title: Behaviour Determinants of the 'Choose-Short Effect'

authors: Hoogstraten, Sarah Michelle

subjects: Hens

abstract: This study aimed to elucidate the mechanisms behind the behavioural phenomenon called the 'choose-short effect' by exploring the hen’s ability to discriminate temporal stimuli in delayed match-to-sample  DMTS) procedure. This experiment aimed to add to the understanding of the behavioural processes that affect animals’ ability to perceive time and how an animal’s own actions can influence their perception of time. The Behaviour Theory of Timing (BeT; Killeen & Fetterman, 1988) assumes that the hens own behaviour mediates their ability to time. This assumption was tested in the present experiment by introducing a ‘response-requirement’ during the sample stimulus on a two alternative forced choice temporal discrimination.  If the assumptions of BeT are correct the response requirement should increase accuracy with temporal discriminations as it can serve as discriminative stimulus signalling in the passage of time. Each hen experienced two experimental phases called ‘No-response required’ (NR) and ‘Response required’ (RR) in a DMTS procedure. In the ‘NR’ conditions the house light was illuminated for either 3 s or 9 s serving as the ‘sample’ stimuli. After the sample stimulus was presented the ‘back-key’ was illuminated and the first response to the back-key activated the choice keys after a randomly selected delay of either 0 s, 3 s, 9 s or 12 s. For the ‘RR’ condition the procedure was the same as the ‘No-light’ condition apart from the ‘back key’ was illuminated throughout the sample presentation.  Results showed that there was no particular group bias towards reporting stimuli as ‘short’. However, the hens had higher accuracy in the ‘RR’ conditions when the ‘back key’ was illuminated throughout sample presentation then when it was not (‘NR’ conditions). This suggests that the animals own behaviour improved their ability to time.

text: Behaviour Determinants of the 'Choose-Short Effect' This study aimed to elucidate the mechanisms behind the behavioural phenomenon called the 'choose-short effect' by exploring the hen’s ability to discriminate temporal stimuli in delayed match-to-sample  DMTS) procedure. This experiment aimed to add to the understanding of the behavioural processes that affect animals’ ability to perceive time and how an animal’s own actions can influence their perception of time. The Behaviour Theory of Timing (BeT; Killeen & Fetterman, 1988) assumes that the hens own behaviour mediates their ability to time. This assumption was tested in the present experiment by introducing a ‘response-requirement’ during the sample stimulus on a two alternative forced choice temporal discrimination.  If the assumptions of BeT are correct the response requirement should increase accuracy with temporal discriminations as it can serve as discriminative stimulus signalling in the passage of time. Each hen experienced two experimental phases called ‘No-response required’ (NR) and ‘Response required’ (RR) in a DMTS procedure. In the ‘NR’ conditions the house light was illuminated for either 3 s or 9 s serving as the ‘sample’ stimuli. After the sample stimulus was presented the ‘back-key’ was illuminated and the first response to the back-key activated the choice keys after a randomly selected delay of either 0 s, 3 s, 9 s or 12 s. For the ‘RR’ condition the procedure was the same as the ‘No-light’ condition apart from the ‘back key’ was illuminated throughout the sample presentation.  Results showed that there was no particular group bias towards reporting stimuli as ‘short’. However, the hens had higher accuracy in the ‘RR’ conditions when the ‘back key’ was illuminated throughout sample presentation then when it was not (‘NR’ conditions). This suggests that the animals own behaviour improved their ability to time.

year: 2015

title: What's the risk? A comparison of actual and perceived driving risk

authors: Charlton, Samuel G.

subjects: Social Sciences

abstract: It has long been presumed that drivers’ perceptions of risk play an important role in guiding on-road behaviour. The answer to how accurately drivers perceive the momentary risk of a driving situation, however, is unknown. This research compared drivers’ perceptions of the momentary risk for a range of roads to the objective risk associated with those roads. Videos of rural roads, filmed from the drivers’ perspective, were presented to 69 participants seated in a driving simulator while they indicated the momentary levels of risk they were experiencing by moving a risk meter mounted on the steering wheel. Estimates of the objective levels of risk for the roads were calculated using road protection scores from the KiwiRAP database (part of the International Road Assessment Programme). Subsequently, the participants also provided risk estimates for still photos taken from the videos. Another group of 10 participants viewed the videos and photos while their eye movements and fixations were recorded. In a third experiment, 14 participants drove a subset of the roads in a car while providing risk ratings at selected points of interest. Results showed a high degree of consistency across the different methods. Certain road situations were rated as being riskier than the objective risk, and perhaps more importantly, the risk of other situations was significantly under-rated. Horizontal curves and narrow lanes were associated with over-rated risk estimates, while intersections and roadside hazards such as narrow road shoulders, power poles and ditches were significantly under-rated. Analysis of eye movements indicated that drivers did not fixate these features and that the spread of fixations, pupil size and eye blinks were significantly correlated with the risk ratings. An analysis of the road design elements at 77 locations in the video revealed five road characteristics that predicted nearly 80% of the variance in drivers’ risk perceptions; horizontal curvature, lane and shoulder width, gradient, and the presence of median barriers.

text: What's the risk? A comparison of actual and perceived driving risk It has long been presumed that drivers’ perceptions of risk play an important role in guiding on-road behaviour. The answer to how accurately drivers perceive the momentary risk of a driving situation, however, is unknown. This research compared drivers’ perceptions of the momentary risk for a range of roads to the objective risk associated with those roads. Videos of rural roads, filmed from the drivers’ perspective, were presented to 69 participants seated in a driving simulator while they indicated the momentary levels of risk they were experiencing by moving a risk meter mounted on the steering wheel. Estimates of the objective levels of risk for the roads were calculated using road protection scores from the KiwiRAP database (part of the International Road Assessment Programme). Subsequently, the participants also provided risk estimates for still photos taken from the videos. Another group of 10 participants viewed the videos and photos while their eye movements and fixations were recorded. In a third experiment, 14 participants drove a subset of the roads in a car while providing risk ratings at selected points of interest. Results showed a high degree of consistency across the different methods. Certain road situations were rated as being riskier than the objective risk, and perhaps more importantly, the risk of other situations was significantly under-rated. Horizontal curves and narrow lanes were associated with over-rated risk estimates, while intersections and roadside hazards such as narrow road shoulders, power poles and ditches were significantly under-rated. Analysis of eye movements indicated that drivers did not fixate these features and that the spread of fixations, pupil size and eye blinks were significantly correlated with the risk ratings. An analysis of the road design elements at 77 locations in the video revealed five road characteristics that predicted nearly 80% of the variance in drivers’ risk perceptions; horizontal curvature, lane and shoulder width, gradient, and the presence of median barriers.

year: 2014-07-01

title: Katoa: A descriptive, comparative and historical analysis

authors: Wessels, Kanauhea Janion

subjects: discontinuous quantification

abstract: Katoa, approximately translated as ‘all, every’, functions as the universal quantifier in te reo Māori (the Māori language), inherited from Proto Polynesian *katoa. Less well known is its occurrence as a postnominal modifier in singular noun phrases, contributing the meaning of ‘whole’, and as a nominal head meaning ‘all (of them), the whole (of it)’. As a postverbal modifier, katoa can quantify a subject noun phrase with the same meanings of ‘all, every’ and ‘whole’, and it can modify situations expressed by the verb, meaning ‘wholly, completely’. In this paper, we examine the behaviour of katoa in te reo Māori, comparing some properties of katoa with the behaviour of quantifiers in related Polynesian languages. This, in turn, informs our understanding of the prehistory of quantification in Polynesian, where we observe evidence of both retention and replacement of quantifier forms.

text: Katoa: A descriptive, comparative and historical analysis Katoa, approximately translated as ‘all, every’, functions as the universal quantifier in te reo Māori (the Māori language), inherited from Proto Polynesian *katoa. Less well known is its occurrence as a postnominal modifier in singular noun phrases, contributing the meaning of ‘whole’, and as a nominal head meaning ‘all (of them), the whole (of it)’. As a postverbal modifier, katoa can quantify a subject noun phrase with the same meanings of ‘all, every’ and ‘whole’, and it can modify situations expressed by the verb, meaning ‘wholly, completely’. In this paper, we examine the behaviour of katoa in te reo Māori, comparing some properties of katoa with the behaviour of quantifiers in related Polynesian languages. This, in turn, informs our understanding of the prehistory of quantification in Polynesian, where we observe evidence of both retention and replacement of quantifier forms.

year: 2024