The confabulation battery: Instructions and international data from normal participants.

Confabulation is an unusual sign in neurological and in neuropsychological pathologies. In this article we present an objective neuropsychological instrument, the Confabulation Battery (CB), which allows the quantifying and qualifying of different types of confabulations. The CB was administered to French and Italian normal participants. Data from the present study will allow clinicians and researchers, using the CB, to know how much and in which memory domains their confabulating patients confabulate compared to normal participants. We present international data, instructions and guidelines for the CB, a tool used in different ways worldwide. Not quantifying confabulations, namely not reporting how much and in which domain patients confabulate, can hardly lead to conclusions on the neurocognitive bases of this phenomenon. Following the instructions in this article, versions of the CB can be adapted in different languages and cultures. Quantification and qualification of confabulation is necessary and demanded in order to compare sensibly data from different research and clinical groups.

Different patterns of confabulation in left visuo-spatial neglect.

Confabulating patients produce statements and actions that are unintentionally incongruous to their history, background, present and future situation. Here we present the very unusual case of a patient with right hemisphere damage and signs of left visual neglect, who, when presented with visual stimuli, confabulated both for consciously undetected and for consciously detected left-sided details. Advanced anatomical investigation suggested a disconnection between the parietal and the temporal lobes in the right hemisphere. A disconnection between the ventral cortical visual stream and the dorsal fronto-parietal networks in the right hemisphere may contribute to confabulatory behaviour by restricting processing of left-sided stimuli to pre-conscious stages in the ventral visual stream.

A longitudinal study of confabulation.

Confabulation, the production of statements and actions that are unintentionally incongruous to the subject's history, background, present and future situation, is a rather infrequent disorder, observed in several conditions affecting the nervous system. Little is known about the quantitative and qualitative evolution of confabulation in time. In this study we evaluated longitudinally the evolution of this disorder in a group of severe confabulators, using the Confabulation Battery (CB), a sensitive tool to detect confabulations in various memory domains. It was found that confabulations were stable over time and not temporally limited. It was also found that "Habits Confabulations" (HCs), i.e., habits and repeated personal events mistaken as specific, unique past and future personal episodes, or well-known public events when semantic knowledge is concerned, was the more frequently observed type of confabulation. Confabulations were also more prominent in the domain of Temporal Consciousness (TC), i.e., a specific form of consciousness that allows individuals to remember their personal past, to be oriented in their present world and to predict their personal future, than in Knowing Consciousness (KC), i.e., a specific form of consciousness allowing individuals to be aware of past, present and future impersonal knowledge and information. Confabulations showed also persistence, i.e., confabulations at the same questions over time, and consistency, i.e., same type of confabulation at the same question over time. These findings are discussed within the framework of the Memory, Consciousness and Temporality Theory.

Recovery from confabulation after normotensive hydrocephalus shunting.

Confabulation, the production of statements and actions that are unintentionally incongruous to the subject's history, background, present and future situation, is observed in several conditions affecting the nervous system, but it has never been described in normotensive hydrocephalus. In this article we report on a patient with normotensive hydrocephalus who suffered from an amnesic-confabulatory syndrome. After hydrocephalus shunting, both amnesia and confabulation cleared up abruptly. We discuss this finding in terms of a possible disconnection of the hippocampus, due to transitory white matter damage, which may have recovered after hydrocephalus shunting.

Impact of time-limited feeding and dietary carbohydrate content on weight loss in group-housed cats.

Twenty-four adult cats were transitioned to time-limited feeding and randomized to either a dry low carbohydrate diet (LC) or a dry reduced energy diet (HC). In Trial 1 the LC and HC groups received equal amounts of food (by weight) for 13 weeks. Both groups consumed all food offered, hence the LC group received more energy/day than the HC group. In Trial 2 all cats were fed the LC diet for 12 weeks, but each group received the energy that the opposite group had received in Trial 1. In Trial 1 only the overweight HC cats (body condition score> 6/9) experienced a significant change in body weight (-0.52 +/- 0.08 kg). In Trial 2, LC/Low Calorie overweight cats lost 0.62 +/- 0.10 kg, whereas, the LC/High Calorie normal weight cats gained 0.68 +/- 0.05 kg. In conclusion, body condition and energy intake but not type of diet influenced weight in this cohort of group-housed cats.

Effect of transcranial magnetic stimulation (TMS) on parietal and premotor cortex during planning of reaching movements.

BACKGROUND: Cerebral activation during planning of reaching movements occurs both in the superior parietal lobule (SPL) and premotor cortex (PM), and their activation seems to take place in parallel. METHODOLOGY: The activation of the SPL and PM has been investigated using transcranial magnetic stimulation (TMS) during planning of reaching movements under visual guidance. PRINCIPAL FINDINGS: A facilitory effect was found when TMS was delivered on the parietal cortex at about half of the time from sight of the target to hand movement, independently of target location in space. Furthermore, at the same stimulation time, a similar facilitory effect was found in PM, which is probably related to movement preparation. CONCLUSIONS: This data contributes to the understanding of cortical dynamics in the parieto-frontal network, and suggests that it is possible to interfere with the planning of reaching movements at different cortical points within a particular time window. Since similar effects may be produced at similar times on both the SPL and PM, parallel processing of visuomotor information is likely to take place in these regions.