Perceptual completion and object-based representations in short-term visual memory

Object-based representations in visual short-term memory (VSTM) were examined using a change detection memory task. A display comprising two rows of four differently colored elements was followed by a probe display in which only one of the rows reappeared. On same trials, the probed row was identical to the corresponding row in the memory display. On different trials, two of the elements in the probed row had their colors exchanged. In each memory display, a task-irrelevant visual element appeared between the two rows, with the potential to function as an occluder. Performance was enhanced when perceptual completion meant that four, rather than eight, objects were perceived in the memory display and when the probe display revealed that the occluded elements continued behind the occluder. It appears that several forms of representation can co-occur to support VSTM, one of which is object based.     

What you get out of memory depends on the question you ask

Following study, participants received 2 tests. The 1st was a recognition test; the 2nd was designed to tap recollection. The objective was to examine performance on Test 1 conditional on Test 2 performance. In Experiment 1, contrary to process dissociation assumptions, exclusion errors better predicted subsequent recollection than did inclusion errors. In Experiments 2 and 3, with alternate questions posed on Test 2, words having high estimates of recollection with one question had high estimates of familiarity with the other question. Results supported the following: (a) the 2-test procedure has considerable potential for elucidating the relationship between recollection and familiarity; (b) there is substantial evidence for dependency between such processes when estimates are obtained using the process dissociation and remember-know procedures; and (c) order of information access appears to depend on the question posed to the memory system.     

Remote delivery of cognitive science laboratories: A solution for small disciplines in large countries

Numerically small disciplines can be jeopardized by geographic difficulties, if student populations at universities are small and distances between them large. This problem could be addressed, if teaching resources could be shared among several universities and students in several locations could be taught simultaneously. We present the results of a trial in simultaneous Internet and videoconferencing delivery of an introductory cognitive science laboratory. The trial relied on off-the-shelf software and hardware. Students found the delivery nearly as effective as a locally run laboratory, despite a noticeable difference in the level of interactivity between the remote and other, local laboratory classes. We discuss possible further improvements in teaching efficiency and efficacy.     

Falsifying mental models: Testing the predictions of theories of syllogistic reasoning

Four experiments are reported that tested the claim, drawn from mental models theory, that reasoners attempt to construct alternative representations of problems that might falsify preliminary conclusions they have drawn. In Experiment 1, participants were asked to indicate which alternative conclusion(s) they had considered in a syllogistic reasoning task. In Experiments 2-4, participants were asked to draw diagrams consistent with the premises, on the assumption that these diagrams would provide insights into the mental representation being used. In none of the experiments was there any evidence that people constructed more models for multiple-model than for single-model syllogisms, nor was there any correlation between number of models constructed and overall accuracy. The results are interpreted as showing that falsification of the kind proposed by mental models theory may not routinely occur in reasoning.     

The Association of Group Self-Identification and Adolescent Drug Use in Three Samples Varying in Risk1

This study provides a cross-sectional analysis of the relations between group self-identification and adolescent drug use in 3 samples of youth: comprehensive high-school, continuation high-school, and runaway/street youth. Youth identified with discrete groups in all 3 samples, and similar general groups were formed. In most comparisons, a high-risk group showed greater levels of drug use than did other groups. This is the first study to demonstrate that group self-identification (a) is a generalizable construct across different types of adolescent samples, (b) is related to use of drugs other than tobacco, and (c) remains a significant correlate of drug use controlling for its relations with demographic variables and several other psychosocial variables.     

Motivational reserve: motivation-related occupational abilities and risk of mild cognitive impairment and Alzheimer disease

Midlife motivational abilities, that is, skills to initiate and persevere in the implementation of goals, have been related to mental and physical health, but their association with risk of mild cognitive impairment (MCI) and Alzheimer's disease (AD) has not yet been directly investigated. This relation was examined with data from the German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe). A total of 3,327 nondemented participants (50.3% of a randomly selected sample) aged 75-89 years were recruited in primary care and followed up twice (after 1.5 and 3 years). Motivation-related occupational abilities were estimated on the basis of the main occupation (assessed at follow-up II) using the Occupational Information Network (O* NET) database, which provides detailed information on worker characteristics and abilities. Cox proportional hazards models were used to evaluate the relative risk of developing MCI and AD in relation to motivation-related occupational abilities, adjusting for various covariates. Over the 3 years of follow-up, 15.2% participants developed MCI and 3.0% developed AD. In a fully adjusted model, motivation-related occupational abilities were found to be associated with a reduced risk of MCI (HR: 0.77; 95% CI: 0.64-0.92). Motivation-related occupational abilities were associated with reduced risk of AD in ApoE ε4 carriers (HR: 0.48; CI: 0.25-0.91), but not in noncarriers (HR: 0.99; CI: 0.65-1.53). These results suggest that midlife motivational abilities are associated with reduced risk of MCI in general and with reduced risk of AD in ApoE ε4 carriers. Revealing the mechanisms underlying this association may inform novel prevention strategies for decelerating cognitive decline in old age.     

Knowing when to move on: cognitive and perceptual decisions in time

We investigated people's ability to decide how much time to spend on the task at hand. To make such decisions well, one must take into account, among other things, the cost of failing and how one's task performance changes as a function of time. We first investigated timing decisions when the underlying task was perceptual. Decisions were highly efficient and suggested that people can make good use of perceptual knowledge and abstract reward information. Previous studies have found that perceptual decisions are generally optimal, but that cognitive decisions are generally suboptimal--a perception-cognition gap. Does a similar gap exist for timing decisions? We compared timing decisions for a perceptual task with timing decisions for more cognitive tasks. Performance was highly similar across the tasks, which suggests that knowledge can be acquired, and used to make timing decisions, in an equally efficient way regardless of whether that knowledge is derived through perceptual or cognitive experience.     

Eye movements of second language learners when reading spaced and unspaced Chinese text

The effect of spacing in relation to word segmentation was examined for four groups of non-native Chinese speakers (American, Korean, Japanese, and Thai) who were learning Chinese as second language. Chinese sentences with four types of spacing information were used: unspaced text, word-spaced text, character-spaced text, and nonword-spaced text. Also, participants' native languages were different in terms of their basic characteristics: English and Korean are spaced, whereas the other two are unspaced; Japanese is character based whereas the other three are alphabetic. Thus, we assessed whether any spacing effects were modulated by native language characteristics. Eye movement measures showed least disruption to reading for word-spaced text and longer reading times for unspaced than character-spaced text, with nonword-spaced text yielding the most disruption. These effects were uninfluenced by native language (though reading times differed between groups as a result of Chinese reading experience). Demarcation of word boundaries through spacing reduces non-native readers' uncertainty about the characters that constitute a word, thereby speeding lexical identification, and in turn, reading. More generally, the results indicate that words have psychological reality for those who are learning to read Chinese as a second language, and that segmentation of text into words is more beneficial to successful comprehension than is separating individual Chinese characters with spaces.     

Overall Hedonic Evaluations and Evaluation of Specific Moments from Past Relationships and High School Days

Two studies were conducted in which student participants gave overall hedonic evaluations of past relationships or their high school days, and, additionally, gave similar evaluations of the best, most memorable, worst, initial, and final moments from them. They also evaluated a typical moment and the percentages of good and bad times in these experiences. Such results from some individuals were given to other participants, who were also asked to make overall evaluations. Overall, the overall evaluations of the original participant related weakly rather than strongly to the evaluations of the specific moments. Generally, the other participants’ overall evaluations converged on those of the original recalling participants, but their overall evaluations of the past relationships were more positive than either their own initial evaluations or those of the original, recalling respondents. In sum, overall evaluations of these long, diverse experiences were not well predicted from valuations of the specific moments we investigated. Hedonic evaluations of past experiences may be influenced by appraisals of their success.