Considerable evidence has demonstrated a critical role for the nucleus accumbens (NAc) in the acquisition and flexibility of behavioral strategies. These processes are guided by the activity of two discrete neuron types, dopamine D1- or D2-receptor expressing medium spiny neurons (D1-/D2-MSNs). Here we used the IntelliCage, an automated…

Background: Previous research on the etiology of ADHD symptoms suggests that neuropsychological differences may be present as early as birth; however, the diagnosis is typically not given until school age. This study aimed to (a) identify early behavioral and cognitive markers of later significant parent and/or teacher ratings of ADHD…

This article focuses on the possibility that autism spectrum disorder (ASD: Asperger syndrome, autism and atypical autism) in its milder forms may be clinically important among a substantial proportion of patients with obsessive-compulsive disorder (OCD), and discusses OCD subtypes based on this proposition. The hypothesis derives from extensive…

Evidence about memory for order information comes from a number of different methodologies: human cognition, patient studies, neuroimaging studies, and animal lesion and behavioral studies. The present article discusses (a) evidence that order and item memory are separable; (b) proposed mechanisms for order memory (interitem associations, direct…

The participation of the hippocampus in classical conditioning is described in terms of a multilayer network portraying stimulus configuration. A model of hippocampal function is presented, and computer simulations are used to study neural activity in the various brain areas mapped according to the model. (SLD)

A review of research on state behavior among students with profound disabilities is presented, and a model depicting interactions of state with endogenous and exogenous variables is offered. Applications of the model are illustrated through four case studies displaying different state patterns. Measurable attributes of state having implications…

Discusses new research directions in the study of emotions, including postulations that emotion is relational rather than intrapsychic; emotion and an individual's goals are closely related; emotion "expressions" are social signals, not merely outward signs of internal states; and the physiology of emotion can regulate and be regulated.…

This rejoinder to critiques (EC 602 213-215) of the authors' article (EC 602 212) on stereotypy and self-injury in the disabled responds to specific objections raised, including misleading statements, failure to address other existing models, misunderstandings, and need to include neurochemical factors. (DB)

Background: Prader-Willi syndrome (PWS) is associated with a characteristic behavioural phenotype whose main features are, alongside compulsive hyperphagia, deficits in social behaviour: social withdrawal, temper tantrums, perseverative speech and behaviour, mental rigidity, stereotyped behaviour, impulsiveness, etc. Similar symptoms may also be…

This essay argues that humans are capable of a large number of affect states; a distinction should be made among acute emotions, chronic moods, and temperamental vulnerabilities to a particular emotion state; and research on human effects will profit from a return to, and reinterpretation of, Sigmund Freud's suggestion of unconscious affect…

Using a connectionist framework, it is possible to develop models exploring effects of biologically relevant variables on behavior. The ability of such models to explain schizophrenic behavior in terms of biological disturbances is considered, and computer models are presented that simulate normal and schizophrenic behavior in an attentional task.…

This review explores the cellular pathology associated with traumatic brain injury (TBI) and its relation to neurobehavioral outcomes, the relationship of brain imaging findings to underlying pathology, brain imaging techniques, various image analysis procedures and how they relate to neuropsychological testing, and the importance of brain imaging…

Proposes a cognitive model of schizophrenia stating that schizophrenic behavior is caused by a disturbance in sensory input and stored material integration. Cites research to support this model. Outlines the manner in which a disturbance in sensory input integration relates to schizophrenic symptoms and discusses the model's relevance for…

This article contrasts aphasic patients' performance of word naming and lexical decision with that of intact college-aged readers. We discuss this contrast within a framework of self-organization; word recognition by aphasic patients is destabilized relative to intact performance. Less stable performance shows itself as an increase in the…

The Conners Rating Scale was used to identify psychoeducational, neuropsychological, and sociobehavioral variables in attempting to define subtypes within a population of 95 children (mean age 10.6 years) with learning disabilities (LD) or documented brain damage. Results supported the sociobehavioral component in LD subtyping and parallels…