The effect of perceptual load on attention-induced motion blindness: the efficiency of selective inhibition

Recent visual marking studies have shown that the carry-over of distractor inhibition can impair the ability of singletons to capture attention if the singleton and distractors share features. The current study extends this finding to first-order motion targets and distractors, clearly separated in time by a visual cue (the letter X). Target motion discrimination was significantly impaired, a result attributed to the carry-over of distractor inhibition. Increasing the difficulty of cue detection increased the motion target impairment, as distractor inhibition is thought to increase under demanding (high load) conditions in order to maximize selection efficiency. The apparent conflict with studies reporting reduced distractor inhibition under high load conditions was resolved by distinguishing between the effects of "cognitive" and "perceptual" load.     

Humans rapidly estimate expected gain in movement planning

We studied human movement planning in tasks in which subjects selected one of two goals that differed in expected gain. Each goal configuration consisted of a target circle and a partially overlapping penalty circle. Rapid hits into the target region led to a monetary bonus; accidental hits into the penalty region incurred a penalty. The outcomes assigned to target and penalty regions and the spatial arrangement of those regions were varied. Subjects preferred configurations with higher expected gain whether selection involved a rapid pointing movement or a choice by key press. Movements executed to select one of two goal configurations exhibited the same movement dynamics as pointing movements directed at a single configuration, and were executed with the same high efficiency. Our results suggest that humans choose near-optimal strategies when planning their movement, and can base their selection of strategy on a rapid judgment about the expected gain associated with possible movement goals.     

The equivalence of the Child Behavior Checklist/1 1/2-5 across parent race/ethnicity, income level, and language

This study examined the equivalence of the Child Behavior Checklist/1 1/2-5 (CBCL/1 1/2-5) in 682 parents of 2- to 4-year-old children stratified by parent race/ethnicity (African American, Latino, and non-Latino White), family income (low vs. middle-upper), and language version (Spanish vs. English). Externalizing Scale means differed by income and child gender. Internalizing Scale means differed by income and parent race/ethnicity. Differential item analyses showed that few items functioned differently by racial/ethnic, language, and income group. A confirmatory factor analysis demonstrated that the Externalizing Scale provided a good fit with the data across racial/ethnic and income groups. However, model fit was improved for the Internalizing Scale when factor weights were allowed to vary. Findings support the equivalence of the CBCL/1 1/2-5 when used with parents of low-income preschool children from African American and Latino backgrounds, although further study of the factor structure for the Internalizing Scale is recommended.     

Domestic dogs (Canis familiaris) use a physical marker to locate hidden food

Dogs can use the placement of an arbitrary marker to locate hidden food in an object-choice situation. We tested domestic dogs (Canis familiaris) in three studies aimed at pinning down the relative contributions of the human’s hand and the marker itself. We baited one of two cups (outside of the dogs’ view) and gave the dog a communicative cue to find the food. Study 1 systematically varied dogs’ perceptual access to the marker placing event, so that dogs saw either the whole human, the hand only, the marker only, or nothing. Follow-up trials investigated the effect of removing the marker before the dog’s choice. Dogs used the marker as a communicative cue even when it had been removed prior to the dog’s choice and attached more importance to this cue than to the hand that placed it although the presence of the hand boosted performance when it appeared together with the marker. Study 2 directly contrasted the importance of the hand and the marker and revealed that the effect of the marker diminished if it had been associated with both cups. In contrast touching both cups with the hand had no effect on performance. Study 3 investigated whether the means of marker placement (intentional or accidental) had an effect on dogs’ choices. Results showed that dogs did not differentiate intentional and accidental placing of the marker. These results suggest that dogs use the marker as a genuine communicative cue quite independently from the experimenter’s actions.     

Anterior temporal cortex and semantic memory: Reconciling findings from neuropsychology and functional imaging

Studies of semantic impairment arising from brain disease suggest that the anterior temporal lobes are critical for semantic abilities in humans; yet activation of these regions is rarely reported in functional imaging studies of healthy controls performing semantic tasks. Here, we combined neuropsychological and PE T functional imaging data to show that when healthy subjects identify concepts at a specific level, the regions activated correspond to the site of maximal atrophy in patients with relatively pure semantic impairment. The stimuli were color photographs of common animals or vehicles, and the task was category verification at specific (e.g., robin), intermediate (e.g., bird), or general (e.g., animal) levels. Specific, relative to general, categorization activated the antero-lateral temporal cortices bilaterally, despite matching of these experimental conditions for difficulty. Critically, in patients with atrophy in precisely these areas, the most pronounced deficit was in the retrieval of specific semantic information.     

Intact emotion-induced recognition bias in neuropsychological patients with executive control deficits

In recognition memory tasks, emotionally negative words are judged more often as "old" relative to emotionally neutral words, suggesting a shift in response bias. We wondered whether this bias shift was due to the flexible regulation of executive control during memory retrieval. To address this question, we investigated individuals with high variability in executive control functions. As expected, we observed that emotional word meaning did indeed have a strong influence on the bias toward responding "old," independent of recognition accuracy and overall response bias. However, these effects were uncorrelated with executive control, as measured by the Trail Making Test, and were fully intact, even in a sample of hospitalized neurological patients with severe executive dysfunctions, some of whom had marked damage in fronto-thalamo-striatal networks. Having concluded that the emotion-induced bias must develop on different grounds, we went on to discuss alternative explanations.     

Training-induced and electrically induced potentiation in the neocortex

Long-term potentiation (LTP) shares many properties with memory and is currently the most popular laboratory model of memory. Although it has not been proven that memory is based on an LTP-like mechanism, there is evidence that learning a motor skill can induce LTP-like effects. This evidence was obtained in a slice-preparation experiment, which precluded within-animal comparisons before and after training. In the present experiments, Long-Evans rats were unilaterally trained to acquire a forelimb reaching and grasping skill. Evoked potentials were found to be larger in motor cortex layer II/III in the trained, compared to the untrained, hemisphere in slice, acute, and chronic preparations. Consistent with previous research, the trained hemisphere was less amenable to subsequent LTP induction. Furthermore, the application of either LTP- or LTD-inducing stimulation during the training phase of the reaching task disrupted the acquisition of the skill, providing further evidence that memory may be based on an LTP mechanism.     

An exploration into the creative abilities of children with ADHD

The purpose of this study is to explore whether ADHD is associated with high creative ability. Sixty-seven children, ages 10 to 12 (33 ADHD and 34 controls) completed the Torrance Tests of Creative Thinking (TTCT), Maier's Two-String Problem, and the Block Design and Vocabulary subsets of the Wechsler Intelligence Scale for Children (WISC-III). The results show that there is no significant difference between the ADHD group's and control group's performance on either the TTCT, Maier's Two-String Problem, or WISC-III, suggesting that children diagnosed with ADHD are no more creative than children without the diagnosis.     

Remote effects of highlights on gloss perception

The perception of a glossy surface in a static monochromatic image can occur when a bright highlight is embedded in a compatible context of shading and a bounding contour. Some images naturally give rise to the impression that a surface has a uniform reflectance, characteristic of a shiny object, even though the highlight may only cover a small portion of the surface. Nonetheless, an observer's impression of gloss may be partial and nonuniform at image regions outside of a highlight. A rating scale and small probe points indicating image locations were used to investigate the differential perception of gloss within a single object. Gloss ratings given by observers were not uniform across a surface, but decreased as a function of distance from a highlight. When, by design, the distance from a highlight was uncoupled from the luminance value at corresponding probe points, the decrease in rated gloss correlated more with distance than with luminance change. Experiments also indicated that gloss ratings may change as a function of estimated surface distance, rather than as a function of image distance. Surface continuity affected gloss ratings, suggesting that surface and gloss processing are closely related.     

An evaluation of the quantity and quality of empirical research in three pastoral care and counseling journals, 1990-1999: has anything changed?

This article summarizes a review of all articles published in Pastoral Psychology, The Journal of Rleigion and Health, and The Journal of Pastoral Care between 1900 and 1999, identifying a total of 737 scholarly articles, of which 165 (22.4%) were research studies. The proportion of research studies, especially quantitative studies, increased significantly between the first and second half of the study period (p < .05). There was a significant positive correlation between compliance with three out of four criteria of internal validity. Three of five criteria of external validity were also positively related to one another. Compared to previous research using identical criteria to assess quantitative studies in the same journals in 1980-1989, the 1990-1999 sample showed improved compliance with respect to specifying the sampling method (p < .001), reporting the response rate (p < .05), and discussing the limitations of research studies (p < .001). However, the overall findings suggest that many researchers in the field do not have a sophisticated knowledge of statistical sampling, statistical analysis, or research design. Several recommendations for increasing the quality of quantitative research are offered.