Hippocampal-dependent episodic memory and stimulus discrimination abilities are both compromised in the elderly. The reduced capacity to discriminate between similar stimuli likely contributes to multiple aspects of age-related cognitive impairment; however, the association of these behaviors within individuals has never been examined in an animal…

Learning to navigate toward a goal is an essential skill. Place learning is thought to rely on the ability of animals to associate the location of a goal with surrounding environmental cues. Using the Morris water maze, a task popularly used to examine place learning, we demonstrate that distal cues provide animals with distance and directional…

Most existing models of dopamine and learning in Parkinson disease (PD) focus on simulating the role of basal ganglia dopamine in reinforcement learning. Much data argue, however, for a critical role for prefrontal cortex (PFC) dopamine in stimulus selection in attentional learning. Here, we present a new computational model that simulates…

Limb apraxia is a neurological disorder characterized by an inability to pantomime and/or imitate gestures. It is more commonly observed after left hemisphere damage (LHD), but has also been reported after right hemisphere damage (RHD). The Conceptual-Production Systems model (Roy, 1996) suggests that three systems are involved in the control of…

"Asparagus Racemosus" (AR) is an Ayurvedic rasayana possessing multiple neuropharmacological activities. The adpatogenic and antidepressant activity of AR is well documented. The present study was undertaken to assess nootropic and anti-amnesic activities of MAR in rats. The Morris water maze (MWM) and elevated plus maze (EPM) models were employed…

This review summarizes a series of experiments aimed at answering the question whether the hippocampus in rats can serve as an animal model of amnesia. It is recognized that a comparison of the functions of the rat hippocampus with human hippocampus is difficult, because of differences in methodology, differences in complexity of life experiences,…

It is still a matter of debate whether constructive apraxia (CA) should be considered a form of apraxia or, rather, the motor expression of a more pervasive impairment in visuo-spatial processing. Constructive disorders were linked to visuo-spatial disorders and to deficits in appreciating spatial relations among component sub-parts or problems in…

Mammillary body atrophy is present in a number of neurological conditions and recent clinical findings highlight the importance of these nuclei for memory. While most accounts of diencephalic amnesia emphasize the functional importance of the hippocampal projections to the mammillary bodies, the present study tested the importance of the other…

Bilinguals must focus their attention to control competing languages. In bilingual aphasia, damage to the fronto-subcortical loop may lead to pathological language switching and mixing and the attrition of the more automatic language (usually L1). We present the case of JZ, a bilingual Basque-Spanish 53-year-old man who, after haematoma in the…

Neuronal modifications that accompany normal aging occur in brain neuropils and might share commonalties across phyla including the most successful group, the Insecta. This study addresses the kinds of neuronal modifications associated with loss of memory that occur in the hemimetabolous insect "Periplaneta americana." Among insects that display…

MOVE problems, like the Tower of London (TOL) or the Water Jug (WJ) task, are planning tasks that appear structurally similar and are assumed to involve similar cognitive processes. Carder et al. [Carder, H.P., Handley, S.J., & Perfect, T.J. ( 2004). Deconstructing the Tower of London: Alternative moves and conflict resolution as predictors of…

Ten Parkinson's Disease (PD) patients and 10 control participants were tested using a task-switching paradigm in which there was a random task sequence, and the task was cued in every trial. Five PD patients showed a unique error profile. Their performance approximated guessing when accuracy was dependent on correct task identification, and was…

A general framework is outlined for describing the relationship of cognition to brain systems. The model provides for empirical investigations at many levels--computational, chronometric, spatial imaging, and cellular--and argues for the logical interrelationship of these areas of investigation. It is applied to selective visual-spatial attention…

The number of people who experience a brain injury increases every year, and 40 percent of all cases involve children (Hill, 1999). In fact, this high rate has led brain injury to become the most commonly acquired disability among children (Bigge, Best, & Heller, 2001), leading to a variety of primary disabilities that affect cognition,…