Improving left spatial neglect through music scale playing

The study assessed whether the auditory reference provided by a music scale could improve spatial exploration of a standard musical instrument keyboard in right‐brain‐damaged patients with left spatial neglect. As performing music scales involves the production of predictable successive pitches, the expectation of the subsequent note may facilitate patients to explore a larger extension of space in the left affected side, during the production of music scales from right to left. Eleven right‐brain‐damaged stroke patients with left spatial neglect, 12 patients without neglect, and 12 age‐matched healthy participants played descending scales on a music keyboard. In a counterbalanced design, the participants' exploratory performance was assessed while producing scales in three feedback conditions: With congruent sound, no‐sound, or random sound feedback provided by the keyboard. The number of keys played and the timing of key press were recorded. Spatial exploration by patients with left neglect was superior with congruent sound feedback, compared to both Silence and Random sound conditions. Both the congruent and incongruent sound conditions were associated with a greater deceleration in all groups. The frame provided by the music scale improves exploration of the left side of space, contralateral to the right hemisphere, damaged in patients with left neglect. Performing a scale with congruent sounds may trigger at some extent preserved auditory and spatial multisensory representations of successive sounds, thus influencing the time course of space scanning, and ultimately resulting in a more extensive spatial exploration. These findings offer new perspectives also for the rehabilitation of the disorder.     

Risk perception as a function of risk exposure amongst rock climbers

ObjectivesThe first objective was to examine the extent to which climbers' climbing safety perceived competence (CSPC) and perceived own absolute (POAR) and comparative (PCR) risk of getting seriously injured whilst climbing is related to risk exposure. The second objective was to examine which variables influence POAR and PCR.MethodTwo hundred and thirty-five climbers (M = 32, SD = 10.2 years of age) completed the following questionnaires: a CSPC scale specifically developed to assess perceived ability to practice climbing safely; indirect measures of PCR, consisting in the subtraction of the participants' assessment of their own risks from their assessment of other climbing referents' risks; and the Life Orientation Test-Revised, measuring dispositional optimism (DO). Participants were approached in their practices sites from Mediterranean regions, and were divided into groups based on their climbing practice's risk exposure; that is, high risk: traditional climbing (TRAD; n = 42); moderate risk: leading (LEAD; n = 89); and low risk: either top-roping (TOP; n = 51) or indoor bouldering (IND; n = 53).ResultsAnalyses of variance showed that TRAD expressed higher CSPC and higher POAR than the other groups. PCR also differed amongst the groups. More specifically, TRAD expressed comparative pessimism and LEAD expressed comparative optimism, as their POAR was, respectively, higher and lower than their perceived average climber's risk. TOP and IND perceived their own risk in a similar way to that of the average climber. Regression analyses showed that DO did not influence POAR or PCR. Past injury episode was positively related to POAR and negatively related to the propensity to express comparative optimism, though only amongst TRAD and LEAD.ConclusionsClimbers' risk perception accurately reflected their risk exposure. Climbers whose climbing modality involves higher risks acknowledged so when evaluating their own absolute and comparative risks of getting seriously injured whilst climbing.     

Recognition of partly occluded objects by fish

The ability to visually complete partly occluded objects (so-called “amodal completion”) has been documented in mammals and birds. Here, we report the first evidence of such a perceptual ability in a fish species. Fish (Xenotoca eiseni) were trained to discriminate between a complete and an amputated disk. Thereafter, the fish performed test trials in which hexagonal polygons were either exactly juxtaposed or only placed close to the missing sectors of the disk in order to produce or not produce the impression (to a human observer) of an occlusion of the missing sectors of the disk by the polygon. In another experiment, fish were first trained to discriminate between hexagonal polygons that were either exactly juxtaposed or only placed close to the missing sectors of a disk, and then tested for choice between a complete and an amputated disk. In both experiments, fish behaved as if they were experiencing visual completion of the partly occluded stimuli. These findings suggest that the ability to visually complete partly occluded objects may be widespread among vertebrates, possibly inherited in mammals, birds and fish from early vertebrate ancestors.     

Median decision techniques as an alternative to the classical statistical inference test

In the research area, the criterion to test a hypothesis is frequently the distance of each subject from the mean of the distribution. This concept of distance is constantly used and re-used as a source of evidence in the search for significant contrasts with respect to models of theoretical probability. This paper proposes a number of ideas regarding the use of new distance indicators related to statistics that rely less heavily on parametric assumptions, in particular, the use of median confidence intervals. We have simulated via EXCEL different data samples for a design of two independent groups under 15 different conditions in two different situations: mean equality and mean differences. The results showed the high sensitivity of the comparison of the confidence intervals, especially if a strict decision criterion is used. However, we did not obtain good results for sensitivity. In fact, in some cases, the comparison of the confidence intervals of the mean worked better than those of median.     

"I need to talk about it": a qualitative analysis of trauma-exposed women's reasons for treatment choice

A significant proportion of individuals suffering from posttraumatic stress disorder do not seek or receive effective treatment. Understanding the reasons why an individual chooses to seek treatment or prefers one treatment to another is a critical step to improve treatment seeking. To begin to understand these reasons, we conducted a qualitative analysis of the reasons women gave for choosing a cognitive-behavioral treatment, prolonged exposure (PE), or a pharmacological treatment, sertraline (SER). A community sample of women with trauma histories were asked to view standardized rationales, to choose among PE, SER, or no treatment, and to give 5 reasons for their choice. Women indicated that they were more likely to prefer the psychotherapy to the medication. Across reasons given, the most commonly cited reason for treatment preference highlighted why or how the treatment worked (e.g., I need to talk about it); and this reason emerged as the strongest predictor of preference for PE. Understanding this role of perceived treatment mechanism may aid clinicians and public health policy officials to identify and address help-seeking barriers regarding treatment.     

Children's scale errors: A by‐product of lexical development?

Scale errors occur when young children seriously attempt to perform an action on an object which is impossible due to its size. Children vary substantially in the incidence of scale errors with many factors potentially contributing to these differences, such as age and the type of scale errors. In particular, the evidence for an inverted U‐shaped curve of scale errors involving the child's body (i.e., body scale errors), which would point to a developmental stage, is mixed. Here we re‐examine how body scale errors vary with age and explore the possibility that these errors would be related to the size and properties of children's lexicon. A large sample of children aged 18–30 months (N = 125) was tested in a scale error elicitation situation. Additionally, parental questionnaires were collected to assess children's receptive and expressive lexicon. Our key findings are that scale errors linearly decrease with age in childhood, and are more likely to be found in early talkers rather than in less advanced ones. This suggests that scale errors do not correspond to a developmental stage, and that one determinant of these errors is the speed of development of the linguistic and conceptual system, as a potential explanation for the individual variability in prevalence.     

Viewing a face (especially one's own face) being touched enhances tactile perception on the face

Observing touch on another person's body activates brain regions involved in tactile perception, even when the observer's body is not directly stimulated. Previous work has shown that in some synaesthetes, this effect induces a sensation of being touched. The present study shows that if perceptual thresholds are experimentally manipulated, viewing touch can modulate tactile experience in nonsynaesthetes as well. When observers saw a face being touched by hands, rather than a face being merely approached by hands, they demonstrated enhanced detection of subthreshold tactile stimuli on their own faces. This effect was specific to observing touch on a body part, and was not found for touch on a nonbodily stimulus, namely, a picture of a house. In addition, the effect was stronger when subjects viewed their own faces rather than another person's face. Thus, observing touch can activate the tactile system, and if perceptual thresholds are manipulated, such activation can result in a behavioral effect in nonsynaesthetes. The effect is maximum if the observed body matches the observer's body.     

Pigeons (Columba livia) associate time intervals with symbols in a touch screen task: evidence for ordinality but not summation

The present experiments examined whether pigeons can sum symbols that are associated with various temporal consequences in a touch screen apparatus. Pigeons were trained to discriminate between two visual symbols that were associated with 0, 1, 2, 3, 4, or 5 s either of delay to 4 s of hopper access (delay group) or duration of hopper access (reward group). In Experiment 1, the pigeons in both groups learned to select the symbol associated with the more favorable outcome, and they successfully transferred this discrimination to novel symbol pairs. However, when tested with 2 pairs of symbols associated with different summed durations, they responded on the basis of a simple response rule rather than the sum of the symbol pair. In Experiment 2, the reward group was presented with four symbols at once and was allowed to successively choose one symbol at a time. All pigeons chose the symbols in order from largest to smallest. This indicates that pigeons formed an ordered representation of symbols associated with different time intervals, even though they did not sum the symbols.     

How fish do geometry in large and in small spaces

It has been shown that children and non-human animals seem to integrate geometric and featural information to different extents in order to reorient themselves in environments of different spatial scales. We trained fish (redtail splitfins, Xenotoca eiseni) to reorient to find a corner in a rectangular tank with a distinctive featural cue (a blue wall). Then we tested fish after displacement of the feature on another adjacent wall. In the large enclosure, fish chose the two corners with the feature, and also tended to choose among them the one that maintained the correct arrangement of the featural cue with respect to geometric sense (i.e. left-right position). In contrast, in the small enclosure, fish chose both the two corners with the features and the corner, without any feature, that maintained the correct metric arrangement of the walls with respect to geometric sense. Possible reasons for species differences in the use of geometric and non-geometric information are discussed.