Latent class recapture models with flexible behavioural response

Recapture models based on conditional capture probabilities are explored. These encompass all possible forms of time-dependence and behavioural response to capture. Covariates are used to deal with observed heterogeneity, while unobserved heterogeneity is modeled through flexible random effects with a finite number of support points

Behavioural effects of hypersaline exposure on the lobster Homarus gammarus (L) and the crab Cancer pagurus (L)

There is scarce existing information in the literature regarding the responses of any marine species, especially commercially valuable decapod crustaceans, to hypersalinity. Hypersaline discharges due to solute mining and desalination are increasing in temperate areas, hence the behavioural responses of the edible brown crab, Cancer pagurus, and the European lobster, Homarus gammarus, were studied in relation to a marine discharge of highly saline brine using a series of preference tests. Both species had a significant behavioural response to highly saline brine, being able to detect and avoid areas of hypersalinity once their particular threshold salinity was reached (salinity 50 for C. pagurus and salinity 45 for H. gammarus). The presence of shelters had no effect on this response and both species avoided hypersaline areas, even when shelters were provided there. If the salinity of commercial effluent into the marine environment exceeds the behavioural thresholds found here, it is likely that adults of these species will relocate to areas of more favourable salinity. In management terms it is advisable to ensure that any hypersaline discharges are limited to the lowest tolerance of all the economically valuable species in the area to avoid loss of revenue in fishery areas

Collecting behavioural addiction treatment data using Freedom of Information requests

There is now a growing movement that views a number of behaviours as potentially addictive including many that do not involve the ingestion of a drug (i.e., behavioural addictions such as gambling addiction and sex addiction). As a consequence of being ‘medicalised’ and ‘pathologised’, such disorders have led individuals to seek treatment for their particular behavioural addiction. This case study examines a new method of collecting data on behavioural addiction treatment via the use of Freedom of Information (FOI) requests. More specifically, this case study briefly overviews two published studies that have used FOI requests to collate data on treatment of gambling addiction and sex addiction within the British National Health Service. It is argued that FOI requests for data have many advantages including almost 100% response rates (as organisations are legally required to respond to information requests), and nationally representative data that are highly objective

Interregional synchrony of visuomotor tracking: perturbation effects and individual differences

The present study evaluated the neural and behavioural correlates associated with a visuomotor tracking task during which a sensory perturbation was introduced that created a directional bias between moving hand and cursor position. The results revealed that trajectory error increased as a result of the perturbation in conjunction with a dynamic neural reorganization of cluster patterns that reflected distinct processing. In particular, a negatively activated cluster, characterizing the degraded information processing due to the perturbation, involved both hemispheres as well as midline area. Conversely, a positively activated cluster, indicative of compensatory processing was strongly confined to the left (dominant) hemisphere. In addition, a brain-behavioural association of good vs. poor performing participants enabled to localize a neural circuit within the left hemisphere and midline area that linked with successful performance. Overall, these data reinforce the functional significance of interregional synchrony in defining response output and behavioural success

Motion adaptation and attention: A critical review and meta-analysis

The motion aftereffect (MAE) provides a behavioural probe into the mechanisms underlying motion perception, and has been used to study the effects of attention on motion processing. Visual attention can enhance detection and discrimination of selected visual signals. However, the relationship between attention and motion processing remains contentious: not all studies find that attention increases MAEs. Our meta-analysis reveals several factors that explain superficially discrepant findings. Across studies (37 independent samples, 76 effects) motion adaptation was significantly and substantially enhanced by attention (Cohen's d = 1.12, p < .0001). The effect more than doubled when adapting to translating (vs. expanding or rotating) motion. Other factors affecting the attention-MAE relationship included stimulus size, eccentricity and speed. By considering these behavioural analyses alongside neurophysiological work, we conclude that feature-based (rather than spatial, or object-based) attention is the biggest driver of sensory adaptation. Comparisons between naïve and non-naïve observers, different response paradigms, and assessment of 'file-drawer effects' indicate that neither response bias nor publication bias are likely to have significantly inflated the estimated effect of attention

Age-related changes in global motion coherence: conflicting haemodynamic and perceptual responses

Our aim was to use both behavioural and neuroimaging data to identify indicators of perceptual decline in motion processing. We employed a global motion coherence task and functional Near Infrared Spectroscopy (fNIRS). Healthy adults (n = 72, 18-85) were recruited into the following groups: young (n = 28, mean age = 28), middle-aged (n = 22, mean age = 50), and older adults (n = 23, mean age = 70). Participants were assessed on their motion coherence thresholds at 3 different speeds using a psychophysical design. As expected, we report age group differences in motion processing as demonstrated by higher motion coherence thresholds in older adults. Crucially, we add correlational data showing that global motion perception declines linearly as a function of age. The associated fNIRS recordings provide a clear physiological correlate of global motion perception. The crux of this study lies in the robust linear correlation between age and haemodynamic response for both measures of oxygenation. We hypothesise that there is an increase in neural recruitment, necessitating an increase in metabolic need and blood flow, which presents as a higher oxygenated haemoglobin response. We report age-related changes in motion perception with poorer behavioural performance (high motion coherence thresholds) associated with an increased haemodynamic response

Perceptual and electrophysiological masking of the auditory brainstem response : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

Effective masking levels of the auditory brainstem response (ABR) to tonepips were established on 10 normal-hearing subjects at 500, 1000, 2000 and 4000 Hz, using white noise. Effective masking levels of perceptual responses to the same stimuli were also established, for both presentation of single (1/second) and repeated (41.7/second) tonepips. Perceptual masking levels for repeated tonepips were significantly higher than levels for single tonepips, indicating temporal summation effects. Levels which effectively masked the ABR did not differ significantly from perceptual masking levels at either presentation rate. A signal-to-noise ratio of -5 to -10 dB was found to provide effective masking for all conditions. For the stimulus and recording parameters in the present study, a behavioural method of determining effective masking levels is considered appropriate. Behavioural thresholds determined for single tonepips were higher than thresholds for repeated tonepips, demonstrating dependence of nHL behavioural references for ABR thresholds on stimulus repetition rate. Effective masking levels determined in the present study may be applied to the use of tonepip ABRs to provide an objective frequency-specific measure of hearing in infants

Looking for a psychology for the inner rational agent

Research in psychology and behavioural economics shows that individuals’ choices often depend on ‘irrelevant’ contextual factors. This presents problems for normative economics, which has traditionally used preference-satisfaction as its criterion. A common response is to claim that individuals have context-independent latent preferences which are ‘distorted’ by psychological factors, and that latent preferences should be respected. This response implicitly uses a model of human action in which each human being has an ‘inner rational agent’. I argue that this model is psychologically ungrounded. Although references to latent preferences appear in psychologically-based explanations of context-dependent choice, latent preferences serve no explanatory purpose

Individual strategies of aggressive and non-aggressive male mice in encounters with trained aggressive residents

To determine whether individual differences in offensive behaviour are related to differences in defensive behaviour, the responses of male wild house mice, Mus domesticus, of an aggressive and a non-aggressive line to defeat by physically stronger residents were analysed. Individuals of the aggressive line engaged in more flight behaviour, whereas the males of the non-aggressive line predominantly showed immobility. The higher flight tendency of the aggressive intruders provoked more attacks by the resident, resulting in more fighting between the resident and an aggressive male than between the resident and a non-aggressive intruder. However, if offered an opportunity to escape from the home-cage of the resident, aggressive males more readily made use of it than non-aggressive intruders. Differences between aggressive and non-aggressive male mice are interpreted in terms of fundamentally different behavioural strategies adopted in response to social interaction. The response of aggressive males can be characterized as an active behavioural strategy by which they tend to determine actively their social situation. In contrast, the prevailing lack of overt attempts to manipulate the situation by the non-aggressive mice points to passive confrontation, in an offensive as well as in a defensive context.