Benefits of nostalgic landmarks for people living with Alzheimer's disease.

Background: Emerging literature shows that nostalgia induced by autobiographical reflection and music confers psychological benefits to people living with dementia.

Objective: Our objective was to test the potential benefits of nostalgic landmarks for people living with Alzheimer's disease.

Methods: We displayed the landmarks as wall-mounted pictures within a virtual environment.

Spatiotemporal dynamics of locomotor decisions in .

Decision-making in animals often involves choosing actions while navigating the environment, a process markedly different from static decision paradigms commonly studied in laboratory settings. Even in decision-making assays in which animals can freely locomote, decision outcomes are often interpreted as happening at single points in space and single moments in time, a simplification that potentially glosses over important spatiotemporal dynamics. We investigated locomotor decision-making in in Y-shaped mazes, measuring the extent to which their future choices could be predicted through space and time.

Nostalgia enhances route learning in a virtual environment.

Salient landmarks enhance route learning. We hypothesised that semantically salient nostalgic landmarks would improve route learning compared to non-nostalgic landmarks. In two experiments, participants learned a route through a computer-generated maze using directional arrows and wall-mounted pictures.

Induction of spatial anxiety in a virtual navigation environment.

Spatial anxiety (i.e., feelings of apprehension and fear about navigating everyday environments) can adversely impact people's ability to reach desired locations and explore unfamiliar places.

Dopaminergic modulation of working memory and cognitive flexibility in a zebrafish model of aging-related cognitive decline.

Healthy aging is associated with a decline in memory and executive function, which have both been linked with aberrant dopaminergic signaling. We examined the relationship between cognitive performance and dopamine function of young and aging zebrafish (Danio rerio). We revealed age-related decreases in working memory and cognitive flexibility in the Free-Movement Pattern (FMP) Y-maze.

The Free-movement pattern Y-maze: A cross-species measure of working memory and executive function.

Numerous neurodegenerative and psychiatric disorders are associated with deficits in executive functions such as working memory and cognitive flexibility. Progress in developing effective treatments for disorders may benefit from targeting these cognitive impairments, the success of which is predicated on the development of animal models with validated behavioural assays. Zebrafish offer a promising model for studying complex brain disorders, but tasks assessing executive function are lacking.

Overshadowing of geometric cues by a beacon in a spatial navigation task.

In three experiments, we examined whether overshadowing of geometric cues by a discrete landmark (beacon) is due to the relative saliences of the cues. Using a virtual water maze task, human participants were required to locate a platform marked by a beacon in a distinctively shaped pool. In Experiment 1, the beacon overshadowed geometric cues in a trapezium, but not in an isosceles triangle.

Fluoxetine restores spatial learning but not accelerated forgetting in mesial temporal lobe epilepsy.

Learning and memory dysfunction is the most common neuropsychological effect of mesial temporal lobe epilepsy, and because the underlying neurobiology is poorly understood, there are no pharmacological strategies to help restore memory function in these patients. We have demonstrated impairments in the acquisition of an allocentric spatial task, in patients with unilateral hippocampal sclerosis. We also show that patients have accelerated forgetting of the learned spatial task and that this is associated with damage to the non-dominant hippocampal formation.

Reduced summation with common features in causal judgments.

In three experiments human participants received training in a causal judgment task. After learning which patterns were associated with an outcome, participants rated the likelihood of the outcome in the presence of a novel combination of the patterns. The first two experiments used two conditions in which two visual patterns were associated with the outcome.

Selective temporal resections and spatial memory impairment: cue dependent lateralization effects.

Patients who had undergone a unilateral trans-sylvian selective amygdalohippocampectomy as treatment for chronic intractable epilepsy were tested in a virtual Morris Water Maze (MWM) task where they were required to locate a hidden platform as a measure of spatial learning. These individuals' performance on spatial tasks was compared to age-matched healthy controls and drug-matched healthy controls. Training occurred in two different maze environments, one with conventional cues such as windows and doors, and another with abstract cues, such as colours and patterns.

Evidence for a shift from place navigation to directional responding in one variant of the Morris water task.

Previous work from our laboratory has demonstrated that rats display a preference for directional responding over place navigation in a wide range of procedural variants of the Morris water task (Hamilton, Akers, Weisend, & Sutherland, 2007; Hamilton et al., 2008). A preference for place navigation has only been observed when the pool is reduced as a cue by filling it with water.

Differential place and response learning in horses displaying an oral stereotypy.

Significant similarities exist between the neural and behavioural features of environmentally and drug-induced stereotypy. For example, exposure to dopamine agonists, such as amphetamine, induces stereotypy and causes alterations in midbrain neurophysiology similar to those observed following chronic stress. An additional behavioural feature of these neural changes in the drug-induced phenotype is an enhanced rate of switching from response-outcome (R-O) to stimulus-response (S-R) learning.

Control of rodent and human spatial navigation by room and apparatus cues.

A growing body of literature indicates that rats prefer to navigate in the direction of a goal in the environment (directional responding) rather than to the precise location of the goal (place navigation). This paper provides a brief review of this literature with an emphasis on recent findings in the Morris water task. Four experiments designed to extend this work to humans in a computerized, virtual Morris water task are also described.

Impaired instrumental choice in crib-biting horses (Equus caballus).

Horses displaying an oral stereotypy were tested on an instrumental choice paradigm to examine differences in learning from non-stereotypic counterparts. Stereotypic horses are known to have dysfunction of the dorsomedial striatum, and lesion studies have shown that this region may mediate response-outcome learning. The paradigm was specifically applied in order to examine learning that requires maintenance of response-outcome judgements.

The relative influence of place and direction in the Morris water task.

Previous work from our laboratory has demonstrated that rats display a preference for directional responding over true place navigation in the Morris water task. The present study evaluated the range of situations in which this preference is observed and attempted to identify methods that favor navigation to the precise location of the escape platform in the room. A preference for directional responding over place navigation was observed in a wide range of procedures that included providing extensive training (Experiment 1), providing only platform placement experience in the absence of active swim training (Experiment 2), training navigation to multiple platform locations in a moving platform variant of the task (Experiment 3), and explicitly training navigation to a precise location in the room, versus navigation in a particular direction, regardless of the pool's position in the room (Experiments 4-5).

Multimodal discrimination learning in humans: evidence for configural theory.

Human contingency learning was used to compare the predictions of configural and elemental theories. In three experiments, participants were required to learn which indicators were associated with an increase in core temperature of a fictitious nuclear plant. Experiments 1 and 2 investigated the rate at which a triple-element stimulus (ABC) could be discriminated from either single-element stimuli (A, B, and C) or double-element stimuli (AB, BC, and AC).

Spatial exploration patterns determine navigation efficiency: trade-off between memory demands and distance travelled.

A total of 41 participants explored a novel square-shaped environment containing five identical boxes each hiding a visually distinct object. After an initial free exploration the participants were required to locate the objects first in a predetermined and subsequently in an optional order task. Two distinct exploration strategies emerged: Participants explored either along the main axes of the room (axial), or in a more spatially spread, circular pattern around the edges of the room (circular).

Summation in autoshaping is affected by the similarity of the visual stimuli to the stimulation they replace.

Pigeons received autoshaping with 2 stimuli, A and B, presented in adjacent regions on a television screen. Conditioning with each stimulus was therefore accompanied by stimulation that was displaced from the screen whenever the other stimulus was presented. Test trials with AB revealed stronger responding if this displaced stimulation was similar to, rather than different from, A and B.