The Smell Identification Test as a measure of olfactory identification ability in schizophrenia and healthy populations: a Rasch psychometric study

This study examines University of Pennsylvania Smell Identification Test (UPSIT; R. L. Doty, 1995) performance in 133 controls and 54 chronic, medicated outpatients with schizophrenia (SZ) using item-response theory modeling. Results show that UPSIT items contribute to 1 factor, cover a range of 8 standard errors of measurement, and articulate 3 ability levels. Although it is not difficult enough to discriminate among persons of above-average ability, the test has diagnostic utility in detecting moderate impairment. Independent of item difficulty, 13 items differentiate patients from controls. When 45 patients and 45 controls were matched on gender and age, patient accuracy remained significantly reduced. The findings support the test's utility and demonstrate how traditional data analysis is insensitive to complexities in test performance.     

Integrity, conscientiousness, and honesty

Undergraduate volunteers from the Psychology participant pool (N=86, age M=22.7, SD=4.8 yr.; 72 of 86 were female) took two tests, a commercially available integrity test (the Personnel Selection Inventory) and the NEO-Five Factor Inventory. Later in the study, each participant was given an opportunity to report dishonestly the amount of time spent in the laboratory and thus to receive more extra-credit points than earned. An observer recorded participants' actual times in the laboratory to provide an accurate assessment of participants' honesty. Analysis indicated that the Personnel Selection Inventory did not predict whether the participant was honest or dishonest in reporting time spent. Conscientiousness as measured by the NEO-Five Factor Inventory, however, not only predicted behavior, but did so significantly better than did the Personnel Selection Inventory. The study provides new information about the value of integrity tests by comparing integrity and personality tests in the simultaneous prediction of a specific criterion.     

Effect of upcoming reward type when rats press a lever for ethanol

Rats' operant responding for sucrose rewards in the 1st half of a session can vary directly with the conditions of reward in the 2nd half. The authors investigated whether that induction effect represented an animal model of emotive states. Rats pressed a lever for either ethanol or sucrose rewards in the 1st half of a 40-min session. The reward in the 2nd half of the session was, across conditions, 1% sucrose, a food pellet, or the same reinforcer delivered in the 1st half. When subjects responded for sucrose, upcoming reward type had little influence on responding in the 1st half of the session. However, when subjects responded for ethanol, upcoming 1% sucrose and food-pellet reinforcement both produced increases in responding. The results suggest that the procedure produced different emotive states, but further work is needed to support such a model. The results also have potential applied implications.     

Multiple study trials and judgments of learning

We compared judgments of learning (JOLs) that were made either (a) after 1 study trial, (b) 2 study trials, or (c) in-between the 1st and 2nd study trials. In regard to the absolute accuracy of JOLs at predicting subsequent recall, we replicated previous findings of an underconfidence-with-practice effect for immediate JOLs and report for the first time a new finding of an underconfidence-with-practice effect for delayed JOLs (i.e., delayed JOLs after one trial overestimated the likelihood of subsequent recall, whereas delayed JOLs after two trials underestimated that likelihood). Also, although delayed JOLs always had a greater relative accuracy than did immediate JOLs, the relative accuracy of immediate and delayed JOLs was approximately the same after 1 versus 2 study trials. These results demonstrate that additional study trials affect the absolute accuracy of all JOLs but not the relative accuracy of any JOLs. Thus an increase in the number of study trials produced an increasing bias to be underconfident about the subsequent likelihood of recall but did not affect people's ordering of which items had been more (versus less) well-learned.     

Assessing the factorial invariance of Harter's self-concept measures: comparing preadolescents with and without spina bifida using child,parent, and teacher report

The purpose of this study was to determine whether the structure of children's self-concept, as rated by children themselves on the Self-Perception Profile for Children (SPPC; Harter, 1985), and the structure of children's competence, as rated by their parents on the Rating Scale of Child's Actual Behavior (PRS) and teachers on the Rating Scale of Child's Actual Behavior (TRS; Harter, 1985), are similar across samples of children with and without spina bifida (children were 8 and 9 years of age; n = 68 in each sample). Using confirmatory factor analyses, results revealed that a multidimensional model for the SPPC and the TRS fit the data well for both samples. On the other hand, the model for both mothers' and fathers' PRS ratings did not fit the data for the spina bifida sample. Further tests of factorial invariance conducted on the SPPC and TRS revealed that the spina bifida and able-bodied samples tended to have the same pattern and magnitude of factor loadings for both instruments. There was some invariance, however, in the amount of unique error variance accounted for across samples. These results bolster our confidence in using the SPPC and TRS to compare children with and without spina bifida.     

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.     

Developments in long-term explicit memory late in the first year of life: behavioral and electrophysiological indices

Coincident with developments in the temporal-cortical explicit memory network, long-term recall abilities are newly emergent late in the first year of human life. We recorded event-related potentials (ERPs) in 9-month-olds as an index of the integrity of the neural substrate underlying a task thought to reflect explicit memory, namely, deferred imitation. ERP measures of recognition memory 1 week after unique laboratory experiences predicted whether and how much infants recalled of the experiences 1 month later. The findings further imply that memory storage and consolidation processes are a major source of variability in long-term recall memory late in the first year of life.     

Modeling unipolar depression as a chaotic process

This study inspected the deterministic structure of unipolar depression. Two women self-monitored sadness hourly 10 times a day for 6 months. One woman had a recurrent history of unipolar depression, and the other did not. Data were analyzed by visual inspection, examination of the Fourier transforms of the time plots, and the correlation dimension. Results suggested that in addition to a strong periodic component that existed only within the depressed subject's mood time series, a low-dimensional chaotic process might have been operating. In the nondepressed control subject, no such periodicity or process could be identified. The findings support maladaptive deterministic theories of mood disorders and have implications for the assessment of unipolar depression.