Prototype-distortion category learning: a two-phase learning process across a distributed network

This paper reviews a body of work conducted in our laboratory that applies functional magnetic resonance imaging (fMRI) to better understand the biological response and change that occurs during prototype-distortion learning. We review results from two experiments (Little, Klein, Shobat, McClure, & Thulborn, 2004; Little & Thulborn, 2005) that provide support for increasing neuronal efficiency by way of a two-stage model that includes an initial period of recruitment of tissue across a distributed network that is followed by a period of increasing specialization with decreasing volume across the same network. Across the two studies, participants learned to classify patterns of random-dot distortions (Posner & Keele, 1968) into categories. At four points across this learning process subjects underwent examination by fMRI using a category-matching task. A large-scale network, altered across the protocol, was identified to include the frontal eye fields, both inferior and superior parietal lobules, and visual cortex. As behavioral performance increased, the volume of activation within these regions first increased and later in the protocol decreased. Based on our review of this work we propose that: (i) category learning is reflected as specialization of the same network initially implicated to complete the novel task, and (ii) this network encompasses regions not previously reported to be affected by prototype-distortion learning.     

Neuropsychological Sequelae of Subthalamic Nucleus Deep Brain Stimulation in Parkinson's Disease: A Critical Review

Neuropsychologists are increasingly involved in surgical candidacy evaluations and postoperative neurobehavioral assessments of patients with movement disorders, most notably those with disease (PD). We review here the initial studies regarding neuropsychological outcomes of deep brain stimulation (DBS) within the subthalamic nucleus (STN) for treatment of PD. Overall, these initial investigations provide preliminary support for the cognitive and neurobehavioral safety of STN DBS. Improvements in self-reported symptoms of depression and diminished verbal fluency were the most common findings, whereas changes in global cognitive abilities, memory, attention, and frontal/executive functions were inconsistent and most often described as nominal and/or transient. The generalizability of this literature is hindered by several methodological limitations, including small samples and the absence of appropriate control participants. The clinical and theoretical implications of these initial studies are highlighted and recommendations are offered to guide future research.     

Electrical Stimulation, Endorphins, and the Practice of Clinical Psychology

Recent studies have demonstrated an alternative to drug treatment for patients presenting with anxiety disorders. This new technique involves electrical stimulation of the peripheral nervous system to induce chemical changes in the brain that can support and promote healing. This method was developed in part from studies of ancient Chinese acupuncture, but it is noninvasive and does not require needles, and it does not depend on prescientific rituals or metaphysical theories. Endorphins, natural neuropeptides active in basal brain structures, act upon anxiolytic receptors. Solid evidence from fMRI and neurochemical studies show that a simple office procedure involving electrical stimulation can stimulate the expression of endorphins in the brain. Patients have demonstrated symptom relief from this simple adjunctive treatment with a concomitant reduction in dependency on psychotropic medications.     

Neuropsychological outcome of GPi pallidotomy and GPi or STN deep brain stimulation in Parkinson's disease

This paper highlights the neuropsychological sequelae of posteroventral pallidotomy (PVP) and deep brain stimulation (DBS) of the subthalamic nucleus (STN) and the internal segment of the globus pallidus (GPi) at 3/6 months postoperatively. Results are based on our extensive experience with PVP and our preliminary observations with DBS. Patients with borderline cognitive or psychiatric functioning risk postoperative decompensation. Nonlateralizing attentional and hemisphere-specific impairments of frontostriatal cognitive functions followed unilateral PVP. "Frontal" behavioral dyscontrol was observed in approximately 25% of patients. Three cases of staged bilateral PVP suggest that premorbid factors may predict outcome, although lesion size and location are also critical. Older patients are at risk for significant cognitive and behavioral decline after bilateral STN DBS, while GPi DBS may be safer.     

Liens entre le déclin sensoriel et cognitif dans le vieillissement normal : revue critique de la littérature et apports de l’approche incarnée et située de la cognition

Biological aging impacts many organs including sensory's ones and the brain, and thus, cognition. Research has shown that the sensory and cognitive decline are positively correlated. The main data from this literature are firstly reviewed in the present article. Then, the four main hypotheses that are generally proposed to explain these associations are presented. According to them, sensory decline is supposed to cause cognitive decline, or vice-versa, or these concomitant changes result from the general alteration of the nervous system. However, none of them seems able to account for all of the existing data. Moreover, the precise mechanisms that may drive these associations remain to be clarified. The rest of the article is then dedicated to the embodied and situated cognition approach as it provides a particularly interesting and adequate framework to account for these links. Indeed, according to this approach, cognitive representations are grounded in their sensorimotor properties. In other words, cognitive functioning is not conceived as detached from sensory functioning, but instead directly dependent of it. Representations are thus thought to emerge from the sensorimotor simulation of the properties involved in these representations. Therefore, sensory decline should directly impact cognitive performance. It is then hypothesized that older adults have low-resolution representations decreasing the signal on noise ratio of traces, increasing sensorimotor interferences and thus decreasing cognitive performance. This approach leads to consider low and high levels of sensory and perceptual functioning, which are both impaired in aging. Therefore, the repercussion of the sensory-perceptual decline is not only valid for present processing, but also extend to all past knowledge. Several predictions are then proposed on (1) the link between high-level perceptual functioning and cognitive functioning in older adults; (2) the possible interaction in young adults between sensory and high-level perceptual functioning as a function of the level of interference of the material involved; (3) the possible link between the motor and cognitive functioning in older adults. The clinical consequences in terms of cognitive stimulation of such a perspective will close the article. It is proposed to develop a stimulation program based on pattern separation mechanism to better process sensory interference in order to train older adults to improve cognitive precision and thus performance.     

Proposal of a common terminology for the neuropsychological rehabilitation

The literature on neuropsychological intervention (NI) uses a variety of terms to refer to equivalent constructs, making it difficult to compare intervention programmes and their outcomes. The purpose of this work is to propose a unified terminological framework for describing NI programmes. The terminological framework was developed based on a previous proposal for common terminology by Johnstone and Stonnington (Rehabilitation of neuropsychological disorders: A practical guide for rehabilitation professionals. Psychology Press, 2011) and driven by Cognitive Psychology concepts. The terminological framework was organized into two sections: (a) NI, which includes types of NI, methods and approaches, instructional methods, and strategies; and (b) neurocognitive functions, which include temporal and spatial orientation, sensation, perception, visuo-constructional abilities, attention, memory, language, reasoning of several sorts (e.g., abstract reasoning, and numerical reasoning), and executive functions. Most NI tasks target a main neurocognitive function, but there are underlying neurocognitive functions that may impair performance in the former. Since it is difficult to create a task that is solely focused on one neurocognitive function, the proposed terminology should not be viewed as a taxonomy, but rather as dimensional, with the same task allowing to work different functions, in varying grades. Adopting this terminological framework will allow to define the targeted neurocognitive functions more accurately and simplify the comparison between NI programmes and their outcomes. Future research should focus on describing the main techniques/strategies for each neurocognitive function and non-cognitive interventions.     

REDUCTIONS IN SELF-INJURY PRODUCED BY TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION

Transcutaneous electrical nerve stimulation is used to reduce pain but also may be useful for self-injurious behavior (SIB). In the current investigation, a microcurrent electromedical device, classified as a transcutaneous electrical nerve stimulator (TENS), was applied with a man with Down syndrome who displayed SIB that persisted in the absence of social contingencies. Although clinically significant results were not maintained, a clear difference in the rates of SIB during active and inactive TENS was observed.     

NEGATIVE REINFORCEMENT IN APPLIED BEHAVIOR ANALYSIS: AN EMERGING TECHNOLOGY

Although the effects of negative reinforcement on human behavior have been studied for a number of years, a comprehensive body of applied research does not exist at this time. This article describes three aspeas of negative reinforcement as it relates to applied behavior analysis: behavior acquired or maintained through negative reinforcement, the treatment of negatively reinforced behavior, and negative reinforcement as therapy. A consideration of research currently being done in these areas suggests the emergence of an applied technology on negative reinforcement.     

CLINICAL EVALUATION OF THE SELF-INJURIOUS BEHAVIOR INHIBITING SYSTEM (SIBIS)

Five cases involving the treatment of longstanding, severe, and previously unmanageable self-injurious behavior are presented. In each case, the behavior was forceful contact with the head or face, and treatment consisted of mild and brief contingent electrical stimulation, delivered automatically or by a therapist, via the Self-Injurious Behavior Inhibiting System. Results of reversal and/or multiple baseline designs, in which sessions ranged in duration from 10 min to all day across a variety of settings, showed that the effects of the system were immediate and produced almost complete elimination of the self-injurious behavior. Controlled and anecdotal follow-up data for four of the five cases suggest continuing benefits and the absence of detrimental side effects associated with treatment. Potential applications of the device, as well as extensions and limitations, are discussed.     

Premonitory urges are associated with decreased grey matter thickness within the insula and sensorimotor cortex in young people with Tourette syndrome

Tourette syndrome (TS) is a neurological disorder characterized by vocal and motor tics and is associated with cortical–striatal–thalamic–cortical circuit (CSTC) dysfunction and hyperexcitability of cortical limbic and motor regions, which are thought to lead to the occurrence of tics. Importantly, individuals with TS often report that their tics are preceded by ‘premonitory sensory phenomena’ (PSP) that are described as uncomfortable cognitive or bodily sensations that precede the execution of a tic, and are experienced as a strong urge for motor discharge. While the precise role played by PSP in the occurrence of tics is controversial, PSP are nonetheless of considerable theoretical and clinical importance in TS, not least because they form the core component in many of the behavioural therapies that are currently used in the treatment of tic disorders. In this study, we investigated the brain structure correlates of PSP. Specifically, we conducted a whole‐brain analysis of cortical (grey matter) thickness in 29 children and young adults with TS and investigated the association between grey matter thickness and PSP. We demonstrate for the first time that PSP are inversely associated with grey matter thickness measurements within the insula and sensorimotor cortex. We also demonstrate that grey matter thickness is significantly reduced in these areas in individuals with TS relative to a closely age‐ and gender‐matched group of typically developing individuals and that PSP ratings are significantly correlated with tic severity.