Janet Metcalfe

Neural Systems and Cue-Induced Cocaine Craving

We have extended our previous work investigating the neural correlates of cue-induced cocaine craving through the use of positron emission tomography with greater spatial resolution (<4.6 mm), an evocative script, and a pixel-by-pixel analysis. Craving and cerebral glucose metabolism were measured after presentation of cocaine-related or neutral cues to 11 cocaine abusers. Cocaine cues elicited a higher degree of craving than has been previously reported and resulted in left hemispheric activation of lateral amygdala, lateral orbitofrontal cortex, and rhinal cortex and right hemispheric activation of dorsolateral prefrontal cortex and cerebellum. The intensity of activation in these areas (except cerebellum), as well as left insula, was also correlated with craving. Deactivation occurred in left ventral pole and left medial prefrontal cortex. The results suggest that induction of drug craving involves a neural network that assigns incentive motivational value to environmental stimuli through the coactivation of brain regions that process information about memories and emotions.

Intuition in insight and noninsight problem solving

People’s metacognitions, both before and during problem solving, may be of importance in motivating and guiding problem-solving behavior. These metacognitions could also be diagnostic for distinguishing among different classes of problems, each perhaps controlled by different cognitive processes. In the present experiments, intuitions on classic insight problems were compared with those on noninsight and algebra problems. The findings were as follows: (1) subjective feeling of knowing predicted performance on algebra problems but not on insight problems; (2) subjects’ expectations of performance greatly exceeded their actual performance, especially on insight problems; (3) normative predictions provided a better estimate of individual performance than did subjects’ own predictions, especially on the insight problems; and, most importantly, (4) the patterns-of-warmth ratings, which reflect subjects’ feelings of approaching solution, differed for insight and noninsight problems. Algebra problems and noninsight problems showed a more incremental pattern over the course of solving than did insight problems. In general, then, the data indicated that noninsight problems were open to accurate predictions of performance, whereas insight problems were opaque to such predictions. Also, the phenomenology of insight-problem solution was characterized by a sudden, unforeseen flash of illumination. We propose that the difference in phenomenology accompanying insight and noninsight problem solving, as empirically demonstrated here, be used to define insight.

Metacognitive and control strategies in study-time allocation

This article investigates how peoples metacognitive judgments influence subsequent study-time-allocation strategies. The authors present a comprehensive literature review indicating that people allocate more study time to judged-difficult than to judged-easy items--consistent with extant models of study-time allocation. However, typically, the materials were short, and participants had ample time for study. In contrast, in Experiment 1, when participants had insufficient time to study, they allocated more time to the judged-easy items than to the judged-difficult items, especially when expecting a test. In Experiment 2, when the materials were shorter, people allocated more study time to the judged-difficult materials. In Experiment 3, under high time pressure, people preferred studying judged-easy sonnets; under moderate time pressure, they showed no preference. These results provide new evidence against extant theories of study-time allocation.

Evidence that judgments of learning are causally related to study choice

Three experiments investigated whether study choice was directly related to judgments of learning (JOLs) by examining people’s choices in cases in which JOLs were dissociated from recall. In Experiment 1, items were given either three repetitions or one repetition on Trial 1. Items given three repetitions received one on Trial 2, and those given one repetition received three on Trial 2—equating performance at the end of Trial 2, but yielding different immediate Trial 2 JOLs. Study choice followed the “illusory” JOLs. A delayed JOL condition in Experiment 2 did not show this JOL bias and neither did study choice. Finally, using a paradigm (Koriat & Bjork, 2005) in which similar JOLs are given to forward and backward associative pairs, despite much worse performance on the backward pairs, study choice again followed the mistaken JOLs. We concluded that JOLs—what people believe they know—directly influence people’s study choices.

Metacognitive Judgments and Control of Study

Recent evidence indicates that peoples judgments of their own learning are causally related to their study behavior and not epiphenomenal. I argue here that people use these metacognitions in an effort to selectively study material in their own region of proximal learning. First they attempt to eliminate materials that are already well learned. Then they progress successively from studying easier to more difficult materials. Successful implementation of this metacognitively guided strategy enhances learning. The necessary components are, first, that the metacognitions be accurate, and second, that the appropriate choices are implemented for study. With these parts in place, the individual is in position to effectively take control of his or her own learning.

Is study time allocated selectively to a region of proximal learning

Five experiments investigated whether people allocate their study time according to the discrepancy reduction model (i.e., to the most difficult items; J. Dunlosky & C. Hertzog, 1998) or to items in their own region of proximal learning. Consistent with the latter hypothesis, as more time was given, people shifted toward studying more difficult items. Experts, whether college students or Grade 6 children, devoted their time to items that were more difficult than did novices. However, in a multiple-trials experiment, people regressed toward easier items on Trial 2 rather than shifting to more difficult items, perhaps because Trial 1 feedback revealed poor learning of the easiest items. These findings are in opposition to the discrepancy reduction model and support the region of proximal learning hypothesis.

Composite Holographic Associative Recall Model (CHARM) and Blended Memories in Eyewitness Testimony

The idea that compositing or blending occurs in human episodic memory stems from two sources: (a) distributed memory models and (b) studies on the errors that occur in eyewitness testimony. These two traditions of researchmtheoretical and empiricalmhave been independent and distinct. Here, data from the eyewitness testimony paradigm are simulated by the distributed model CHARM (Composite Holographic Associative Recall Model). Of focal concern are Lofluss studies, which have been interpreted in favor of the blending hypothesis, and McCloskey and Zaragozas studies, which have been interpreted as refuting Loftuss position. Both of these seemingly contradictory results, as well as recent findings with yes/no recognition, fall out of the model. Finally, the model predicts empirically found color shifts and provides specifications for when blends and memory impairments will and will not be expected.

Cue familiarity but not target retrievability enhances feeling-of-knowing judgments.

Two hypotheses concerning peoples ability to predict later memory performance for unrecalled items were investigated. The target retrievability hypothesis states that feeling-of-knowing judgments (FKJs) are based on partial target information; and the cue familiarity hypothesis asserts that they are based on recognition of the cues. In Experiments 1 and 2, subjects either generated or read the targets of paired associates. Half of the cues had been primed in a pleasantness-rating task. The generation manipulation increased recall but had no effect on FKJs. Cue priming had no effect on recall but increased FKJs. In Experiment 3, using general information questions, primed after the initial recall attempt, both cue and target priming increased FKJs. Experiment 4, which remedied difficulties in Experiment 3, showed no effect of target priming whereas cue priming increased FKJs. The results favor the cue familiarity hypothesis.

The Dynamics of Learning and Allocation of Study Time to a Region of Proximal Learning

In contrast to the dominant discrepancy reduction model, which favors the most difficult items, people, given free choice, devoted most time to medium-difficulty items and studied the easiest items first. When study time was experimentally manipulated, best performance resulted when most time was given to the medium-difficulty items. Empirically determined information uptake functions revealed steep initial learning for easy items with little subsequent increase. For medium-difficulty items, initial gains were smaller but more sustained, suggesting that the strategy people had used, when given free choice, was largely appropriate. On the basis of the information uptake functions, a negative spacing effect was predicted and observed in the final experiment. Overall, the results favored the region of proximal learning framework.

Cognitive Optimism: Self-Deception or Memory-Based Processing Heuristics?

In a wide variety of cognitive tasks, peoples expectations of what their own performance is, was, and will be are an overestimate of reality. After documenting a number of situations in which people exhibit such overconfidence, several reasons for it are discussed. It is suggested that in these situations, the optimistic bias is not attributable exclusively to self-deception or wishful thinking. Rather, the information yielded up by the cognitive system, in combination with the heuristics used for making judgments of future and past performance tailored to the specific questions asked of participants, produces a bias toward believing that one knows, knew, and will perform better than actual performance substantiates. Consequently, in the cognitive domain, the inflated beliefs that result in overconfidence also result in cessation of efforts before the correct solution of problems is ascertained, before accurate retrieval of memorial information is attained, or before adequate learning of new material has been accomplished. This effect seems in contrast to findings on peoples moods and self-esteem in real-world or threatening situations that suggest that an optimistic bias in these domains be person protective and adaptive.