Gradations of awareness in a modified sequence learning task

We argue performance in the serial reaction time (SRT) task is associated with gradations of awareness that provide examples of fringe consciousness [Mangan, B. (1993b). Taking phenomenology seriously: the “fringe” and its implications for cognitive research. Consciousness and Cognition, 2, 89–108, Mangan, B. (2003). The conscious “fringe”: Bringing William James up to date. In B. J. Baars, W. P. Banks & J. B. Newman (Eds.), Essential sources in the scientific study of consciousness (pp. 741–759). Cambridge, MA: The MIT Press.], and address limitations of the traditional SRT procedure, including criticism of exclusion generation tasks. Two experiments are conducted with a modified SRT procedure where irrelevant stimulus attributes obscure the sequence rule. Our modified paradigm, which includes a novel exclusion task, makes it easier to demonstrate a previously controversial influence of response stimulus interval (RSI) on awareness. It also allows identification of participants showing fringe consciousness rather than explicit sequence knowledge, as reflected by dissociations between different awareness measures. The NEO-PI-R variable Openness to Feelings influenced the diversity of subjective feelings reported during two awareness measures, but not the degree of learning and awareness as previously found with traditional SRT tasks [Norman, E., Price, M. C., & Duff, S. C. (2006). Fringe consciousness in sequence learning: the influence of individual differences. Consciousness and Cognition, 15(4), 723–760.]. This suggests possible distinctions between two components of fringe consciousness.     

A Sex Difference on a Novel Spatial Working Memory Task in Humans

Neurophysiological and behavioral evidence suggests that the prefrontal cortex (PFC) may be sexually differentiated in nonhuman primates. The present study examined whether there are sex differences in working memory in humans that might reflect sexual differentiation of human PFC. Male and female undergraduates were administered a novel multitrial spatial working memory task (SPWM) and a verbal working memory task. In three experiments, females committed significantly fewer working memory errors and took significantly less time to reach criterion than males on the SPWM task. The female advantage was not accounted for by differences in general intellectual ability, attention, perceptual speed, incidental memory, or speed of verbal access. In Study 3, a sex difference was also observed on a measure of verbal working memory. The findings suggest that some prefrontal functions may be sexually differentiated in humans.     

Some supplementary methods for the analysis of the RBANS

Supplementary methods for the analysis of the Repeatable Battery for the Assessment of Neuropsychological Status are made available, including (a) quantifying the number of abnormally low Index scores and abnormally large differences exhibited by a case and accompanying this with estimates of the percentages of the normative population expected to exhibit at least this number of low scores and large differences, (b) estimating the overall abnormality of a case's Index score profile using the Mahalanobis Distance Index (MDI), (c) reporting confidence limits on differences between a case's Index scores, and (d) offering the option of applying a sequential Bonferroni correction when testing for reliable differences. With the exception of the MDI, all the methods can be obtained using the formulas and tables provided in this article. However, for the convenience of clinicians, and to reduce the possibility of clerical error, the methods have also been implemented in a computer program. More importantly, the program allows the methods to be applied when only a subset of the Indexes is available. The program can be downloaded from www.abdn.ac.uk/~psy086/dept/RBANS_Supplementary_Analysis.htm     

Assessing executive functions in traumatic brain injury: an exploratory study of the Executive Interview

Executive dysfunction is a frequent sequela of traumatic brain injury. Two correlational studies using samples of inpatients and outpatients diagnosed with traumatic brain injury were undertaken to evaluate the validity of a bedside screening test of executive functioning, the 1992 Executive Interview EXIT 25 by Royall, Mahurin, and Gray. In the first study of 23 inpatients receiving rehabilitation, the EXIT 25 was strongly related to both the Mini-Mental State Examination and the Modified Mini-Mental State Examination. In the second study of 20 outpatients, the EXIT 25 correlated with other executive function measures and with ratings of functional disability at discharge, although a ceiling effect raised questions about its utility for patients with mild to moderate disability. Further study of the EXIT 25 is justified with a larger sample of inpatients, although caution should be exercised when using the EXIT 25 in mildly impaired outpatients.     

How do I remember that I know you know that I know?

Communication is aided greatly when speakers and listeners take advantage of mutually shared knowledge (i.e., common ground). How such information is represented in memory is not well known. Using a neuropsychological-psycholinguistic approach to real-time language understanding, we investigated the ability to form and use common ground during conversation in memory-impaired participants with hippocampal amnesia. Analyses of amnesics' eye fixations as they interpreted their partner's utterances about a set of objects demonstrated successful use of common ground when the amnesics had immediate access to common-ground information, but dramatic failures when they did not. These findings indicate a clear role for declarative memory in maintenance of common-ground representations. Even when amnesics were successful, however, the eye movement record revealed subtle deficits in resolving potential ambiguity among competing intended referents; this finding suggests that declarative memory may be critical to more basic aspects of the on-line resolution of linguistic ambiguity.     

The effect of presemantic acoustic adaptation on semantic “satiation”

A decrement in the strength of the meaning of a word after rapid repetition of that word has been called “semantic satiation.” This study asked whether this “satiation” might be produced by presemantic acoustic adaptation. Category words were utilized to prime the meaning of target words. The adaptation or “satiation” procedure, 30 rapid repetitions of the primes, was compared with a control condition of 3 repetitions. Participants listened to a series of prime words, each repeated by either the same speaker or many speakers, and then made semantic decisions on target words. When all the repetitions of a prime word are produced by the same speaker, presemantic and semantic repetitions are confounded. When the repetitions are produced by different speakers, presemantic acoustic repetition is abolished. A semantic decrement was detected with single-speaker, but not with multiple-speaker, repetitions of prime words. This study concluded that the semantic “satiation” observed here was a decrement in the activation level of semantic representations induced by presemantic acoustic adaptation.     

Walking speed and global cognition: results from the OKLAHOMA Study

Executive functioning and processing speed have been related to physical functioning in non-demented, elderly samples; however, the relationship between walking speed and global cognition has not been examined. Six hundred and seventy-five community dwelling older adults were enrolled through their primary care physicians. Walking speed was assessed on a 50-foot course at usual pace. Global cognition was assessed with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Total Scale score. After adjusting for age, gender, and education, there was a strong inverse relationship between walking speed and global cognition, with slower walkers performing worse on the cognitive measures, faster walkers performing better on the cognitive measures, and the intermediate walkers performing in the middle. In these older adults, global cognition was related to walking speed.