Olfactory recognition of individual competitors by means of faeces in horse (<Emphasis Type="Italic">Equus caballus</Emphasis>)

Living in complex social systems requires perceptual and cognitive capacities for the recognition of group membership and individual competitors. Olfaction is one means by which this can be achieved. Many animals can identify individual proteins in urine, skin secretions, or saliva by scent. Additionally, marking behaviour in several mammals and especially in horses indicates the importance of sniffing conspecifics’ faeces for olfactory recognition. To test this hypothesis, we conducted two separate experiments: Experiment 1 addressed the question of whether horses can recognise the group membership of other horses by sniffing their faeces. The horses were presented with four faecal samples: (1) their own, (2) those of other members of their own group, (3) those of unfamiliar mares, and (4) those of unfamiliar geldings. Experiment two was designed to assess whether horses can identify the group member from whom a faecal sample came. Here, we presented two groups of horses with faecal samples from their group mates in random distribution. As controls, soil heaps and sheep faecal samples were used. In experiment one, horses distinguished their own from their conspecifics’ faeces, but did not differentiate between familiarity and sex. In experiment two, the horses from both groups paid most attention to the faeces of the horses from which they received the highest amount of aggressive behaviours. We therefore suggest that horses of both sexes can distinguish individual competitors among their group mates by the smell of their faeces.     

Human frontal midline theta and its synchronization to gamma during a verbal delayed match to sample task

The involvement of oscillatory activity, especially at theta and gamma frequency, in human working memory has been reported frequently. A salient pattern during working memory is electroencephalographic frontal midline theta activity which has been suggested to reflect monitoring functions in order to deal with a task. In general, theta activity has been credited with integrative functions of distributed activity. In the present study, we focused on electroencephalographic power analyses and cross-frequency phase synchronization in order to test whether frontal midline theta activity is linked to more locally generated gamma oscillations during the performance of a verbal delayed match to sample task. The task consisted of two different conditions where subjects either had to reorganize three consonant letters in alphabetical order (manipulation condition) or where they merely had to retain the three consonant letters (retention condition). Results revealed higher frontal midline theta activity for the manipulation of maintained stimulus material compared to pure retention of stimulus material. Interestingly, power differences between conditions were most pronounced during the second half of the delay period. Cross-frequency phase synchronization between frontal midline theta activity and distributed gamma activity, on the other hand, was predominant during the first half of the delay period and was stronger for manipulation compared to retention. We suggest that coupling of frontal midline theta to gamma activity reflects monitoring functions on the temporal segregation of memory items, whereas higher frontal midline theta power in the second half of the delay period might be associated with rehearsal processes. Rehearsal processes in the manipulation condition are likely more pronounced, because rehearsal of a new letter string in a limited time window requires higher mental effort compared to pure retention where rehearsal processes may already start at the beginning of the delay period.     

The semantics of prosody: acoustic and perceptual evidence of prosodic correlates to word meaning

This investigation examined whether speakers produce reliable prosodic correlates to meaning across semantic domains and whether listeners use these cues to derive word meaning from novel words. Speakers were asked to produce phrases in infant-directed speech in which novel words were used to convey one of two meanings from a set of antonym pairs (e.g., big/small). Acoustic analyses revealed that some acoustic features were correlated with overall valence of the meaning. However, each word meaning also displayed a unique acoustic signature, and semantically related meanings elicited similar acoustic profiles. In two perceptual tests, listeners either attempted to identify the novel words with a matching meaning dimension (picture pair) or with mismatched meaning dimensions. Listeners inferred the meaning of the novel words significantly more often when prosody matched the word meaning choices than when prosody mismatched. These findings suggest that speech contains reliable prosodic markers to word meaning and that listeners use these prosodic cues to differentiate meanings. That prosody is semantic suggests a reconceptualization of traditional distinctions between linguistic and nonlinguistic properties of spoken language.     

Executive function and weight status in children: A one-year longitudinal perspective

There is considerable evidence for an association between obesity and impaired executive function (EF) in adolescents and adults. However, little research has examined EF in overweight or obese children. Furthermore, data on EF in underweight individuals is lacking. In addition, there is no consensus on the directionality of the relationship between Body Mass Index (BMI) and EF, and longitudinal studies are rare. Thus, the present study examined whether children differ in their performance on a battery of EF tasks depending on their weight status (underweight, normal-weight, overweight), and investigated the longitudinal cross-lagged associations between EF and BMI. Hot EF (delay of gratification, affective decision-making), cool EF (attention shifting, inhibition, working memory [WM] updating), and BMI were assessed in 1,657 German elementary-school children at two time points, approximately one year apart. Overweight children exhibited slightly poorer attention shifting, WM updating, and affective decision-making abilities as compared to normal-weight children. Unexpectedly, they did not show any deficits in inhibition or delay of gratification. EF levels of underweight children did not differ significantly from those of normal-weight children. Furthermore, poor attention shifting and enhanced affective decision-making predicted a slightly higher BMI one year later, and a higher BMI also predicted poorer attention shifting and WM updating one year later. The latter association between BMI and subsequent EF scores, however, diminished when controlling for socioeconomic status. Results indicate that hot and cool EF plays a role in the weight development of children, and might be a promising factor to address in preventive interventions.     

Treating chronic tinnitus: comparison of cognitive-behavioural and habituation-based treatments

Using a randomized control group trial the long-term efficacy of a habituation-based treatment as conceived by Jastreboff, and a cognitive-behavioural tinnitus coping training were compared. An educational intervention was administered as a control condition. Both treatments were conducted in a group format (habituation-based treatment, 5 sessions; tinnitus coping training, 11 sessions). Educational intervention was delivered in a single group session. Patients were categorized according to their level of disability due to tinnitus (low, high), age and gender and then randomly allocated to the treatment conditions (habituation-based treatment, n = 30; tinnitus coping training, n = 27; educational intervention, n = 20). Data assessment included follow-ups of up to 21 months. Several outcome variables including disability due to tinnitus were assessed either by questionnaire or diary. Findings reveal highly significant improvements in both tinnitus coping training and habituation-based treatment in comparison with the control group. While tinnitus coping training and habituation-based treatment do not differ significantly in reduction of tinnitus disability, improvement in general well-being and adaptive behaviour is greater in tinnitus coping training than habituation-based treatment. The decrease in disability remains stable throughout the last follow-up in both treatment conditions.     

Physiological and behavioral parameters of infants' categorization: changes in heart rate and duration of examining across trials

This report investigates the relations between duration of examining and heart rate (HR) across several trials of an object-examination task. A total of N= 20 11-month-olds were familiarized with a sequence of 10 different exemplars from the same global category (animals or furniture) before they received an exemplar from the contrasting category at test. Consistent with previous findings, HR was lower during states of focused attention (i.e. examining) than during states of casual attention (i.e. looking) or non-looking. Over the familiarization trials, examining stayed about the same, while mean HR increased. At test, examining increased and mean HR decreased, indicating that infants focused their attention on the out-of-category object. Psychophysiological and behavioral measures of attention were systematically related over trials, suggesting that heart rate provides a suitable objective measure to study infants' categorization performance in object-examination tasks.     

Affect regulation and food intake in bulimia nervosa: emotional responding to food cues after deprivation and subsequent eating

Emotional responding to salient food cues and effects of food deprivation and consumption were investigated in 32 women with bulimia and 32 control women. One half of each group was food deprived before viewing unpleasant, neutral, pleasant, and food-related pictures. Then participants could eat from a buffet before viewing a parallel picture set. Women with bulimia showed a substantial potentiation of startle responses during viewing of food cues relative to control women. This startle potentiation was attenuated by food deprivation and augmented by increased food consumption. These data support the affective regulation model suggesting that food cues prompt negative affective states in women with bulimia, who are overwhelmed by fasting. The resulting deprivation increases the incentive value of food cues and may thus trigger binge eating.     

Fear of the new? Geckos hesitate to attack novel prey,feed near objects and enter a novel space

Animal Cognition - Neophobia, the fear of novelty, is an ecologically important response which enables animals to avoid potentially harmful situations. Neophobia is a cognitive process by which...