Effects of a violation of an expected increase or decrease in intensity on detection of change within an auditory pattern

An infrequent physical increase in the intensity of an auditory stimulus relative to an already loud frequently occurring “standard” is processed differently than an equally perceptible physical decrease in intensity. This may be because a physical increment results in increased activation in two different systems, a transient and a change detector system (signalling detection of an increase in transient energy and a change from the past, respectively). By contrast, a decrease in intensity results in increased activation in only the change detector system. The major question asked by the present study was whether a psychological (rather than a physical) increment would continue to be processed differently than a psychological decrement when both stimuli activated only the change detector system. Participants were presented with a sequence of 1000 Hz tones that followed a standard rule-based alternating high-low intensity pattern (LHLHLH). They were asked to watch a silent video and thus ignore the auditory stimuli. A rare “deviant” was created by repeating one of the stimuli (e.g., LHLHLLLH. The repetition of the high intensity stimulus thus acted as a relative, psychological increment compared to what the rule would have predicted (the low intensity); the repetition of the low intensity stimulus acted as a relative, psychological decrement compared to what the rule would have predicted (the high intensity). In different conditions, the intensity difference between the low and high intensity tones was either 3, 9 or 27 dB. A large MMN was elicited only when the separation between the low and high intensities was 27 dB. Importantly, this MMN peaked significantly earlier and its amplitude was significantly larger following presentation of the psychological increment. Thus, a deviant representing an increment in intensity relative to what would be predicted by the auditory past is processed differently than a deviant representing a decrement, even when activation of the transient detector system is controlled. The psychological increment did not however elicit a later positivity, the P3a, often thought to reflect the interruption of the central executive and a forced switching of attention.     

Being Fit and Looking Healthy: Young Women’s and Men’s Constructions of Health and Fitness

We drew on Foucault's notion of ‘practices of the self’ to examine how young people take up, negotiate, and resist the imperatives of a public health discourse concerned with the relationships between health, fitness, and the body. We did this through a discussion of the ways young women and men talk about their own and others' bodies, in the context of a number of in-depth interviews conducted for the Life Activity Project, a study of the place and meaning of physical activity in young people's lives, funded by an Australian Research Council Grant. We found that the young women and men in the study engaged the health/fitness discourse very differently: for the young men, health conflated with fitness as an embodied capacity to do physical work; and for the young women, health was a much more difficult and complex project associated with managing and monitoring practices associated with eating and exercise to maintain an ‘appropriate’ body shape.     

Long-lasting perceptual priming and semantic learning in amnesia: a case experiment.

An investigation of perceptual priming and semantic learning in the severely amnesic subject K.C. is reported. He was taught 64 three-word sentences and tested for his ability to produce the final word of each sentence. Despite a total lack of episodic memory, he exhibited (a) strong perceptual priming effects in word-fragment completion, which were retained essentially in full strength for 12 months, and (b) independent of perceptual priming, learning of new semantic facts, many of which were also retained for 12 months. K.C.'s semantic learning may be at least partly attributable to repeated study trials and minimal interference during learning. The findings suggest that perceptual priming and semantic learning are subserved by two memory systems different from episodic memory and that both systems (perceptual representation and semantic memory) are at least partially preserved in some amnesic subjects.     

Visual influences on speech perception processes

An experiment is reported, the results of which confirm and extend an earlier observation that visual information for the speaker’s lip movements profoundly modifies the auditorv perception of natural speech by normally hearing subjects. The effect is most pronounced when there is auditory information for a bilabial utterance combined with visual information for a nonlabial utterance. However, the effect is also obtained with the reverse combination, although to a lesser extent. These findings are considered for their relevance to auditory theories of speech perception.     

Partial reinforcement effects and type of reward

In two experiments 68 rats were trained to bar press or run down a straight runway for food or for water under conditions of either continuous reinforcement or partial reinforcement. In both experiments, there was greater persistence of behavior which had been reinforced with food than with water. In Expt 2, the partial reinforcement extinction effect (PREE) was observed with food reward, but not with water.Within the context of the experimental procedures used, it can be concluded that the rat has mechanisms for developing persistence which are dependent on the specific motivational system involved. This conclusion is related to theories of partial reinforcement effects and to possible biological origins of the mechanisms.     

Brief Therapy in Adult Psychiatry – Further Outcomes

A report of a one-year follow-up of thirty-six referrals treated with solution-focused brief therapy by a supervised team in a mental health setting is described. A good outcome was reported for twenty-three cases (64%). These results are comparable with our previous work and with one other statistically validated outcome study on solution-focused therapy.     

Threat appraisals, distress and the development of positive life changes after September 11th in a Canadian sample

Several surveys have reported the negative psychological impact on the general public of the terrorist attacks in the USA of September 11th, 2001. Yet the attacks also led many people to make positive changes in their relationships, values and priorities. A survey of 80 adults in Ottawa, Canada demonstrated that greater perceived threat and greater initial distress reactions significantly predicted the extent to which people reported positive changes in their lives (e.g. closer to family, refocused priorities). Initial distress and greater perceived threat also correlated positively with whether people provided help after the disaster. Follow-up data on 40 of these participants 11 months later revealed significant stability over time for the extent of positive life changes reported, and demonstrated that degree of initial distress and perceived threat continued to correlate positively with life change reports at this later point in time. The data are consistent with the argument that the perception of growth may develop out of one's personal experience of emotional pain.