Time judgments in global temporal contexts

With three experiments, we examined the effects of global temporal context on time judgments as gauged by constant errors (CEs) and estimates of a preferred period (P). In Experiment 1, participants in seven different conditions listened to sequences of a given rate (with interonset intervals ranging from 200 to 800 msec) and judged the relative duration of a final (comparison) time interval. No P emerged. In Experiments 2 and 3, we embedded the same rates in different global (session) contexts that varied according to (1) mean session rate, (2) standard deviation, (3) range, and (4) number of different rates in a session. Evidence from CEs indicated that P varied primarily as a function of mean session rate and range of tempi. The best predictor of errors involved a measure termed relative range (RR = range/mean session rate). A general algorithm incorporating RR successfully predicts P, and the implications of this algorithm are discussed.     

Production of graphic symbol sentences by individuals with aphasia: efficacy of a computer-based augmentative and alternative communication intervention

The study employed a single-subject multiple baseline design to examine the ability of 9 individuals with severe Broca's aphasia or global aphasia to produce graphic symbol sentences of varying syntactical complexity using a software program that turns a computer into a speech output communication device. The sentences ranged in complexity from simple two-word phrases to those with morphological inflections, transformations, and relative clauses. Overall, results indicated that individuals with aphasia are able to access, manipulate, and combine graphic symbols to produce phrases and sentences of varying degrees of syntactical complexity. The findings are discussed in terms of the clinical and public policy implications.     

Boundary extension: the role of magnification, object size, context, and binocular information

Boundary extension is a tendency to remember close-up scenes as if they extended beyond the occluding boundaries. The authors explored the contributing factors using brief retention intervals and computer-generated images. Boundary extension turns out to be more complex than previously thought and is not linked to the effects of image magnification and field-of-view changes. Although this is consistent with the idea that boundary extension is the product of the activation of a mental schema that provides information of what is likely to exist outside the picture boundaries, the authors also found that properties of the object at the center of the picture can affect boundary extension independently of the information at the boundaries. In a test of boundary extension using stereograms, the effect does not seem to depend on amount of perceived depth, suggesting a weaker link to perception of space than previously hypothesized.     

Study repetition and the rejection of conjunction lures

Four experiments were conducted to provide further support for a dual-process approach to conjunction errors in recognition memory over a single-process approach. In Experiments 1, 2a, and 2b study words were repeated once (2 presentations) or several times (8 or 16 presentations), and a response signal delay (RSD) was manipulated (short vs long). Short RSD groups produced lower hit rates but higher conjunction error rates compared to long RSD groups. Repetition effects on conjunction errors occurred for short RSD but not long RSD groups. In Experiment 3, additional judgements on new items were solicited to show that the "null" effects for long RSD groups in the earlier experiments were, in fact, illusory. Together, the experiments provide evidence for recollection-based rejections of conjunction lures and support a dual-process theory of recognition memory over a single-process model.     

An examination of three sets of MMPI-2 personality disorder scales

Three sets of personality disorder scales (PD scales) can be scored for the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989). Two sets (Levitt & Gotts, 1995; Morey, Waugh, & Blashfield, 1985) are derived from the MMPI (Hathaway & McKinley, 1983), and a third set (Somwaru & Ben-Porath, 1995) is based on the MMPI-2. There is no validity research for the Levitt and Gotts scale, and limited validity research is available for the Somwaru and Ben-Porath scales. There is a large body of research suggesting that the Morey et al. scales have good to excellent convergent validity when compared to a variety of other measures of personality disorders. Since the Morey et al. scales have established validity, there is a question if additional sets of PD scales are needed. The primary purpose of this research was to determine if the PD scales developed by Levitt and Gotts and those developed by Somwaru and Ben-Porath contribute incrementally to the scales developed by Morey et al. in predicting corresponding scales on the MCMI-II (Millon, 1987). In a sample of 494 individuals evaluated at an Army medical center, a hierarchical regression analysis demonstrated that the Somwaru and Ben-Porath Borderline, Antisocial, and Schizoid PD scales and the Levitt and Gotts Narcissistic and Histrionic scales contributed significantly and meaningfully to the Morey et al. scales in predicting the corresponding MCMI-II (Millon, 1987) scale. However, only the Somwaru and Ben-Porath scales demonstrated acceptable internal consistency and convergent validity.     

Civilian PTSD scales: relationships with trait characteristics and everyday distress

Strong associations between civilian posttraumatic stress disorder (PTSD) scales and measures of general psychological distress suggest that the scales are nonspecific to PTSD. Three common PTSD scales were administered to 122 undergraduates who had experienced an emotionally salient, nontraumatic event: a college examination. Results indicated that normal levels of anxiety associated with the examination were positively correlated with scores on the Impact of Event Scale-Revised, Revised Civilian Mississippi Scale, and PTSD Checklist-Civilian Version. Multiple regression analyses indicated that substantial variance in the PTSD scales was accounted for by trait characteristics such as negative and positive affectivity and affect intensity (R2 .29 to .53). Negative affectivity correlated as highly with PTSD measures (r = .46 to .71) as those measures correlated with each other (r = .48 to .65). A high proportion of participants exceeded clinical cutoffs on these measures. The findings suggest that these PTSD scales may be overly sensitive to nontraumatic stressors such as everyday distress and trait characteristics.     

When does word meaning affect immediate serial recall in semantic dementia?

Patients with semantic dementia can show superior immediate recall of words that they still understand relatively well, as compared with more semantically degraded words, suggesting that conceptual knowledge makes a major contribution to phonological short-term memory. However, a number of studies have failed to show such a recall difference, challenging this view. We examined the effect of several methodological factors on the recall of known and degraded words in 4 patients with semantic dementia, in order to investigate possible reasons for this discrepancy. In general, our patients did exhibit poorer recall of the degraded words and made more phonological errors on these items. In addition, set size affected the magnitude of the recall advantage for known words. This finding suggests that semantic degradation influenced the rate of learning in the immediate recall task when the same items were presented repeatedly. The methods used to select known and degraded items also impacted on the recall difference. List length, however, did not affect the advantage for known words. The coherence of items in phonological short-term memory was affected by their semantic status, but not by the length of the material to be retained. The implications of these findings for the role of semantic and phonological representations in verbal short-term memory are discussed.     

Comparing learning environments in U.S. military officer education: a brief replication

A 2003 comparative study on learning environments at two military officer training sites was replicated using different methodology. Satisfaction with learning environment and with administrative inprocessing was higher at Fort Leavenworth than at Fort Dix. Most students expressed a preference for Fort Leavenworth. Satisfaction with institutional support and educational facilities appears to influence perceived satisfaction with a learning environment and with preference for training sites among senior military officers.     

Transfer of spatial behavior between different environments: implications for theories of spatial learning and for the role of the hippocampus in spatial learning

In 3 experiments, rats were required to find a submerged platform located in 1 corner of an arena that had 2 long and 2 short sides; they were then trained to find the platform in a new arena that also had 2 long and 2 short sides but a different overall shape. The platform in the new arena was easier to find if it was in a corner that was geometrically equivalent, rather than the mirror image, of the corner where it had previously been located. The final experiment revealed that hippocampal lesions impaired rats' ability to find the platform in these arenas. The results suggest that rats did not use the overall shape of the arena to locate the platform but relied on more local cues and that the hippocampus plays a role in navigation based on these cues.