Reorientation in a two-dimensional environment: I. Do adults encode the featural and geometric properties of a two-dimensional schematic of a room?

Adults searched for a goal in images of a rectangular environment. The goal's position was constant relative to featural and geometric cues, but the absolute position changed across trials. Participants easily learned to use the featural cues to find the target, but learning to use only geometric information was difficult. Transformation tests revealed that participants used the color and shape of distinct features to encode the goal's position. When the features at the correct and geometrically equivalent corners were removed, participants could use distant features to locate the goal. Accuracy remained above chance when a single distant feature was present, but the feature farthest from the goal yielded lower accuracy than one closer. Participants trained with features spontaneously encoded the geometric information. However, this representation did not withstand orientation transformations.     

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.     

Effects of ontogeny on performance of rats in a novel object-recognition task

The current experiment investigated ontogenetic forgetting on a novel object-recognition task similar to that of Besheer and Bevins. 18-day-old pups (n = 49) and adult (n = 29) rats were tested at two retention intervals (1 min. or 120 min.). By employing exclusion criteria which demanded minimum amounts of object exploration at training and test, the performance of 18-day-old pups but not that of adults was significantly impaired at 120 min. relative to 1 min. Analysis indicated that the ontogeny of the learning and memory measured in novel object recognition follows a developmental trend similar to that of other forms of learning, with older animals remembering more and thus performing better than younger animals. Unfortunately, given the extreme variability inherent to the task and large N necessary to achieve significance, the use of this task in studies of learning, memory, and development is discouraged.     

Contraction bias in memorial quantifying judgment: does it come from a stable compressed memory representation or a dynamic adaptation process?

A common response bias in psychophysical judgments is regression toward the mean (overestimation of small and underestimation of large values, or the response contraction bias). The same bias is observed in magnitude estimation from memorized quantities. Participants estimated alphabetic interval distances between 2 letters for different levels of interletter distances. The underestimated and overestimated values and the point of least error changed, depending on the level of alphabetic distances judged; furthermore, their estimation showed a progressively increasing tendency toward the mean, rendering the estimation progressively less accurate as the estimation task was repeated. We conclude that the regression toward the mean in memorial quantifying judgment derives from a cognitive adaptation process rather than from a permanent, compressed memory representation of the stimuli. Two opposing views on the adaptive meaning of this judgment bias are discussed.     

Correlates of aggression in African American and Puerto Rican children

The authors examined a cross-sectional interrelationship of psychosocial domains as they relate to aggression in a group of African American and English-speaking Puerto Rican children living in New York City. The population included 80 biological children of African American and Puerto Rican young adults who had been participating in the authors' ongoing longitudinal study, and 77 mothers or mother substitutes (rearing mothers) of those children. The authors performed hierarchical multiple regression analysis. The results indicated that (a) the child's personality and maternal attributes were significantly related to the child's aggression, despite control on all of the other domains and (b) the ethnic identification and discrimination domain was no longer related to the child's aggression with control on the mother-child relationship domain or on the child's personality domain. The findings have implications for clinical practice and public policy.     

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.     

Conceptions and questions concerning morphological processing

The understanding of the nature and extent of morphological processing is critical to the overall investigation of how words are organized in the mind. In this overview article, we discuss the nature of morphological processing and the domain of morphological processing research. We claim that investigations crucially involve the understanding of relations among morphologically simple and morphologically complex words, and sketch how specific questions of morphological processing within the 2004 special issue on the mental lexicon fall under these categories. Finally, we discuss issues of construct, content and ecological validity within the field and what morphological processing can reveal about the association of form and meaning in the mind.     

Violence: incidence and frequency of physical and psychological assaults affecting mental health providers in Georgia

Threats to the physical safety and psychological well-being of mental health professionals present serious problems, according to 1,131 licensed mental health professionals in the state of Georgia. The professionals included clinical social workers, marriage and family therapists, professional counselors, psychiatrists, psychologists, and social workers. From a total of 6,431 surveys sent out, 1,131 (18%) were returned. The results revealed 2.696 separate accounts of 14,120 acts of physical or psychological assaults committed by 8,292 perpetrators. The results also showed that 61% of the respondents had been victimized in violent acts of a psychological or physical nature and that 29% had feared for their lives at least once during their professional careers. These data are consistent with other research that indicates that 6 out of 10 professionals will be assaulted during their professional careers.     

What is "marked" in visual marking? Evidence for effects of configuration in preview search

Visual search for a conjunction target is facilitated when distractor sets are segmented over time: the preview benefit Watson and Humphreys (1997) suggested that this benefit involved inhibition of old items (visual marking, VM). We investigated whether the preview benefit is sensitive to the configuration of the old distractors. Old distractors changed their location prior to the occurrence of the new items, while also either changing or maintaining their configuration. Configuration changes disrupted search. The results are consistent with object-based VM, which is sensitive to the configuration of old stimuli.