Probabilistic models of cognition: conceptual foundations

Remarkable progress in the mathematics and computer science of probability has led to a revolution in the scope of probabilistic models. In particular, 'sophisticated' probabilistic methods apply to structured relational systems such as graphs and grammars, of immediate relevance to the cognitive sciences. This Special Issue outlines progress in this rapidly developing field, which provides a potentially unifying perspective across a wide range of domains and levels of explanation. Here, we introduce the historical and conceptual foundations of the approach, explore how the approach relates to studies of explicit probabilistic reasoning, and give a brief overview of the field as it stands today.     

Vision as Bayesian inference: analysis by synthesis?

We argue that the study of human vision should be aimed at determining how humans perform natural tasks with natural images. Attempts to understand the phenomenology of vision from artificial stimuli, although worthwhile as a starting point, can lead to faulty generalizations about visual systems, because of the enormous complexity of natural images. Dealing with this complexity is daunting, but Bayesian inference on structured probability distributions offers the ability to design theories of vision that can deal with the complexity of natural images, and that use 'analysis by synthesis' strategies with intriguing similarities to the brain. We examine these strategies using recent examples from computer vision, and outline some important implications for cognitive science.     

Some effects of alcohol on eyewitness memory

Male volunteers (N = 120) in small groups of 5 to 10 watched a staged theft involving live actors. Some (n = 47) were under the influence of alcohol (average blood alcohol level of .10) at the time. Some subjects (n = 58) were interviewed immediately after the event, and all were interviewed 1 week later. The delayed interview included the presentation of a photospread that either did or did not contain the picture of the "thief." Alcohol suppressed the amount recalled during the immediate interview and both the amount and accuracy of recall after the 1-week delay. Alcohol had no influence on the ability of witnesses to recognize the thief's picture. When the thief's picture was not present in the photospread, however, alcohol increased the rate of false identifications. An immediate interview substantially improved the amount of information subjects were able to recall 1 week later.     

Associative learning and imagery training in children

Two experiments are reported which examine imagery as a factor in children's learning to associate object pairs. The results of the first experiment indicated that presenting the objects in an interacting fashion greatly facilitated subsequent recognition performance. The outcome of Experiment II revealed that children can be trained to form their own interaction images. These findings are discussed in terms of their relevance to contemporary views of mediation in children's learning.     

The effects of delay and imagery training on the recall and recognition of object pairs

The present study represents a further investigation of an imagery training procedure previously developed by the authors (Yuille & Catchpole, 1973). Subjects given a brief training session in the use of an interacting imaginal mnemonic showed significantly higher performance than nontrained Ss on tests of immediate, delayed, and second learning set memory. While both recognition and recall were equally affected by the procedure, with recognition showing its usual superiority, the type of immediate memory test did not affect delayed recall. The findings are interpreted as supporting the preference of young children for visual coding.     

Negotiating false memories: interviewer and rememberer characteristics relate to memory distortion

In a recent study, more than half of the participants were led to create a partial or complete false memory for an emotional childhood event (e.g., serious animal attack). Using a subsample from that study, we examined the hypothesis that memory distortion is related to characteristics of interviewers and rememberers. The relations between susceptibility to memory distortion and (a) dissociation (Dissociative Experiences Scale) and (b) personality traits (NEO-Five Factor Inventory) were investigated. Results indicated that participants who exhibited memory distortion scored significantly higher on the dissociative scale than their counterparts who did not exhibit memory distortion. Further, susceptibility to memory distortion was associated with higher extraversion scores in interviewers and lower extraversion scores in participants. This pattern of findings suggests that false memories may derive from a social negotiation between particular interviewers and rememberers.     

A Bayesian Theory of Sequential Causal Learning and Abstract Transfer

Two key research issues in the field of causal learning are how people acquire causal knowledge when observing data that are presented sequentially, and the level of abstraction at which learning takes place. Does sequential causal learning solely involve the acquisition of specific cause‐effect links, or do learners also acquire knowledge about abstract causal constraints? Recent empirical studies have revealed that experience with one set of causal cues can dramatically alter subsequent learning and performance with entirely different cues, suggesting that learning involves abstract transfer, and such transfer effects involve sequential presentation of distinct sets of causal cues. It has been demonstrated that pre‐training (or even post‐training) can modulate classic causal learning phenomena such as forward and backward blocking. To account for these effects, we propose a Bayesian theory of sequential causal learning. The theory assumes that humans are able to consider and use several alternative causal generative models, each instantiating a different causal integration rule. Model selection is used to decide which integration rule to use in a given learning environment in order to infer causal knowledge from sequential data. Detailed computer simulations demonstrate that humans rely on the abstract characteristics of outcome variables (e.g., binary vs. continuous) to select a causal integration rule, which in turn alters causal learning in a variety of blocking and overshadowing paradigms. When the nature of the outcome variable is ambiguous, humans select the model that yields the best fit with the recent environment, and then apply it to subsequent learning tasks. Based on sequential patterns of cue‐outcome co‐occurrence, the theory can account for a range of phenomena in sequential causal learning, including various blocking effects, primacy effects in some experimental conditions, and apparently abstract transfer of causal knowledge.     

A detailed examination of mediation in PA learning

This paper reports a single experiment in which verbal and imaginal mediators were compared in paired-associate learning. Pair concreteness and delay of recall (immediate vs 1-week delay) were also manipulated. The dependent variables included the latencies of mediator discovery and mediator production, response recall, mediator recall, and recall latency. A variety of differences between verbal and imaginal codes were found in the dependent measures. In addition, a profound effect of immediate recall on subsequent recall was discovered. The results are discussed in terms of the differences between the two modalities of memory.     

Syntactic facilitation of children's associative learning: An instructional effect

An experiment is reported in which connective recall, as well as noun recall, was obtained in a pair-associate learning, syntactic facilitation paradigm. Dfferences in the pattern of noun and connective recall, and a partial independence in the two types of recall, were obtained. These results were interpreted as consistent with the hypothesis that experimenter-supplied verb links facilitate noun pair learning by serving an instructional role, indicating to the subject how a pair might be coded.     

Nonholistic processing in mental rotation: Some suggestive evidence

A series of experiments, using a modification of the Shepard and Metzler mental rotation task, was performed to investigate Shepard’s “holistic rotation” hypothesis. Effective figural complexity was manipulated in the experiments in two distinct ways. In one manipulation, blocks were added to the standard 10-blockfigures. In the other manipulation, the figures used and the direction of angular rotation were restricted so that some featural information in the figures was redundant, that is, unnecessary for the discrimination task at hand. There were two major conclusions. First, when figural complexity is effectively manipulated, it has a powerful effect on the “speed of mental rotation,” as measured by the slope of the curve relating reaction time to angular disparity. Second, it is possible, by ignoring featural redundancy, to construct experimental paradigms in which “complexity” of figures is apparently manipulated but has no effect on speed of mental rotation. This fact provides a possible explanation of why some previous experiments have failed to find a complexity effect in mental rotation.