No direction specific costs in trans-saccadic memory.

Even though we frequently execute saccades, we perceive the external world as coherent and stable. An important mechanism of trans-saccadic perception is spatial remapping: the process of updating information across eye movements. Previous studies have indicated a right hemispheric dominance for spatial remapping, which has been proposed to translate into enhanced trans-saccadic memory for locations that are remapped into the right compared to the left hemisphere in healthy participants. Previous study designs suffered from several limitations, however (i.e. multiple eye movements had to be made instead of one, fixations were not controlled for, and ceiling effects were likely present). We therefore compared accuracy of trans-saccadic memory for central items after left- versus rightward eye movements, and secondary, for items that were remapped within the left versus right visual field. Participants memorized the location of a briefly presented item, made one saccade, and subsequently decided in what direction the item had shifted. We used a staircase to adjust task difficulty. Bayesian repeated measures ANOVAs were used to compare between left versus right eye movements and items in the left versus right visual field. We found most evidence against directional differences in trans-saccadic memory (BF10 = 0.23). We found some evidence suggestive of enhanced trans-saccadic memory for items that were remapped within the left compared to the right visual field (BF10 = 4.00). The latter result could be explained by a leftward spatial attention bias. As such, the hypothesized right hemispheric dominance for spatial remapping does not result in asymmetric trans-saccadic memory capacities in healthy participants.

[Treatment of neglect, an attention disorder]. / De behandeling van neglect, een aandachtstoornis.

- Neglect occurs in 30-50% of patients in the subacute phase post-stroke. Patients with neglect ignore one side of their body or one part of the space around them. - Treatment of neglect is important, as patients with neglect recover more slowly and are less independent compared to patients without neglect.- Visual scanning training is currently recommended in the guidelines as a treatment. The focus of this intensive treatment is on compensation, not on recovery. Scientific evidence for its effectiveness is scarce. - Other treatments, such as prism adaptation, limb activation training and brain stimulation are being investigated. However, the available evidence for their effectiveness is insufficient as yet. - In addition to neuropsychological tests, outcome measures at the level of functioning in daily life should be included in studies regarding the treatment of neglect.- New research is increasingly focusing on combining different treatments, which should ultimately be adapted for each patient individually.

Functional assessment of region-specific neglect: are there differential behavioural consequences of peripersonal versus extrapersonal neglect?

BACKGROUND: Region-specific types of neglect (peripersonal and extrapersonal) have been dissociated, yet, differential behavioural consequences are unknown. OBJECTIVE: The aim of the current study was to investigate behavioural consequences at the level of basic activities of daily living of region-specific neglect, using the Catherine Bergego Scale (CBS). METHODS: 118 stroke patients were screened within the first two weeks after admission to the rehabilitation center for inpatient rehabilitation. RESULTS: Patients with peripersonal neglect and patients with neglect for both regions had significantly higher total score on the CBS compared to nonneglect patients. Total scores for patients with extrapersonal neglect were comparable to non-neglect patients. ADL impairments were found across activities (e.g., looking towards one side, forgetting body parts, colliding) for both patients with peripersonal neglect and patients with neglect for both regions. Patients with extrapersonal neglect were only impaired on the item on way finding. CONCLUSIONS: When diagnosing neglect, it is relevant to distinguish the type of region-specific neglect and, where needed, to adjust the rehabilitation program accordingly. As the CBS is not developed to typically measure ADL in extrapersonal neglect, it would be of importance to add other (instrumental) activities that heavily rely on processing information in farther space.

The influence of vertically and horizontally aligned visual distractors on aurally guided saccadic eye movements.

Eye movements towards a new target can be guided or disrupted by input from multiple modalities. The degree of oculomotor competition evoked by a distractor depends on both distractor and target properties, such as distractor salience or certainty regarding the target location. The ability to localize the target is particularly important when studying saccades made towards auditory targets, since determination of elevation and azimuth of a sound are based on different processes, and these processes may be affected independently by a distractor. We investigated the effects of a visual distractor on saccadic eye movements made to an auditory target in a two-dimensional plane. Results showed that the competition evoked by a vertical visual distractor was stronger compared with a horizontal visual distractor. The eye movements that were not captured by the vertical visual distractor were still influenced by it: a deviation of endpoints was seen in the direction of the visual distractor. Furthermore, the interference evoked by a high-contrast visual distractor was stronger compared with low-contrast visual stimuli, which was reflected by a faster initiation of an eye movement towards the high-contrast visual distractor and a stronger shift of endpoints in the direction of the high-contrast visual distractor. Together, these findings show that the influence of a visual distractor on aurally guided eye movements depends strongly on its location relative to the target, and to a lesser extent, on stimulus contrast.