Association between psychotropic drug prescription and suicide rates in Scotland: population study.

AIMS AND METHOD: Rates of prescriptions of antidepressants and suicide are inversely correlated at an epidemiological level. Less attention has been paid to relationships between other drugs used in mental health and suicide rates. Here we tested relationships between prescriptions of anxiolytics and antipsychotics and suicide rates in Scotland. RESULTS: Suicide rates were inversely correlated with prescriptions of antidepressants and antipsychotics over 14 years (2004-2018), and positively with prescriptions of anxiolytics. CLINICAL IMPLICATIONS: This illustrates the role of medications used in mental health in suicide prevention, and highlights the importance of identifying causal mechanisms that link anxiolytics with suicide.

Auditory Verbal Experience and Agency in Waking, Sleep Onset, REM, and Non-REM Sleep.

We present one of the first quantitative studies on auditory verbal experiences ("hearing voices") and auditory verbal agency (inner speech, and specifically "talking to (imaginary) voices or characters") in healthy participants across states of consciousness. Tools of quantitative linguistic analysis were used to measure participants' implicit knowledge of auditory verbal experiences (VE) and auditory verbal agencies (VA), displayed in mentation reports from four different states. Analysis was conducted on a total of 569 mentation reports from rapid eye movement (REM) sleep, non-REM sleep, sleep onset, and waking. Physiology was controlled with the nightcap sleep-wake mentation monitoring system. Sleep-onset hallucinations, traditionally at the focus of scientific attention on auditory verbal hallucinations, showed the lowest degree of VE and VA, whereas REM sleep showed the highest degrees. Degrees of different linguistic-pragmatic aspects of VE and VA likewise depend on the physiological states. The quantity and pragmatics of VE and VA are a function of the physiologically distinct state of consciousness in which they are conceived.

Transcranial direct current stimulation of the motor cortex in waking resting state induces motor imagery.

This study investigates if anodal and cathodal transcranial direct current stimulation (tDCS) of areas above the motor cortex (C3) influences spontaneous motor imagery experienced in the waking resting state. A randomized triple-blinded design was used, combining neurophysiological techniques with tools of quantitative mentation report analysis from cognitive linguistics. The results indicate that while spontaneous motor imagery rarely occurs under sham stimulation, general and athletic motor imagery (classified as athletic disciplines), is induced by anodal tDCS. This insight may have implications beyond basic consciousness research. Motor imagery and corresponding motor cortical activation have been shown to benefit later motor performance. Electrophysiological manipulations of motor imagery could in the long run be used for rehabilitative tDCS protocols benefitting temporarily immobile clinical patients who cannot perform specific motor imagery tasks - such as dementia patients, infants with developmental and motor disorders, and coma patients.

The role of functional and perceptual attributes: evidence from picture naming in dementia.

We examined the performance of a group of people with moderately severe Alzheimer's type dementia on a naming task. We found that functional information plays an important role in determining naming performance on both living and non-living things. Perceptual information may play some role in naming living things. We also found some evidence that the semantic category to which an item belongs may also have some effect on naming performance. We argue that both the sensory-functional and domain-specific knowledge hypotheses may be correct: the brain is to some organized on taxonomic grounds, while the semantic representations of living and non-living things depend differentially on perceptual and functional information. These representations can be differentially disrupted by damage to modality-specific stores. At a moderate level of severity, dementia causes global damage that has the effect of disrupting both the localized taxonomic and the modality-specific stores. We discuss the nature of functional information.

Does Cognitive Neuropsychology have a future?

Reflections stimulated by Rapp, B. (Ed.) (2001). 'The handbook of cognitive neuropsychology: What deficits reveal about the human mind'. Philadelphia: Psychology Press.

Promises, promises.

In the target article I argued that cognitive neuropsychologists have increasingly deviated from the original goals and methods of the subject. In this reply to the commentators, I argue that future progress using neuropsychological approaches to understanding behaviour is most likely to be made by the use of converging sources of evidence that are garnered by an interdisciplinary methodology. Neuroimaging data may have a role to play in such an enterprise, but are unlikely to be prominent in cognitive psychological theorisation in isolation.

Accessing semantic knowledge in dementia: evidence from a word definition task.

We examine production of word definitions by people with probable Alzheimer's disease (pAD). In the first experiment, healthy young adults defined concrete, imageable nouns to provide a baseline of definitional ability. Analysis of these definitions identified the key defining features of each target item. In the second experiment, pAD participants and elderly controls produced definitions of the same items. In the third experiment, healthy young participants rated the adequacies of these definitions. Although as expected the pAD participants produced fewer good definitions than the other two groups, most of their responses still contained some relevant information. pAD definitions contained fewer pieces of information and the information they produced was more tangential to the primary concept than that provided by the young or elderly participants. We identify two possible explanations in semantic loss and metalinguistic impairment. We consider metalinguistic impairment to provide the more plausible explanation of pAD patients' definitional performance.