Necessity, Sufficiency, and Perspective Effects in Causal Conditional Reasoning

A growing body of research indicates that in causal conditional reasoning, the conclusion that P is necessary for Q is suppressed where alternative conditions for Q are available. Similarly, the conclusion that P is sufficient for Q is suppressed where disabling conditions for P or additional requirements for Q are available. This paper describes experiments in which these factors were used to produce 'perspective effects' in causal contexts that appear identical to the perspective effects found in previous research with deontic tasks. It is therefore proposed that deontic perspective effects are themselves also attributable to the influence of pragmatic factors upon perceived necessity and sufficiency. A generalized theory based on a modification of the mental model theory of deontic reasoning is presented, which accounts for perspective effects across the two domains.     

Table talk: inviting students to share the feast

This account describes part of the first morning of the AFT accredited South Yorkshire Foundation Course in Family Therapy and Systemic Practice. The course committee members join together in a reflective conversation about the course. We share with the students our ‘kitchen table’ discussions, the history of our involvement, and how it has affected our lives. We aim to introduce social constructionist practice in which we present the context of the course and address the power relationships in the room by being transparent about our own experiences. We hope to create an atmosphere in which learning can flourish.     

Effectiveness of a primary care exercise referral intervention for changing physical self-perceptions over 9 months.

This study investigated the effectiveness of a 10-week primary care exercise referral intervention on the physical self-perceptions of 40-70 year olds. Participants (N=142) were assessed, randomized to an exercise or control group, and reassessed at 16 and 37 weeks. The Physical Self-Perception Profile (PSPP; K. R. Fox, 1990), fitness, physical activity, body mass index, body fat (skinfolds), and hip and waist circumference were assessed. A multivariate analysis of variance revealed significant Group X Time interactions, with the exercise group showing greater physical self-worth, physical condition, and physical health at 16 and 37 weeks. Changes in all PSPP scales at baseline and 37 weeks were related to changes in anthropometric measures and adherence to the 10-week exercise program but not to changes in submaximal fitness parameters.     

Single band amplitude envelope cues as an aid to speechreading

Amplitude envelopes derived from speech have been shown to facilitate speech-reading to varying degrees, depending on how the envelope signals were extracted and presented and on the amount of training given to the subjects. In this study, three parameters related to envelope extraction and presentation were examined using both easy and difficult sentence materials: (1) the bandwidth and centre frequency of the filtered speech signal used to obtain the envelope; (2) the bandwidth of the envelope signal determined by the lowpass filter cutoff frequency used to “smooth” the envelope fluctuations; and (3) the carrier signal used to convey the envelope cues. Results for normal hearing subjects following a brief visual and auditory-visual familiarization/training period showed that (1) the envelope derived from wideband speech does not provide the greatest benefit to speechreading when compared to envelopes derived from selected octave bands of speech; (2) as the bandwidth centred around the carrier frequency increased from 12.5 to 1600 Hz, auditory-visual (AV) performance obtained with difficult sentence materials improved, especially for envelopes derived from high-frequency speech energy; (3) envelope bandwidths below 25 Hz resulted in AV scores that were sometimes equal to or worse than speechreading alone; (4) for each filtering condition tested, there was at least one bandwidth and carrier condition that produced AV scores that were significantly greater than speech-reading alone; (5) low-frequency carriers were better than high-frequency or wideband carriers for envelopes derived from an octave band of speech centred at 500 Hz; and (6) low-frequency carriers were worse than high-frequency or wideband carriers for envelopes derived from an octave band centred at 3150 Hz. These results suggest that amplitude envelope cues can provide a substantial benefit to speechreading for both easy and difficult sentence materials, but that frequency transposition of these signals to regions remote from their “natural” spectral locations may result in reduced performance.