Sagvolden, Johansen, Aase, and Russell (Sagvolden et al.) examine attention-deficit/hyperactivity disorder (ADHD) at levels of analysis ranging from neurotransmitters to behavior. At the behavioral level they attribute aspects of ADHD to anomalies of delay-of-reinforcement gradients. With a normal gradient, responses followed after a long delay by a reinforcer may share in the effects of that reinforcer; with a diminished or steepened gradient they may fail to do so. Steepened gradients differentially select rapidly emitted responses (hyperactivity), and they limit the (...) effectiveness with which extended stimuli become conditioned reinforcers, so that observing behavior is less well maintained (attention deficit). Impulsiveness also follows from steepened gradients, which increase the effectiveness of smaller, more immediate consequences relative to larger, more delayed ones. Individuals who vary in the degree to which their delay gradients are steepened will show different balances between hyperactivity and attention deficit. Given the range of ADHD phenomena addressed, it may be unnecessary to appeal to additional behavioral processes such as extinction deficit. Extinction deficit is more likely a derivative of attention deficit, in that failure to attend to stimuli differentially correlated with extinction should slow its progress. The account suggests how relatively small differences in delay gradients early in development might engender behavioral interactions leading to very large differences later on. The steepened gradients presumably originate in properties of neurotransmitter function, but behavioral interventions that use consistently short delays of reinforcement to build higher-order behavioral units as a scaffolding to support complex cognitive and social skills may nonetheless be feasible. Key Words: ADHD; attention deficit; delay gradient; exponential decay; extinction deficit; hyperactivity; impulsiveness; intervention; observing responses; self-control. Footnotes1000 Jeffrey Gray was the BBS Editor for this treatment. When he accepted Sagvolden et al. for publication, he invited Catania, who was one of the reviewers of the original submission, to prepare a precommentary. Com-mentators were then invited to respond to the Sagvolden et al. article, to the Catania precommentary, or to both. (shrink)

Attention-deficit/hyperactivity disorder (ADHD) is currently defined as a cognitive/behavioral developmental disorder where all clinical criteria are behavioral. Inattentiveness, overactivity, and impulsiveness are presently regarded as the main clinical symptoms. The dynamic developmental behavioral theory is based on the hypothesis that altered dopaminergic function plays a pivotal role by failing to modulate nondopaminergic (primarily glutamate and GABA) signal transmission appropriately. A hypofunctioning mesolimbic dopamine branch produces altered reinforcement of behavior and deficient extinction of previously reinforced behavior. This gives rise (...) to delay aversion, development of hyperactivity in novel situations, impulsiveness, deficient sustained attention, increased behavioral variability, and failure to “inhibit” responses (“disinhibition”). A hypofunctioning mesocortical dopamine branch will cause attention response deficiencies (deficient orienting responses, impaired saccadic eye movements, and poorer attention responses toward a target) and poor behavioral planning (poor executive functions). A hypofunctioning nigrostriatal dopamine branch will cause impaired modulation of motor functions and deficient nondeclarative habit learning and memory. These impairments will give rise to apparent developmental delay, clumsiness, neurological “soft signs,” and a “failure to inhibit” responses when quick reactions are required. Hypofunctioning dopamine branches represent the main individual predispositions in the present theory. The theory predicts that behavior and symptoms in ADHD result from the interplay between individual predispositions and the surroundings. The exact ADHD symptoms at a particular time in life will vary and be influenced by factors having positive or negative effects on symptom development. Altered or deficient learning and motor functions will produce special needs for optimal parenting and societal styles. Medication will to some degree normalize the underlying dopamine dysfunction and reduce the special needs of these children. The theory describes how individual predispositions interact with these conditions to produce behavioral, emotional, and cognitive effects that can turn into relatively stable behavioral patterns. Key Words: catecholamine; clumsiness; dopamine; hyperkinesis; hyperkinetic disorder; impulsivity; monoamine; neuromodulator; overactivity; pollutants; reinforcement; reward; verbally governed behavior; soft signs; variability. (shrink)

The reinforcement/extinction disorder hypothesis (Sagvolden et al.) is an important counterweight to the executive dysfunction model of attention-deficit/hyperactivity disorder (ADHD). However, like that model, it conceptualises ADHD as pathophysiologically homogeneous, resulting from a common core dysfunction. Recent studies reporting neuropsychological heterogeneity suggest that this common core dysfunction may be the scientific equivalent of a red herring.

The rediscovery of the silver-backed chevrotain, an endemic species to Vietnam, in 2019, after almost 30 years of being lost to science, is a remarkable outcome for the global conservation agenda. However, along with the happiness, there is a tremendous concern for the conservation of the species as eating wildmeat, including chevrotain, is deeply rooted in the socio-cultural values of Vietnamese. Meanwhile, conservation plans face multiple obstacles since the species has not been listed in the list of endangered, precious, and (...) rare wildlife prioritized for protection and is still classified by the IUCN as lacking data. Given the limited effectiveness of conservation measures, this essay discusses the determining roles of local actions, community cooperation, and humanistic values oriented toward eco-surplus culture in addressing the global biodiversity conservation agenda, specifically the conservation of the silver-backed chevrotain. Local actions and community cooperation for conservation can be actualized to achieve conservation goals through citizen and community sciences, integration of modern technologies (e.g., Internet, crowdfunding platforms, social media, AI, etc.), and the bonding capability of humanistic values that prioritize environmental healing. Communicating conservation information to the community, especially the children, has to stimulate their thinking and imagination about nature, develop their curiosity and desire to protect wildlife, and eventually build eco-surplus core values in their mindsets. To successfully awaken the humanistic values within the community and incorporate them into conservation endeavors, the conservation message with the name “mouse-deer”, “chevrotain”, or scientific name (Tragulus versicolor) is largely insufficient as they show an unfamiliar feeling. Therefore, we suggest calling the mouse-deer “cheo cheo”, a local name that can create familiarity and closeness, awaken the environmental conscience and humanistic values, and stimulate thinking and imagination. All these factors are essential for conservationists, scientists, and the government to support the community in building the eco-surplus culture. (shrink)

The dynamic developmental theory (DDT) has benefited from the insights of the commentators, particularly in terms of the implications for the proposed steepened delay gradients in attention-deficit/hyperactivity disorder (ADHD). The introduction of modified memory processes as a basis for the delay gradients improved the links to aspects of ADHD. However, it remains unclear whether the hyperactive-impulsive and inattentive subtypes are separate subgroups or may be explained as different outcomes of the same genetic factors and thus explicable by the same (...) principles. The DDT suggests that altered reinforcement and extinction processes define an endophenotype in ADHD that can be related dimensionally to inattention, hyperactivity, and impulsivity. The relation between the suggested endophenotype, characterized by changes in basic learning mechanisms, and other endophenotypes characterized by delay aversion or response disinhibition, needs to be tested in future studies. (shrink)

Political actions by Fridays for Future, Extinction Rebellion, and other climate activists often involve violations of legal regulations – such as compulsory education requirements or traffic laws – and have been criticized for this in the public sphere. In this essay, I defend the view that these violations of the law constitute a form of morally justified civil disobedience against climate policies. I first show that these actions satisfy the criteria of civil disobedience even on relatively strict conceptions of (...) civil disobedience. I then argue that they meet plausible justification conditions for civil disobedience because they are directed against serious and clear injustices, which legal means of influence have failed to remedy for decades. Finally, I reject the objection that civil disobedience against climate policy violates basic democratic principles because it claims authority to override democratically enacted agreements. When addressed to Fridays for Future activists, the objection misfires for the reason alone that these activists are largely minors that are excluded from democratic participation. Moreover, disobedience even by adult activists is justified by the existence of serious democratic deficits in our climate policies, especially since it can help to correct them. Such deficits include the lack of representation of the interests of people affected by climate change in the future and globally. (shrink)

People’s awareness of tactile stimuli has been investigated in far less detail than their awareness of stimuli in other sensory modalities. In an attempt to fill this gap, we provide an overview of studies that are pertinent to the topic of tactile consciousness. We discuss the results of research that has investigated phenomena such as “change blindness”, phantom limb sensations, and numerosity judgments in tactile perception, together with the results obtained from the study of patients affected by deficits that can (...) adversely affect tactile perception such as neglect, extinction, and numbsense. The similarities as well as some of the important differences that have emerged when visual and tactile conscious information processing have been compared using similar experimental procedures are highlighted. We suggest that conscious information processing in the tactile modality cannot be separated completely from the more general processing of spatial information in the brain. Finally, the importance of considering tactile consciousness within the larger framework of multisensory information processing is also discussed. (shrink)

As mounting evidence highlights the human-driven extinction of avian species, reconnecting people with nature—particularly these feathered creatures—has become essential for engaging the public in conservation and the preservation of avian biodiversity. Paradoxically, heightened awareness of the benefits birds bring has fueled the rise of aviary bird-keeping for entertainment in Vietnam. This paper seeks to unravel the absurdity of bird keepers who claim to love nature and support conservation while engaging in practices that exploit and commodify birds for human interests. (...) By contrasting the values generated by birds in aviaries with those in their natural habitats, it underscores the role of an eco-deficit culture—or, more fundamentally, humanity's insatiable greed—in fostering this absurd form of "nature love.". (shrink)

Encoding sensory events entails processing of several physical attributes. Is the processing of any of these attributes a pre-requisite of conscious awareness? This selective review examines a recent set of behavioral and event-related potentials, studies conducted in patients with visual and auditory unilateral neglect or extinction, with the aim of establishing what aspects of initial processing are impaired in these patients. These studies suggest that extinguished visual stimuli excite the sensory cortices, but perhaps to a lesser degree than acknowledged (...) stimuli do. However, encoding spatial attributes of auditory and visual stimuli appear to be preferentially impaired. In light of results from patients with other neuro-behavioral deficits, it is argued that egocentric spatial information is an essential pre-requisite for knowing that an external event occurred. In contrast, information handled by mostly domain-specific circuits, such as in the ventral temporal lobe, supports awareness of the identity of a stimulus, but not of its mere presence. Without spatial information, the stimulus identity will remain implicit. (shrink)

The “dynamic developmental” theory of attention-deficit/hyperactivity disorder (ADHD) has come full circle from Wender's (1971) reinforcement hypothesis. By specifying the principle of time constraints on reinforcement and extinction, the present theory allows for empirical validation. However, the theory implies, but does not discuss, implications for the neurophysiology of comorbidity in ADHD. The authors' attribution of comorbid oppositional behavior to parental and societal reinforcement leaves out biological factors.

In the target article, Sagvolden and collaborators propose that attentional-deficit/hyperactivity disorder (ADHD) is the result of a general behavioral deficit which is mainly caused by a hypofunctioning mesolimbic dopaminergic system. Although we partly agree with this view, we think that it tends to overlook the dysfunction of prefrontal and frontostriatal executive functions by considering them to be a consequence of alterations in reward and extinction mechanisms. Rather, we believe that ADHD is the result of an overall cognitive (...) and behavioral condition, associated to a generalized dopaminergic network dysfunction, and may not be easily attributable to a single basic behavioral function. (shrink)

Major contributions emanating from Sagvolden et al.'s theory include elucidation of the role in attention-deficit/hyperactivity disorder (ADHD) of temporal information processing, social learning, and response extinction learning. Key issues include a need for clearer explanation of the relative role of impulsivity versus response suppression/inhibition in the dual process model, and delineation of genotype-environment correlations versus interactions in the social and experiential mechanisms posited.

Derived from a rat model, the theory of Sagvolden et al. offers an all-explanatory model of attention-deficit/hyperactivity disorder (ADHD) anatomy, behaviour, and cognition as being caused predominantly by a hypo-dopaminergic mesolimbic (affecting the mesocortical and nigrostriatal) system, leading to abnormal reward and extinction processes. This model suffers from oversimplification and reductionism, reflecting the limitations of the use of animal models to explain higher mental disorders.

Individuals with anxiety disorders show deficits in the discrimination between a cue that predicts an aversive outcome and a safe stimulus that predicts the absence of that outcome. This impairment has been linked to increased spontaneous recovery of fear following extinction, however it is unknown if there is a link between discrimination and return of fear in a novel context. It is also unknown if impaired discrimination mediates the relationship between trait anxiety and either spontaneous recovery or context renewal. (...) The present study used a differential fear conditioning paradigm to examine the relationships between trait anxiety, discrimination learning, spontaneous recovery and context renewal in healthy volunteers. Fear learning was assessed using continuous ratings of US expectancy and subjective ratings of fear. Discrimination mediated the relationships between trait anxiety and both spontaneous recovery and context renewal such that elevated trait anxiety was associated with poorer discrimination, which in turn was associated with increased fear at test phases. Results are discussed in terms of the genesis and maintenance of anxiety disorders. (shrink)

Early and automatic neuropsychological processes may be influenced by altered dopaminergic functions but cannot be fully explained by these or by altered reinforcement and extinction processes. The reinforcement-extinction model is excellent for understanding certain causal pathways of attention-deficit/hyperactivity disorder, but it can hardly explain the heterogeneous developmental trajectories of ADHD fully. It should be integrated into a multiple pathways model.

Ritalin use has increased by 500 percent in the last five years. The reasons for this dramatic surge are rooted in changes and pressures in psychiatry and society at large.

This article presents qualitative interview data to explore the health-related carework of low-income women caregivers with special-needs children and the implications of carework for women’s financial security. The author documents “direct” and “advocacy” carework as two types of caregiving that low-income women carry out in the context of declining government resources for poor disabled children. The author shows that the unique demands of carework responsibilities and the conditions of low-wage work combine to limit caregivers’ employment and education options as well (...) as their long-term prospects for financial stability. (shrink)

The accounts of social freedom offered by G. W. F. Hegel and Axel Honneth identify the normative demands on social institutions and explain how individual freedom is realized through rational participation in such institutions. While both offer normative reconstructions of the market economy, public sphere and family, they both derive the norms of educational institutions from education’s role in preparing people for participation in other institutions. We argue that this represents a significant defect in their accounts of social freedom because (...) they both fail to account for the distinctive aims and norms of education. Only educational institutions bring individuals into a both shared and autonomous standpoint necessary for participation in social life. We thus argue both that Hegel’s and Honneth’s accounts are empirically inadequate and that they neglect the normative demands on schools to contribute to individual moral and intellectual development. (shrink)

Este estudio reflexiona sobre la hipótesis de que la crisis del discurso político en las sociedades latinoamericanas ha provocado un repliegue de los ciudadanos hacia las representaciones de los medios, que han instaurado nuevas modalidades interpretativas sobre los principales problemas sociales..

The comprehension problem in Broca's patients does not stem from an inability to represent argument traces. There can be good comprehension in the presence of (object) traces and impaired comprehension can result in constructions where there are no (object) argument traces. This leads to an alternative understanding of Broca's comprehension, one that places the locus of the impairment in an inability to construct syntactic representation on time.

Eye movements during false-belief tasks can reveal an individual's capacity to implicitly monitor others' mental states (theory of mind - ToM). It has been suggested, based on the results of a single-trial-experiment, that this ability is impaired in those with a high-functioning autism spectrum disorder (ASD), despite neurotypical-like performance on explicit ToM measures. However, given there are known attention differences and visual hypersensitivities in ASD it is important to establish whether such impairments are evident over time. In addition, investigating implicit (...) ToM using a repeated trial approach allows an assessment of whether learning processes can reduce the ASD impairment in this ability, as is the case with explicit ToM. Here we investigated the temporal profile of implicit ToM in individuals with ASD and a control group. Despite similar performance on explicit ToM measures, ASD-diagnosed individuals showed no evidence of implicit false-belief tracking even over a one-hour period and many trials, whereas control participants did. These findings demonstrate that the systems involved in implicit and explicit ToM are distinct and hint that impaired implicit false-belief tracking may play an important role in ASD. Further, they indicate that learning processes do not alleviate this impairment across the presentation of multiple trials. (shrink)

We describe a significant practical consequence of taking anthropic biases into account in deriving predictions for rare stochastic catastrophic events. The risks associated with catastrophes such as asteroidal/cometary impacts, supervolcanic episodes, and explosions of supernovae/gamma-ray bursts are based on their observed frequencies. As a result, the frequencies of catastrophes that destroy or are otherwise incompatible with the existence of observers are systematically underestimated. We describe the consequences of the anthropic bias for estimation of catastrophic risks, and suggest some directions for (...) future work. (shrink)

Humans have slowly built more productive societies by slowly acquiring various kinds of capital, and by carefully matching them to each other. Because disruptions can disturb this careful matching, and discourage social coordination, large disruptions can cause a “social collapse,” i.e., a reduction in productivity out of proportion to the disruption. For many types of disasters, severity seems to follow a power law distribution. For some of types, such as wars and earthquakes, most of the expected harm is predicted to (...) occur in extreme events, which kill most people on Earth. So if we are willing to worry about any war or earthquake, we should worry especially about extreme versions. If individuals varied little in their resistance to such disruptions, events a little stronger than extreme ones would eliminate humanity, and our only hope would be to prevent such events. If individuals vary a lot in their resistance, however, then it may pay to increase the variance in such resistance, such as by creating special sanctuaries from which the few remaining humans could rebuild society. (shrink)