Contrasting Cortical Activity Associated with Category Memory and Recognition Memory

We collected functional neuroimaging data while volunteers performed similar categorization and recognition memory tasks. In the categorization task, volunteers first studied a series of 40 dot patterns that were distortions of a nonstudied prototype dot pattern. After a delay, while fMRI data were collected, they categorized 72 novel dot patterns according to whether or not they belonged to the previously studied category. In the recognition task, volunteers first studied five dot patterns eight times each. After a delay, while fMRI data were collected, they judged whether each of 72 dot patterns had been studied earlier. We found strikingly different patterns of brain activity in visual processing areas for the two tasks. During the categorization task, the familiar stimuli were associated with decreased activity in posterior occipital cortex, whereas during the recognition task, the familiar stimuli were associated with increased activity in this area. The findings indicate that these two types of memory have contrasting effects on early visual processing and reinforce the view that declarative and nondeclarative memory operate independently.     

Relaxing decision criteria does not improve recognition memory in amnesic patients

An important question about the organization of memory is whether information available in non-declarative memory can contribute to performance on tasks of declarative memory. Dorfman, Kihlstrom, Cork, and Misiaszek (1995) described a circumstance in which the phenomenon of priming might benefit recognition memory performance. They reported that patients receiving electroconvulsive therapy improved their recognition performance when they were encouraged to relax their criteria for endorsing test items as familiar. It was suggested that priming improved recognition by making information available about the familiarity of test items. In three experiments, we sought unsuccessfully to reproduce this phenomenon in amnesic patients. In Experiment 3, we reproduced the methods and procedure used by Dorfman et al. but still found no evidence for improved recognition memory following the manipulation of decision criteria. Although negative findings have their own limitations, our findings suggest that the phenomenon reported by Dorfman et al. does not generalize well. Our results agree with several recent findings that suggest that priming is independent of recognition memory and does not contribute to recognition memory scores.     

Conceptualizing Religious Practices in Psychological Research: Problems and Prospects

This article addresses the problems and prospects that follow from the conceptualization of religious phenomena and practices for scientific investigation in the psychology of religion. Two Western research traditions—instrumentalism and operationalism—are described and their potential contribution to a mismatch between what researchers intend to study and what they actually study is illustrated through two exemplar studies. The exemplar studies show how researchers’ concern with methodological rigor can compromise the rich and thick meanings of religious practices, resulting in the misrepresentation of the practices and misleading both the psychological and religious research consumer. Several suggestions for dealing with these problems are discussed.     

Integration of temporal and ordinal information during serial interception sequence learning

The expression of expert motor skills typically involves learning to perform a precisely timed sequence of movements. Research examining incidental sequence learning has relied on a perceptually cued task that gives participants exposure to repeating motor sequences but does not require timing of responses for accuracy. In the 1st experiment, a novel perceptual-motor sequence learning task was used, and learning a precisely timed cued sequence of motor actions was shown to occur without explicit instruction. Participants learned a repeating sequence through practice and showed sequence-specific knowledge via a performance decrement when switched to an unfamiliar sequence. In the 2nd experiment, the integration of representation of action order and timing sequence knowledge was examined. When either action order or timing sequence information was selectively disrupted, performance was reduced to levels similar to completely novel sequences. Unlike prior sequence-learning research that has found timing information to be secondary to learning action sequences, when the task demands require accurate action and timing information, an integrated representation of these types of information is acquired. These results provide the first evidence for incidental learning of fully integrated action and timing sequence information in the absence of an independent representation of action order and suggest that this integrative mechanism may play a material role in the acquisition of complex motor skills.     

Immediate truth – Temporal contiguity between a cognitive problem and its solution determines experienced veracity of the solution

A temporal contiguity hypothesis for the experience of veracity is tested which states that a solution candidate to a cognitive problem is more likely to be experienced as correct the faster it succeeds the problem. Experiment 1 varied the onset time of the appearance of proposed solutions to anagrams (50 ms vs. 150 ms) and found for both correct and incorrect candidates that faster appearing solutions were more frequently judged as being correct, although participants were not aware of the difference in onset delay. Experiment 2 replicated this effect with mathematical equations, shorter onset latencies (0 ms vs. 50 ms), and a reversed sequence (presenting first the solution and then the problem). Experiment 3 showed that the probability of judging a word as the solution of a remote associate insight problem decreases linearly with increasing onset delay (50 ms, 150 ms, 300 ms). Possible neurobiological-cognitive explanations for this effect are proposed.     

The perception of clicks in linguistic and nonlinguistic messages

Three experiments were run analyzing Ss’ abilities to locate clicks in auditory messages. In Expenment 1 it was found that the intonation pattern of the linguistic message largely determined the types of errors Ss made in click placement; syntactic factors were only marginally effective and semantic factors were effectively irrelevant. In addition to these linguistic factors, there was evidence that such nonlinguistic factors as attention, memory, and response biases were contributing to the data. Experiment 2 supplied additional evidence favoring these nonlinguistic factors. Experiment 3 was a mock-up of Experiment 2 except that broad-band white noise was used as the primary message instead of English sentences. The patterns of placement errors Ss made in these several experiments (especially Experiments 2 and 3) were sufficiently similar to one another to force the conclusion that nonlinguistic factors are primarily responsible for the errors Ss make in trying to locate clicks in messages. A neo-Titchenerian attention hypothesis based upon the law of prior entry was proposed to account for the data.     

Performing the unexplainable: Implicit task performance reveals individually reliable sequence learning without explicit knowledge

Memory-impaired patients express intact implicit perceptual-motor sequence learning, but it has been difficult to obtain a similarly clear dissociation in healthy participants. When explicit memory is intact, participants acquire some explicit knowledge and performance improvements from implicit learning may be subtle. Therefore, it is difficult to determine whether performance exceeds what could be expected on the basis of the concomitant explicit knowledge. Using a challenging new sequence-learning task, robust implicit learning was found in healthy participants with virtually no associated explicit knowledge. Participants trained on a repeating sequence that was selected randomly from a set of five. On a performance test of all five sequences, performance was best on the trained sequence, and two-thirds of the participants exhibited individually reliable improvement (by chi-square analysis). Participants could not reliably indicate which sequence had been trained by either recognition or recall. Only by expressing their knowledge via performance were participants able to indicate which sequence they had learned.     

The use of control groups in artificial grammar learning

Experimenters assume that participants of an experimental group have learned an artificial grammar if they classify test items with significantly higher accuracy than does a control group without training. The validity of such a comparison, however, depends on an additivity assumption: Learning is superimposed on the action of non-specific variables—for example, repetitions of letters, which modulate the performance of the experimental group and the control group to the same extent. In two experiments we were able to show that this additivity assumption does not hold. Grammaticality classifications in control groups without training (Experiments 1 and 2) depended on non-specific features. There were no such biases in the experimental groups. Control groups with training on randomized strings (Experiment 2) showed fewer biases than did control groups without training. Furthermore, we reanalysed published research and demonstrated that earlier experiments using control groups without training had produced similar biases in control group performances, bolstering the finding that using control groups without training is methodologically unsound.