Latent inhibition and contextual associations

Attenuated responding to a conditioned stimulus (CS) after preexposure to that CS (latent inhibition) has traditionally been attributed to reductions in CS associability. Alternatively, CS-context associations formed during CS preexposure later interfere with the acquisition or expression of CS-outcome associations. Three lick suppression experiments with rats contrasted these accounts. Presumably, exposure to the context attenuates the CS-context association without altering CS associability. With a fixed amount of CS preexposure, latent inhibition decreased with increasing context exposure during or after (but not before) CS preexposure. When the ratio of context preexposure duration to CS preexposure was fixed, latent inhibition increased with CS preexposure. These results suggest that latent inhibition is a direct function of the strength of CS-context associations formed during preexposure.     

Functional MRI evidence for an abstract, not perceptual, word-form area

Previous studies have found an area in left ventral visual cortex that responds more to words and pseudowords than to consonant strings. Does this area respond to the perceptual form of wordlike stimuli, or is it responding to some more abstract, linguistic property, such as orthographic regularity (i.e., conformity with the spelling rules of the language)? During a functional magnetic resonance imaging experiment, participants read alternating-case words and pseudowords, which are orthographically regular but are perceptually unfamiliar. These stimuli activated the same area that was activated by pure-case words and pseudowords. These results suggest that the response of the so-called word-form area is not based on perceptual familiarity but rather on some more abstract feature such as orthographic regularity.     

The impact of competition on intrinsic motivation and creativity: considering gender, gender segregation and gender role orientation

The present research investigated whether competition influences children's artistic creativity and intrinsic motivation toward an art activity. Study 1 tested the hypothesis that boys' creativity would be enhanced by competition, while girls' creativity would be undermined. Fifty children (aged 6–10) made paper collages in one of two conditions; half competed for prizes and half did not. Results supported our hypotheses, and further showed that when children self-segregated by gender, the impact of competition was much more pronounced. Study 2 was designed to clarify the unexpected gender-segregation finding from Study 1. The Children's Sex Role Inventory [Boldizar, J.P. (1991). Assessing sex typing and androgyny in children: the Children's Sex Role Inventory. Developmental Psychology, 27, 505–515] was administered to 143 children (aged 6–11). One week later, these children made paper collages in one of four conditions; in addition to manipulating competition, assigned seating ensured that half of children were segregated by gender and half were not. Following the collage activity, an intrinsic and extrinsic motivation questionnaire was administered. Masculine children reported higher levels of intrinsic motivation when competing and when segregated by gender; they also reported higher levels of extrinsic motivation, especially when segregated by gender. These findings demonstrate that gender role is an important factor in determining children's responses to competition.     

The role of inferior frontal cortex in phonological processing

Recent neuroimaging studies of language processing are examining the neural substrate of phonology because of its critical role in mapping sound information onto higher levels of language processing (e.g., words) as well as providing codes in which verbal information can be temporarily stored in working memory. However, the precise role of the inferior frontal cortex in spoken and written phonological tasks has remained elusive. Although lesion studies have indicated the presence of selective deficits in phonological processing, the location of lesions underlying these impairments has not revealed a consistent pattern. Despite efforts to refine methods and tasks, functional neuroimaging studies have also revealed variability in activation patterns. Reanalysis of evidence from these neuroimaging studies suggests that there are functional subregions within the inferior frontal gyrus that correspond to specific components of phonological processing (e.g., orthographic to phonological conversion in reading, and segmentation in speech).     

Model stability of the 15-item Geriatric Depression Scale across cognitive impairment and severe depression

The 15-item Geriatric Depression Scale (GDS) is used in a wide variety of clinical and research settings. The study's purpose was to further establish the validity of the 15-item GDS by exploring the underlying factor structure in a healthy, nondemented sample of older adults and then analyzing whether this factor structure remained stable across a sample of demented individuals and a sample of individuals with a history of depression 6 months after discharge from an inpatient psychiatric setting. A 2-factor model fit the data best in the exploratory analyses. The 2 factors, Life Satisfaction and General Depressive Affect, found in the nondemented sample (r = .39) remained stable across cognitive impairment (r = .12) but merged into a 1-factor model in the psychiatric sample (r = .93). The results indicate that nondepressed older adults with poor life satisfaction may be identified as depressed on screening instruments such as the 15-item GDS.     

Construct validity of parent ratings of inhibitory control.

Recent literature has emphasized the need to examine executive functions (EF) in children using multiple sources, including both parent rating and performance-based measures. Computerized Go/No-Go tests, including commercially available continuous performance tests (CPTs), represent one of the most commonly used methods of assessing inhibitory control - a variable central to the executive function construct. We examined the relationship between parent ratings of inhibitory control and CPT performance in two mixed clinical samples. Experiment 1 examined 109 children ages 6-18 using the Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000) and the Conners' CPT-II (Conners, 2000). In this sample, ratings on the BRIEF Inhibit scale (mean T-score = 62.3) were significantly higher than the CPT-II commissions score (mean T-score = 50.7; p < .0001); and the BRIEF and CPT-II scores were not highly correlated (r = - .12). Experiment 2 examined a sample of 131 children ages 7-18 using the BRIEF and the Tests of Variables of Attention (TOVA; Greenberg, 1996). In this sample, parent ratings on the BRIEF Inhibit scale (mean T-score = 56.8) were similar to TOVA commissions scores (mean T-score = 58.6; p = .33), although still poorly correlated (r = -.02). Factor analyses exploring covariance between BRIEF scales CPT-II variables (Experiment 1) and between BRIEF and TOVA (Experiment 2) yielded similar findings. In both experiments, all eight BRIEF scales loaded on a single factor, with no overlap with either the CPT-II or the TOVA. In mixed outpatient clinical samples, the BRIEF appears to measure different elements of inhibitory control than those assessed by computerized continuous performance tests.     

Personhood and neuroscience: naturalizing or nihilating?

Personhood is a foundational concept in ethics, yet defining criteria have been elusive. In this article we summarize attempts to define personhood in psychological and neurological terms and conclude that none manage to be both specific and non-arbitrary. We propose that this is because the concept does not correspond to any real category of objects in the world. Rather, it is the product of an evolved brain system that develops innately and projects itself automatically and irrepressibly onto the world whenever triggered by stimulus features such as a human-like face, body, or contingent patterns of behavior. We review the evidence for the existence of an autonomous person network in the brain and discuss its implications for the field of ethics and for the implicit morality of everyday behavior.     

The influence of sad mood on cognition

Neuroimaging has identified an overlapping network of brain regions whose activity is modulated by mood and cognition. Studies of depressed individuals have shown changes in perception, attention, memory, and executive functions. This suggests that mood has a pervasive effect on cognition. Direct evidence of the effect of sad mood on cognition is surprisingly limited, however. Published studies have generally addressed a single cognitive ability per study because the fleeting nature of laboratory-induced mood precludes extended testing, and robust findings are limited to mood effects on memory for emotional stimuli. In this study, sad mood was induced and prolonged, enabling the effects of mood to be assessed for an array of abilities, including those that share neural substrates with sad mood and those affected by depression. Sad mood affected memory for emotional words and facial emotion recognition, but not the other processes measured, with a significant nonuniformity of effect over tasks. These results are consistent with circumscribed effects of sad mood on certain emotion-related cognitive processes, but not on cognition more generally.