicated that 5‐ and 7‐year‐olds successfully judged the impact of artists' emotions on paintings, but 3‐year‐olds did not. Performance on the picture task was related to that on the false belief task, but not to the emotion or interpretive tasks. Taken together, the results suggest that children's view of visual symbols includes a consideration of the qualities of the artist beginning around 5 years, and there appears to be a common link between judgments of the mind behind the visual symbol in the picture task and judgments of mental state reasoning in the false belief task.     

Inattentional blindness for negative relationships in human causal learning

The present study focuses on the effect of selective attention on causal learning. Three effects of the level of attention to predictive symptoms in positive and negative contingency learning tasks are reported. First, participants accurately detected a positive relationship between an incidental cue and a contingent outcome, although judgements were slightly lower than those for the attended cue. Second, participants were unable to detect negative relationships between incidental cues and outcomes, which suggests a major role of selective attention in this type of learning. Third, participants retrieved the frequency of each trial type more accurately in the attended conditions than in the incidental conditions. These findings show how attention guides and constrains human causal learning and reveal an inattentional blindness effect for negative contingency learning.     

Inattentional blindness for negative relationships in human causal learning

The present study focuses on the effect of selective attention on causal learning. Three effects of the level of attention to predictive symptoms in positive and negative contingency learning tasks are reported. First, participants accurately detected a positive relationship between an incidental cue and a contingent outcome, although judgements were slightly lower than those for the attended cue. Second, participants were unable to detect negative relationships between incidental cues and outcomes, which suggests a major role of selective attention in this type of learning. Third, participants retrieved the frequency of each trial type more accurately in the attended conditions than in the incidental conditions. These findings show how attention guides and constrains human causal learning and reveal an inattentional blindness effect for negative contingency learning.     

The role of outcome inhibition in interference between outcomes: A contingency‐learning analogue of retrieval‐induced forgetting

Current associative theories of contingency learning assume that inhibitory learning plays a part in the interference between outcomes. However, it is unclear whether this inhibitory learning results in the inhibition of the outcome representation or whether it simply counteracts previous excitatory learning so that the outcome representation is neither activated nor inhibited. Additionally, these models tend to conceptualize inhibition as a relatively transient and cue‐dependent state. However, research on retrieval‐induced forgetting suggests that the inhibition of representations is a real process that can be relatively independent of the retrieval cue used to access the inhibited information. Consistent with this alternative view, we found that interference between outcomes reduces the retrievability of the target outcome even when the outcome is associated with a novel (non‐inhibitory) cue. This result has important theoretical implications for associative models of interference and shows that the empirical facts and theories developed in studies of retrieval‐induced forgetting might be relevant in contingency learning and vice versa.     

The recognition heuristic in memory‐based inference: is recognition a non‐compensatory cue?

The recognition heuristic makes the strong claim that probabilistic inferences in which a recognized object is compared to an unrecognized one are made solely on the basis of whether the objects are recognized or not, ignoring all other available cues. This claim has been seriously challenged by a number of studies that have shown a clear effect of additional cue knowledge. In most of these studies, either recognition knowledge was acquired during the experiment, and/or additional cues were provided to participants. However, the recognition heuristic is more likely to be a tool for exploiting natural (rather than induced) recognition when inferences have to be made from memory. In our study on natural recognition and inferences from memory, around 85% of the inferences followed recognition information even when participants had learned three cues that contradicted recognition and when some of the contradictory cues were deemed more valid than recognition. Nevertheless, there were strong individual differences in the use of recognition. Whereas about half of the participants chose the recognized object regardless of the number of conflicting cues—suggestive of the hypothesized noncompensatory processing of recognition—the remaining participants were influenced by the additional knowledge. The former group of participants also tended to give higher estimates of recognition's validity. In addition, we found that the use of recognition for an inference may be affected by whether additional cue knowledge has been learned outside or within the experimental setting. Copyright © 2007 John Wiley & Sons, Ltd.