Age similarities in the inertial properties of attention.

Adult age differences in the mode of allocation of visual attention were investigated, using a visual search task with a circular display containing one target letter and seven distractor letters. In two experiments, a total of 56 younger adults (M = 20 years) and 56 older adults (M = 66 years) searched for a target appearing with equal probability at one of two cued locations. The first cue appeared 115 msec before display onset, and the second cue appeared with display onset; distance between the two cued locations was varied. Target identification performance indicated that attention was inertial, in that reaction time for second-cued targets was related either to the area of the portion of the visual field containing possible target locations or to the mean path length of a serial self-terminating search. There were no age-related decrements in the allocation of visual attention.     

The sound of enemies and friends in the neighborhood

Previous studies (e.g., Pecher, Zeelenberg, & Wagenmakers, 2005) found that semantic classification performance is better for target words with orthographic neighbors that are mostly from the same semantic class (e.g., living) compared to target words with orthographic neighbors that are mostly from the opposite semantic class (e.g., nonliving). In the present study we investigated the contribution of phonology to orthographic neighborhood effects by comparing effects of phonologically congruent orthographic neighbors (book-hook) to phonologically incongruent orthographic neighbors (sand-wand). The prior presentation of a semantically congruent word produced larger effects on subsequent animacy decisions when the previously presented word was a phonologically congruent neighbor than when it was a phonologically incongruent neighbor. In a second experiment, performance differences between target words with versus without semantically congruent orthographic neighbors were larger if the orthographic neighbors were also phonologically congruent. These results support models of visual word recognition that assume an important role for phonology in cascaded access to meaning.     

Privileged Access by Irrelevant Speech to Short-term Memory: The Role of Changing State

Memory for visually presented items is impaired by speech that is played as an irrelevant background. The paper presents the view that changing state of the auditory material is an important prerequisite for this disruption. Four experiments studied the effects of sounds varying in complexity in an attempt to establish which features of changing state in the auditory signal lead to diminished recall. Simple unvarying or repetitive speech sounds were not sufficient to induce the irrelevant speech effect (Experiment 1): in addition, simple analogues of speech, possessing regular or irregular envelopes and using a range of carriers, failed to imitate the action of speech (Experiment 2). Variability of between-utterance phonology in the irrelevant stream (Experiment 3) emerged as a crucial factor. Moreover, predictability of the syllable sequence did not reduce the degree of disruption (Experiment 4) suggesting that supra-syllabic characteristics of the speech are of little importance. The results broadly support the idea that disruption of short-term memory only occurs when the speech stream changes in state. It is argued that disruption occurs in memory when cues to serial order based on phonological representations of heard material interfere with the phonological codes of visual origin. It is suggested that cues to changing state of the speech input contaminate those associated with items of visual origin, which are already in a phonological store.     

Cerebral White Matter Integrity and Cognitive Aging: Contributions from Diffusion Tensor Imaging

The integrity of cerebral white matter is critical for efficient cognitive functioning, but little is known regarding the role of white matter integrity in age-related differences in cognition. Diffusion tensor imaging (DTI) measures the directional displacement of molecular water and as a result can characterize the properties of white matter that combine to restrict diffusivity in a spatially coherent manner. This review considers DTI studies of aging and their implications for understanding adult age differences in cognitive performance. Decline in white matter integrity contributes to a disconnection among distributed neural systems, with a consistent effect on perceptual speed and executive functioning. The relation between white matter integrity and cognition varies across brain regions, with some evidence suggesting that age-related effects exhibit an anterior–posterior gradient. With continued improvements in spatial resolution and integration with functional brain imaging, DTI holds considerable promise, both for theories of cognitive aging and for translational application.     

Childhood Emotional Abuse and Young Adulthood Dating Violence: The Moderating Role of Stress Reactivity

Dating violence has been linked to past experiences of childhood emotional abuse; however, little research has explored how stress reactivity functions within interpersonal relationships to amplify or attenuate these associations. The present study investigated the moderating effects of cortisol stress reactivity on associations between retrospective self-reported childhood emotional abuse and later self-reported interpersonal violence in young adult dating relationships. The current sample consisted of 57 young adult heterosexual dating partners (46 females, 11 males) between the ages of 18 and 24. Salivary cortisol samples were collected before and after a stress task to measure stress reactivity. Moderation analyses were conducted through the PROCESS macro in SPSS version 22. The relation between childhood emotional abuse and dating violence varied depending on cortisol reactivity, such that the association between childhood emotional abuse and young adult dating violence was stronger for those who demonstrated low levels of cortisol reactivity. The association between childhood emotional abuse and dating violence was not significant for those who demonstrated high cortisol reactivity. Findings underscore the importance of studying physiological mechanisms that may confer risk in the relationship between child emotional abuse and later interpersonal consequences.     

Human Sensitivity To Concurrent Schedules Of Reinforcement: Effects Of Observing Schedule-correlated Stimuli

The determinants of human sensitivity to concurrent variable-interval variable-interval schedules of reinforcement have been difficult to identify, in part because of procedural differences separating published experiments. This experiment investigated vigilance to stimuli correlated with concurrent schedules. Across phases, 3 college students were provided with either no schedule-correlated stimuli, an observing response that provided brief access to the stimuli, or a contingency that required the subject to identify the stimulus correlated with the source of each obtained reinforcer. Sensitivity, as quantified by the generalized matching equation, was low when no stimuli were available. When the stimuli were response contingent, 1 subject observed them, and her behavior became more sensitive to the distribution of reinforcers across the concurrent schedules. When the procedure required discrimination of the stimulus correlated with each reinforcer, the other 2 subjects also observed the stimuli, and their schedule sensitivity was increased as well. These results implicate procedural differences, rather than inherent behavioral differences, as the source of differences in sensitivity to schedules of reinforcement between humans and nonhumans.     

Effects of aerobic exercise training, age, and physical fitness on memory-search performance

We investigated the effects of exercise training on memory performance. One group of 13 men (M = 42.92 years of age) participated in supervised aerobic exercise (jogging) three times a week for 12 weeks. A second group of 15 men (M = 43.67 years of age) performed anaerobic exercise (strength training) for the same period of time. Subjects' reaction time (RT) performance in a memory-search task was assessed both before (Time 1) and after (Time 2) the 12 weeks of exercise training. Results indicated that there was no significant change in memory-search performance over time as a function of exercise training. Analyses of the Time 2 RTs demonstrated that aspects of memory-search performance were related significantly both to subjects' initial (Time 1) level of fitness and to age, but not to the amount of change in fitness associated with aerobic exercise training over this 12-week duration in this age group.