Face processing in different brain areas,and critical band masking

Neurophysiological evidence is described showing that some neurons in the macaque inferior temporal visual cortex have responses that are invariant with respect to the position, size, view, and spatial frequency of faces and objects, and that these neurons show rapid processing and rapid learning. Critical band spatial frequency masking is shown to be a property of these face‐selective neurons and of the human visual perception of faces. Which face or object is present is encoded using a distributed representation in which each neuron conveys independent information in its firing rate, with little information evident in the relative time of firing of different neurons. This ensemble encoding has the advantages of maximizing the information in the representation useful for discrimination between stimuli using a simple weighted sum of the neuronal firing by the receiving neurons, generalization, and graceful degradation. These invariant representations are ideally suited to provide the inputs to brain regions such as the orbitofrontal cortex and amygdala that learn the reinforcement associations of an individual's face, for then the learning, and the appropriate social and emotional responses generalize to other views of the same face. A theory is described of how such invariant representations may be produced by self‐organizing learning in a hierarchically organized set of visual cortical areas with convergent connectivity. The theory utilizes either temporal or spatial continuity with an associative synaptic modification rule. Another population of neurons in the cortex in the superior temporal sulcus encodes other aspects of faces such as face expression, eye‐gaze, face view, and whether the head is moving. These neurons thus provide important additional inputs to parts of the brain such as the orbitofrontal cortex and amygdala that are involved in social communication and emotional behaviour. Outputs of these systems reach the amygdala, in which face‐selective neurons are found, and also the orbitofrontal cortex, in which some neurons are tuned to face identity and others to face expression. In humans, activation of the orbitofrontal cortex is found when a change of face expression acts as a social signal that behaviour should change; and damage to the human orbitofrontal and pregenual cingulate cortex can impair face and voice expression identification, and also the reversal of emotional behaviour that normally occurs when reinforcers are reversed.     

Inattention/Overactivity Following Early Severe Institutional Deprivation: Presentation and Associations in Early Adolescence

The current study examined the persistence and phenotypic presentation of inattention/overactivity (I/O) into early adolescence, in a sample of institution reared (IR) children adopted from Romania before the age of 43 months. Total sample comprised 144 IR and 21 non-IR Romanian adoptees, and a comparison group of 52 within-UK adoptees, assessed at ages 6 and 11 years. I/O was rated using Rutter Scales completed by parents and teachers. I/O continued to be strongly associated with institutional deprivation, with continuities between ages 6 and 11 outcomes. There were higher rates of deprivation-related I/O in boys than girls, and I/O was strongly associated with conduct problems, disinhibited attachment and executive function but not IQ more generally, independently of gender. Deprivation-related I/O shares many common features with ADHD, despite its different etiology and putative developmental mechanisms. I/O is a persistent domain of impairment following early institutional deprivation of 6 months or more, suggesting there may be a possible pathway to impairment through some form of neuro-developmental programming during critical periods of early development.     

Do Theory of Mind and Executive Function Deficits Underlie the Adverse Outcomes Associated with Profound Early Deprivation?: Findings from the English and Romanian Adoptees Study

Theory of Mind (ToM) and Executive Function (EF) have been associated with autism and with attention-deficit hyperactivity disorder (ADHD), and hence might play a role in similar syndromes found following profound early institutional deprivation. In order to examine this possibility the current study included a group of 165 Romanian adoptees, of whom 144 were adopted into the UK from deprived institutional settings before 43months of age, and a group of 52 within-UK adoptees, all adopted before 6months of age. Both groups were assessed at 6 and 11years. The Strange Stories task was used to assess ToM and the Stroop task was used to assess EF, both at age 11. The Romanian adoptees displayed deficits in both ToM and EF compared with the within-UK adoptee group. The degree of deficit was greater for children who had experienced more than 6months of institutional deprivation. Deficits in both domains (ToM and EF) were associated with each of the three apparently deprivation-specific problems, namely quasi-autism, disinhibited attachment and inattention/overactivity. Statistical analyses indicated a mediating role for both ToM and EF with respect to quasi-autism; possibly a partial mediating role for EF with respect to inattention/overactivity; and probably no mediating role for either ToM or EF in the case of disinhibited attachment. In conclusion, there is evidence for a possible mediating role for ToM and EF in the development of some apparently deprivation-specific difficulties in institution-reared Romanian adoptees, but neither accounts for the overall pattern of deprivation-related difficulties.     

Anxiety sensitivity, conscious awareness and selective attentional biases in children

The current study investigated whether physical anxiety sensitivity (AS) is associated with selective attentional biases to affective stimuli in children. The dot-probe paradigm was used to examine the deployment of attention towards words pertaining to anxiety symptomatology, socially threatening words, and positive words, in samples of 8-10-year-old children. Word pairs were presented under both masked and unmasked conditions. Irrespective of masking, children high in physical AS displayed an attentional vigilance for emotional words relative to neutral words, whereas those low in physical AS displayed a relative avoidance of such material. The results of this study are interesting as they not only suggest the presence of automatic AS-related biases in childhood, but that this is a general emotionality bias rather than one related to specific anxiety-related stimuli.     

Is Genuine Satisficing Rational?

There have been different interpretations of satisficing rationality. A common view is that it is sometimes rationally permitted to choose an option one judges is good enough even when one does not know that it is the best option. But there is available a more radical view of satisficing. On this view, it is rationally permitted to choose an option one judges is good enough even when a better option is known to be available. In this paper I distinguish between two possible interpretations of ‘genuine’ satisficing, a de re and a de dicto interpretation. I then argue that while de re genuine satisficing is always irrational, de dicto genuine satisficing might be rationally permissible. In fact, de dicto genuine satisficing does not appear to be covered by existing accounts of satisficing behaviour.

Effects of required rates of responding upon choice

Pigeons' responses in the presence of two concurrently available (initial-link) stimuli produced one of two different (terminal-link) stimuli according to identical but independent variable-interval schedules. Responses in the presence of each terminal-link stimulus produced equal frequencies of food reinforcement, but in the presence of one of the stimuli, food depended upon the emission of a response rate either higher or lower than a specified value (differential reinforcement of rates). The measure of preference, the dependent variable, was the distribution of responses in the presence of the concurrently available stimuli of the initial links. Each pigeon, the responding of which was appropriately controlled by the response-rate requirements in the two terminal-link stimuli, consistently preferred the stimulus not associated with a response-rate requirement.     

The origins and evolution of bioethics: some personal reflections

Bioethics was officially baptized in 1972, but its birth took place a decade or so before that date. Since its birth, what is known today as bioethics has undergone a complex conceptual metamorphosis. This essay loosely divides that metamorphosis into three stages: an educational, an ethical, and a global stage. In the educational era, bioethics focused on a perceived "dehumanization" of medicine by the rising power of science and technology. Remedies were sought by introducing humanities, ethics, and human "values" into the medical curriculum. Ethics was one among the humanistic disciplines, but not the dominant one. In the second era, ethics assumed a dominant role as ever more complex dilemmas emerged from the rapid pace of biological research. As such dilemmas were applied to medical practice, the need for a more rigorous and more formal analysis of their moral status was clear. Philosophically-trained ethicists had an obvious role. They began to teach, write, and profoundly influence medical education and practice. In the third -- and present -- period, the breadth of problems has become so broad that ethicists must, themselves, draw on disciplines well beyond their expertise -- e.g., law, religion, anthropology, economics, political science, psychology, and the like. The era of bioethics as a global enterprise is upon us. The original hope for humanizing medicine has not been overtly successful; however, much has been accomplished of value to patients, the profession, and society. Medical morality has been transformed into a formal, systematic study of a whole range of issues of the greatest significance to humanity. Now the major challenge is one of identity, or inter-relationships and connections between the theoretical and the practical. Bioethics has outgrown its beginnings.