Stimulus-dependent flexibility in non-human auditory pitch processing

Songbirds and humans share many parallels in vocal learning and auditory sequence processing. However, the two groups differ notably in their abilities to recognize acoustic sequences shifted in absolute pitch (pitch height). Whereas humans maintain accurate recognition of words or melodies over large pitch height changes, songbirds are comparatively much poorer at recognizing pitch-shifted tone sequences. This apparent disparity may reflect fundamental differences in the neural mechanisms underlying the representation of sound in songbirds. Alternatively, because non-human studies have used sine-tone stimuli almost exclusively, tolerance to pitch height changes in the context of natural signals may be underestimated. Here, we show that European starlings, a species of songbird, can maintain accurate recognition of the songs of other starlings when the pitch of those songs is shifted by as much as ±40%. We observed accurate recognition even for songs pitch-shifted well outside the range of frequencies used during training, and even though much smaller pitch shifts in conspecific songs are easily detected. With similar training using human piano melodies, recognition of the pitch-shifted melodies is very limited. These results demonstrate that non-human pitch processing is more flexible than previously thought and that the flexibility in pitch processing strategy is stimulus dependent.     

The influence of indirect and direct emotional processing on memory for facial expressions

We used the remember-know procedure (Tulving, 1985 ) to test the behavioural expression of memory following indirect and direct forms of emotional processing at encoding. Participants (N=32) viewed a series of facial expressions (happy, fearful, angry, and neutral) while performing tasks involving either indirect (gender discrimination) or direct (emotion discrimination) emotion processing. After a delay, participants completed a surprise recognition memory test. Our results revealed that indirect encoding of emotion produced enhanced memory for fearful faces whereas direct encoding of emotion produced enhanced memory for angry faces. In contrast, happy faces were better remembered than neutral faces after both indirect and direct encoding tasks. These findings suggest that fearful and angry faces benefit from a recollective advantage when they are encoded in a way that is consistent with the predictive nature of their threat. We propose that the broad memory advantage for happy faces may reflect a form of cognitive flexibility that is specific to positive emotions.     

Intraoperative conversion to open technique: is informed consent implied?

This case raises issues regarding the anesthesia and surgical components of preoperative informed consent and the differing views of anesthesiologists and surgeons with regards to informed consent, in the context of conversion to open surgery from a minimally invasive approach.     

The Effects of Animal-Assisted Activities on College Students Before and After a Final Exam

Final exams at colleges and universities have proven to be a time of anxiety and stress for students. This paper contains an exploration the effects of Animal-Assisted Activities (AAA) on exam anxiety through the use of blood pressure readings before and after interacting with therapy dogs. A comparison of the experimental and control groups interacting with therapy dogs has shown statistical significance for the reduction of blood pressure for those students who will or have taken a final exam. Having owned a pet, as well, as the age of the participant were not significant predictors of whether or not therapy dogs would reduce blood pressure.     

Ageing affects conceptual but not perceptual memory processes

Whereas age effects commonly occur in tests of explicit memory, tests of implicit memory often show age invariance. In two experiments, the traditional confound between test type (implicit vs explicit) and retrieval process (conceptually driven vs perceptually driven) was removed by using conceptually driven and perceptually driven tests of both implicit and explicit memory. Experiment 1 revealed a significant age effect for conceptually driven retrieval and no age effect for perceptually driven retrieval, regardless of the type of memory being measured. Experiment 2 highlighted a difference between the two age groups in their ability to utilise semantic encoding in a nominally perceptually driven explicit memory test. The paper concludes that although perceptually driven processing is stable over age, particular care must be taken to minimise contamination from conceptually driven retrieval processes in such investigations.     

A Review of: “Couple Power Therapy”

Abstract

Events of parental divorce: Stressfulness ratings by children, parents, and clinicians, by S. A. Wolchik, I. N. Sandler, S. L. Braver,&;B. S. Fogas, 1986, 14, 59-74     

The interaction of respiration and visual feedback on the control of force and neural activation of the agonist muscle

The purpose of this study was to compare force variability and the neural activation of the agonist muscle during constant isometric contractions at different force levels when the amplitude of respiration and visual feedback were varied. Twenty young adults (20–32 years, 10 men and 10 women) were instructed to accurately match a target force at 15% and 50% of their maximal voluntary contraction (MVC) with abduction of the index finger while controlling their respiration at different amplitudes (85%, 100% and 125% normal) in the presence and absence of visual feedback. Each trial lasted 22 s and visual feedback was removed from 8–12 and 16–20 s. Each subject performed three trials with each respiratory condition at each force level. Force variability was quantified as the standard deviation of the detrended force data. The neural activation of the first dorsal interosseus (FDI) was measured with bipolar surface electrodes placed distal to the innervation zone. Relative to normal respiration, force variability increased significantly only during high-amplitude respiration (∼63%). The increase in force variability from normal- to high-amplitude respiration was strongly associated with amplified force oscillations from 0 to 3 Hz (R² ranged from .68 to .84, p < .001). Furthermore, the increase in force variability was exacerbated in the presence of visual feedback at 50% MVC (vision vs. no-vision: .97 vs. .87 N) and was strongly associated with amplified force oscillations from 0 to 1 Hz (R² = .82) and weakly associated with greater power from 12 to 30 Hz (R² = .24) in the EMG of the agonist muscle. Our findings demonstrate that high-amplitude respiration and visual feedback of force interact and amplify force variability in young adults during moderate levels of effort.