Ageing effects on the attention demands of walking

Attention demands of walking were determined in six male and six female young adults (mean 26.3 yr) and 12 gender-matched healthy, active older adults (mean 71.1 yr) using a dual task procedure with a reaction time (RT) secondary task. In three conditions an auditory stimulus, a visual stimulus and both stimuli (auditory/visual) were presented. Relative to no-walking baselines, increased RT was found in all conditions revealing an attentional cost of normal walking. When participants traversed the laboratory walkway and also positioned one of their feet within a target area on the ground, attention demands were greater than in unconstrained walking. In the targeting task, RTs to the visual stimulus were longer than for the auditory stimulus due to the interference associated with viewing both the stimulus monitor and the foot-target. Older participants' RTs in the visual and auditory/visual conditions, but not in the auditory condition, were significantly longer than for the young group in both walking tasks but RTs for young and older adults were not different in no-walking baseline trials. Inspection of mean RT functions at time intervals following gait initiation (0-3000 ms from the first step) suggested a fluctuating attentional cost of walking with increased demands associated with contingencies requiring step length regulation. The findings have applied significance in demonstrating the possibility of increased falls and pedestrian accident risk in older individuals in dual task situations such as road crossing.     

Differentiating Cognitive Content between Depressed and Anxious Outpatients

Quantitative research suggests that depressed and anxious patients can be differentiated based on their cognitive content. This study used qualitative research methods to separate the specific components of open‐ended depressive and anxious thought content in 79 psychiatric outpatients. Patients with major depressive disorder (MDD; n = 36), generalized anxiety disorder (GAD; n = 10), and other psychiatric disorders (PC; n = 33) were instructed to (a) describe their most bothersome problem; (b) imagine the worst possible negative outcome followed by the best possible positive outcome; and (c) describe associated thoughts and emotions for each scenario. The content of patients' responses were coded to examine (a) the types and severity of problems; (b) the presence or absence of hopelessness, catastrophizing, hopefulness, and unrealistic positive expectations; and (c) the presence or absence of particular emotions associated with imagined worst and best outcomes. More GAD patients than MDD and PC patients indicated anticipated anxious emotions associated with imagined worst outcomes, and fewer MDD patients than GAD and PC patients indicated anticipated happiness associated with imagined best outcomes. No group differences emerged for the other variables considered. These findings suggest that depressed and anxious patients differ in their cognitive expectancies about future life events in terms of their own anticipated emotional reactions.     

The representation of pitch in auditory imagery: Evidence from S-R compatibility and distance effects

In three experiments we explored the nature of representations constructed during the perception and imagination of pitch. We employed a same–different task to eliminate the influence of nonauditory information and to minimise use of cognitive strategies on auditory imagery. A reference tone of frequency 1000, 1500, or 2000 Hz, or an imagined tone of a pitch indicated by a visual cue, was followed by a comparison tone (1000, 1500, or 2000 Hz) to which either a speeded same or different response was required. In separate experiments, same–different judgements were mapped to vertically (Experiments 1 and 2) and horizontally arranged responses (Experiment 3). Judgements of tones closer in pitch yielded longer reaction times and higher error rates than more distant tones, indicating a pitch distance effect for perceptual and imagery tasks alike. In addition, in the imagery task, same–different responses were faster when low-pitched tones demanded a bottom or left key response and high-pitched tones a top or right response than vice versa, suggesting that pitch is coded spatially. Together, these behavioural effects support the assumption that both perceived and imagined pitch are translated into an analogical representation in the spatial domain.