Developmental perspectives on primate gesture: 100 years in the making

Animal Cognition - This paper is an introduction to the special issue entitled Evolving the study of gesture: evaluating and unifying theories of gesture acquisition in great apes. The gestures of...     

Words fail: Lesion-symptom mapping of errors of omission in post-stroke aphasia

Impaired object naming is a core deficit in post-stroke aphasia, which can manifest as errors of commission – producing an incorrect word or a non-word – or as errors of omission – failing to attempt to name the object. Detailed behavioural, computational, and neurological investigations of errors of commission have played a key role in the development of neurocognitive models of word production. In contrast, the neurocognitive basis of omission errors is radically underspecified despite being a prevalent phenomenon in aphasia and other populations. The prevalence of omission errors makes their neurocognitive basis important for characterizing an individual's deficits and, ideally, for personalizing treatment and evaluating treatment outcomes. This study leveraged established relationships between lesion location and errors of commission to investigate omission errors in picture naming. Omission error rates from the Philadelphia Naming Test for 123 individuals with post-stroke aphasia were analysed using support vector regression lesion-symptom mapping. Omission errors were most strongly associated with left frontal and mid-anterior temporal lobe lesions. Computational model analysis further showed that omission errors were positively associated with impaired semantically driven lexical retrieval rather than phonological retrieval. These results suggest that errors of omission in aphasia predominantly arise from lexical–semantic deficits in word retrieval and selection from a competitor set.     

Groups perform better than the best individuals on letters-to-numbers problems: informative equations and effective strategies

One-hundred 3-person groups and 300 individuals solved 2 letters-to-numbers problems, requiring identification of the coding of 10 letters to 10 numbers by proposing an equation in letters, receiving the answer in letters, proposing a hypothesis, and receiving feedback on the hypothesis on each trial. There were 5 instruction conditions: (a). standard, (b). use at least 3 letters on all equations, (c). use at least 4 letters on all equations, (d). number 1 known before beginning problem, and (e). number 9 known before beginning problem. The groups had fewer trials to solution, proposed more complex equations, and identified more letters per equation than the best individuals. Performance was best under instructions to use at least 4 letters and with the number 9 known.     

Strength of religious faith and psychological adjustment in intercollegiate athletes

In light of recent research examining the distress buffering properties of religion in intercollegiate athletes' lives, the present study investigated associations among religious faith and depressive symptoms, trait anxiety, and loneliness. Using self-report questionnaires, religious faith was not correlated with depressive symptoms, trait anxiety, and loneliness in 57 intercollegiate athletes.     

Triangular Interactions of Unmarried African American Mothers and Fathers with their 3-Month-Old Infants

We examined the responsivity of unmarried African American fathers to bids from their 3-month-old infants during the Lausanne Trilogue Play (LTP), and the responses of mothers subsequent to father-baby exchanges. Twenty mother-father-infant triads (75% noncoresidential) with parents between the ages of 14 and 53 took part in the investigation. All fathers and the majority of mothers were African American with reported incomes at least 200% below the U.S. poverty line. All participants had previously completed a prenatal intervention study examining formation of coparenting alliances across their transitions to parenthood and were observed while playing together in videotaped LTP sessions at 3-months postpartum. We microanalyzed infants’ gaze orientation toward their fathers and the sequence of parent behaviors after babies’ bids to fathers. Father responses to bids from the infant were characterized as withdrawal, nonwithdrawal but failure to adapt behavior he had been showing prior to the baby’s bid, or affective and/or behavioral adjustment in response to the baby’s bid. Maternal reactions to the father-baby exchange were coded as either reinforcing, opposing, or neutral. Analyses revealed that fathers showed substantial evidence of intuitive parenting and matching behavior, and mothers overwhelmingly supported, rather than interfered with or disrupted, baby-father exchanges. Results are discussed in contradistinction to deceptive commonplace depictions of African American families that focus largely on deficits rather than strengths, and recommendations for family research and practice are offered.