problems in addition to the signs of the Wernicke-Korsakoff syndrome. Many of the patients were closely examined over long periods and the authors make the point that repeated examinations for as long as ten years in some instances allowed them to describe the natural history of the syndrome. and this they do in their third chapter. Again the description of the pathological findings is precise and comprehensive and the authors stress the periventricular distribution of the lesions and their bilateral symmetry. The authors consider specifically the neuropathological substrate on which are based the defective memory, ocular motor signs, the ataxia, the global confusional state and the occasional disturbance of olfactory and gustatory function. They argue a unity between Wernicke's disease and Korsakoff's psychosis and discuss the relationship between these two and alcoholic cerebellar degeneration, central pontine myelinolysis and other myelinolytic syndromes and interestingly discuss the problem of \"alcoholic dementia\" concluding that the nosological status ofalcoholic dementia is by

https://jnnp.bmj.com/content/jnnp/52/10/1218.2.full.pdf

Neuropsychology Mental Structure

In adult life, people normally know what they are doing. This experience of controlling one's own actions and, through them, the course of events in the outside world is called 'sense of agency'. It forms a central feature of human experience; however, the brain mechanisms that produce the sense of agency have only recently begun to be investigated systematically. This recent progress has been driven by the development of better measures of the experience of agency, improved design of cognitive and behavioural experiments, and a growing understanding of the brain circuits that generate this distinctive but elusive experience. The sense of agency is a mental and neural state of cardinal importance in human civilization, because it is frequently altered in psychopathology and because it underpins the concept of responsibility in human societies.

Sense of agency in the human brain

Ability in various cognitive domains is often assessed by measuring task performance, such as the accuracy of a perceptual categorization. A similar analysis can be applied to metacognitive reports about a task to quantify the degree to which an individual is aware of his or her success or failure. Here, we review the psychological and neural underpinnings of metacognitive accuracy, drawing on research in memory and decision-making. These data show that metacognitive accuracy is dissociable from task performance and varies across individuals. Convergent evidence indicates that the function of the rostral and dorsal aspect of the lateral prefrontal cortex (PFC) is important for the accuracy of retrospective judgements of performance. In contrast, prospective judgements of performance may depend upon medial PFC. We close with a discussion of how metacognitive processes relate to concepts of cognitive control, and propose a neural synthesis in which dorsolateral and anterior prefrontal cortical subregions interact with interoceptive cortices (cingulate and insula) to promote accurate judgements of performance.

/pdf/the-neural-basis-of-metacognitive-ability-dfqq4zhu2r.pdf

The Neural Basis of Metacognitive Ability

The theory of event coding (TEC) is a general framework explaining how perceived and produced events (stimuli and responses) are cognitively represented and how their representations interact to generate perception and action. This article discusses the implications of TEC for understanding the control of voluntary action and makes an attempt to apply, specify, and concretize the basic theoretical ideas in the light of the available research on action control. In particular, it is argued that the major control operations may take place long before a stimulus is encountered (the prepared-reflex principle), that stimulus-response translation may be more automatic than commonly thought, that action selection and execution are more interwoven than most approaches allow, and that the acquisition of action-contingent events (action effects) is likely to subserve both the selection and the evaluation of actions.

/pdf/action-control-according-to-tec-theory-of-event-coding-2h7u71dgzo.pdf

Action control according to TEC (theory of event coding)

The authors theorize that 2 neurocognitive sequence-learning systems can be distinguished in serial reaction time experiments, one dorsal (parietal and supplementary motor cortex) and the other ventral (temporal and lateral prefrontal cortex). Dorsal system learning is implicit and associates noncategorized stimuli within dimensional modules. Ventral system learning can be implicit or explicit It also allows associating events across dimensions and therefore is the basis of cross-task integration or interference, depending on degree of cross-task correlation of signals. Accordingly, lack of correlation rather than limited capacity is responsible for dual-task effects on learning. The theory is relevant to issues of attentional effects on learning; the representational basis of complex, sequential skills; hippocampal-versus basal ganglia-based learning; procedural versus declarative memory; and implicit versus explicit memory.

/pdf/the-cognitive-and-neural-architecture-of-sequence-5byln9idcx.pdf

The cognitive and neural architecture of sequence representation.

Subliminal priming of actions influences sense of control over effects of action

The feeling of controlling events through one's actions is fundamental to human experience, but its neural basis remains unclear. This 'sense of agency' (SoA) can be measured quantitatively as a temporal linkage between voluntary actions and their external effects. We investigated the brain areas underlying this aspect of action awareness by using theta-burst stimulation to locally and reversibly disrupt human brain function. Disruption of the pre-supplementary motor area (pre-SMA), a key structure for preparation and initiation of a voluntary action, was shown to reduce the temporal linkage between a voluntary key-press action and a subsequent electrocutaneous stimulus. In contrast, disruption of the sensorimotor cortex, which processes signals more directly related to action execution and sensory feedback, had no significant effect. Our results provide the first direct evidence of a pre-SMA contribution to SoA.

/pdf/disrupting-the-experience-of-control-in-the-human-brain-pre-5xe5bk40i1.pdf

Disrupting the experience of control in the human brain: pre-supplementary motor area contributes to the sense of agency

"Sense of agency" refers to the feeling of controlling an external event through one's own action. On one influential view, sense of agency is inferred after an action, by "retrospectively" comparing actual effects of actions against their intended effects. In contrast, a "prospective" component of agency, generated during action selection, and in advance of knowing the actual effect, has received less attention. Here, we used functional magnetic resonance imaging to investigate prospective contributions of action selection processes to sense of agency. To do so, we dissociated action selection processes from action-outcome matching, by subliminally priming responses to a target. We found that participants experienced greater control over action effects when the action was compatibly versus incompatibly primed. Thus, compatible primes facilitated action selection processing, in turn boosting sense of agency over a subsequent effect. This prospective contribution of action selection processes to sense of agency was accounted for by exchange of signals across a prefrontal-parietal network. Specifically, we found that the angular gyrus (AG) monitors signals relating to action selection in dorsolateral prefrontal cortex, to prospectively inform subjective judgments of control over action outcomes. Online monitoring of these signals by AG might provide the subject with a subjective marker of volition, prior to action itself.

http://www.summer12.isc.uqam.ca/page/docs/readings/Haggard-Patrick/An%20online%20neural%20substrate%20for%20sense%20of%20agency.pdf

An Online Neural Substrate for Sense of Agency

When sharing a task with another person that requires turn taking, as in doubles games of table tennis, performance on the shared task is similar to performing the whole task alone. This has been taken to indicate that humans co-represent their partner’s task share, as if it were their own. Task co-representation allows prediction of the other’s responses when it is the other’s turn, and leads to response conflict in joint interference tasks. However, data from our lab cast doubt on the view that task co-representation and resulting response conflict are the only or even primary source of effects observed in task sharing. Recent findings furthermore suggest another potential source of interference in joint task performance that has been neglected so far: Self-other discrimination and conflict related to agent identification (i.e., determining whether it is “my” or the other’s turn). Based on these findings we propose that participants might not always co-represent what their partner is supposed to do, but instead co-represent that another agent is responsible for part of the task, and when it is his turn. We call this account the actor co-representation account.

What is shared in joint action? Issues of co-representation, response conflict, and agent identification

Distortions of time perception are generally explained either by variations in the rate of pacing signals of an "internal clock", or by lag-adaptation mechanisms that recalibrate the perceived time of one event relative to another. This study compares these accounts directly for one temporal illusion: the subjective compression of the interval between voluntary actions and their effects, known as 'intentional binding'. Participants discriminated whether two cutaneous stimuli presented after voluntary or passive movements were simultaneous or successive. In other trials, they judged the temporal interval between their movement and an ensuing tone. Temporal discrimination was impaired following voluntary movements compared to passive movements early in the action-tone interval. In a control experiment, active movements without subsequent tones produced no impairment in temporal discrimination. These results suggest that voluntary actions transiently slow down an internal clock during the action-effect interval. This in turn leads to intentional binding, and links the effects of voluntary actions to the self.

/pdf/how-voluntary-actions-modulate-time-perception-1drti391il.pdf

Dorit Wenke

Papers

Subliminal priming of actions influences sense of control over effects of action

Disrupting the experience of control in the human brain: pre-supplementary motor area contributes to the sense of agency

An Online Neural Substrate for Sense of Agency

What is shared in joint action? Issues of co-representation, response conflict, and agent identification

How voluntary actions modulate time perception.