A model of the neuropsychology of anxiety is proposed. The model is based in the first instance upon an analysis of the behavioural effects of the antianxiety drugs (benzodiazepines, barbiturates, and alcohol) in animals. From such psychopharmacologi-cal experiments the concept of a “behavioural inhibition system” (BIS) has been developed. This system responds to novel stimuli or to those associated with punishment or nonreward by inhibiting ongoing behaviour and increasing arousal and attention to the environment. It is activity in the BIS that constitutes anxiety and that is reduced by antianxiety drugs. The effects of the antianxiety drugs in the brain also suggest hypotheses concerning the neural substrate of anxiety. Although the benzodiazepines and barbiturates facilitate the effects of γ-aminobutyrate, this is insufficient to explain their highly specific behavioural effects. Because of similarities between the behavioural effects of certain lesions and those of the antianxiety drugs, it is proposed that these drugs reduce anxiety by impairing the functioning of a widespread neural system including the septo-hippocampal system (SHS), the Papez circuit, the prefrontal cortex, and ascending monoaminergic and cholinergic pathways which innervate these forebrain structures. Analysis of the functions of this system (based on anatomical, physiological, and behavioural data) suggests that it acts as a comparator: it compares predicted to actual sensory events and activates the outputs of the BIS when there is a mismatch or when the predicted event is aversive. Suggestions are made as to the functions of particular pathways within this overall brain system. The resulting theory is applied to the symptoms and treatment of anxiety in man, its relations to depression, and the personality of individuals who are susceptible to anxiety or depression.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0140525X00013066

Précis of The Neuropsychology of Anxiety: An Enquiry into the Functions of the Septo-Hippocampal System..

We examine two different descriptions of the behavioral functions of the hippocampal system. One emphasizes spatially organized behaviors, especially those using cognitive maps. The other emphasizes memory, particularly working memory, a short-term memory that requires iexible stimulus-response associations and is highly susceptible to interference. The predictive value of the spatial and memory descriptions were evaluated by testing rats with damage to the hippocampal system in a series of experiments, independently manipulating the spatial and memory characteristics of a behavioral task. No dissociations were found when the spatial characteristics of the stimuli to be remembered were changed; lesions produced a similar deficit in both spatial and nonspatial test procedures, indicating that the hippocampus was similarly involved regardless of the spatial nature of the task. In contrast, a marked dissociation was found when the memory requirements were altered. Rats with lesions were able to perform accurately in tasks that could be solved exclusively on the basis of reference memory. They performed at chance levels and showed no signs of recovery even with extensive postoperative training in tasks that required working memory. In one experiment all the characteristics of the reference memory and working memory procedures were identical except the type of memory required. Consequently, the behavioral dissociation cannot be explained by differences in attention, motivation, response inhibition, or the type of stimuli to be remembered. As a result of these experiments we propose that the hippocampus is selectively involved in behaviors that require working memory, irrespective of the type of material (spatial or nonspatial) that is to be processed by that memory.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/F9ABFA09F5AC96A64D15572521BD2C6C/S0140525X00062713a.pdf/div-class-title-hippocampus-space-and-memory-div.pdf

Hippocampus, space, and memory

The Evolution of Language

Hippocampal connections and spatial discrimination.

Wallace, Tylor, Wundt, Johannesson, and others have proposed that human language had its basis in hand and arm gestures. The Gardners' work with the chimpanzee Washoe, Premack's study of the chimpanzee Sarah, and continuing experiments along these lines indicate that neural restructuring would not have been necessary for the protohominid acquisition of a simple propositional gesture or sign language which did not involve cross-modal transfer at a high level from the visual to the auditory channel or vice versa. Evidence from primate studies, early tool-using, the continuing functions of gesture in human communication, lateral dominance in its relation to speech and tool manipulation, and other sources is presented to support a model of glottogenesis. It is argued that a preexisting gestural language system would have provided an easier pathway to vocal language than a direct outgrowth of the "emotional" use of vocalization characteristic of nonhuman primates.

Primate Communication and the Gestural Origin of Language

The present experiments examine axonal sprouting of optic tract projections as a consequence of occipital cortex removal. Eyes were removed bilaterally in experimental rats 16 months following unilateral occipital cortex ablation. Seven animals survived this procedure. Controls included rats sacrificed 16 months after unilateral occipital cortex ablation, one week after unilateral occipital cortex destruction, and one week after bilateral or unilateral eye removal. Brains were serial-sectioned and stained by the Nauta-Gygax method for degenerating axons.



Sprouting occurred only at two loci, the caudal half of the ventral lateral geniculate nucleus, pars lateralis, and the caudal portion of lateral nucleus of the optic tract and subjacent medial quarter of pretectal nucleus. These loci have in common that they are regions of convergence in a major fashion of the two fiber systems, the occipitofugal and retinofugal projections on which experiments were done. However, sprouting did not occur in other similarly deafferented regions. Explanations for this specificity of sprouting are discussed.



Optic tract sprouting was observed only at paraterminal portions of the axon and not as collateral sprouts along its course.



A suggested relationship between axonal sprouting and functional plasticity is discussed.

Sprouting of optic tract projections in the brain stem of the rat

Partial Klu¨ver-Bucy syndrome produced by cortical disconnection

Vocalizations of three monkeys (Cebus albifrons) were established as operants: they increased in frequency when followed by positive reinforcement and yielded to stimulus control.

https://link.springer.com/content/pdf/10.3758%2FBF03343194.pdf

James A. Horel

Papers

Sprouting of optic tract projections in the brain stem of the rat

Partial Klu¨ver-Bucy syndrome produced by cortical disconnection

Operant control of vocal behavior in the monkey Cebus albifrons

Functional localization in the cerebellum of the bird and its bearing on the evolution of cerebellar function