On Potentiality And Respect For Embryos: A Reply To Mary Mahowald

In order to understand the nature of human embryos I first distinguish between active and passive potentiality, and then argue that the former is found in human gametes and embryos (even in embryos in vitro that may fail to be implanted) because they all have an indwelling power or capacity to initiate certain changes. Implantation provides necessary conditions for the actualization of that prior, active potentiality. This does not imply that embryos are potential persons that do not deserve the same respect as actual persons. To claim that embryos become persons is to understand the predicate person as a phase sortal, roughly equivalent to adult person. This entails that we would not be essentially persons. In order to explain the traditional understanding of person as a proper sortal rather than a phase sortal, the author distinguishes between proximate and remote potentiality, and shows that, unlike feline embryos, human embryos, by their genetic constitution, possess the remote potentiality to later exercise the typically human activities. It follows that they are already persons essentially.     

Non-invasive estimation of local field potentials for neuroprosthesis control

Recent experiments have shown the possibility of using the brain electrical activity to directly control the movement of robots or prosthetic devices in real time. Such neuroprostheses can be invasive or non-invasive, depending on how the brain signals are recorded. In principle, invasive approaches will provide a more natural and flexible control of neuroprostheses, but their use in humans is debatable given the inherent medical risks. Non-invasive approaches mainly use scalp electroencephalogram (EEG) signals and their main disadvantage is that these signals represent the noisy spatiotemporal overlapping of activity arising from very diverse brain regions, i.e., a single scalp electrode picks up and mixes the temporal activity of myriads of neurons at very different brain areas. In order to combine the benefits of both approaches, we propose to rely on the non-invasive estimation of local field potentials (LFP) in the whole human brain from the scalp measured EEG data using a recently developed inverse solution (ELECTRA) to the EEG inverse problem. The goal of a linear inverse procedure is to de-convolve or un-mix the scalp signals attributing to each brain area its own temporal activity. To illustrate the advantage of this approach we compare, using an identical set of spectral features, classification of rapid voluntary finger self-tapping with left and right hands based on scalp EEG and non-invasively estimated LFP on two subjects using a different number of electrodes.

From sensory to long-term memory: evidence from auditory memory reactivation studies

Everyday experience tells us that some types of auditory sensory information are retained for long periods of time. For example, we are able to recognize friends by their voice alone or identify the source of familiar noises even years after we last heard the sounds. It is thus somewhat surprising that the results of most studies of auditory sensory memory show that acoustic details, such as the pitch of a tone, fade from memory in ca. 10-15 s. One should, therefore, ask (1) what types of acoustic information can be retained for a longer term, (2) what circumstances allow or help the formation of durable memory records for acoustic details, and (3) how such memory records can be accessed. The present review discusses the results of experiments that used a model of auditory recognition, the auditory memory reactivation paradigm. Results obtained with this paradigm suggest that the brain stores features of individual sounds embedded within representations of acoustic regularities that have been detected for the sound patterns and sequences in which the sounds appeared. Thus, sounds closely linked with their auditory context are more likely to be remembered. The representations of acoustic regularities are automatically activated by matching sounds, enabling object recognition.     

Further examination of the psychometric properties of the comprehensive effects of alcohol questionnaire

Although the expectancies component of the Comprehensive Effects of Alcohol Questionnaire has previously been shown to be factorially valid, the factor structure of its valuations component has not previously been examined. The aims of this paper were: (i) to replicate the factor structure of the expectancies items; (ii) to explore the factor structure of the valuations items; and (iii) to investigate the utility of using the Comprehensive Effects of Alcohol Questionnaire to predict drinking behavior. The questionnaire was administered to 1004 university students along with measures of quantity and frequency of alcohol consumption. Fromme, Stroot, and Kaplan's (1993) factor structure of the expectancies scales was replicated. The factor structures of the negative valuations scales were characterized by 2 rather than 3 factors. Negative expectancies improved upon the prediction of drinking quantity and frequency over-and-above positive expectancies, and valuations further improved prediction over-and-above expectancies. Theoretical and clinical implications are discussed.     

Comprehension of human communicative signs in pet dogs (Canis familiaris).

On the basis of a study by D. J. Povinelli, D. T. Bierschwale, and C. G. Cech (1999), the performance of family dogs (Canis familiaris) was examined in a 2-way food choice task in which 4 types of directional cues were given by the experimenter: pointing and gazing, head-nodding ("at target"), head turning above the correct container ("above target"), and glancing only ("eyes only"). The results showed that the performance of the dogs resembled more closely that of the children in D. J. Povinelli et al.'s study, in contrast to the chimpanzees' performance in the same study. It seems that dogs, like children, interpret the test situation as being a form of communication. The hypothesis is that this similarity is attributable to the social experience and acquired social routines in dogs because they spend more time in close contact with humans than apes do, and as a result dogs are probably more experienced in the recognition of human gestures.     

Attachment behavior of adult dogs (Canis familiaris) living at rescue centers: forming new bonds

In this study, 60 shelter dogs (Canis familiaris) were observed in the modified version of the Strange Situation Test, which has proved to be a useful method for studying dogs' attachment behavior toward humans (J. Topál, A. Miklósi, V. Csányi, & A. Dóka, 1998). Before testing, 40 dogs were handled 3 times for 10 min. In the test, handled dogs encountered 2 persons: the handler in the role of the "owner" (OW) and an unfamiliar person (UP), whereas the 20 nonhandled dogs encountered unfamiliar persons in both roles. Dogs in the handled group exhibited more contact seeking with the entering OW, less physical contact with the UP, less frequent following of the leaving UP, and less standing by the door in the presence of the OW. The specific response of the handled dogs toward the handler fulfilled the operational criteria of attachment. In shelter conditions, the remarkable demand for social contact with humans may result in rather fast forming of attachment even in adult dogs.     

Parallel working memory for spatial location and food-related object cues in foraging pigeons: binocular and lateralized monocular performance

During foraging, animals can increase their success by both remembering feeding sites and remembering food-related object cues. Because earlier studies have tested either the site or object memory in isolation, the aim of the present study was to evaluate how efficiently birds can utilize both memories simultaneously. Furthermore, the idea was tested that lateralization might be the principle of brain organization that allows for efficient parallel processing. Pigeons learned to search for food in a complex maze with 16 baited sites. To obtain the maximum reward they had to perform two tasks in parallel, a spatial working memory task and an object-specific working memory task. Birds performed well on this dual task but, compared with spatial working memory alone, they were impaired during the first choices of a trial (Experiment 1). When the left and the right brain hemispheres were tested separately by means of monocular occlusion (Experiment 2), object discrimination was better when birds used their right eye/left hemisphere. This was most pronounced during the first choices of a trial. On the spatial component of the task, performance on binocular trials was better than on monocular trials, but monocularly both hemispheres performed at the same level. Results show that on this dual task, discrimination of food-related object cues predominantly involved the left brain hemisphere whereas both hemispheres contributed equally to spatial performance.