Biomedical subjects

Bob Uttl

Publications and source records attributed to Bob Uttl.

7 recordsLinked to original sources

PubMed2006

Behavioral inhibition and prefrontal cortex in decision-making.

Every day we make innumerable decisions; some require no effort at all whereas others require considerable deliberation and weighing of various options. Despite the importance of decision-making in our lives and increased research interest, the specific neural mechanisms underlying decision-making remain unclear. We propose that the brain has at least two cortical pathways that independently generate a decision about appropriate behavior in given circumstances. These two pathways are extensions of the dorsal and ventral streams of the visual processing pathways. The parieto-premotor (extended dorsal) pathway makes decisions about motor actions in a largely autonomous and automatic fashion whereas the temporo-ventrolateral prefrontal (extended ventral) pathway is involved primarily in deliberate decisions and inhibitory control over behavior through the inhibitory function of the ventrolateral prefrontal cortex.

Animals↗

PubMed2006

Age-related changes in event-cued visual and auditory prospective memory proper.

We rely upon prospective memory proper (ProMP) to bring back to awareness previously formed plans and intentions at the right place and time, and to enable us to act upon those plans and intentions. To examine age-related changes in ProMP, younger and older participants made decisions about simple stimuli (ongoing task) and at the same time were required to respond to a ProM cue, either a picture (visually cued ProM test) or a sound (auditorily cued ProM test), embedded in a simultaneously presented series of similar stimuli (either pictures or sounds). The cue display size or loudness increased across trials until a response was made. The cue size and cue loudness at the time of response indexed ProMP. The main results showed that both visual and auditory ProMP declined with age, and that such declines were mediated by age declines in sensory functions (visual acuity and hearing level), processing resources, working memory, intelligence, and ongoing task resource allocation.

Adolescent↗

PubMed2006

Object color affects identification and repetition priming.

We investigated the influence of color on the identification of both non-studied and studied objects. Participants studied black and white and color photos of common objects and memory was assessed with an identification test. Consistent with our meta-analysis of prior research, we found that objects were easier to identify from color than from black and white photos. We also found substantial priming in all conditions, and study-to-test changes in an object's color reduced the magnitude of priming. Color-specific priming effects were large for color-complex objects, but minimal for color-simple objects. The pattern and magnitude of priming effects was not influenced either by the extent to which an object always appears in the same color (i.e., whether a color is symptomatic of an object) or by the object's origin (natural versus fabricated). We discuss the implications of our findings for theoretical accounts of object perception and repetition priming.

Color Perception↗

PubMed2005

Measurement of individual differences: lessons from memory assessment in research and clinical practice.

An examination of test manuals and published research indicates that widely used memory tests (e.g., Verbal Paired Associates and Word List tests of the Wechsler Memory Scale, Rey Auditory Verbal Learning Test, and California Verbal Learning Test) are afflicted by severe ceiling effects. In the present study, the true extent of memory ability in healthy young adults was tested by giving 208 college undergraduates verbal paired-associate and verbal learning tests of various lengths; the findings demonstrate that healthy adults can remember much more than is suggested by the normative data for the memory tests just mentioned. The findings highlight the adverse effects of low ceilings in memory assessment and underscore the severe consequences of ceiling effects on score distributions, means, standard deviations, and all variability-dependent indices, such as reliability, validity, and correlations with other tests. The article discusses the optimal test lengths for verbal paired-associate and verbal list-learning tests, shows how to identify ceiling-afflicted data in published research, and explains how proper attention to this phenomenon can improve future research and clinical practice.

Adolescent↗

PubMed2003

Rising verbal intelligence scores: implications for research and clinical practice.

Evidence suggests that scores on various intelligence tests have been rising at a fast rate. To find out whether performance on the Wechsler Adult Intelligence Scale (WAIS) Vocabulary subtest has also been rising, the authors searched major psychology journals for investigations involving healthy younger and older adult participants and collected the reported WAIS Vocabulary scores. The meta-analysis shows that WAIS Vocabulary scores have been rising at the rate of 0.117/year (corresponding to 1.52 IQ points/decade) for younger adults and 0.367/year (corresponding to 4.79 IQ points/decade) for older adults.

Adolescent↗

PubMed2002

North American Adult Reading Test: age norms, reliability, and validity.

The North American Adult Reading Test (NAART) is a quickly administered index that is widely used to estimate verbal intellectual ability. We have administered NAART to 351 healthy adults between 18 to 91 years of age to examine psychometric properties of the NAART and to elucidate influence of age, education and gender on NAART performance. The results showed that the NAART is a reliable and valid measure of verbal intelligence, comparable in psychometric properties to the WAIS-R Vocabulary test and with equal psychometric properties in young, middle-aged and older adults. The NAART scores increase across the adult life span (approximately 4.5 points or approximately 0.5 SD) and with education (approximately 1.5 points/year of education) but they are unrelated to gender. The shorter version--the NAART35--is equally reliable and valid in predicting the WAIS-R Vocabulary. We provide norms as well as various equations for precise predictions of the NAART, the NAART35, and the WAIS-R Vocabulary scores based on age and education. Hierarchical regression analyses demonstrated that the verbal intelligence indexes are useful in predicting and interpreting performance on at least some, but not necessarily all neuropsychological tests, in addition to participants' age.

Adolescent↗

PubMed2002

Verbal Paired Associates tests limits on validity and reliability.

The Verbal Paired Associates (VPA) subtest from the Wechsler Memory Scale-III (WMS-III) is one of the most widely used instruments for assessing explicit episodic memory performance. The normative data for the VPA subtest in the WMS-III manual show clear evidence of performance ceiling effects that limit the usefulness of this instrument. For this reason, we developed a new 15-item VPA test and we report normative data obtained from a partially stratified sample of 351 healthy adults between 18 and 91 years of age. Only a small fraction of participants obtained perfect scores on our new Paired Associates test. The results show the expected large age-related decline in memory acquisition, indexed by performance on the first study test trial, together with a much smaller age effect on learning across trials. The results also show that performance on the Paired Associates test is related to education, verbal IQ, and to a lesser extent, participants' sex. We provide various equations for precise predictions of Paired Associates test performance.

Journal Article↗