14 research outputs found
Necessary connections: âFeelings photographsâ in criminal justice research
Visual representations of prisons and their inmates are common in the news and social media, with stories about riots, squalor, drugs, self-harm and suicide hitting the headlines. Prisonersâ families are left to worry about the implications of such events on their kin, while those incarcerated and less able to understand social cues, norms and rules, are vulnerable to deteriorating mental health at best, to death at worst. As part of the life-story method in my research with offenders who are on the autism spectrum, have mental health problems and/or have learning difficulties, and prisonerâs mothers, I asked participants to take photographs, reflecting upon their experiences. Photographs in this case, were primarily used to help respondents consider and articulate their feelings in follow-up interviews. Notably, seeing (and imagining) is often how we make a connection to something (object or feeling), or someone (relationships), such that images in fiction, news/social media, drama, art, film and photographs can shape the way people think and behave â indeed feel about things and people. Images and representations ought to be taken seriously in researching social life, as how we interpret photographs, paintings, stories and television shows is based on our own imaginings, biography, culture and history. Therefore, we look at and process an image before words escape, by âseeingâ and imagining. How my participants and I âcollaborateâ in doing visual methods and then how we make meaning of the photographs in storying their feelings, is insightful. As it is, I wanted to enable my participants to make and create their own stories via their photographs and narratives, whilst connecting to them, along with my own interpretation and subjectivities
Four theorems on the psychometric function
In a 2-alternative forced-choice (2AFC) discrimination task, observers choose which of two stimuli has the higher value. The psychometric function for this task gives the probability of a correct response for a given stimulus difference, Îx. This paper proves four theorems about the psychometric function. Assuming the observer applies a transducer and adds noise, Theorem 1 derives a convenient general expression for the psychometric function. Discrimination data are often fitted with a Weibull function. Theorem 2 proves that the Weibull "slope" parameter, β, can be approximated by [Formula: see text], where [Formula: see text] is the β of the Weibull function that fits best to the cumulative noise distribution, and [Formula: see text] depends on the transducer. We derive general expressions for [Formula: see text] and [Formula: see text], from which we derive expressions for specific cases. One case that follows naturally from our general analysis is Pelli's finding that, when [Formula: see text], [Formula: see text]. We also consider two limiting cases. Theorem 3 proves that, as sensitivity improves, 2AFC performance will usually approach that for a linear transducer, whatever the actual transducer; we show that this does not apply at signal levels where the transducer gradient is zero, which explains why it does not apply to contrast detection. Theorem 4 proves that, when the exponent of a power-function transducer approaches zero, 2AFC performance approaches that of a logarithmic transducer. We show that the power-function exponents of 0.4-0.5 fitted to suprathreshold contrast discrimination data are close enough to zero for the fitted psychometric function to be practically indistinguishable from that of a log transducer. Finally, Weibull β reflects the shape of the noise distribution, and we used our results to assess the recent claim that internal noise has higher kurtosis than a Gaussian. Our analysis of β for contrast discrimination suggests that, if internal noise is stimulus-independent, it has lower kurtosis than a Gaussian
RECAPP-XPR: A smartphone application for presenting and recalling experimentally controlled stimuli over longer timescales
We report two experiments that used smartphone applications for presenting and recalling verbal stimuli over extended timescales. In Experiment 1, we used an iPhone application that we had developed, called RECAPP-XPR, to present 76 participants with a single list of eight words presented at a rate of one word every hour, followed by a test of free recall an hour later. The experiment was exceptionally easy to schedule, taking only between 5 and 10 min to set up using a web-based interface. RECAPP-XPR randomly samples the stimuli, presents the stimuli, and collects the free recall data. The stimuli disappear shortly after they have been presented, and RECAPP-XPR collects data on when each stimulus was viewed. In Experiment 2, the study was replicated using the widely used image-sharing application Snapchat. A total of 197 participants were tested by 38 student experimenters, who manually presented the stimuli as âsnapsâ of experimentally controlled stimuli using the same experimental rates that had been used in Experiment 1. Like all snaps, these stimuli disappeared from view after a very short interval. In both experiments, we observed significant recall advantages for the first and last list items (primacy and recency effects, respectively), and there were clear tendencies to make more transitions at output between near-neighboring items, with a forward-ordered bias, consistent with temporal contiguity effects. The respective advantages and disadvantages of RECAPP-XPR and Snapchat as experimental software packages are discussed, as is the relationship between single-study-list smartphone experiments and long-term recency studies of real-world events
Understanding the potential negative impact of interventions on children: A SCPHN student's perspective
Multisensory perception reflects individual differences in processing temporal correlations
The Visual Analogue Scale for Rating, Ranking and Paired-Comparison (VAS-RRP): A new technique for psychological measurement
Nicotinamide as Independent Variable for Intelligence, Fertility, and Health: Origin of Human Creative Explosions?
Meat and nicotinamide acquisition was a defining force during the 2-million-year evolution of the big brains necessary for, anatomically modern, to survive. Our next move was down the food chain during the Mesolithic 'broad spectrum', then horticultural, followed by the Neolithic agricultural revolutions and progressively lower average 'doses' of nicotinamide. We speculate that a fertility crisis and population bottleneck around 40â000âyears ago, at the time of the Last Glacial Maximum, was overcome by (but not the ) by concerted dietary change plus profertility genes and intense sexual selection culminating in behaviourally modern . Increased reliance on the 'de novo' synthesis of nicotinamide from tryptophan conditioned the immune system to welcome symbionts, such as TB (that excrete nicotinamide), and to increase tolerance of the foetus and thereby fertility. The trade-offs during the warmer Holocene were physical and mental stunting and more infectious diseases and population booms and busts. Higher nicotinamide exposure could be responsible for recent demographic and epidemiological transitions to lower fertility and higher longevity, but with more degenerative and auto-immune disease