Access to environmental stimulation via eyelid responses for persons with acquired brain injury and multiple disabilities: a new microswitch arrangement

This study assessed a new microswitch arrangement for eyelid responses using an optic sensor placed above the cheekbone and a small sticker on the person's eyelid. This new arrangement, which was designed to avoid interference of the microswitch with the person's visual functioning, was tested on three adults with acquired brain injury and multiple (consciousness, communication, and motor) disabilities. The study was carried out according to a non-concurrent multiple baseline design across participants. Data showed the new microswitch arrangement was suitable for all three participants, who increased their responding during the intervention phase of the study when their responses allowed them to access preferred stimulation. Practical implications of the findings are discussed.     

BDNF serum levels in subjects developing or not post-traumatic stress disorder after trauma exposure

Post-traumatic stress disorder (PTSD) is a syndrome resulting from exposure to a severe traumatic event that poses threatened death or injury and produces intense fear and helplessness. The neural structures implicated in PTSD development belong to the limbic system, an important region for emotional processing. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that serves as survival factor for selected populations of central nervous system (CNS) neurons and plays a role in the limbic system by regulating synaptic plasticity, memory processes and behavior. Impaired BDNF production in the brain can lead to a variety of CNS dysfunctions including symptoms associated with PTSD. However, so far fewer studies have investigated this neurotrophin in patients with PTSD. Furthermore, given the multiple role of BDNF in various CNS disorders, it cannot be excluded that traumatic events per se may influence neurotrophin levels, without a direct association to the PTSD syndrome.     

The scientific turn in metaphysics: a factualist approach

In a recent paper, Cumpa (Am Philos Q 51(4): 319–324, 2014) argues that a scientific turn in metaphysics requires the acceptance of a materialist criterion of fundamentality, according to which the most fundamental metaphysical category is the one that provides us with a reconciliation of the ordinary world and the physical universe. He concludes that the dominant category of substance cannot be the most fundamental category, for it does not satisfy this criterion of fundamentality. The most fundamental category is instead the category of fact. Although convincing, the defense of factualism over substantialism offered by Cumpa takes into account the case of classical physics without considering the physical universe of quantum mechanics. My aim in this paper is to offer a completion to Cumpa’s factualist approach. To achieve my aim, I show that substances cannot provide a satisfactory account of the relationship between the ordinary world and the physical universe even in the case of quantum mechanics, whereas a factualist approach does.

     

Assessing the automaticity of the exogenous orienting of tactile attention

We examined whether or not abrupt tactile onsets are capable of exogenously capturing tactile spatial attention when visual spatial attention is focused elsewhere. In experiment 1, we compared performance under dual-task conditions (where participants performed a tactile exogenous cuing task and a rapid serial visual presentation--RSVP--task at the same time) with their performance under single-task conditions (where the participants had to perform only the cuing task, although the RSVP stream was still presented in the background) and to a no-stream condition (where only the cuing task was presented). Tactile cuing was completely suppressed in both the dual-task and single-task conditions, showing that exogenous tactile spatial orienting is modulated by visual-spatial attention, which hence appears to be far from truly automatic. In experiment 2, we demonstrated that the abolishment of exogenous tactile orienting was not caused by the transient presentation of abrupt onset stimuli (letters). These results therefore show that exogenous spatial attentional orienting toward abrupt peripheral tactile stimuli is possible as long as perceptual resources are not depleted by a perceptually demanding (RSVP) task.     

Some variables affecting rate of key pecking during response-independent procedures (autoshaping)

Rate of key pecking by pigeons subjected to response-independent procedures in which a stimulus on the response key preceded food presentation was investigated in eight experiments. Color and shape of the stimulus, duration of the stimulus, probability of food following the stimulus, duration of the intertrial interval, and duration of food presentation were varied separately and in combination. All variables studied, except color and shape of the stimulus, had a reliable effect on pecking rate, but some variables had stronger effects than others. Rapid key pecking may be obtained with a variety of response-independent procedures, as well as by response-dependent reinforcement. The results of experiments in which food is both dependent on key pecking and correlated with stimulus conditions are not representative of simple operant effects. Key pecking is an ideal response for studying the simultaneous operation of response-reinforcer and stimulus-reinforcer effects.     

Key pecking under response-independent food presentation after long simple and compound stimuli

Sixteen pigeons were trained to peck a key using a response-independent (auto-shaping) procedure of food presentation. The 4-sec grain presentations were independent of responding but a keylight stimulus preceded each, with a 4-min interval between the grain presentation and the next stimulus. Subjects were divided into four groups, with two durations of the keylight (30 or 120 sec) and either one or four successive colors on the response key preceding food delivery. In Phase 2, the birds were continued with the same keylight duration but were presented the alternative number of key colors. All pigeons pecked the key during the stimulus. Birds in the two groups with the 30-sec stimulus duration began to respond significantly sooner than birds with the 120-sec duration. There were no significant differences in rate of pecking between groups by the last five days of Phase 1. In Phase 1, the pigeons exposed to the four stimulus components showed an increase in rate of pecking over the four components as grain presentation approached. The pigeons with one stimulus component did not exhibit this regularity. Analogous conditions in Phase 2 had similar results except for one group. The implications of the occurrence of key pecking due to response-independent food delivery for multiple and chained schedules were pointed out.     

De-polarizing verbal irony

In three studies participants were asked to rate the degree of irony perceived in comments relating to five variations of a scenario, ranging from one pole to the opposite pole and passing through three in-between states. In study 1, the comments pertained to the polar extremes of a dimension, e.g. “It’s uphill!” stated with reference to varying degrees of steepness both uphill and downhill (i.e. steep, slightly steep, flat, slightly sloping downhill and steeply sloping downhill). In study 2, the comments were of an “intermediate” nature (e.g. “This hill is neither uphill nor downhill!”) and, as in Study 1, they were used to refer to the same five varying degrees of the same dimension. Study 3 involved the stimuli from both of the first two experiments in a between-participants design.

The results consistently demonstrated that verbal irony does not only apply to (weakly or strongly) polarised statements and situations, but it can also apply to intermediate comments and experiences. The perceptual structure of the dimensions involved modulates the effect.     

New perspectives in assessing deception: The evolution of the truth machine

In recent years a growing interest has arisen in the development of tools for the detection of deception. Since William M. Marston's first publication (1917) on the use of the polygraph as a lie detector, the application of this tool, commonly known as the truth machine, has evolved. Modern technologies are now trying to push the issue further, investigating brain activity during deception using functional Magnetic Resonance Imaging (fMRI). The aim of this paper is to summarise the evolution of research from the original use of the polygraph to the use of new technologies in detecting deception, in order to provide an overview of the recent developments on the use of measurements of deception, and promote new research in this highly important domain of applied cognitive psychology.     

Perceptual and Response Bias in Unilateral Neglect: Two Modified Versions of the Milner Landmark Task

Perceptual and response bias in estimating the proportion of the two segments of prebisected lines were disambiguated in a group of 121 patients suffering from left neglect by means of two variants of the Milner Landmark task (Milner et al., 1993). The first variant, LANDMARK-V, required a verbal response; the second variant, LANDMARK-M, required manual pointing. The paper reports and discusses the results obtained on each task and their correlations, as well as the relationships between either kind of bias and the intrahemispheric location of the lesion. It is argued that besides their usefulness as a diagnostic tool the proposed variants of the Milner Landmark task provide results that are worth further investigation in their own right.